U.S. Department of the Interior Bureau of Land Management

Final Environmental Impact Statement Leavitt Reservoir Expansion Project DOI-BLM-WY-R020-2016-0048-EIS

U.S. Department of the Interior Estimated Total Cost Associated with Developing and Bureau of Land Management Producing This FEIS -- $886,146 Cody Field Office

April 2019 BLM/WY/PL-18/013+1440

United States Department of the Interior BUREAU OF LAND MANAGEMENT Wind Ri\'er!Bighom Basin Di:;1rict IO I South 23rd Street Worland, WY 82401-3743 www.blm.gov/wy

Dear Reader:

The final Environmental Impact Statement (EIS) forthe Leavitt Reservoir Expansion Project (LREP) is hereby submitted for your review. The Bureau of Land Management (BLM) prepared the finalEIS to analyze the potential impacts of and alternativesto the LREP proposed by the Wyoming Water Development Commission (WWDC). The proposed LREP is partially on BLM-administered lands and private lands in Big Hom County, Wyoming, north of Shell.

Under the Proposed Action, the WWDC proposes to enlarge the water storage capacity of Leavitt Reservoir located north of Shell, in Bighorn County, Wyoming. The expanded Leavitt Reservoir would primarily be used to supply irrigated lands in the Beaver Creek and Shell Creek drainages with supplemental late season irrigation supply. The existing Leavitt Reservoir is an off-channel, man-made 643-acre-foot (AF)reservoir. The existing reservoir and dam inundate approximately 45 acres. The LREPe would expand the reservoir to approximately 203 surface acreswith a total pool capacity of 6,604 AF.e The proposed normal high water level 4,860 acre feet (NHWL). Approximately 330 acres of the LREPe would be on BLM-administered land, and approximately 365 acres of private land would be affectedtoe expand Leavitt Reservoir and constructthe supportinginfrastructure.e

This final EIS analyzes three alternativesin detail:

• No Action Alternative -The No Action Alternative would continue the currentoperation practicese at Leavitt Reservoir. There would be no increase in the current capacity of the reservoir to meete late season irrigation needs in Beaver Creek or Shell Creek drainages.e • Proposed Action Alternative-The Proposed Action Alternative would involve expanding thee existing Leavitt Reservoir by 5,961 AF to a total storage capacity of 6,604 AF to reduce droughte vulnerability and irrigation shortages. Storage in the expanded Leavitt Reservoir would includee the existing 643 AF, 1,500 AF fora minimum environmental/recreation pool, and 4,461 AF for ae supplemental irrigationsupply. The additional storage forthe expanded Leavitt Reservoirwoulde be filledfrom the Beaver Creek diversion when bypass flowsare greater than 5 cubic feetpere second (cfs).e • Operational Alternative- The Operational Alternative would involve expanding the existinge Leavitt Reservoir by 5,961 AF to a total storage capacity of 6,604 AFto reduce droughte vulnerability and irrigation shortages. Storage in the expanded Leavitt Reservoirwould includee the existing 643 AF, 1,500 AFfor a minimum environmental/recreation pool, and 4,461 AF forae supplemental irrigation supply. This alternativeis identical to the Proposed Action Alternativee except there would be no minimum bypass flow during diversion from Beaver Creek.e

The final EIS also contains a brief discussion of other alternatives that were considered but eliminated fromdetailed analysis. The BLM has identifiedthe applicant's Proposed Action, as the Agency's preferred alternativein this final EIS. The identificationof a preferredalternative does not constitute a commitment or decision in principle, and there is no requirement to select the preferred alternativein the Agency's Record of Decision. If warranted, the BLM may select a different alternativethan the preferred alternative in its Record of Decision. 2

The finalEIS was prepared in accordance with the National Environmental Policy Act of 1969, as amended (NEPA) as well as the Council on Environmental Quality's NEPA Regulations (40 Code of Federal Regulations Part 1500), BLM Handbook H-1790-1, and BLM Wyoming or national guidance to address possible environmental and socioeconomic impacts that could result fromimplementation of the ACRP. In developing the finalEIS, the BLM considered public commentson the draftEIS and revised the document accordingly. Edited text are highlighted in grey. Responses to public comments can be foundin Appendix 6.3 of the final EIS.

This finalEIS is not a decision document. The publication of the Notice of Availability (NOA) in the Federal Registerfor the finalEIS initiates a 30-day availability period. Following the conclusion of that period and in accordance with the One Federal Decision policy established in Executive Order 13807, a single record of decision (ROD) will be prepared and signed to disclose the BLM's and U.S. Army Corps of Engineers' final decision.

Thank you for your interest in this project. For further information, please visit the LREP webpage at https://go.usa.gov/xOwjg or contact Holly Elliott, BLM LREP Project Manager, at 307-34 7-5193 or [email protected].

Sincerely, Final Environmental Impact Statement Leavitt Reservoir Expansion Project

Lead Agency: U.S. Department of the Interior, Bureau of Land Management Project Location: Cody Field Office, Wyoming Comments and Further Information on the Final EIS: Bureau of Land Management, Cody Field Office Attn: AFM Minerals and Lands – Leavitt Reservoir EIS 1002 Blackburn Street Cody, Wyoming 82414 [email protected] BLM Authorized Officer Responsible for Preparing Final EIS: Kimber Liebhauser, District Manager This document is being made available for a 30-day public availability period which begins the day after the U.S. Environmental Protection Agency publishes a Notice of Availability in the Federal Register. Abstract

The Wyoming Water Development Commission (WWDC) proposes to enlarge the water storage capacity of Leavitt Reservoir located north of Shell, in Bighorn County, Wyoming. The expanded Leavitt Reservoir would primarily be used to supply irrigated lands in the Beaver Creek and Shell Creek drainages with supplemental late season irrigation supply. The existing Leavitt Reservoir is an off-channel, man-made 643-acre-foot (AF) reservoir. It is located in Township 54 North, Range 92 West, Sections 13, 14, 23, 24, and 25. The existing reservoir and dam inundate approximately 45 acres. The Leavitt Reservoir Expansion Project (LREP) would expand the reservoir to approximately 203 surface acres with a total pool capacity of 6,604 AF (i.e., a 5,961-AF expansion). This would be accomplished with a new, approximately 1,800-foot long earthen dam embankment with a maximum height of approximately 80 feet and a crest width of 21 feet. Approximately 330 acres (or 47 percent) of the LREP would be on Bureau of Land Management (BLM)-administered land, and approximately 365 acres of private land would be affected to expand Leavitt Reservoir and construct the supporting infrastructure. The proposed normal high water level (NHWL) would be elevation 4,860 feet. The proposed NHWL would have approximately 5.6 miles of shoreline (approximately 3.2 miles more than the existing Leavitt Reservoir). BLM must decide whether and under what conditions to grant a right-of-way (ROW) for the portion of the LREP that would be constructed on BLM-managed land. This decision constitutes a federal action necessary to determine, based on the selected alternative, whether construction of the proposed LREP could take place and will be made in accordance with the Federal Land Policy and Management Act of 1976. BLM’s decision will be communicated through publication of a Record of Decision (ROD). Three alternatives are analyzed in this Environmental Impact Statement (EIS): a No Action Alternative, Proposed Action Alternative, and Operational Alternative. The No Action Alternative is based on the continued operations and capacity of Leavitt Reservoir as it currently exists. The Proposed Action Alternative would involve expanding the existing Leavitt Reservoir by 5,961 AF to a total storage capacity of 6,604 AF to reduce drought vulnerability and irrigation shortages. Storage in the expanded Leavitt Reservoir would include the existing 643 AF, 1,500 AF for a minimum environmental/recreation pool, and 4,461 AF for a supplemental irrigation supply. The additional storage for the expanded Leavitt Reservoir would be filled from the Beaver Creek diversion when bypass flows are greater than 5 cubic feet per second. The Operational Alternative is identical to the Proposed Action Alternative except there would be no minimum bypass flow during diversion from Beaver Creek. The BLM has identified the applicant’s Proposed Action, as the Agency’s preferred alternative in this Final EIS. Based on the resource impact analyses, mitigation measures to minimize potential adverse impacts have been recommended in Chapter 4 of the EIS. Mitigation measures may be included as conditions of BLM’s ROW grant (if issued).

This page intentionally left blank Table of Contents

Page

EXECUTIVE SUMMARY ...... ES-1 BLM Purpose and Need ...... ES-1 U.S. Army Corps of Engineers (USACE) Purpose and Need...... ES-1 Scoping ...... ES-2 Cooperating Agencies ...... ES-2 Alternatives ...... ES-2 Affected Environment ...... ES-3 Environmental Consequences ...... ES-3 Cumulative Impacts ...... ES-4

CHAPTER 1 INTRODUCTION AND BACKGROUND ...... 1-1 1.1 Project Description and Background ...... 1-1 1.2 BLM Purpose and Need ...... 1-2 1.3 U.S. Army Corps of Engineers (USACE) Purpose and Need ...... 1-2 1.4 Other Required Permits and Approvals ...... 1-2 1.5 Agency and Public Scoping Issues ...... 1-2

CHAPTER 2 PROPOSED ACTION AND ALTERNATIVES ...... 2-1 2.1 No Action Alternative ...... 2-1 2.2 Proposed Action Alternative ...... 2-2 2.3 Operational Alternative ...... 2-4 2.4 Alternatives Considered but Not Carried Forward for Detailed Analysis...... 2-4 2.5 Alternatives Comparison ...... 2-14

CHAPTER 3 AFFECTED ENVIRONMENT RESOURCE DISCUSSIONS ...... 3-1 3.1 Cultural Resources, Historic Trails, and Native American Concerns ...... 3-1 3.2 Geology ...... 3-3 3.3 Lands and Realty ...... 3-4 3.4 Noise ...... 3-5 3.5 Paleontological Resources ...... 3-6 3.6 Range Resources ...... 3-8 3.7 Recreation ...... 3-9 3.8 Socioeconomics ...... 3-10 3.9 Soils ...... 3-14 3.10 Transportation ...... 3-15 3.11 Vegetation ...... 3-17 3.12 Visual Resources ...... 3-19 3.13 Water Resources ...... 3-21 3.14 Wildlife and Aquatic Biological Resources ...... 3-28 3.15 Wetlands/Riparian Vegetation ...... 3-34

Leavitt Reservoir Expansion Project –Final EIS – 2019 i Table of Contents

Page

CHAPTER 4 ENVIRONMENTAL IMPACTS ...... 4-1 4.1 Cultural Resources and Native American Concerns ...... 4-2 4.2 Geology ...... 4-4 4.3 Lands and Realty ...... 4-5 4.4 Noise ...... 4-6 4.5 Paleontological Resources ...... 4-7 4.6 Range Resources ...... 4-8 4.7 Recreation ...... 4-9 4.8 Socioeconomics ...... 4-11 4.9 Soils ...... 4-14 4.10 Transportation ...... 4-15 4.11 Vegetation ...... 4-18 4.12 Visual Resources ...... 4-20 4.13 Water Resources ...... 4-22 4.14 Wildlife and Aquatic Biological Resources ...... 4-32 4.15 Wetlands/Riparian Vegetation ...... 4-44 4.16 Mitigation and Mitigation Effectiveness for the Proposed Action Alternative ...... 4-46 4.17 Mitigation and Mitigation Effectiveness for the Operational Alternative ...... 4-52

CHAPTER 5 CUMULATIVE IMPACTS ...... 5-1 5.0 Cumulative Impacts Introduction ...... 5-1 5.1 Cumulative Impacts ...... 5-1 5.2 Residual Impacts ...... 5-9 5.3 Relationship between Local Short-term Use of the Human Environment and Maintenance and Enhancement of Long-term Productivity ...... 5-11 5.4 Irreversible and Irretrievable Commitment of Resources ...... 5-14

CHAPTER 6 CONSULTATION AND COORDINATION ...... 6-1 6.1 Agency Participation/Coordination ...... 6-1 6.2 List of Preparers and Reviewers ...... 6-2 6.3 Consultation ...... 6-2 6.4 Public Involvement ...... 6-3

List of Appendices Appendix 1 Tables for the LREP Final EIS, Chapters 1, 2, 3, 4, and 6 Appendix 2 Figures for the LREP Final EIS, Chapters 1, 2, 3, and 4 Appendix 3 Acronyms and Abbreviations & Glossary Appendix 4 References Appendix 5 List of Preparers

ii Leavitt Reservoir Expansion Project –Final EIS – 2019 Table of Contents

Chapters 3, 4, and 6 Appendices Appendix 3.14 Special Status Wildlife Species Status, Habitat Preferences, and Potential to Occur in the Analysis Area Appendix 3.15 Surface Water Monthly Flow and Average Monthly Flow Data Appendix 4.4 Roadway Construction Noise Model (RCNM), Version 1.1 Appendix 4.12 Leavitt Reservoir Visual Assessment Appendix 4.13-1-A Average Streamflow with and without the Leavitt Reservoir Expansion Project Appendix 4.13-1-B Median Streamflow with and without the Leavitt Reservoir Expansion Project Appendix 4.13.2 Beaver Creek E. Coli Data Appendix 6.3 Response to Comments on the Draft EIS for the Leavitt Reservoir Expansion Project

Leavitt Reservoir Expansion Project –Final EIS – 2019 iii Table of Contents

This page intentionally left blank

iv Leavitt Reservoir Expansion Project –Final EIS – 2019 Executive Summary

EXECUTIVE SUMMARY

The state of Wyoming, through the Wyoming Water Development Commission (WWDC) has proposed the Leavitt Reservoir Expansion Project (LREP) as a means of increasing water storage in the Shell Valley watershed. On July 1, 2015, the WWDC applied for a new right-of-way (ROW) from the U.S. Department of the Interior (DOI) Bureau of Land Management (BLM) Cody Field Office (CYFO) to enlarge the existing reservoir. The BLM determined that an analysis of the significant natural and human environmental effects of the proposed LREP and reasonable range of alternatives through publication of an environmental impact statement (EIS) was necessary. This EIS was prepared in accordance with the Council on Environmental Quality’s (CEQ’s) National Environmental Policy Act (NEPA) Regulations (40 Code of Federal Regulations [CFR] Part 1500), BLM Handbook H-1790-1, and BLM Wyoming or national guidance (BLM 2008a). The BLM is the lead federal agency responsible for preparing this EIS. The Bighorn Basin Record of Decision (ROD) and Approved Resource Management Plan Amendment (RMPA), which includes the BLM CYFO Approved Resource Management Plan, was approved on September 21, 2015, and provides future direction for approximately 3.2 million surface acres and 4.2 million acres of federal mineral estate in northwest Wyoming. The WWDC proposes to expand the water storage capacity of Leavitt Reservoir located north of Shell, in Big Horn County, Wyoming. The expanded Leavitt Reservoir would primarily be used to supply irrigated lands in the Beaver Creek and Shell Creek drainages with supplemental late season irrigation supply. The existing Leavitt Reservoir is an off-channel, manmade 643-acre-foot (AF) reservoir inundating approximately 45 acres. The LREP would expand the reservoir to approximately 203 surface acres with a total pool capacity of 6,604 AF (i.e., a 5,961-AF expansion). This would be accomplished with a new, approximately 1,800-foot long earthen dam embankment with a maximum height of approximately 80 feet (as measured from existing ground at centerline to top of dam) and a crest width of 21 feet. Approximately 330 acres (or 47 percent) of the LREP would be on BLM-administered land, and approximately 365 acres of private land would be affected to expand Leavitt Reservoir and construct the supporting infrastructure. The proposed normal high water level (NHWL) would be elevation 4,860 feet. The proposed NHWL would have approximately 5.6 miles of shoreline (approximately 3.2 miles more than the existing Leavitt Reservoir). A map showing the location of the proposed Leavitt Reservoir expansion and total reservoir and pipeline disturbance is presented on Figure 1-1 in Chapter 1. BLM Purpose and Need BLM has authority for the LREP under the Federal Land Policy and Management Act of 1976 (FLPMA) (Public Law [P.L.] 94-579, 43 United States Code [USC] 1701 et seq.). The FLPMA recognizes ROWs as one of the “principal or major uses” of public lands. The need for this federal action, established by BLM’s responsibility under the FLPMA to provide these ROWs, is driven by documented late season irrigation shortages in the Shell Valley watershed. The purpose of this federal action is to provide access to BLM-managed public lands for increased watershed storage capacity in the Shell Valley watershed. BLM must address the purpose and need for the proposed LREP because much of the proposed LREP and associated infrastructure would be located on BLM land administered by the CYFO. BLM must decide whether and under what conditions to grant a ROW for the portion of the LREP that would be constructed on BLM-managed land. This decision constitutes a federal action necessary to determine, based on the selected alternative, whether construction of the proposed LREP could take place and will be made in accordance with FLPMA. BLM’s decision will be communicated through publication of a ROD. U.S. Army Corps of Engineers (USACE) Purpose and Need The overall purpose for the LREP, as determined by the USACE permitting process, is to reduce late season irrigation shortages by an average of 3,267 AF in the 30 percent driest water years, to lands in the lower portion of Shell Creek watershed, including the Beaver Creek watershed. The LREP is needed to meet a portion of the existing demand for late season irrigation water within the service area of the proposed reservoir expansion. The USACE is a Cooperating Agency (see Cooperating Agencies below) on the proposed LREP because the project is anticipated to involve the discharge of dredged or fill material into waters of the United States (U.S.) as defined in 40 CFR 230.3. WWDC intends to apply for a USACE Permit (Section 404 Permit), pursuant to Section 404 of the Clean Water Act (CWA), to place fill material in

Leavitt Reservoir Expansion Project – Final EIS – 2019 ES-1 Executive Summary jurisdictional waters of the U.S., including wetlands. Prior to construction, a Section 404 Permit from the USACE, Omaha District (Cheyenne, Wyoming) would be required. This permit issuance constitutes a second federal action necessary to determine whether construction of the proposed LREP could take place. Scoping In accordance with NEPA (40 CFR 1501.7), BLM initiated the scoping process for the LREP through publication of a Notice of Intent (NOI) to prepare an EIS in the Federal Register (Vol. 78, No. 126, pages 39313 to 39314) on September 29, 2017, to provide for an early and open process to gather information from the public and interested agencies on the issues and alternatives to be evaluated in the EIS. Pursuant to NEPA and the FLPMA, the NOI informed the public of BLM’s intent, through the CYFO, to prepare an EIS for the proposed LREP. The NOI announced the beginning of the 45-day scoping period to solicit public comments and identify issues. The scoping comment period ended on November 13, 2017. The BLM hosted one Cooperating Agency and one public scoping meeting on October 26, 2017, and provided an opportunity for the BLM to inform attendees about the LREP and the EIS process, including how to comment and be involved in the LREP, and to solicit input on the scope of the LREP and potential issues. The most frequent issues and concerns raised by the commenters during the scoping process included: • Analysis of potential changes to water quality parameters based on changes in flow through operational changes; • Potential effects on fisheries habitats and other aquatic species; and • Potential impacts to surface water flows, stream morphology, and source water protection areas as a result of operational changes. Other issues/concerns that were found to be repeated included: • Concern for hydrologic resources in general, and the need to thoroughly analyze potential impacts to and relationship between water resource categories (e.g., water quality, surface water, water rights, groundwater, stream morphology, etc.); and • Importance of recreation opportunities and analysis of potential impacts as a result of actions associated with the LREP at the selected project location. The BLM considered the comments submitted during scoping and the issues identified in its alternatives development process (see Chapter 2). Cooperating Agencies For agency scoping, the BLM sought broad input from local, state, and federal governmental agencies through invitations to serve as a Cooperating Agency on the LREP. Invitations were extended to entities with statutory authority over the proposed LREP, and entities for which the proposed LREP has a physical nexus (40 CFR 1501.6 and 1508.5). Formal Cooperating Agency Memorandums of Understanding for the LREP exist with: • USACE, Omaha District • Wyoming State Engineer’s Office • U.S. Environmental Protection Agency, • Wyoming Department of Environmental Region 8 (USEPA) Quality, Water Quality Division • WWDC • Wyoming Department of Agriculture • Wyoming Governor’s Office • South Big Horn Conservation District • Wyoming Office of State Lands and Investments • Big Horn County Board of Commissioners • Wyoming Game and Fish Department

Alternatives Chapter 2 of the EIS describes the alternatives analyzed in detail which include the No Action Alternative and two action alternatives – the Proposed Action Alternative and Operational Alternative. In developing the alternatives, BLM followed the guidance set forth in 40 CFR 1500-1508 and the BLM NEPA Handbook H-1790-1. The BLM developed the Operational Alternative to incorporate input from the Cooperating

ES-2 Leavitt Reservoir Expansion Project – Final EIS – 2019 Executive Summary

Agencies that was received throughout the alternatives development process. The alternatives analyzed in detail in this EIS include the: • No Action Alternative – The No Action Alternative would continue the current operation practices at Leavitt Reservoir. There would be no increase in the current capacity of the reservoir to meet late-season irrigation needs in Beaver Creek or Shell Creek drainages. • Proposed Action Alternative – The Proposed Action Alternative would involve expanding the existing Leavitt Reservoir by 5,961 AF to a total storage capacity of 6,604 AF to reduce drought vulnerability and irrigation shortages. Storage in the expanded Leavitt Reservoir would include the existing 643 AF, 1,500 AF for a minimum environmental/recreation pool, and 4,461 AF for a supplemental irrigation supply. The additional storage for the expanded Leavitt Reservoir would be filled from the Beaver Creek diversion when bypass flows are greater than 5 cubic feet per second (cfs). • Operational Alternative – The Operational Alternative would involve expanding the existing Leavitt Reservoir by 5,961 AF to a total storage capacity of 6,604 AF to reduce drought vulnerability and irrigation shortages. Storage in the expanded Leavitt Reservoir would include the existing 643 AF, 1,500 AF for a minimum environmental/recreation pool, and 4,461 AF for a supplemental irrigation supply. This alternative is identical to the Proposed Action Alternative except there would be no minimum bypass flow during diversion from Beaver Creek. The BLM NEPA Handbook (H-1790-1) calls for expression of the BLM’s preferred alternative in the Draft EIS if one exists (BLM 2008a). The BLM has identified the applicant’s Proposed Action, as the agency’s preferred alternative in this Final EIS. The identification of a preferred alternative does not constitute a commitment or decision in principle, and there is no requirement to select the preferred alternative in the agency’s ROD. If warranted, the BLM may select a different alternative than the preferred alternative in its ROD. Alternatives Considered but Eliminated from Detailed Analysis Many alternatives were considered as possible alternatives for the LREP but were eliminated from detailed analysis because the BLM determined that they were ineffective (did not respond to the purpose and need), technically or economically infeasible, and/or would create substantial adverse impacts to biological and/or water resources. Section 2.4 of the EIS describes each of the alternatives considered and provides the reasoning as to why those alternatives were not carried forward for detailed analysis in the EIS. Affected Environment Chapter 3 of the EIS describes the affected environment of the LREP for the following resources anticipated to be impacted by the LREP: cultural resources, historic trails, and Native American concerns; geology; land use; noise; paleontological resources; range resources; recreation; socioeconomics; soils; transportation; vegetation; visual resources; water resources; wildlife and aquatic biological resources; and wetlands/riparian vegetation. The existing condition of these resources are described in Chapter 3 and provide the basis to address the issues brought forward during scoping. The information presented in Chapter 3 serves as a baseline for comparison of the direct, indirect, and cumulative impacts of each of the alternatives. Environmental Consequences Chapter 4 of the EIS describes the direct and indirect impacts expected to occur as a result of implementing the No Action Alternative, Proposed Action Alternative, and Operational Alternative for the LREP. The impact analysis for each resource was focused on the new disturbance over and above the existing disturbance associated with each alternative. The resource-specific effects of the alternatives were evaluated quantitatively and qualitatively, as appropriate based on available data and the nature of the resource analyzed. Impacts may be beneficial or adverse, may be assessed based on their duration, severity, or relation to the LREP, and may vary in severity. The level of impact is based on regulatory standards, criteria and ordinances, available scientific documentation, and professional judgment of the technical evaluator. The WWDC would implement certain environmental protection measures, design features, and procedures to avoid or reduce adverse impacts of the action alternatives. Based on the impact analyses, mitigation measures to minimize potential adverse impacts are identified in Chapter 4. Mitigation measures may be included as conditions of BLM’s

Leavitt Reservoir Expansion Project – Final EIS – 2019 ES-3 Executive Summary

ROW grant (if issued) and/or the USACE Section 404 Permit (if issued), or other federal, state, or local permits. Within each resource section, a discussion of potential environmental consequences includes: 1) anticipated impacts, 2) impacts analysis, and 3) a summary of unavoidable adverse impacts (i.e., those impacts that are unavoidable and cannot be mitigated). Mitigation measures for the anticipated resource impacts are discussed in Section 4.16 (Proposed Action) and Section 4.17 (Operational Alternative). A summary of the Chapter 4 impact analysis by resource and alternative is provided in Table 2-8 in Appendix 1 of the EIS. Cumulative Impacts Discussions of cumulative impacts, residual impacts, the relationship between local short-term uses of the human environmental and maintenance and enhancement of long-term productivity, and the irreversible/irretrievable commitment of resources that would result from the LREP, in combination with other reasonably foreseeable future actions (RFFAs), can be found in Chapter 5. The regulations for implementing NEPA define cumulative impacts as “the impact on the environment which results from the incremental impact of the action when added to other past, present, and RFFAs, regardless of what agency (federal or non-federal) or person undertakes such other actions. Cumulative impacts can result from individually minor but collectively significant actions taking place over a period of time” (40 CFR 1508.7). Cumulative impacts consider total environmental effects from a proposed action. The USACE’s Section 404(b)(1) Guidelines state that “cumulative impacts are the changes in an aquatic ecosystem that are attributable to the collective effect of a number of individual discharges of dredged or fill material. Although the impact of a particular discharge may constitute a minor change in itself, the cumulative effect of numerous such piecemeal changes can result in a major impairment of the water resources and interfere with the productivity and water quality of existing aquatic ecosystems” (40 CFR 230.11(g)(1)). For each resource, the cumulative impact analysis area was developed appropriate to the geographical extent of anticipated cumulative impacts. For some resources (e.g., cultural resources; geology; land use; noise; range resources; recreation; socioeconomics; soils; transportation; visual resources, water resources; wildlife; aquatic biological resources; and wetlands/riparian vegetation), the cumulative impact analysis area is the same as the analysis area for environmental impacts discussed in Chapter 4. For other resources (e.g., paleontological resources and vegetation), the cumulative impact analysis area is much larger. According to the BLM CYFO, there are approximately 1,430 acres of active or un-reclaimed bentonite mines in the Shell Creek watershed, along with an additional 1,290 acres of planned mining and 730 acres of mines that have already been reclaimed. The nearest planned or active mining area is located approximately 1.75 miles southwest of the current Leavitt Reservoir (BLM 2017a). The LREP would result in a total short-term disturbance of approximately 702 acres during construction and a long-term disturbance of approximately 285 acres during operation of the expanded reservoir. The reservoir inundation area would be increased by 158 acres from the current reservoir size of 45 acres to a total of 203 acres. Notable impacts from the LREP include the following: • Long-term benefit to agriculture due to the increased supply of irrigation water; • Long-term recreational benefit due to the expanded reservoir; • Potential impacts to known cultural resource sites and sites of tribal significance; • Inundation of three geologic formations containing paleontological resources (including several localities); • Creation of approximately 45 construction jobs and 14 direct and indirect jobs during reservoir operation; • Increase in farm income (approximately $1.1 million) and taxes (approximately $389,000); • Reduced peak flows on Beaver Creek and potential water quality impacts (both beneficial and adverse);

ES-4 Leavitt Reservoir Expansion Project – Final EIS – 2019 Executive Summary

• Permanent removal of 17.15 acres of existing wetlands; permanent impacts to 39.48 acres of surface waters; and permanent removal of 2.26 acres of woody riparian vegetation; and • Temporary impacts to noise, grazing and traffic. See Chapter 5 of the EIS for the full cumulative impacts analysis for the LREP.

Leavitt Reservoir Expansion Project – Final EIS – 2019 ES-5 Executive Summary

This page intentionally left blank

ES-6 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 1 – Introduction and Background

CHAPTER 1 INTRODUCTION AND BACKGROUND

The state of Wyoming, through the Wyoming Water Development Commission (WWDC), proposes the Leavitt Reservoir Expansion Project (LREP) as a means of increasing water storage to address late-season irrigation needs in the Shell Valley watershed. The U.S. Department of the Interior (DOI), Bureau of Land Management (BLM) prepared this Environmental Impact Statement (EIS) to analyze the direct, indirect, and cumulative effects of increased water development in the Shell Valley watershed. The proposed LREP is on both BLM-administered lands and private lands in Big Horn County, Wyoming, within the Shell Creek watershed, a tributary to the Bighorn River (see Figure 1-1). 1.1 Project Description and Background Leavitt Reservoir lies within an unnamed ephemeral draw along the Beaver Creek drainage, a perennial tributary to Shell Creek. The reservoir is an existing off-channel reservoir, as water is supplied from Beaver Creek and Davis Draw, both of which are tributary to Shell Creek, via the Leavitt Supply Ditch. Shell Creek flows from the western side of the Bighorn Mountains to its confluence with the Bighorn River near Greybull, Wyoming. Leavitt Reservoir is within the semi-arid foothills west of the Bighorn Mountains, east of Greybull and north of Shell. It is at approximately 44.64°N, -107.87°W, in Sections 13, 14, 23, 24, and 25 of T54N, R92W. On July 1, 2015, the WWDC applied for a new right-of-way (ROW) from the BLM by submitting an Application for Transportation and Utility Systems and Facilities on Federal Lands to expand the water storage capacity of Leavitt Reservoir. The expansion project will be authorized by ROW WYW-166003 for a 30 year term. This EIS is expected to provide for full public disclosure on the LREP and to aid in decision-making. This EIS was prepared in accordance with the Council on Environmental Quality’s (CEQ’s) National Environmental Policy Act (NEPA) Regulations (40 Code of Federal Regulations [CFR] Part 1500), BLM Handbook H-1790-1, and BLM Wyoming or national guidance. The BLM Cody Field Office (CYFO) is the lead federal agency responsible for preparing the EIS. The Shell Valley Watershed Improvement District (SVWID) was created in 1981 and is under the governing authority of the South Big Horn Conservation District. The purposes of the SVWID are to provide for the storage, conservation, development, utilization, and disposal of water; to preserve and protect land and water resources; to provide for the prevention of floodwater and sediment damage; to provide for the protection and prevention of erosion; and to enter into any other program or practice either singularly or in concert with others to protect and promote the health, safety, and general welfare of the people of the SVWID. Land ownership and administration within the Shell Creek Watershed is a mixture of private, federal (i.e., BLM and U.S. Forest Service [USFS]), and state of Wyoming lands. The BLM Cody Field Office manages lands north of U.S. Highway 14 (US 14), while the BLM Worland Field Office manages lands south of US 14. After being approached by the SVWID, the WWDC contracted various baseline studies of the Shell Creek watershed in 2010, 2013, and 2015 to identify potential sites for increased water storage for late season irrigation needs within the watershed. In the Shell Valley Watershed Plan Level I Study (Engineering Associates et al. 2010), twelve reservoir sites were assessed relative to water availability, storage, distribution, construction costs, and permitting constraints. These assessments were made from existing data and reconnaissance surveys to determine which sites could be viable water storage locations. The Shell Valley Storage Level II Study (States West 2013) included hydrologic analysis and site screening of 17 potential storage sites and evaluated the Upper Leavitt, Douglas Draw, and Shell Canal Tunnel reservoir sites in detail based on the screen results. The screening resulted in the preparation of preliminary designs and cost estimates for the three most viable sites in that study. Following the Level II study, an economic analysis proceeded that included the calculation of potential direct and indirect benefits and costs for the Upper Leavitt site (States West 2013). The Phase II Project Report for the Shell Valley Storage Level II Study (Wenck 2015) was then prepared and included more intensive investigations of the Upper Leavitt site, including completion of hydrological modeling, in-depth geotechnical explorations and analysis, wetland delineation, cultural and paleontological surveys, and revised preliminary designs and cost estimates (Wenck 2015).

Leavitt Reservoir Expansion Project – Final EIS – 2019 1-1 Chapter 1 – Introduction and Background

1.2 BLM Purpose and Need BLM has authority for the LREP under the Federal Land Policy and Management Act of 1976 (FLPMA) (Public Law [P.L.] 94-579, 43 United States Code [USC] 1701 et seq.). The FLPMA recognizes ROWs as one of the “principal or major uses” of public lands. The Secretary of the Interior is authorized to grant or issue ROWs for “reservoirs, canals, ditches, flumes, laterals, pipes, pipelines, tunnels, and other facilities and systems for the impoundment, storage, transportation, or distribution of water” per FLPMA Section 1761(1)(a). The need for this federal action, established by BLM’s responsibility under the FLPMA to provide these ROWs, is driven by documented late season irrigation shortages in the Shell Valley watershed. The purpose of this federal action is to provide access to BLM-managed public lands for increased watershed storage capacity in the Shell Valley watershed. BLM must decide whether and under what conditions to grant a ROW for the portion of the project that would be constructed on BLM-managed land. This decision constitutes a federal action necessary to determine, based on the selected alternative, whether construction of the proposed LREP could take place and will be made in accordance with the FLPMA. BLM’s decision will be communicated through publication of a ROD. 1.3 U.S. Army Corps of Engineers (USACE) Purpose and Need The overall purpose for the LREP, as determined for the USACE permitting process, is to reduce late season irrigation shortages by an average of 3,267 AF in the 30 percent driest water years, to lands in the lower portion of Shell Creek watershed, including the Beaver Creek watershed. The LREP is needed to meet a portion of the existing demand for late season irrigation water within the service area of the proposed reservoir expansion. The USACE is a Cooperating Agency (discussed in Section 1.5 below) on the proposed LREP because the project is anticipated to involve the discharge of dredged or fill material into waters of the United States (U.S.) as defined in 40 CFR 230.3. WWDC intends to apply for a Department of the Army Permit (Section 404 Permit), pursuant to Section 404 of the Clean Water Act (CWA), to place fill material in jurisdictional waters of the U.S., including wetlands. Prior to construction, a Section 404 Permit from the USACE, Omaha District (Cheyenne, Wyoming office) would be required. This permit issuance constitutes a second federal action necessary to determine whether construction of the proposed LREP could take place. The USACE will evaluate WWDC’s application under a public interest review, as well as the environmental criteria set forth in the Section 404(b)(1) Guidelines (40 CFR 230), regulations promulgated by the U.S. Environmental Protection Agency (USEPA), as well as the USACE regulations for implementing NEPA (33 CFR 325, Appendix B). The Section 404(b)(1) Guidelines require the project permitted is the least environmentally damaging practicable alternative The USACE’s decision will be communicated through publication of a Record of Decision (ROD). 1.4 Other Required Permits and Approvals Construction and operation of any of the proposed alternatives under consideration for the LREP would require a BLM ROW grant and other environmental permits and approvals. After issuance of the Final EIS, BLM must wait at least 30 days before issuing a ROD as specified in 40 CFR 1506.10. BLM’s ROD will include information prescribed at 40 CFR 1505.2, including the decision made, the rationale for the decision, the factors influencing the decision, mitigation, and the Conditions of Approval. In addition, other federal, state, and local permits and approvals may be required to implement the selected alternative. This EIS provides information for the other regulatory agencies with jurisdictional responsibility for lands and resources affected by the proposed LREP. Table 1-1 in Appendix 1 lists the permits and approvals that may be necessary for initiation and completion of the selected alternative. 1.5 Agency and Public Scoping Issues This section summarizes the agency and public scoping issues raised during the scoping period (September 29, 2017 through November 13, 2017). For agency scoping, the BLM sought broad input from local, state, and federal governmental agencies through invitations to serve as a Cooperating Agency on the LREP. Invitations were extended to entities with statutory authority over the proposed LREP, and entities for which the proposed LREP has a physical nexus (40 CFR 1501.6 and 1508.5). Formal Cooperating Agency Memorandums of Understanding (MOUs) exist with:

1-2 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 1 – Introduction and Background

• USACE, Omaha District • Wyoming State Engineer’s Office (SEO) • USEPA, Region 8 • Wyoming Department of Environmental Quality, Water Quality Division (WDEQ, WQD) • WWDC • Wyoming Department of Agriculture • Wyoming Governor’s Office • South Big Horn Conservation District • Wyoming Office of State Lands and Investments • Big Horn County Board of Commissioners • Wyoming Game and Fish Department (WGFD) The state agencies listed above are afforded Cooperating Agency status under the “MOU between the DOI, BLM, Wyoming State Office, and the state of Wyoming, by and through the Office of the Governor as a Cooperating Agency for All Planning and National Environmental Policy Act Analyses for which the BLM is the Lead Federal Agency” (State of Wyoming and BLM 2014). WWDC is afforded Cooperating Agency status under the “MOU between the State of Wyoming (by and through the WWDC) and the DOI, BLM Wyoming BLM State Director Regarding Development of the EIS for the LREP.” Separate MOUs between BLM and the South Big Horn Conservation District, and between BLM and the Big Horn County Board of Commissioners, were also executed. Throughout the NEPA process, USACE focused their review on evaluating the Proposed Project according to the CWA Section 404(b)(1) Guidelines. This process is part of the USACE Section 404(b)(1) permitting process that would authorize the placement of fill materials into wetlands and other waters of the U.S. pending Proposed Project approval by the BLM. USEPA’s focus has been on their review and independent comment of the EIS as required by Section 309 of the Clean Air Act. USEPA’s review was primarily concerned with identifying and recommending appropriate measures to avoid and mitigate significant environmental impacts associated with the LREP and the adequacy of information presented in this EIS. In accordance with NEPA (40 CFR 1501.7), to provide for an early and open process to gather information from the public and interested agencies on the issues and alternatives to be evaluated in the EIS, the BLM initiated a public scoping process through the publication of a Notice of Intent (NOI) that announced the preparation of an EIS for the LREP. The NOI was published in the Federal Register on September 29, 2017, and announced the beginning of the 45-day scoping period to solicit public comments and identify issues. The scoping comment period began September 29, 2017, and ended November 13, 2017. During the public scoping period, BLM held one Cooperating Agency scoping meeting and one public scoping meeting. The NEPA scoping process and scoping comments received by the BLM during the process are detailed in the Leavitt Reservoir Expansion Project Environmental Impact Statement, Final Scoping Report (AECOM 2017). That report includes a list of topics raised by commenters and specific issues raised during the NEPA scoping process. It also includes copies of all comment submissions received during scoping. The most frequent issues and concerns raised during the scoping process included: • Analysis of potential changes to water quality parameters based on changes in flow through operational changes; • Potential effects on fisheries habitats and other aquatic species; • Potential impacts to surface water flows, channel morphology, and Source Water Protection areas as a result of operational changes; • Concern for hydrologic resources in general, and the need to thoroughly analyze potential impacts to and relationships between water resource categories (e.g., water quality, surface water, water rights, groundwater, stream morphology, etc.); and • Importance of recreation opportunities and analysis of potential impacts as a result of actions associated with the LREP at the selected project location. The BLM considered the comments submitted during scoping and the issues identified when developing alternatives to the Proposed Action (see Chapter 2).

Leavitt Reservoir Expansion Project – Final EIS – 2019 1-3 Chapter 1 – Introduction and Background

This page intentionally left blank

1-4 Leavitt Reservoir Expansion Project – Final EIS – 2019

Chapter 2 – Proposed Action and Alternatives

CHAPTER 2 PROPOSED ACTION AND ALTERNATIVES

In preparing this Environmental Impact Statement (EIS), the Bureau of Land Management (BLM) developed and assessed reasonable alternatives that meet the purpose and need identified in Chapter 1. The BLM explored and objectively evaluated reasonable alternatives; Section 2.4 documents why certain alternatives were eliminated from detailed study as required by the National Environmental Policy Act (NEPA) (40 Code of Federal Regulations [CFR] Part 1502.14 (a)). In addition to the action alternatives, 40 CFR Part 1502.14(d) directs federal agencies to include a No Action Alternative in analyses. The No Action Alternative is the only alternative that does not need to respond to the purpose and need for the proposed undertaking. The action alternatives are responsive to issues identified during the scoping period. The action alternatives are intended to minimize adverse impacts on physical, biological, and socioeconomic resources from expanded water development while providing for a level of resource use and development consistent with current laws, regulations, and BLM management policies. The following sections summarize the three alternatives analyzed in detail in this EIS. The sections will assist decision-makers and the public in understanding the potential environmental consequences of each alternative. The three alternatives analyzed include the: • No Action Alternative: Continue the current operation practices at Leavitt Reservoir. There would be no increase in the current capacity of the reservoir to meet late-season irrigation needs in Beaver Creek or Shell Creek drainages. • Proposed Action Alternative: Expand the existing Leavitt Reservoir by 5,961 acre feet (AF) to a total storage capacity of 6,604 AF to reduce drought vulnerability and irrigation shortages. Storage in the expanded Leavitt Reservoir would include the existing 643 AF; 1,500 AF for a minimum environmental/recreation pool; and 4,461 AF for a supplemental irrigation supply. The additional storage for the expanded Leavitt Reservoir would be filled from the Beaver Creek diversion when bypass flows are greater than 5 cubic feet per second (cfs). • Operational Alternative: Expand the existing Leavitt Reservoir by 5,961 AF to a total storage capacity of 6,604 AF to reduce drought vulnerability and irrigation shortages. Storage in the expanded Leavitt Reservoir would include the existing 643 AF; 1,500 AF for a minimum environmental/recreation pool; and 4,461 AF for a supplemental irrigation supply. This alternative is identical to the Proposed Action Alternative except there would be no minimum bypass flow during diversion from Beaver Creek. 2.1 No Action Alternative NEPA requires that the EIS alternatives analysis include the alternative of “no action” (40 CFR 1502.14(d)). The Council on Environmental Quality (CEQ) explains that “no action” means “the proposed activity would not take place and the resulting environmental effects from taking no action would be compared with the effects of permitting the proposed activity or an alternative activity to go forward.” The No Action Alternative serves as the baseline for analysis of potential impacts. Leavitt Reservoir is a 643 AF off-channel reservoir located near the town of Shell in Big Horn County, Wyoming, at approximately 44.64° north (N), -107.87° west (W). It is a manmade reservoir located on BLM and private land and has an approximate normal high water level (NHWL) elevation of 4,797 feet above mean sea level. Leavitt Reservoir and dam inundate approximately 45 acres. The existing reservoir has approximately 2.4 miles of shoreline. Access to the existing Leavitt Reservoir is from the existing Bear Creek Road. Figure 2-1 in Appendix 2 is a map showing the location of the No Action Alternative and appurtenant facilities (Table 2-1 in Appendix 1) that are discussed below. • Water Source and Supply System: The existing Leavitt Reservoir is supplied by Beaver Creek and Davis Draw, both of which are tributary to Shell Creek, via the Bernie, Trout, and Leavitt Supply ditches.

Leavitt Reservoir Expansion Project – Final EIS – 2019 2-1 Chapter 2 – Proposed Action and Alternatives

• Dam Features: The existing Leavitt Reservoir dam is a 1,000-foot long-dam with a maximum height of 45 feet and a crest width of 15 feet. The upstream slope of the earthen embankment was built at a 3 horizontal (H):1 vertical (V) gradient and the downstream slope was built at a 2:1 gradient. The spillway is an unlined channel located on the right abutment, approximately 50 feet wide with 2:1 side slopes. • Outlet Works: The primary components of the outlet works are an upstream inclined sluice gate and a 220-foot-long 15-inch diameter outlet pipe discharging at the downstream toe. • Reservoir Operations: Water stored in the reservoir is associated with lands irrigated by the Trout, Calvin, Tolen, Bernie, Mathews, St. Jermain, London, Davis, South Boulder Creek Aggregate, Trone and Hurt, Kenyon, Williams, Anderson, Arthur Mason, Pense, Beaver, Loveland, Odessa, Red Bluff, Denney, Dunshee, Linn, and Cropsey ditches, plus the Porter Canal and the Barnett pipeline (see Figure 2-2 in Appendix 2). Storage water is released to the unnamed draw in which the reservoir resides and is conveyed to Beaver Creek. Downstream ditches are served directly, and upstream ditches are served by exchange. The reservoir is typically emptied by the end of the irrigation season and filled over the fall/winter and during spring runoff. The existing 643 AF of Wyoming water rights are held by private individuals. 2.2 Proposed Action Alternative The Proposed Action Alternative is to expand the water storage capacity of Leavitt Reservoir, an existing off-channel storage site for irrigation, located near the town of Shell, Wyoming. Under a permitted acreage scenario, the expanded reservoir is anticipated to provide 3,600 AF of firm yield in 8 out of 10 years from the additional storage capacity that would be available (Wenck 2015). End of the month storage of the reservoir, assuming similar hydrology to the last 10 years of available data, are shown in Table 2-2 and the corresponding graph in Appendix 1. Water for the LREP would be supplied by Beaver Creek. At the NHWL (6,604 AF), the reservoir surface area would be approximately 203 acres. The minimum (environmental/recreation) pool surface acreage of the expanded reservoir would be approximately 93 acres. The expanded reservoir is expected to naturally develop fringe wetlands similar to the existing fringe wetlands. The expanded reservoir would have similar side slopes in general, but would have steeper slopes along the upstream periphery than the existing Leavitt Reservoir. Construction of the expanded Leavitt Reservoir would occur continuously over approximately 22 months. The functional life of the LREP is expected to exceed 50 years (WWDC 2015). Table 2-3 lists the major components of the Proposed Action Alternative. Figure 2-3 in Appendix 2 displays the appurtenant facilities of the Proposed Action Alternative that are discussed in the following sections. Figures 2-4 and 2-5 in Appendix 2 provide perspective views of the Proposed Action Alternative and expanded Leavitt Reservoir area. The estimated total cost of construction of the LREP is $39.8 million (WWDC 2015). The items included in that estimate are discussed in Table 2-3 below. A more detailed breakdown of costs for LREP can be found in Table 6-3 of the Wyoming Water Development Commission (WWDC) Phase II Project Report for the Shell Valley Storage Level II Study (WWDC 2015). Table 2-3. Proposed Action Alternative Components Description

Leavitt Reservoir Expansion Components Includes the existing 643 AF, and an additional 5,961 AF to a total storage capacity of 6,604 AF, including a 1,500 AF environment/recreation pool and 4,461 AF of new storage. New earthen dam embankment (see Dam Features below). Approximately 330 acres (or 47 percent) of the LREP would be on BLM land, and approximately 365 acres of private land would be affected. The proposed NHWL would be elevation 4,860 feet, and would have approximately 5.6 miles of shoreline (approximately 3.2 miles more than the existing Leavitt Reservoir). Water source and supply system. Existing 643 AF of Wyoming water rights would be held by private individuals, water rights for water stored in the expanded reservoir would be held by either the state of Wyoming or the SVWID. Water would be supplied by a 2-mile-long, buried 42-inch-diameter water supply pipeline fed by a diversion on Beaver Creek (primary water supply).

2-2 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 2 – Proposed Action and Alternatives

Table 2-3. Proposed Action Alternative Components Description Additional storage for the expanded Leavitt Reservoir would be filled from the Beaver Creek diversion when bypass flows are greater than 5 cfs (with a supply system capacity of 75 cfs). Diversion structure would include a concrete barrier wall, a headgate (a gate for controlling the water flowing into the pipeline/channel/irrigation ditch), a diversion intake overflow wall, and a sluice gate. Diversion is proposed to be located on private land where an easement would be acquired. The pipeline would traverse private land to the reservoir inlet. When diverting the 643 AF that is currently diverted for storage, no bypass flow would remain in the creek. When filling the expanded storage volume, diversion would only occur of the portion of flow in Beaver Creek in excess of 5 cfs. Supply pipeline tunnel option would be located approximately 1,500 feet downstream from the diversion structure and would be installed using tunneling methods for environmental impact avoidance (approximately 600 lineal feet of tunnel). Reservoir supply pipeline would provide water to the proposed upstream wetland mitigation site, allowing constructed wetlands to receive water supply. Approximately 25 AF of water would be required during construction for embankment compaction, dust control, and the vehicle wash plant. Water may have to be purchased from irrigators during low flow conditions in Beaver Creek. Dam Features (Figure 2-6 in Appendix 2) Earthen Dam Embankment New, approximately 1,800-foot-long earthen dam embankment with a maximum height of 80 feet and a crest width of 21 feet Dam embankment would consist of a compacted impermeable core, sandier shells, an internal granular drain, riprap protection on the upstream face, and stability berms. Existing dam embankment will be lowered and repurposed as a berm for mitigation wetlands proposed to be established below the new dam embankment. Any material removed from the existing dam will be used on site in required project fills associated with the Proposed Action. Estimated excavation volumes are presented in Table 2-4 in Appendix 1. Estimated construction volumes are presented in Table 2-5 in Appendix 1. Two borrow areas east of the reservoir would be temporary disturbances and reclaimed. Total embankment quantity of fill is estimated to be approximately 1.4 million cy (925,000 cy from the expanded reservoir pool for the low permeability core and downstream shell of the dam; 500,000 cy processed at the borrow areas and transported by truck to the embankment). 30,000 cy of riprap required for the dam embankment (20,000 cy is expected to be produced from the borrow areas and 10,000 cy imported from existing quarries). Pipeline construction will require approximately 28,000 lineal feet of pipe. Auxiliary Spillway Proposed auxiliary spillway would release flow in excess of the capacity of the outlet works (125 cfs), and would not be activated under normal operations. New 20-foot open unlined channel auxiliary spillway with a concrete cutoff wall located west of the right abutment of the dam. Outlet Works Primary components of the outlet works would include a gated structure, a pipeline of varying diameters, an access tunnel, a control building with valves to regulate the outflow of water, a stilling pool for discharge below the existing dam, and a pipeline for direct release to Beaver Creek. Capacities of the outlet works would be approximately 125 cfs when the reservoir is at its NHWL, and 100 cfs at its environment/recreation pool level. Reservoir Delivery Infrastructure – Transfer Pipeline Six miles downstream from the reservoir outlet, a diversion and approximate 3-mile-long buried 36-inch/24-inch transfer pipeline would convey water released from the expanded Leavitt Reservoir

Leavitt Reservoir Expansion Project – Final EIS – 2019 2-3 Chapter 2 – Proposed Action and Alternatives

Table 2-3. Proposed Action Alternative Components Description Support Facilities/Staging Areas Support facilities and potential construction staging areas would be located within the pool area below the NHWL in areas that would minimize impacts to construction operations and the environment. Roads and Access Access to the LREP site would be from the existing Bear Creek Road; the grade for approximately 0.87 mile of Bear Creek Road would be raised on the east side of the reservoir. Borrow areas would be accessed from existing county and access roads on the Double Doc Ranch. County Road 39 would provide pipeline access. Recreational Facilities and Public Access Recreational facilities including a boat ramp, picnic facilities, restroom and trash facilities, parking area, and recreation pool. 0.5 mile of an unimproved access trail may need to be relocated. Utilities/Power The utility provider will select the tie-in location and transmission corridor during final engineering design. Any disturbance associated with utility installation would occur within disturbance footprint. If a power line is needed, the utility company would contact BLM for an additional power line ROW. Constructed Wetlands Potential wetland areas to be developed include approximately 11 acres downstream of the proposed dam, 24 acres on the reservoir rim, and 18 acres in the north wetland area (total estimated 53 acres). Reservoir Operations Expanded reservoir would primarily be filled with diversions from Beaver Creek during spring run-off once a 5 cfs minimum bypass flow is exceeded. The supply system could also divert storable flows during the fall and winter seasons once a 5 cfs minimum bypass flow is exceeded. The supplemental irrigation water would be released starting in July, continue through August, and extend into September. Under a permitted acreage scenario, the expanded reservoir is anticipated to provide 3,600 AF of firm yield in 8 out of 10 years from the additional storage that would be available. Sources: States West 2013; Wenck 2015; Wenck 2017a

2.3 Operational Alternative This alternative is identical to the Proposed Action Alternative except no minimum bypass flow would have to remain in the creek; that is, similar to current diversion practice, all the flow in the creek may be diverted. This is most likely to occur during diversions in fall and winter seasons. Under this Operational Alternative, irrigation shortage reductions in Beaver Creek and Shell Creek would be increased by approximately 155 AF relative to the Proposed Action Alternative (which is estimated to reduce shortages by an average of 3,286 AF for the 30 percent driest water years). 2.4 Alternatives Considered but Not Carried Forward for Detailed Analysis As discussed briefly in Chapter 1, (Section 1.1), the WWDC contracted various baseline technical studies of the Shell Creek watershed in 2010, 2013, and 2015 to identify potential sites for increased water storage for late season irrigation needs within the watershed. In the 2010 study (WWDC 2010b), 12 reservoir sites were assessed relative to water availability, storage, distribution, construction costs, and environmental permitting constraints. The 2013 study (States West 2013) further included hydrologic analysis and environmental site screening of 17 potential storage sites and specifically evaluated the Upper Leavitt, Douglas Draw, and Shell Canal Tunnel reservoir sites in detail. Following those studies, a third level of screening analysis (Wenck 2015) occurred and included preliminary design and cost estimates for the three most viable sites in the study. Figure 2-7 in Appendix 2 shows where each of the alternatives analyzed in the WWDC Level II, study (Wenck 2015) are located within the watershed (Collingwood Draw Complex and Red Canyon Reservoir are not shown).

2-4 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 2 – Proposed Action and Alternatives

According to the Clean Water Act (CWA) Section 404(b)(1) guidelines, an alternative is practicable if it is available and capable of being implemented after taking into consideration cost, existing technology, and logistics in light of overall project purposes. If an otherwise practicable alternative is available in an area not presently owned by the applicant, but which could reasonably be obtained, utilized, expanded or managed in order to fulfill the basic purpose of the proposed activity, it may be considered. The alternatives described in this section were considered as possible alternatives for the LREP but were eliminated from detailed analysis and meet the requirements of both the BLM and U.S. Army Corps of Engineers (USACE) in regards to alternative development. The screening criteria consisted of applying the following hierarchical screens to each alternative: 1) did the alternative meet the purpose and need, then 2) is the alternative technically feasible or are there any engineering fatal flaws, followed by 3) the cost of the alternatives, 4) and/or would the alternative create substantial adverse impacts to known sensitive resources (including wetlands and perennial waters, paleontological resources, and sensitive species or sensitive species management areas). Table 2-6 describes each of the alternatives considered and provides reasoning as to why these alternatives were not carried forward for detailed analysis in the EIS.

Leavitt Reservoir Expansion Project – Final EIS – 2019 2-5 Chapter 2 – Proposed Action and Alternatives

Table 2-6. Alternatives Considered but Not Carried Forward for Detailed Analysis Alternative Alternative Description Screening Criteria Analysis Alternatives with Modifications of the Proposed Action This alternative would include the LREP as proposed by WWDC with alternate means (i.e., alternate diversion locations and/or ditch and pipeline routes) of conveying water to and from the expanded Leavitt Reservoir. Three alternate diversion locations were considered by WWDC (Level II, Phase II Study): • One diversion would be located on Beaver Creek approximately 700 feet This alternative will not be included in detailed analysis for the following upstream of the proposed diversion point; reason: • Another diversion point would be located at the existing Calvin Ditch Environmental resource impacts. All three alternate diversion points would diversion approximately 1,600 feet upstream of the proposed diversion point; be located upstream of the proposed diversion point of LREP causing an and increased length of Beaver Creek that would be impacted by reduced flow • A third diversion point would be the existing Trout and Bernie ditch due to diversion. Additional impacts to perennial stream would likely cause Plumbing diversions, the most upstream of which (Bernie Ditch) is located about greater direct permanent losses to typically higher functioning aquatic Alternative 1.7 miles upstream of the proposed diversion point. habitats than LREP. Furthermore, the two alternate supply pipeline routes starting on the east side of Beaver Creek would have additional impact to Three alternate supply pipeline routes were considered by WWDC (Level II, Waters of the U.S. (compared to Proposed Action Alternative and Phase II Study): Operational Alternative) due to disturbance of Beaver Creek at a second • Two start on the east side of Beaver Creek (one at the existing Calvin Ditch location where the route crosses the creek. Given the additional diversion) and then cross under Beaver Creek before continuing west to the environmental constraints over the LREP, this alternative is screened out expanded reservoir; from further consideration. • One alternative route is to enlarge the existing Trout and Bernie ditches which currently supply the existing Leavitt Reservoir; and • One alternate transfer pipeline route was considered by WWDC which would involve construction of a pipeline for the entire distance from the expanded reservoir to Shell Canal.

2-6 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 2 – Proposed Action and Alternatives

Table 2-6. Alternatives Considered but Not Carried Forward for Detailed Analysis Alternative Alternative Description Screening Criteria Analysis This alternative will not be included in detailed analysis for the following reason: Technical feasibility not met/engineering fatal flaw. Sustained yield of the This alternative would include a groundwater source of supplemental irrigation deep aquifers is not known at this time nor is the potential for impact to supply to provide a similar amount of additional irrigation water as the LREP. To other water users (both groundwater and surface water), although this is meet the same level of irrigation shortages as the LREP, a large volume would be likely given the number of wells. The large number of wells (60 to 100) Groundwater needed for a short duration (July, August, and September). Given typical well required under this alternative would need to be spaced out over a large area Alternative yields from the likely aquifers to be tapped under this alternative (100 to and would require unknown lengths of connecting pipelines resulting in 300 gallons per minute from the Madison-Bighorn Aquifer system), between 60 large and dispersed surface disturbance, along with multiple access and 100 wells drilled to depths of 2,000 to 3,000 feet would be required to requirements. Given the variability of aquifer fracturing which controls provide the same shortage reduction as the LREP. aquifer yield, more than 60 to 100 locations would likely need to be drilled to obtain sufficient flow volume to reduce irrigation shortages which would result in additional disturbance and access requirements. Given the technical and engineering constraints this alternative is not practicable and is screened out from further consideration. This alternative will not be included in detailed analysis for the following This alternative would include additional water supplies obtained through leasing reason: of existing water rights to provide a similar amount of additional irrigation water Purpose and need not met. While it is possible to lease water rights, it is Water Leasing as the LREP. The only potentially available surface water supply in the Shell only allowed on a temporary basis. All existing surface water supplies in the Alternative Valley is the 300 acre-feet of storage the Town of Greybull owns in Shell Shell Valley watershed are primarily utilized by agriculture; water stored in Reservoir. Currently, this storage is leased to the Shell Canal and a bentonite existing reservoirs is not available to address the identified irrigation mine in the area through a temporary water use agreement. shortages. Given that the purpose and need is not met, this alternative is not practicable and is screened out from further consideration. This alternative will not be included in detailed analysis for the following This alternative would include water conservation measures to provide the same reasons: level of shortage reduction as the LREP. The water conservation in this scenario This alternative is not practicable because of logistics and cost. The could be achieved by reducing water loss from the stream source to the point of alternative hypothetically could be implemented; however, it is speculative use by improving irrigation system efficiencies. This would be accomplished at best to assume that private landowners would execute in a reasonable using existing technology through the installation of center pivot sprinklers on time frame the conservation technology presented in the alternative Conservation irrigated fields and either lining or piping irrigation ditches. Under this description. Additionally the total cost to implement and operate the Alternative alternative, it was assumed that all ditches were piped (Shell Canal lined) and conservation scenario is $86.4M ($53.5M for ditch efficiency improvements 70 percent of the irrigated acreage currently served by Leavitt (8,744 acres) plus $32.9M for additional sprinkler application systems). This overall cost would be converted to center pivot sprinkler to increase application efficiency. is more than twice the cost of the LREP. The cost to irrigators (due to lack This would result in replacing 86 miles of open ditches with pipelines and of funding assistance) is 19 times the cost of the LREP, which is beyond converting 6,871 irrigated acres to center pivot sprinklers (1,873 acres are already their ability to pay (Wenck 2017b). Given the logistics and costs associated irrigated with sprinklers). with this alternative, it is not practicable, and is screened out from further consideration.

Leavitt Reservoir Expansion Project – Final EIS – 2019 2-7 Chapter 2 – Proposed Action and Alternatives

Table 2-6. Alternatives Considered but Not Carried Forward for Detailed Analysis Alternative Alternative Description Screening Criteria Analysis This alternative will not be included in detailed analysis for the following This alternative would include a smaller expansion of the existing Leavitt reason: Reservoir in combination with conservation practices (e.g., ditch lining, irrigation water management, etc.) to provide a similar amount of additional irrigation water This alternative is not practicable because of logistics and cost. The as the Proposed Action. Under this alternative the reservoir expansion would be alternative hypothetically could be implemented; however, it is speculative approximately 2,000 AF (1,000 AF irrigation pool, 643 AF existing reservoir, and at best to assume that private landowners would execute in a reasonable 357 AF conservation pool) and would serve Beaver Creek and Shell Creek below time frame the conservation technologies presented in the alternative Combination the confluence with Beaver Creek (i.e., transfer pipeline eliminated). In addition, description. Additionally, the total cost to replace 40 miles of open ditch Alternative since the Shell Creek portion of the service area has the greatest potential for with pipelines and operate the conservation scenario is $65.1M ($19.6M for efficiency improvements this alternative assumed that the Freese Ditch, Whaley ditch efficiency improvements plus $21.2M for additional sprinkler Ditch, and Shell Canal would be piped (Shell Canal lined) and 70 percent of the application systems plus $24.3M for a smaller expansion of Leavitt acreage currently served by these ditches (5,789 acres) would be converted to Reservoir). This overall cost is more than one-and-a-half times the cost of center pivot sprinklers to increase application efficiency. This would result in the LREP. The cost to irrigators (due to lack of funding assistance) is replacing 40 miles of open ditches with pipelines and converting 4,393 irrigated 11 times the cost of the LREP, which is beyond their ability to pay (Wenck acres to center pivot sprinklers (1,396 acres are already irrigated with sprinklers). 2018). Given the logistics and costs associated with this alternative, it is not practicable, and is screened out from further consideration. Alternative Reservoir Locations Coyote Draw dam would be located in a valley between Canyon Creek and This alternative will not be included in detailed analysis for the following Beaver Creek approximately 1.5 miles south-southeast of Leavitt Reservoir. reason: Considered capacities ranged up to 7,000 AF, with corresponding dam heights of up to 110 feet. At reservoir capacities above approximately 3,500 AF, a side Technical feasibility not met/engineering fatal flaw. Geologic/geotechnical Coyote Draw “saddle” dam would be required in a lower area to the east of the main dam. This constraints surrounding this site include associated gypsum and calcite-filled Reservoir reservoir would be located within the Beaver Creek watershed and would be able fractures and slickenside joints in mudstone that could dissolve and create to serve irrigation needs along Beaver Creek. This reservoir would require seepage pathways and foundation settlement concerns (States West 2013, diversion and have significant flow from Beaver Creek. The Coyote Reservoir Chapter 3 p. 24 of 91). Given the technical and engineering constraints of dam would be located entirely on BLM lands and the reservoir would be located existing technology this alternative is not practicable and is screened out from almost entirely on BLM lands with less than 10 acres on private lands. further consideration. The Beaver Creek Confluence dam would be located at the confluence of North Beaver Creek and South Beaver Creek. The construction of a new Beaver Creek Reservoir would inundate approximately 1 mile of North Beaver Creek and This alternative will not be included in detailed analysis for the following 0.75 mile of South Beaver Creek, both perennial streams. Considered capacities reasons: Beaver Creek ranged up to 17,000 AF, with corresponding dam heights of up to 210 feet. This Technical feasibility not met. A significant portion (65 acres) of the Confluence reservoir would be located within the Beaver Creek watershed and would be able surrounding private land required for the reservoir is currently being Reservoir to serve irrigation needs along Beaver Creek. The Beaver Creek Confluence site irrigated, inhibiting acquisition of land ownership or right-of-way. Given the would be located above many of the points of need and would have significant technical constraints of this alternative it is not practicable and is screened flow available from both the North Fork and South Fork of Beaver Creek. The out from further consideration. Beaver Creek Confluence dam and reservoir would be located almost entirely on private lands with a small portion of the dam located on BLM land.

2-8 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 2 – Proposed Action and Alternatives

Table 2-6. Alternatives Considered but Not Carried Forward for Detailed Analysis Alternative Alternative Description Screening Criteria Analysis North Beaver Creek dam would be located near Little Bald Mountain near US 14 This alternative will not be included in detailed analysis for the following in the upper reaches of North Beaver Creek. The construction of a new Beaver reasons: Creek Reservoir would inundate approximately 0.75 mile of North Beaver Creek, North Beaver a perennial stream. This reservoir would be located within the Beaver Creek Purpose and need not met. The North Beaver Creek site is located above all Creek watershed and would be able to serve irrigation needs along Beaver Creek. Flows of the points of need within the service area, but is located too far up the Reservoir would be provided from the headwaters of the North Beaver Creek drainage. drainage basin to harvest enough water to meet the needs of this project Considered capacities ranged up to 7,000 AF, with corresponding dam heights of (States West 2013, Chapter 3 p. 6 of 91). Given that the purpose and need is up to 270 feet. The North Beaver Creek dam and reservoir would be located not met, this alternative is not practicable and is screened out from further entirely on Forest Service lands. consideration.

The Bratsky Draw Reservoir site is located in a broad, ephemeral valley between This alternative will not be included in detailed analysis for the following Beaver Creek and Horse Creek, approximately 1.5 miles upstream from the reason: confluence of Bratsky Draw and Shell Creek. Water would be provided through seasonal runoff within the local watershed, as well as through diversion from Technical feasibility not met/engineering fatal flaw. On site geotechnical Bratsky Draw Beaver Creek and/or Shell Creek. A diversion from Shell Creek would be and geological investigation determined a 1,000 foot long landslide exists at Reservoir approximately 7 miles. Storage capacities considered ranged up to 7,600 AF the left abutment of the proposed dam (States West 2013, Chapter 3, p. 29 of behind a dam height of 115 feet. Approximately one-half of the Bratsky dam and 91). Given the technical feasibility and engineering constraints associated most of the reservoir would be on BLM land. The balance of the facility would be with this alternative it is not practicable and is screened out from further on private land. consideration. This alternative will not be included in detailed analysis for the following reason: The Shell Reservoir Enlargement dam would be located at the existing Shell Technical feasibility not met/engineering fatal flaw. Geologic/geotechnical Reservoir approximately 18 miles east of the town of Shell. This reservoir would constraints as well as dam efficiency (volume of fill verses dam storage) Shell Reservoir have adequate supply from Shell Creek. Considered enlargement capacities concerns related to the location (headwaters) within the drainage (States Enlargement ranged up to 14,000 AF, with corresponding dam heights of up to 205 feet. This West 2013, Chapter 3 p. 69 of 91). This reservoir creates a logistical site would be located entirely within the Bighorn National Forest on lands constraint to supply irrigated lands identified in Beaver Creek due to administered by the USFS. distance, elevation, rugged terrain, and difficulties in maintenance. Given the technical feasibility and engineering constraints associated with this alternative it is not practicable and is screened out from further consideration. This alternative will not be included in detailed analysis for the following reason: Trapper Chimney Rock dam would be located near the Trapper Lodge Ranch and Chimney Rock approximately 3 miles southeast of the town of Shell. Considered Technical feasibility not met/engineering fatal flaw. Geologic/geotechnical Trapper capacities ranged up to 12,000 AF, with corresponding dam heights of up to 205 constraints surrounding this site include associated Chugwater and Goose Chimney Rock feet. A diversion from Trapper Creek would be required to supply this reservoir. Egg Formations containing gypsiferous carbonate which are prone to Reservoir Nearly all of the Trapper Chimney Rock dam and reservoir would be on BLM dissolution and would require extensive treatment to the dam and reservoir land, with a small portion of the reservoir on private land. foundation (States West 2013, Chapter 3, p. 54 of 91). Given the technical feasibility and engineering constraints associated with this alternative it is not practicable and is screened out from further consideration.

Leavitt Reservoir Expansion Project – Final EIS – 2019 2-9 Chapter 2 – Proposed Action and Alternatives

Table 2-6. Alternatives Considered but Not Carried Forward for Detailed Analysis Alternative Alternative Description Screening Criteria Analysis This alternative will not be included in detailed analysis for the following The Willett Lake dam would be located on Willett Creek at the existing Willett reason: Lake approximately 18 miles east of the town of Shell and approximately Environmental resource impacts. A reservoir site located on a perennial 4.6 miles from the Ranger Creek Campground. The construction of a new Willett stream would likely cause greater direct permanent losses to typically higher Lake Reservoir would inundate approximately 0.75 mile of Willett Creek, a Willett Lake functioning aquatic habitats (they provide wildlife habitat or other benefits) perennial stream. Water supply for the reservoir would be provided by Willett compared to potential reservoir sites not located on perennial streams. The Creek. Considered capacities ranged up to 9,000 AF, with corresponding dam construction of a new Willett Lake Reservoir would inundate approximately heights of up to 240 feet. This site would be located entirely within the Bighorn 0.75 mile of Willett Creek, a perennial stream. This impact to the aquatic National Forest on lands administered by the USFS. ecosystem eliminates this alternative from consideration when compared to the Proposed Action Alternative and Operational Alternative. This alternative will not be included in detailed analysis for the following The Lower Willett Reservoir dam would be located on Willett Creek reason: approximately 16 miles east of the town of Shell and approximately 1.7 miles Environmental resource impacts. A reservoir site located on a perennial from the Ranger Creek Campground. The construction of the Lower Willett stream would likely cause greater direct permanent losses to typically higher Lower Willett Reservoir would inundate approximately one mile of Willett Creek, a perennial functioning aquatic habitats (they provide wildlife habitat or other benefits) Reservoir stream. Water supply for the reservoir would be provided by Willet Creek. compared to potential reservoir sites not located on perennial streams. The Considered capacities ranged up to 8,000 AF, with corresponding dam heights of construction of the Lower Willett Reservoir would inundate approximately up to 125 feet. This site would be located entirely within the Bighorn National one mile of Willett Creek, a perennial stream. This impact to the aquatic Forest on lands administered by the USFS. ecosystem eliminates this alternative from consideration when compared to the Proposed Action Alternative and Operational Alternative. This alternative will not be included in detailed analysis for the following reason: The Sheldon Gulch dam would be located in a valley adjacent to Potato Ridge. Purpose and need not met. This reservoir location would be located below Water supply would be from Shell Canal. Considered capacities ranged up to most of the points of need in the service area (States West 2013, Chapter 3 7,000 AF, with corresponding dam heights of up to 85 feet. This site would be Sheldon Gulch p. 34 of 91) and would not reduce late season irrigation shortages by an located below most of the points of need in the service area. Nearly all of the Reservoir average of 3,267 AF in the 30 percent driest water years, to lands in the Sheldon Gulch dam and most of the reservoir would be on BLM land. A very lower portion of Shell Creek watershed, including Beaver Creek watershed. small part of the reservoir would be on State land. The balance of the facility The reservoir has logistical constraints due to distance, elevation, rugged would be on private land. terrain, and difficulties in maintenance. Given that the purpose and need is not met, this alternative is not practicable and is screened out from further consideration.

2-10 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 2 – Proposed Action and Alternatives

Table 2-6. Alternatives Considered but Not Carried Forward for Detailed Analysis Alternative Alternative Description Screening Criteria Analysis This alternative will not be included in detailed analysis for the following The Douglas Draw dam would be located along US 14 approximately 1 mile west reason: of the town of Shell. Considered capacities ranged up to 5,000 AF, with corresponding dam heights of up to 120 feet. A diversion from Shell Creek would Technical feasibility not met/engineering fatal flaw. Geologic/geotechnical Douglas Draw provide a sufficient supply of water to this reservoir. Although this reservoir constraints surrounding this site include associated gypsum and calcite-filled Reservoir could discharge to Shell Creek above Shell Canal, it would not serve any needs fractures and slickenside joints in mudstone that could dissolve and create on Beaver Creek. Although the Douglas Draw dam and reservoir would be seepage pathways and foundation settlement concerns (States West 2013, entirely on BLM land, nearly all of the pipeline from Shell Creek, that would be Chapter 3, p. 44 of 91). Given the technical feasibility and engineering required to supply the reservoir would be on private land. constraints associated with this alternative it is not practicable and is screened out from further consideration.

The Upper Willett Reservoir dam would be located on Willett Creek This alternative will not be included in detailed analysis for the following approximately 16 miles east of the town of Shell and approximately 2.3 miles reasons: from the Ranger Creek Campground. The construction of the Upper Willett Upper Willett Reservoir would inundate approximately 0.6 mile of Willett Creek, a perennial Technical feasibility not met. Due to the location in the upper reaches of the Reservoir stream. Water supply for the reservoir would be provided by Willett Creek. drainage basin resulting in a relatively inefficiency (water storage capacity Considered capacities ranged up to 5,000 AF, with corresponding dam heights of versus dam fill) of the site (States West 2013, Chapter 3 p. 78 of 91). Given up to 205 feet. This site would be located entirely within the Bighorn National the technical and engineering constraints of existing technology this Forest on lands administered by the USFS. alternative is not practicable and is screened out from further consideration. This alternative will not be included in detailed analysis for the following reason: The Trapper Off Channel dam would be located near the Trapper Lodge Ranch near the confluence of Trapper Creek and Bush Creek approximately 3 miles Technical feasibility not met/engineering fatal flaw. Geologic/geotechnical Trapper south-east of the town of Shell. Supply for this reservoir would be provided by constraints surrounding this site include associated Chugwater and Goose Off-Channel Trapper Creek. Considered capacities ranged up to 4,400 AF, with corresponding Egg Formations containing gypsiferous carbonate which are prone to Reservoir dam heights of up to 125 feet. The majority of the reservoir would be on BLM dissolution and would require extensive treatment to the dam and reservoir land; all of the dam and a small portion of the reservoir would be on private land. foundation (States West 2013, Chapter 3, p. 64 of 91). Given the technical and engineering constraints of existing technology this alternative is not practicable and is screened out from further consideration.

Leavitt Reservoir Expansion Project – Final EIS – 2019 2-11 Chapter 2 – Proposed Action and Alternatives

Table 2-6. Alternatives Considered but Not Carried Forward for Detailed Analysis Alternative Alternative Description Screening Criteria Analysis The Trapper Creek Complex includes two watershed tributaries to Trapper Creek. The primary site, Trapper Creek, would be located near the Trapper Lodge Ranch at the confluence of Trapper Creek and Bush Creek approximately 3 miles southeast of the town of Shell. Water for the Trapper Creek site would be from the current system that has gravity feed piping from Trapper Creek through a This alternative will not be included in detailed analysis for the following relatively deep notch cut in the ridge east of the site, and into pipe for irrigating reason: Trapper Creek alfalfa. Considered capacities ranged up to 3,400 AF, with corresponding dam Technical feasibility not met/engineering fatal flaw. Geologic/geotechnical and Trapper heights of up to 120 feet. About half of the Trapper Creek reservoir and most of constraints surrounding this site associated Chugwater and Goose Egg East Complex/ the dam would be on private land, with the remainder on BLM land. Formations containing gypsiferous carbonate are prone to dissolution and Trapper Creek The secondary site, Trapper Creek East, is located on Bush Creek (an ephemeral would require extensive treatment to the dam and reservoir foundation Reservoir drainage) immediately upstream of its confluence with Trapper Creek. Water for (States West 2013, Chapter 3, p. 59 of 91). Given the technical and the Trapper Creek East site would be provided by seasonal high flows in Bush engineering constraints of existing technology this alternative is not Creek and possibly piped water from Trapper Creek. Water storage capacity for practicable and is screened out from further consideration. the Trapper Creek East site was estimated based on maximum potential dam height and water elevation of 65 feet. Storage capacity behind the assumed dam height is 734 AF. The majority of the Trapper Creek East site occurs on public land. The Collingwood Draw Complex includes three potential storage sites (Upper, Middle, and Lower), located in a broad, ephemeral valley south of Shell Creek. The Upper and Middle sites are located entirely on public land, while the Lower site is primarily on public land, although the potential dam site would be on This alternative will not be included in detailed analysis for the following private land. The Middle and Lower sites are both relatively small, and would reason: experience minimal environmental impacts. Water storage capacity for the Upper Purpose and need not met. This reservoir location would not reduce late Collingwood site would be 2,692 AF, the Middle site would be 11 AF, and the Lower site season irrigation shortages by an average of 3,267 AF in the 30 percent Draw Complex would be 71 AF. driest water years, to lands in the lower portion of Shell Creek watershed, Water for the Upper and Middle sites would be provided by seasonal runoff in the including Beaver Creek watershed. Given that the purpose and need is not Collingwood Draw watershed. Water would be conveyed through McDonald met, this alternative is not practicable and is screened out from further Ditch and Shell Creek, but would require pumping. Water for the Lower site consideration. would be provided from seasonal runoff collected in Collingwood Draw and could also be diverted from the Shell Canal. Water would be conveyed through the Whaley Ditch.

2-12 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 2 – Proposed Action and Alternatives

Table 2-6. Alternatives Considered but Not Carried Forward for Detailed Analysis Alternative Alternative Description Screening Criteria Analysis The Highline Reservoir Expansion would be located along US 14 approximately This alternative will not be included in detailed analysis for the following 1 mile west of the town of Shell. A relatively small, existing reservoir would be reason: enlarged which would require raising the dam height along the old highway which currently serves as the existing dam. A diversion from Shell Creek would Purpose and need not met. This reservoir location would not reduce late High Line be required to supply this reservoir. Considered capacities ranged up to 2,000 AF, season irrigation shortages by an average of 3,267 AF in the 30 percent Reservoir with corresponding dam heights of up to 65 feet. Nearly all of the Highline dam driest water years, to lands in the lower portion of Shell Creek watershed, and reservoir would be on BLM land, with the remainder of the dam and reservoir including Beaver Creek watershed. Given that the purpose and need is not and nearly all of the pipeline from Shell Creek (that would be required to supply met, this alternative is not practicable and is screened out from further the reservoir) on private land. consideration. The Red Canyon reservoir site is located within a steeply incised, unnamed drainage between the confluence of Beaver Creek to the west, and Red Canyon Creek to the east. An ephemeral drainage that carries seasonal high flows This alternative will not be included in detailed analysis for the following meanders through the bottom of the site. Water for the Red Canyon site would be reasons: provided by seasonal high flows in the unnamed tributary drainage between Red Purpose and need not met. This reservoir location would not reduce late Red Canyon Canyon and Beaver creeks. Additional water for the site would have to be season irrigation shortages by an average of 3,267 AF in the 30 percent Reservoir diverted from areas upstream (e.g., Red Canyon and Beaver creeks). Water driest water years, to lands in the lower portion of Shell Creek watershed, storage capacity for the site was estimated based on a dam height and maximum including Beaver Creek watershed. Given that the purpose and need is not water depth of 65 feet. Storage capacity at the assumed dam height is met, this alternative is not practicable and is screened out from further approximately 546 AF. The dam site and lower portion of the reservoir would be consideration. located on private land. The upper portion of the reservoir would fill portions of the drainage on public land administered by the BLM. This alternative will not be included in detailed analysis for the following The Shell Canal Tunnel dam would be located along the Shell Canal reason: approximately 0.25 mile from the Shell Canal Tunnel. Water supply for this Shell Canal Purpose and need not met. This reservoir location would not reduce late reservoir would be provided by the Shell Canal. A capacity of 225 AF was Tunnel season irrigation shortages by an average of 3,267 AF in the 30 percent considered, with a corresponding dam height of 50 feet. This dam would be Reservoir driest water years, to lands in the lower portion of Shell Creek watershed, limited by topography and the presence of the Shell Canal. All of the Shell Canal including Beaver Creek watershed. Given that the purpose and need is not Tunnel dam and reservoir would be on private land. met, this alternative is not practicable and is screened out from further consideration.

Leavitt Reservoir Expansion Project – Final EIS – 2019 2-13 Chapter 2 – Proposed Action and Alternatives

2.5 Alternatives Comparison Table 2-7 provides a comparison of the major attributes for the No Action Alternative, Proposed Action Alternative, and Operational Alternative. Table 2-8 in Appendix 1 provides a comparison of impacts by resource for the alternatives. Detailed discussion of the environmental and cumulative impacts from these three alternatives is presented in Chapters 4 and 5, respectively. Table 2-7. Comparison of Major Attributes for Each Alternative Attributes No Action Alternative Proposed Action Alternative Operational Alternative Beaver Creek and Davis Draw Water Source/ (both are tributary to Shell Same as Proposed Action Primarily Beaver Creek Supply Creek), via the Bernie, Trout, Alternative and Leavitt Supply ditches 6,604 AF (this includes the existing 643 AF, 1,500 AF for a minimum Same as Proposed Action Storage Capacity 643 AF environmental/ recreation pool, and Alternative 4,461 AF for a supplemental irrigation supply) Same as Proposed Action Inundation Area 45 acres 203 acres Alternative The existing 643 AF of Wyoming water rights would be held by the The existing 643 AF of private individuals who currently Wyoming water rights for the hold them; the water rights for the Same as Proposed Action Water Rights existing Leavitt Reservoir are additional water stored in the Alternative held by private individuals expanded reservoir would be a new water right held by either the state of Wyoming or the SVWID The additional storage for the Under the current water right, The expanded Leavitt expanded Leavitt Reservoir would diversion into the existing Reservoir would be filled Bypass be filled with diversions from reservoir is conducted with no with diversions from Beaver Beaver Creek during spring run-off bypass flow Creek with no bypass flow with a 5 cfs bypass flow Existing 1,000-foot-long dam New approximately 1,800-foot- embankment with a maximum long earthen dam embankment with Same as Proposed Action Dam Embankment height of 45 feet and a crest a maximum height of 80 feet and a Alternative width of 15 feet crest width of 21 feet New 20-foot open unlined channel Existing spillway is an unlined auxiliary spillway with a concrete Same as Proposed Action Spillway channel located on the right cutoff wall located west of the right Alternative dam abutment abutment of the dam A gated structure, a pipeline of varying diameters, an access An upstream inclined sluice tunnel, a control building with Primary gate and a 220-foot-long 15- valves to regulate the outflow of Same as Proposed Action Components of inch diameter outlet pipe water, a stilling pool for discharge Alternative Outlet Works discharging at the downstream below the existing dam, and a toe pipeline for direct release to Beaver Creek Access to the LREP site would be from the existing Bear Creek Road; From the existing Bear Creek the grade for approximately Same as Proposed Action Access Road 0.87 mile of Bear Creek Road Alternative would be raised on the east side of the reservoir Two borrow areas east of the Same as Proposed Action Borrow Areas Not applicable reservoir Alternative

2-14 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 2 – Proposed Action and Alternatives

Table 2-7. Comparison of Major Attributes for Each Alternative Attributes No Action Alternative Proposed Action Alternative Operational Alternative Such facilities and potential construction staging areas would be Same as Proposed Action Support Facilities Not applicable located within the pool area below Alternative the NHWL A 2-mile-long, buried 42-inch- Not applicable (storage water diameter water supply pipeline fed is released to the unnamed by a diversion on Beaver Creek; a Same as Proposed Action Pipelines draw in which the reservoir diversion and approximate 3-mile- Alternative resides and is conveyed to long buried 36-inch/24-inch Beaver Creek) transfer pipeline A boat ramp, picnic facilities, Recreational Same as Proposed Action Not applicable restroom and trash facilities, and Facilities Alternative parking area Not yet known as the utility provider will select the tie-in location and transmission corridor Same as Proposed Action Utilities/Power Not applicable during final engineering design; Alternative power will be required for the dam control building and supply and transfer diversions Notes: AF = acre-feet cfs = cubic feet per second NHWL = normal high water level SVWID = Shell Valley Watershed Improvement District

Leavitt Reservoir Expansion Project – Final EIS – 2019 2-15 Chapter 2 – Proposed Action and Alternatives

This page intentionally left blank

2-16 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 3 – Affected Environment Resource Discussions

CHAPTER 3 AFFECTED ENVIRONMENT RESOURCE DISCUSSIONS

The existing physical, biological, social, and economic conditions of the environment within the Leavitt Reservoir Expansion Project (LREP) area that may be affected by implementation of the proposed LREP and the alternatives is described in this chapter. The resource descriptions of existing conditions provide the baseline upon which environmental consequences are analyzed in Chapter 4, Environmental Impacts, and Chapter 5, Cumulative Impacts. The description of the existing environment is based on field and desktop studies, as well as available information obtained from published documents and resource agency personnel. The current design for the major LREP components are representative designs. The exact alignments and/or footprints of these components would be selected to minimize interference with environmentally sensitive areas, roads, watercourses, and property boundaries. Thus, the descriptions of the affected environment for the LREP alternatives are based on reasonable characterizations of the resources. Refer to Chapter 2 for details on the alternatives. 3.1 Cultural Resources, Historic Trails, and Native American Concerns As defined in the Bureau of Land Management’s (BLM’s) Cody Field Office (CYFO) Approved Resource Management Plan (RMP), cultural resources include: any pre-historic or historic district, site, building structure, or object considered important to a culture, subculture, or community for scientific, traditional, religious, or other purposes. Archeological resources are areas where pre-historic or historic activity measurably altered the earth or where deposits of physical remains (e.g., projectile points, pottery, or bottles) are discovered. Architectural and engineering resources include standing buildings, districts, bridges, dams, and other structures of historic or aesthetic value. Traditional resources can include archeological resources, structures, topographic features, habitats, plants, wildlife, and minerals that Native Americans or other groups consider essential for the preservation of traditional culture . . . (BLM 2015:3-140). Evidence of past cultures can be found throughout the Bighorn Basin dating back as early as 12,000 to 15,000 years ago with the Paleoindian period, extending into the Archaic period and Late Prehistoric period, and culminating with the Historic period (BLM 2015a). Most of the pre-historic sites consist of campsites or habitations, lithic scatters, lithic procurement sites, stone circles, stone alignments, and rock cairns. Other pre-historic site types outlined in the BLM RMP include burials, ceremonial stone alignments, rock art, rock shelters, ceramic sites, quarries and secondary lithic procurement sites, hunting blinds, structures, and bison kill and butchering sites (BLM 2015a). Recorded historic cultural resources in the region include homesteads, early ranches and farms, stock herding camps, irrigation systems, early oil fields and associated camps, bridges, and urban buildings (BLM 2015a). The process of the subsistence-based hunter-gatherer lifestyle and the resulting land use is evident in the archaeological record, which contains features and cultural material of indigenous tribes of the Bighorn Basin. Landscape features as well as some sites in the region have a long oral history that spans thousands of years. Chronometric data related to temporally diagnostic projectile points discovered in the area indicate predominantly Archaic and Late Pre-historic occupations. Pre-historic stone circles, stone cairns, and lithic scatters are typical of those observed throughout the Bighorn Basin and intermountain regions and generally lack attributes that associate them with specific periods or cultures. Lithic materials within the LREP area are primarily gray chalcedonies and cherts largely derived from the Morrison formation (Frison and Bradley 1980) consisting of thousands of cobbles that occur naturally along the base of the badland areas in the northern and western regions of the LREP area. The projectile points and lithic tools found at numerous sites indicate that lithic procurement, tool stone manufacture, and hunting were likely primary activities. The riparian areas along Beaver Creek and Shell Creek would have provided access to numerous faunal and plant resources. Historic-era resources in the Bighorn Basin reflect an economy largely based on agricultural activities centered on farming and ranching. Historic resources in the area include a few ditch and canal segments, small debris scatters, and a foundation remnant.

Leavitt Reservoir Expansion Project – Final EIS – 2019 3-1 Chapter 3 – Affected Environment Resource Discussions

3.1.1 Cultural Resources 3.1.1.1 Analysis Area The direct area of potential effect (APE) for cultural resources encompasses the footprint of the proposed development where ground disturbance and/or impacts may occur, including the normal high water level (NHWL) of the reservoir, associated transfer pipelines, access roads, borrow areas, and a variable buffer for a total planned disturbance of approximately 702 acres. The direct APE also includes a 200-foot buffer along the NHWL, and 100-foot buffer from the proposed borrow areas, wetlands, and access roads and pipelines centerlines. The indirect APE consists of the foreground up to 3 miles or the visual horizon, whichever is closer, from the proposed LREP toward any sites of traditional religious or cultural significance or sites where the integrity of the element of setting contributes to the National Register of Historic Places (NRHP) significance. 3.1.1.2 Cultural Resource Context The LREP is in the Davis Draw locality along Beaver Creek, in a transition zone where the High Plains join the eastern flank of the Bighorn Mountains, roughly 6 miles to the east. Overall, the reservoir’s position on the landscape provides optimal conditions for human occupation and would allow inhabitants to exploit a wide variety of resources associated with the dissected rolling sagebrush-steppe and badland areas north of Shell Creek and the Bighorn Mountains to the east. Cultural resources within the LREP area are predominantly prehistoric in nature and consist of lithic scatters, secondary lithic procurement sites, rock cairns/alignments, and habitation/campsites. One site (48BH612) contains artifacts from both the Pre-historic and Historic periods. Nine cultural resource investigations that overlap with the LREP cultural resource direct APE took place between 1980 and 2017. The findings of the previous investigations indicate that 23 cultural sites are within the LREP cultural resource direct APE (Table 3-1). In regard to NRHP eligibility, one site (48BH1269) is listed in the NRHP, one site (48BH609) is recommended eligible for listing in the NRHP under Criterion D (as it has yielded or may be likely to yield, information important in history or prehistory), 15 sites are recommended not eligible for the NRHP, three are unevaluated, two are unevaluated by the Office of the Wyoming State Archaeologist (OWSA) and recommended not eligible by Barron Cultural Resource Consultants, and one is unevaluated by OWSA and recommended eligible by Barron Cultural Resource Consultants. Following tribal on-site visits conducted on December 14, 2017, sites 48BH4242, 48BH4244, and 48BH4245 have been recommended eligible for the NRHP under Criterion A as possessing tribal significance (email communication with Devin Old Man, Northern Arapaho Tribal Historic Preservation Officer [THPO] Lead on January 9, 2018; e-mail communication with Josh Mann, Eastern Shoshone THPO Lead on January 10, 2018; and phone communication with William Big Day, Crow Nation THPO Lead, on January 9, 2018). A total of 126 sites are found within 3 miles of the LREP project. This number does not differentiate between those sites within the indirect APE of the LREP and those that are not. Twenty-three of these sites are within the direct APE. Site type surrounding the LREP reflect largely pre-historic occupations (n=88) and most commonly consists of pre-historic lithic scatters that may or may not contain hearth features. If found significant, these sites are generally only considered eligible under NRHP Criterion D. Of note, the Hanson Site (48BH329) is listed in the NRHP as significant to prehistory as a large well-preserved Paleoindian occupation. Other pre-historic site types include cairn features, hunting blinds, and rock art. Some of these site types may be considered sites of Native American concern. Historic sites include bridges, irrigation features, graves, debris, and buildings. Sites of traditional religious or cultural significance that are within the LREP indirect APE are identified as those resources eligible for listing in the NRHP under Criterion A or C, and where integrity of the element of setting contributes to the Historic Properties’ significance. Based on a review of data, five sites within 3 miles of the LREP may meet this criterion and include a burial (48BH1853), two rock art locations (48BH4058 and 48BH4293), and two sites with stone features (48BH968 and 48BH4442). 3.1.2 Historic Trails Congress established the National Trails System in 1968 and presently, National Historic Trails are protected by the BLM as part of the National Conservation Lands. No National Historic Trails or regionally significant historic trails or trail segments have been identified within the LREP (BLM 2015a).

3-2 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 3 – Affected Environment Resource Discussions

3.1.3 Native American Concerns The U.S. has a unique relationship with and responsibility to Native American tribes. That responsibility extends to the federal government’s historic preservation activities, which mandate that federal consultation with Native American tribes be meaningful, in good faith, and entered into on a government-to-government basis. Guiding regulations for both the National Environmental Policy Act (NEPA) and the National Historic Preservation Act (NHPA) and the Wyoming State Protocol (BLM and SHPO 2014) now make tribal consultation a requirement for almost any project that requires federal action, permitting, or oversight. Subsequently, tribal participation in development projects such as the LREP is increasing. Many Native American people are concerned about the activities that occur in their aboriginal territory. Indigenous tribes have occupied the Bighorn Basin for thousands of years, and the BLM recognizes and honors traditional ties that bind tribal communities and Native American people to the Bighorn Basin and lands associated with the LREP. Native American interests often include sites related to cultural practices or beliefs which are designated as Traditional Cultural Places (TCPs). TCPs are crucial to maintaining a tribe’s cultural identity. National Register Bulletin 38 (Parker and King 1990) defines a TCP as a place eligible for the NRHP because of its association with cultural practices and beliefs that are (1) rooted in the history of a community and (2) important to maintaining the continuity of that community’s traditional beliefs and practices (Parker and King 1990). The location of these sites is kept confidential administratively. The BLM will maintain appropriate access to traditional use areas and ceremonial and sacred sites to tribes within the LREP area of analysis, and has consulted with affected tribes to address access to culturally important resources within the LREP area. Presently, the BLM has indicated that there are no TCPs as defined by National Register Bulletin 38 (Parker and King 1990) in the LREP area (BLM 2015a). However, this does not mean that Native American tribes do not have resource concerns or TCPs in the planning area that have yet to be formally recognized (BLM 2015a). In December 2016, the BLM CYFO, as the lead federal agency for the LREP, initiated consultation with six tribes with ancestral ties to the LREP area of analysis and an interest in participating in the EIS process: the Blackfeet Tribe, the Crow Nation, the Eastern Shoshone Tribe, the Northern Arapaho Tribe, the Northern Cheyenne Tribe, and the Shoshone Bannock Tribe. On October 13, 2017, the BLM CYFO notified these tribes of BLM’s publication of the Notice of Intent to prepare an EIS in the Federal Register and requested their input and assistance in identifying any potential cultural concerns regarding the LREP. The Crow Nation, the Eastern Shoshone Tribe, and the Northern Arapaho Tribe responded, declaring interest in participating in the EIS process and participating in any subsequent site visits scheduled by the BLM. On December 14, 2017, the BLM; tribal representatives from Crow Nation, the Eastern Shoshone Tribe, and the Northern Arapaho Tribe; the manager of the Double Doc Ranch (a private property within the LREP disturbance footprint); and a representative of SWCA (part of BLM’s third-party EIS contractor team), visited the LREP study area to conduct site visits and elicit comments about the LREP, sites of religious or cultural significance that may be in the area, and any perceived impacts potentially caused by the proposal. In addition, three cultural resource sites previously left unevaluated (48BH4242, 48BH4244, and 42BH4245) were visited in order to gain tribal input regarding site significance and possible impacts resulting from the LREP. Minutes from the on-site meeting soliciting comments from tribal and agency personnel were disseminated to BLM and the tribal representatives. The respective THPOs from the Crow Nation, the Eastern Shoshone Tribe, and the Northern Arapaho Tribe recommended the previously unevaluated sites (i.e., 48BH4242, 48BH4244, and 42BH4245) as eligible for listing in the NRHP under Criterion A, due to holding tribal significance, based on field observations. 3.2 Geology 3.2.1 Geologic Setting The LREP analysis area for geological resources includes the reservoir inundation area, construction footprint, and existing quarries that would be used to supply concrete and rip rap for the earthen dam embankment. This area was selected for analysis because it encompasses the entire ground disturbance associated with the proposed reservoir expansion. Leavitt Reservoir is located on the west flank of the Bighorn Mountains at a general elevation of approximately 4,800 feet above mean sea level (amsl). The Bighorn Mountains are a northwest-to-southeast trending anticlinal range that rises to an elevation of 14,000 feet amsl. The topography in the LREP study area is characterized by benches and mesas cut by drainages. A major physiographic feature that occurs southwest and adjacent to the Bighorn Mountains is the Bighorn Basin, a topographical and structural basin that also trends northwest to southeast.

Leavitt Reservoir Expansion Project – Final EIS – 2019 3-3 Chapter 3 – Affected Environment Resource Discussions

3.2.2 Stratigraphy The core of the Bighorn Mountains is composed of Precambrian rock. On the west flank of the range, Phanerozoic sedimentary rocks dip into the Bighorn Basin, and consist of geologic units that range in age from Cambrian to unconsolidated Holocene deposits (Table 3-2) (Noggle-Perrin 1989). The bedrock at the current reservoir site and along much of the proposed transfer pipeline alignment consists of the Lower Cretaceous Cloverly Formation (Figures 3-1 and 3-2), which is comprised of sandstone and mudstone layers that would provide the foundation for the proposed new dam. The Cloverly Formation has been divided by Ostrom (1970) into five distinct stratigraphic units. Four of these units (Units V, VI, VII, and VIII) have been identified near the LREP study area. Unit VIII is referred to as the Sykes Mountain Member and is the youngest unit in the sequence. It consists of brown siltstone and sandstone interbedded with some dark gray shale layers. The other three units found in the study area consist of claystone in Unit VII, discontinuous channel sandstones with occasional conglomerate in Unit VI, and a lower claystone layer (Unit V). The proposed dam foundation would be built on Units V, VI, and VII (Wenck 2015). Claystones and mudstones of the Cloverly Formation commonly contain calcite- or gypsum-filled fractures (States West 2013). During geotechnical investigations for the LREP, numerous iron stained and gypsum-filled fractures were identified from boreholes and test pits completed in the Cloverly (RJH Consultants, Inc. 2013). Unit V of the formation is composed of bentonitic claystone with frequent to abundant concretions (Ostrom 1970). The Thermopolis Shale also contains bentonitic layers and is exposed just to the southwest of the study area, but does not underlie Leavitt Reservoir. Unconsolidated alluvium and terrace deposits are also present near Leavitt Reservoir. The alluvium occurs in drainages while the terrace deposits are located on benches adjacent to the streams. Under the Proposed Action, terrace deposits northeast of the existing reservoir would be excavated to provide borrow material for the earthen dam embankment (Figure 3-1). 3.2.3 Structural Geology and Minerals An exploratory oil and gas test well, Leavitt Fee No. 1, was drilled adjacent to the existing Leavitt Reservoir in the southwest (SW) ¼, northeast (NE) ¼ of Section 24. The well was drilled to a total depth of 1,542 feet to the Permian Phosphoria Formation. No production data are available for this well, and the well status is listed in Wyoming Oil and Gas Conservation Commission records as permanently abandoned. The southwest flank of the Bighorn Mountains is characterized by numerous folds and faults in the sedimentary rock section. These structures generally parallel the northwest-to-southeast trend of the mountain range (BLM 2009a). Nearer to the proposed reservoir site, Noggle-Perrin (1989) mapped a fault about 500 feet south of the reservoir that cuts the Cloverly Formation and the Thermopolis Shale. There is no information to indicate the amount of movement along this fault. Another structure in the reservoir area is a small anticlinal fold that intersects the upper reaches of the reservoir and trends from southwest to northeast. 3.3 Lands and Realty This section discusses the affected environment for lands and realty in and around the LREP. Land use is the manner in which land is developed and is used for various activities, such as commerce, recreation, or transportation. The spatial analysis area that will be used to assess the direct, indirect, and cumulative impacts to lands and realty from the Proposed Action and alternatives consists of the LREP disturbance footprint including the wetland and borrow pit areas. This area was chosen because it would be directly affected by the development and operation of the LREP due to surface disturbance from constructing LREP components, expansion of the water surface, and creation of wetlands. Land use will change or shift within the footprint and wetland and borrow pit areas. Outside of the analysis area there would be no changes to land use. The proposed LREP is located within Big Horn County, Wyoming. Big Horn County is considered rural and the main land use is agriculture. The population density is just 3.6 people per square mile (BHC 2009). Over three-quarters of the county consists of public lands managed by the federal government and 57.2 percent of the public lands are managed by the BLM. Land use on federal lands is guided by federal land management plans such as the BLM CYFO Approved RMP. Land use on private lands is in part determined by the Big Horn County Land Use Plan. Approximately 47 percent (330 acres) of the analysis area is managed by BLM. The remainder is private

3-4 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 3 – Affected Environment Resource Discussions

(approximately 365 acres or 52 percent) and state lands (approximately 7 acres or 1 percent). Table 3-3 shows the surface management of Big Horn County. 3.3.1 Rights-of-Way BLM’s Lands and Realty Program manages a wide range of public land transactions including ROW authorizations. ROWs are authorizations to use a specific piece of public land for a specific purpose such as roads, transmission lines, and pipelines. BLM lands within RMP planning areas are designated as either open or closed to ROWs or as avoidance areas. The project area is adjacent to a ROW avoidance/mitigation area. Outside of municipalities and the federal government, there are no county regulations that would affect the location or design of commercial, industrial, transportation, or utility facilities in Big Horn County. There are existing road and telephone ROWs near the LREP area but they would not be affected by the LREP. The existing ROWs include; WYW-035402 (Beaver Creek Ranch, reservoir), WYW-75523 (TCT West, buried telephone line), and WYW-79349 (Big Horn County, road). 3.4 Noise Noise is generally defined as loud, unpleasant, unexpected, or undesired sound that is typically associated with human activity and that interferes with or disrupts normal activities. Although prolonged exposure to high noise levels has been demonstrated to cause hearing loss, the principal human response to environmental noise is annoyance. The response of individuals to noise is diverse and is influenced by the type of noise, the perceived importance of the noise, and the appropriateness of the noise in relation to its setting, the time of day, the type of activity during which the noise occurs, and the sensitivity of the individual. The decibel (dB) scale is commonly used in noise measurements and evaluation. The dB scale is logarithmic: a 100-fold increase in sound energy corresponds to an increase of 20 dB. Noise level from a point source such as concentrated construction activity will decrease by 6 dBA (A-weighted sound level measurement) for every doubling of the distance away from the source. This concept is known as geometric spreading and is based on the inverse square law. This law states that the intensity of the influence at any given radius is the source strength divided by the area of the sphere. The energy twice as far from the source is spread over four times the area, hence the sharp drop off in intensity. Sound intensity follows the inverse square law, assuming there are no reflections or reverberations. When comparing similar sounds (e.g., changes in traffic noise levels), a 3-dBA change in sound-pressure level is considered detectable by the human ear in most situations. A 5-dBA change is readily noticeable by most people, and a 10-dBA change is perceived to be a doubling (or halving) of sound or noise. 3.4.1 Analysis Area The analysis area for noise for the proposed LREP is a 1-mile buffer around the LREP area, including the expanded reservoir area, borrow areas, and transfer pipeline. This area was chosen because for most construction projects, noise impacts attenuate to background levels at distances of less than one mile from the noise source. 3.4.2 Noise Standards 3.4.2.1 Federal There are no federal regulations that limit overall environmental noise levels. However, there are federal guidance documents that address environmental noise and regulations for specific sources (e.g., aircraft or federally funded highways). The Noise Control Act and the U.S. Department of Housing and Urban Development (HUD) guidelines are the federal regulatory criteria against which proposed LREP noise is evaluated in Section 4.4 of the EIS. In order to establish federal noise emission control requirements and to ensure assistance and guidance to states and localities, The U.S. Environmental Protection Agency (USEPA) has published guidelines that address the issue of community noise that contain goals for noise levels affecting residential land use of the day-night level (Ldn) of less than 55 dBA for exterior levels and Ldn of less than 45 dBA for interior levels (USEPA 1974). 3.4.2.2 State and Local Regulations Wyoming maintains general standards for noise that include regulation of traffic on highways. Specifically, Wyoming Statute 31-5-953 requires that every vehicle be equipped, maintained, and operated so as to prevent

Leavitt Reservoir Expansion Project – Final EIS – 2019 3-5 Chapter 3 – Affected Environment Resource Discussions excessive or unusual noise. Motor vehicles must be equipped with a muffler or other effective noise-suppressing system in good working order and in constant operation. 3.4.3 Analysis Area Conditions Existing noise conditions are evaluated based on land use. Local conditions such as traffic, topography, and winds characteristic of the region can alter background noise conditions. In general, the Ldn sound levels at outdoor quiet urban nighttime noise levels range from 40 to 50 dBA (USEPA 1974). However, given that most of the proposed LREP passes through largely undeveloped, sparsely populated areas, the majority of the analysis area would be expected to have background noise Ldn of about 35 dBA or less. In addition to natural background noise, noise sources could include agricultural activities, low-density traffic on rural roads, recreational activities, and aircraft overflights. Existing land use in the LREP analysis area was estimated based on aerial photography. The LREP is located adjacent to or through quiet, sparsely populated suburban or rural areas. Therefore, estimated existing daytime equivalent sound level (Leq) is considered to be 43 dBA and estimated existing nighttime Leq is considered to be 37 dBA (ANSI 1993). 3.4.4 Noise-Sensitive Receptors The proposed LREP is within 1 mile of scattered residential areas and unique noise-sensitive receptors (see Figure 3-3). In addition, the Brown/Howe Dinosaur areas of critical environmental concern (ACEC), West Slope Special Recreation Management Area (SRMA), the Shell Greater Sage-Grouse Priority Habitat Management Area (PHMA), and Greater Sage-Grouse General Habitat Management Area (GHMA) are located within the noise analysis area (BLM 2013). The analysis area consists predominantly of open space. No wilderness areas or other public recreation spaces that require low noise limits are within the analysis area. 3.5 Paleontological Resources Paleontological resources are any fossilized remains, traces, or imprints of organisms preserved in or on the earth’s crust, that are of paleontological interest and that provide information about the history of life on earth. Paleontological resources are considered non-renewable resources because the organisms they represent no longer exist, and such resources, if destroyed, cannot be replaced. The BLM (2008b) defines a significant paleontological resource as any paleontological resource that is considered to be of scientific interest, including most vertebrate fossil remains (e.g., bone, scales, scutes) and traces (e.g., skin impressions, burrows, tracks, coprolites [feces], gastroliths [stomach stones]), and certain rare or unusual invertebrate and plant fossils. The LREP analysis area for direct impacts to paleontological resources includes the LREP disturbance footprint and 100-foot buffer. The analysis area for indirect impacts to paleontological resources includes a 1-mile buffer around the LREP disturbance footprint. These analysis areas provide information on known paleontological resources underlying the LREP, as well as the potential to encounter unknown paleontological resources. Indirect effects are anticipated to be from increased human usage, which is unlikely to extend beyond 1 mile from the LREP disturbance footprint. To provide a thorough understanding of the paleontological resources in the area, the previously recorded locality search extended 1 mile from the analysis area, while the literature reviews focused on the Bighorn Basin, the reviews covered the geographic extent of the geologic units mapped within the analysis area. 3.5.1 Assessment of Paleontological Potential The Potential Fossil Yield Classification (PFYC) is a ranking of geologic units according to their potential to contain vertebrate fossils or noteworthy occurrences of invertebrate or plant fossils. The BLM has assigned a PFYC ranking (1–5) to each geologic unit (formation, member, or other distinguishable unit) based on the taxonomic diversity and abundance of previously recorded scientifically significant paleontological resources associated with the unit and the potential for future discoveries, with a higher class number indicating higher potential (BLM 2016). BLM data (2015b, 2002) and published geologic mapping (Noggle-Perrin 1989; Love and Christiansen 1985; Manahl 1985) indicate that the LREP analysis area overlies three PFYC 2 geologic units (Quaternary alluvium, terrace deposits [including those along Beaver Creek], and landslide deposits), one PFYC 3 geologic units (the Thermopolis Shale, including the Muddy Sandstone), and two PFYC 5 geologic units (the Early Cretaceous Cloverly Formation, including the Sykes Mountain Formation and “rusty beds,” and the late Jurassic Morrison

3-6 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 3 – Affected Environment Resource Discussions

Formation). Table 3-4 details the paleontological sensitivity of the geologic units underlying the LREP analysis area. The deposits of Quaternary age have low potential to contain scientifically significant fossils and are therefore not discussed further. The area immediately surrounding the LREP analysis area contains extensive exposures of the PFYC 3 Mowry Shale, including the Shell Creek Shale. However, since these units are outside of the LREP spatial analysis area and are located stratigraphically above those geologic units that outcrop within the spatial analysis areas, they have low potential to be disturbed and are not discussed in detail. For a more detailed discussion of the geologic setting of the LREP area, refer to Section 3.2. 3.5.2 Paleontological Context All geologic units within the LREP analysis area have the potential to contain fossils of varying abundance, taxonomic diversity, and significance. The Morrison Formation of the Bighorn Basin is widely known for its dinosaur quarries and particularly Allosaurus and the large sauropods they contain (Foster 2007). Excavations have been ongoing in the Morrison Formation east of the LREP for over 90 years. Other fossils from the Morrison Formation include dinosaur tracks, gastropods, fish, non-dinosaurian reptiles including crocodiles and turtles, amphibians, and mammals (Jennings et al. 2006; Foster 2007; Platt and Hasiotis 2008). The Cloverly Formation is known to contain dinosaurian taxa, as well as a few taxa of fish, turtles, crocodiles, and mammals (Ostrom 1970). In the time since the completion of the original LREP paleontological survey report (Moses and Shoup 2012), Oreska et al. (2013) compiled an updated taxonomic list that nearly doubles the number of known taxa from the Cloverly Formation. Carrano et al. (2016) conducted an associated paleoecological analysis utilizing recently collected fossils primarily from Unit V. Oreska et al. (2013) concluded from an extensive multi-year survey effort that natural erosion of Cloverly Formation exposures is very slow, as some of the 1962 quarries were readily visible in the early 2000s and contained freshly broken rock. Fossils of the Thermopolis Shale, including the Muddy Sandstone, include forams; fresh-water pelecypods, Inoceramus, and gastropods (upper shale, just below Muddy sandstone); sponge spicules; plants, leaves; trace fossils (e.g., trails and casts); fish teeth and bone fragments; crocodilian, cf. Coelosuchus reedi (lower Thermopolis Shale); the type specimen of the short-necked plesiosaur, Edgarosaurus muddy (Muddy Sandstone); the turtle Glyptops. Eicher (1960) noted crabs, turtles, and fish at one Thermopolis Shale locality (Locality 21) a little more than 1 mile west of the LREP; this resource is not listed in the locality search results. Three previously documented Cloverly Formation localities are within the LREP analysis area, and thirteen Morrison or Cloverly Formation localities are within 1 mile of the LREP analysis area (Hurley 2017). These 16 localities include theropod trackways, dinosaur quarries, individual bones, vertebrate microsites, plants, and the type location of the Cloverly Formation. Two of the Morrison Formation localities are within the Brown- Howe Dinosaur ACEC. No fossil localities of Pleistocene age have been documented within 1 mile of the LREP analysis area. Of the three previously recorded localities within the LREP analysis area, all are located in the Cloverly Formation and one has been extensively collected, yielded many vertebrate and invertebrate taxa, and is being used in ongoing research (Carrano et al. 2016; Oreska et al. 2013). Isolated surface fossils were collected from the other two, but the main bone bearing layer was not found. BLM-approved paleontologists performed paleontological fieldwork in three separate phases in 2012, 2015, and 2017 on approximately 800 acres (Moses 2017; Shoup 2015; Moses and Shoup 2012). During the field surveys, two new localities, a highly fragmented fossil tree specimen and several unidentifiable vertebrate bones, were documented and one previously recorded locality was re-recorded (Moses 2017; Moses and Shoup 2012). These were all recorded on BLM-administered land within the Cloverly Formation. No scientifically unique paleontological resources were identified or collected during the field surveys; however, at least one of the localities was extensively collected between 2003 and 2010 and before the LREP field survey. Oreska et al. (2013) inferred that the unit that originally contained these fossils had eroded, as the fossils were lying on nearly barren strata. Monitoring was conducted within the LREP in 2012 and 2013; no paleontological resources were documented during this work (Moses 2013, 2012). The results of literature review, previously recorded locality search, and the field survey indicate that buried paleontological resources may be present within the LREP but not exposed at the surface.

Leavitt Reservoir Expansion Project – Final EIS – 2019 3-7 Chapter 3 – Affected Environment Resource Discussions

3.6 Range Resources Livestock grazing occurs on the majority of the rangelands in the Beaver Creek sub-watershed. Livestock grazing has been occurring in the watershed since the 1880s. The General Land Office (GLO) oversaw grazing on public domain land outside Forest Reserve perimeters before 1934. The Taylor Grazing Act of 1934 (43 United States Code [U.S.C.] Ch. 8a Section 315 et seq.) initiated comprehensive management of these lands under the Division of Grazing (Grazing Service). The Grazing Service and GLO merged in 1946 to form the BLM. The Federal Land Policy and Management Act of 1976 (FLPMA) (43 U.S.C. Ch. 35 Section 1701 et seq.), Public Rangelands Improvement Act of 1978 (43 U.S.C. Ch. 37 Section 1901 et seq.), and BLM manual guidance under 43 Code of Federal Regulations (CFR) also direct management of livestock grazing on BLM lands. Rangelands in the Beaver Creek sub-watershed exist under private, U.S. Forest Service (USFS), state of Wyoming Office of State Lands and Investments, and BLM surface ownership. Three BLM livestock grazing allotments and three grazing permits associated with these allotments have the potential to be affected by the proposed LREP (see Figure 3-4). Grazing permits for lands in the LREP area are issued under 43 CFR 4100 by the BLM CYFO. Other livestock grazing occurs on private lands outside the BLM allotments but within the LREP area. The vegetation in the LREP area is indicative of the Wyoming Basin native and disturbed shrublands, grasslands, and riparian areas. Section 3.11 provides a detailed description of the vegetation resources in the LREP area. Livestock grazing is managed to meet the BLM CYFO Approved RMP (BLM 2015b), which includes the Wyoming Standards for Healthy Rangelands and Guidelines, and grazing permit requirements. The LREP has the potential to affect the number of Animal Unit Months (AUMs) available within the three allotments affected by the LREP. The loss of 3 temporary AUMs and 11 permanent AUMs requires the BLM to notify the permittee per 43 CFR 4110.4-2. Therefore, the spatial analysis area for direct, indirect, and cumulative effects to range resources is the boundary of those allotments. A description of the range resources within each of the three allotments is provided in the following subsections. Allotment information detailed in Sections 3.6.1 through 3.6.3 is derived from the respective Allotment Management Plans (AMPs) for the Lost, Crandall, and Beaver Creek allotments (BLM 2008c, 2011a, 2015d). 3.6.1 Lost Allotment The Lost allotment covers approximately 6,347 acres, 5,353 acres of which are federal, with an authorized active grazing capacity of 106 AUMs. The allotment permittee is authorized to conduct sheep or cattle grazing there from October 1 to November 30 annually under a grazing permit authorized through 2021. The allotment includes fence range improvements and access to Leavitt Reservoir for water. The Lost allotment is managed using a rest rotation grazing system in conjunction with the North Shell Common Use Area, which includes the Lost, North Shell, Claypits, and Crandall allotments. Table 3-5 lists the rest-rotation for the three-year cycle. 3.6.2 Crandall Allotment The Crandall allotment covers approximately 870 acres, 592 acres of which are federal, with an authorized grazing active capacity of 12 AUMs. The permittee is authorized to conduct sheep or cattle grazing there from October 1 to November 30 annually under a grazing permit authorized through 2021. The allotment includes fence range improvements and access to Leavitt Reservoir for water. The Crandall allotment is managed using a rest rotation grazing system in conjunction with the North Shell Common Use Area, which includes the allotments: Lost, North Shell, Claypits, and Crandall. Table 3-5 shows the rest-rotation for the three year cycle. 3.6.3 Beaver Creek Allotment The Beaver Creek allotment covers approximately 1,824 acres, 1,742 acres of which are federal, with an authorized active grazing capacity of 107 AUMs. The permittee is authorized to conduct cattle grazing from May 20 to June 15 annually under a grazing permit authorized through 2021. The allotment includes fence range improvements and access to Leavitt Reservoir for water.

3-8 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 3 – Affected Environment Resource Discussions

The Beaver Creek allotment is managed using a rotation grazing system in conjunction with the North Shell allotment. Table 3-6 shows the rest-rotation for the three-year cycle in the Beaver Creek allotment. There is a single pasture in the Beaver Creek allotment. 3.7 Recreation The spatial analysis area that will be used to assess the direct, indirect, and cumulative impacts to recreation from the Proposed Action consists of the LREP disturbance footprint including the wetland area. This spatial analysis area was selected because Leavitt Reservoir will introduce, or re-introduce, new opportunities that will be enjoyed within this immediate area, and may also influence those users to enjoy other opportunities within the area. 3.7.1 Overview Recreational opportunities are offered to the public on all BLM-administered lands in the LREP area. The LREP area is in the flatlands of Shell Valley, part of the Bighorn Basin, at the western base of the Bighorn National Forest. The area surrounding the LREP offers very limited fishing opportunities. Beaver Creek holds cutthroat trout and brook trout and its two forks, North Beaver Creek and South Beaver Creek, are “core conservation populations” which is the highest classification the Wyoming Game and Fish Department (WGFD) has in cutthroat trout management. Cedar Creek, Red Canyon Creek, and Ewen Pence Gulch Reservoir are classified as “unsuitable” for trout or other game fish by the WGFD. Shell Creek flows along U.S. Highway (US 14) to the south of the LREP, is a popular destination for fishing and hiking opportunities. The Bighorn River, the major river of the Bighorn Basin, flows west of the recreation analysis area from the south and offers opportunities to pursue warm species fish and floating opportunities. Leavitt Reservoir is an existing reservoir that has very limited boating and fishing and only when water levels allow. Targeted species for fishing are no longer present (Rau 2017). There is a route leading into the reservoir that currently serves as a primitive boat ramp. There is evidence of picnicking and other lakeside activities, like fishing and hunting, in the LREP area. The surrounding area is rural and agricultural. There is dispersed recreation throughout the LREP area in a narrow range of recreational settings, of which recreation can occur in combination with other resource activities. Recreation in the LREP area includes, but is not limited to, hunting, sightseeing, horseback riding, hiking, off-highway vehicle (OHV) use, photography, wildlife viewing, fishing, rock hounding, and camping. 3.7.2 Recreation Setting and Activities The LREP area falls within the BLM CYFO’s West Slope SRMA (see Figure 3-5). The West Slope SRMA recreation setting characteristic (RSC) condition for the LREP describes the physical, social, and operational recreation setting qualities or components that are to be maintained or enhanced. There are six RSC classifications: primitive, back country, middle country, front country, rural, and urban. Middle country from the RSC is synonymous with semi-primitive motorized from the CYFO recreation Geographic Information System (GIS) layers, which are shown on Figure 3-5 (BLM 2010a). The majority of the LREP area is identified as middle country; however, the eastern borrow pit, eastern portion of the supply pipeline, and part of the center and southern portions of the access road and transfer pipeline are in the rural classification (Figure 3-5). Table 3-7 provides the RSC qualities for the middle country and rural classifications. 3.7.2.1 Special Designations and Visual Resources BLM Special Designations consist of ACECs, Wilderness, Wilderness Study Areas (WSAs), Scenic Byways, and National Historic Trails. Generally, special designations offer recreational opportunities that are mostly primitive. There is one special designation area that abuts the LREP area, the Brown/Howe Dinosaur ACEC. The Brown/Howe Dinosaur ACEC is being managed to protect paleontology, the relevant and important value for which it was designated (see Section 3.3.1.2 for more information on ACECs). Although visual resources are described in Section 3.12, recreation and visual resources are often intertwined as visitors seek out natural areas and scenic vistas as part of the recreational experience. The LREP area is managed as Visual Resource Management (VRM) Class II and Class III which allows for little to moderate changes to the landscape, respectively. See Section 3.12 for more information.

Leavitt Reservoir Expansion Project – Final EIS – 2019 3-9 Chapter 3 – Affected Environment Resource Discussions

3.7.2.2 Special Recreation Permits/Hunting and Fishing Dispersed recreation, such as hunting, hiking, rockhounding, driving for pleasure, and limited fishing activities are observed within the LREP, with hunting the most common recreational activity for local users on BLM-administered public lands in the LREP area. Historically, fishing was very popular when Leavitt Reservoir was able to support a desirable fishery. Other rivers with proximity to the LREP are popular destination fishing areas, and Shell Creek is the most popular of those. Hunting opportunities available in the Bighorn Basin also are available to non-residents. The numbers of hunters and fishermen remain fairly constant over time because they depend on wildlife population numbers and available licenses. There is no trend toward increased recreation related to hunting and fishing (BLM 2015c). The BLM CYFO has active Special Recreation Permit (SRP) programs, administering approximately 45 to 50 SRPs per year for outfitters, activities, and events. None of these are specifically targeted at Leavitt Reservoir (Rau 2017) as the reservoir is located within big and trophy game hunt areas that are very large and include areas within the nearby mountains. There are approximately 30 different SRP holders who are authorized to use the hunt areas that contain Leavitt Reservoir. SRPs within the LREP are issued for antelope, black bear, deer, elk, and mountain lion. 3.8 Socioeconomics 3.8.1 Introduction This section describes the affected environment for socioeconomic conditions in the socioeconomic analysis area of the LREP. The analysis area for the socioeconomic analysis is Big Horn County, Wyoming which is located in the north-central part of the state. Big Horn County was selected for two reasons. First, published economic data are typically limited to the county level and are not available for sub-county areas. Second, indirect economic effects (such as “multiplier” effects from changes in earnings or employment) are commonly dispersed beyond an immediate project area, so including the county as a whole better captures the extent of localized economic effects from the Proposed Action and any alternatives. The remainder of this section provides a brief overview of the affected environment for the socioeconomic analysis area, followed by a more detailed discussion of the resources that will be most directly affected by the Proposed Action. The Proposed Action will primarily affect the construction sector in the short-term and the agricultural sector in the long-term. Construction activities could also affect the housing market in the analysis area on a short-term basis. 3.8.2 Methodology Information to characterize the affected environment for socioeconomic resources were gathered from local, state, and federal data sources, including the U.S. Census, the U.S. Census Bureau’s American Community Survey, the Bureau of Economic Analysis, the Wyoming Department of Revenue, and the U.S. Department of Agriculture (USDA). 3.8.3 Overview of Socioeconomic Affected Environment 3.8.3.1 Population As of 2016, Big Horn County had a total population of 11,931 people. About 65 percent of the Big Horn County’s residents live in small towns and cities with populations that range from 118 people (Manderson) to around 2,400 (Lovell). Big Horn County also has a large population of rural residents that account for the remaining 35 percent of the population (U.S. Census Bureau 2012-2016 American Community Survey [ACS] 5-year Estimates). 3.8.3.2 Demographic Characteristics The demographic characteristics of Big Horn County are similar to the state of Wyoming as a whole, but there are differences within the communities contained in Big Horn County. The population of native Hawaiian and Pacific Islanders living in Burlington is approximately 5.6 percentage points larger than the state (5.8 percent and 0.2 percent, respectively). In Frannie, the populations of African Americans and American Indians or Alaskan Natives are 6.5 and 12.0 percentage points larger than their respective state populations. The Hispanic and Latino populations of Lovell and Greybull are 6.6 and 8.1 percentage points larger than Hispanic and Latino population for the state (U.S. Census Bureau 2011-2015 ACS 5-year Estimates).

3-10 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 3 – Affected Environment Resource Discussions

3.8.3.3 Income and Poverty Average annual household incomes in the analysis area were $51,679 between 2011 and 2015, which is approximately $7,000 less than the statewide average during the same period. Several communities in the analysis area had household incomes below the county average. In Manderson, households earned approximately $28,000 per year between 2011 and 2015. The average unemployment rate in the analysis area during this time was 4.4 percent (U.S. Census Bureau 2011-2015 ACS 5-year Estimates). The poverty rate in the analysis area is similar to the state of Wyoming, with about 1 out of 10 individuals living in poverty. There were notable differences in three of the communities within the analysis area. The average poverty rates in Byron, Deaver, and Frannie were all between 5.1 and 15.2 percentage points higher than the statewide average between 2011 and 2015 (U.S. Census Bureau 2011-2015 ACS 5-year Estimates). 3.8.3.4 Housing The analysis area contained an average of 5,373 housing units between 2011 and 2015. In the communities within the analysis area, the average housing stock between 2011 and 2015 ranged from a low of 66 units in Frannie to a high of 1,067 units in Lovell. The market for short-term housing in the analysis area had an average vacancy rate of 12.3 percent between 2011 and 2015, which was below the 14.9 percent vacancy rate for the state as a whole. During this time median monthly rents averaged $595 in the analysis area compared to $789 for the state as a whole. The median monthly home value in the analysis area between 2011 and 2015 was $141,400 compared to $194,800 for the state (U.S. Census Bureau ACS 5-year averages 2011 to 2015). The analysis area contained an average of 5,373 housing units between 2011 and 2015. In the communities within the analysis area, the average housing stock between 2011 and 2015 ranged from a low of 66 units in Frannie to a high of 1,067 units in Lovell. The market for short-term housing in the analysis area had an average vacancy rate of 12.3 percent between 2011 and 2015, which was below the 14.9 percent vacancy rate for the state as a whole. During this time median monthly rents averaged $595 in the analysis area compared to $789 for the state as a whole. The median monthly home value in the analysis area between 2011 and 2015 was $141,400 compared to $194,800 for the state (U.S. Census Bureau ACS 5-year averages 2011 to 2015). 3.8.4 Economic Environment 3.8.4.1 Employment and Earnings by Industry Farming and construction make important contributions to the economy of the analysis area. In 2015, farming was the largest non-government employer, followed by mining, quarrying, and oil and gas extraction; retail trade; and construction. In total, the farm sector accounts for over 11.1 percent of the analysis area’s employment or about 775 jobs. However, job growth since 2001 has been focused on other industries, including: real estate (51.0 percent); manufacturing (32.9 percent) and in information services (30.0 percent). The mining, quarrying, and oil and gas extraction sector was the largest private source of employee compensation, accounting for approximately $41.0 million. The construction sector was the second largest private source of employee compensation, accounting for $19.7 million in 2015 (U.S. Bureau of Economic Analysis 2016). 3.8.4.2 Agriculture Earnings Figure 3-6 shows the total net income, defined as the revenue received by farms less the costs incurred to produce farm output, of farms in the analysis area from 1970 to 2015. Net farm income fluctuated over that period. From 1970 until 1976, net farm incomes were positive and reached more than $57.0 million in 1973. From 1976 to 1986, net farm incomes were negative with the exception of the period from 1978 to 1981. By 1987, net farm incomes had become positive again and varied between approximately $2.0 million to $26.0 million until 2002. Between 2006 and 2010, net farm incomes were negative, but became positive again in 2011. Since that time, they have varied between approximately $5.0 and $15.0 million per year.

Leavitt Reservoir Expansion Project – Final EIS – 2019 3-11 Chapter 3 – Affected Environment Resource Discussions

Figure 3-6. Total Net Income of Farms, Including Corporate Farms, in Big Horn County from 1970 to 2015

70 60

50 40 30 20 10 0

Millions of 2016 $s -10 -20 -30 1970 1972 1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014

Source: U.S. Department of Commerce 2016. Note: Figure was produced by Headwater Economics.

Table 3-8 shows the sources of farm income and expenses in the analysis area by each income source in 2015. In total, farms generated approximately $89.8 million of income and $85.5 million of expenses in 2015. The production and sale of crops, including sugar beets, grain, beans, and hay, is the largest source of income for farms in the analysis area. In 2015, the sale of crops generated approximately $40.4 million of income. The production of livestock and livestock products created $38.1 million of income during the same time period. Farms in the analysis area also received $11.4 million worth of other income from government payments, rents, and other miscellaneous sources. Farms in the analysis area earned a net income of approximately $5.6 million after accounting for production-related expenses. Figure 3-7 shows the income received by farms in the analysis area from the production and sale of crops and livestock from 1970 to 2015. After reaching a peak in 1973, farm income declined until the early 1980’s, after which it stabilized at a new, lower level. Since 1980, income from the production and sale of crops and livestock has varied between approximately $20.0 and $50.0 million per year for each commodity, respectively. The production and sale of crops has generally generated more income for farms in the analysis area than livestock production with the brief exception of the period from 2000 to 2007. Figure 3-7. Farm Income Received from Sale of Crops and Livestock in Big Horn County from 1970 to 2015 (2016 $’s)

120

100

80

60

40 Millions of 2016 $s 20

0 1970 1972 1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 Livestock & Products Crops

Source: U.S. Department of Commerce 2016. Note: Figure was produced by Headwater Economics.

3-12 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 3 – Affected Environment Resource Discussions

Table 3-9 shows the amount of irrigated land in the analysis area in 2007 and 2012. In 2012, there were 108,707 acres of irrigated land of which 78,283 acres were harvested cropland and 30,424 acres were irrigated pasture or other irrigated land. According to the 2012 Agricultural Census, the value of agriculture land, including buildings, was estimated to be approximately $462.0 million in 2012 compared to $384.0 million in 2007. As a result, the average farm value in the analysis area rose to $736,714 in 2012, compared to $618,696 in 2007. Irrigated land accounts for most of the agricultural land value in the study area. According to the Wyoming Department of Revenue, the locally assessed value of irrigated agricultural land in Big Horn County was $14.8 million in 2016. All of the agricultural land in Big Horn County had an assessed value of approximately $16.0 million in 2016 (Wyoming Department of Revenue 2016). 3.8.5 Recreation and Tourism Economy Residents and visitors to the analysis area participate in a number of recreational activities, including camping, hunting, hiking, OHV use, fishing, boating, flat-water recreation, horseback riding, and bird-watching (BLM 2015a). Visitors who travel to the region to take advantage of these recreation opportunities make important contributions to the region’s recreation economy by purchasing goods and services from local businesses. Service providers like hotels, restaurants, guiding services, and others provide goods and services to recreationists in the analysis area. Residents and visitors who recreate in the analysis area spend money at service providers and this spending creates jobs in the local economy. In total, there were 379 travel and tourism related jobs in the analysis area in 2016 (U.S. Department of Commerce 2018). The majority of travel and tourism related jobs are in the retail trade and accommodation and food sectors, which together employ approximately 95 percent of the workers in the travel and tourism sector of the analysis area. Seventeen people are employed in the arts, entertainment, and recreation sector. Employees in the recreation and tourism sector earned an average of $13,177 per year in 2016 (2017 dollars), below the average of $40,621 for all jobs in the analysis area (U.S. Department of Labor 2017). 3.8.6 Non-market Economic Values According to the BLM’s 2015 Bighorn Basin RMP Revision Project, Proposed RMP and Final EIS, many residents in the analysis area place a high value on rural landscapes and rural lifestyles (BLM 2015a). Residents value the open space and rural viewscapes as well as the lifestyles associated with farm and ranch operations, livestock grazing, and the abundant recreational opportunities. However, many of these values are not reflected in market prices because they cannot be converted to financial values. They are what economists call ‘non-market’ values and they refer to the happiness and well-being that people get from certain goods or services. The comments received by the BLM reflect the types of non-market values held by local residents in the analysis area. 3.8.7 Environmental Justice Populations The following discussion of baseline conditions within the analysis area uses data at the county, community, and census tract levels to determine if there are environmental justice populations within the analysis area with meaningfully higher percentages of minority or low-income residents than the state in which they are located. The Council on Environmental Quality (CEQ) has oversight for the federal government’s compliance with Executive Order (EO) 12898 and NEPA, and has developed guidance on principles and approaches for addressing environmental justice under NEPA. CEQ defines a minority as “a person who is a members of the following population groups: American Indian or Alaskan Native; Asian or Pacific Islander; Black, not of Hispanic origin; or Hispanic;” and outlines the following criteria for identifying minority populations that constitute an environmental justice population under EO 12898: “ (a) the minority population of the affected area exceeds 50 percent or (b) the minority population percentage of the affected area is meaningfully greater than the minority population percentage in the general population or other appropriate unit of geographic analysis” (CEQ 1997). Additionally, “[a] minority population also exists if there is more than one minority group present and the minority percentage, as calculated by aggregating all minority persons, meets one of the above-stated thresholds” (CEQ 1997). Therefore, for the purposes of this analysis, a conservative approach was used to identify potential environmental justice populations; it is assumed that if the affected area minority and/or poverty status populations are more than 5 percentage points greater than those of the reference area (e.g., the state in which the counties are located), there may be an environmental justice population of concern.

Leavitt Reservoir Expansion Project – Final EIS – 2019 3-13 Chapter 3 – Affected Environment Resource Discussions

Low-income populations were defined as those individuals and families who are considered to be living below poverty levels. Minority population data for the analysis area were obtained from the U.S. Census Bureau’s ACS 5-year estimates (2015), and were described earlier in this section. For this analysis, a population is considered a “minority” based on all races and ethnicities that are not “White (Non-Hispanic).” For determining the presence of low-income communities as environmental justice populations, communities in the analysis area were evaluated against a reference population defined as the state of Wyoming. CEQ guidelines (1997) define a community with potential environmental justice populations as one that has a greater percentage of minority or low-income populations than does an identified reference community. Minority populations are those populations having 1) 50 percent minority population in the affected area, or 2) a meaningfully greater minority population than the reference area (CEQ 1997). While the CEQ does not specify what the reference community has to be, the most common practice is to use state averages for this purpose. Thus, all communities where the percentage of individuals living below the poverty level was 5 percentage points or more above the corresponding percentage across the state, or in which the total minority population was over 50 percent, or in which the proportion of residents comprising individual minority groups was 5 percentage points or more greater than the average proportion of residents from those groups across the state, were considered potential environmental justice populations. • Byron (based on the proportion of residents living below the poverty line); • Burlington (based on the proportion of minority residents); • Deaver (based on the proportion of residents living below the poverty line); • Frannie (based on the proportion of both minority and low-income residents); • Greybull (based on the proportion of minority residents) and • Lovell (based on proportion of minority residents) 3.9 Soils The proposed LREP area is located within the Northern Intermountain Desertic Basins Major Land Resource Area (MLRA), which covers a portion of the elevated and dissected Bighorn Basin (NRCS 2006). The majority of this MLRA (approximately 67 percent) is located in the Bighorn Basin, topographically positioned within a syncline located between anticlinal mountain ranges. The average annual precipitation in most parts of the MLRA is 6 to 12 inches and the maximum precipitation occurs in spring and fall. The average annual temperature is 39 to 48 degrees Fahrenheit (°F) and can vary widely within short periods due to the influx of cooler mountain air into the basins below. The soils in this MLRA are primarily shallow to deep, well-drained loams with a mesic soil temperature regime, an aridic soil moisture regime, and mixed mineralogy. The analysis area for direct impacts to soils is the LREP disturbance footprint. This analysis area was chosen because direct impacts would only occur within the LREP disturbance footprint. The analysis area for indirect impacts to soils is a 0.25-mile buffer of the LREP disturbance footprint. This area was chosen to provide an adequate area outside the LREP disturbance footprint for determining indirect effects, particularly those that are downstream from the LREP disturbance footprint. Thirty-five soil types (soil map units) occur within the analysis area (27 soil types occur within the LREP disturbance footprint; and 8 additional soil types occur outside of the LREP disturbance footprint but within the analysis area). Table 3-10 provides the acres of each soil type (soil map units or soil complexes) within the analysis area and the LREP disturbance footprint. 3.9.1 Soil Properties Soil properties generally used to assess soil health, susceptibility to erosive forces, and resilience to surface disturbing activities were quantified to evaluate potential impacts to the soil resource. There are seven soil properties that are critical to quantifying and evaluating potential impacts to soils for the proposed project: hydric soils, prime and unique farmlands, wind erosion, surface runoff, degradation potential, compaction

3-14 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 3 – Affected Environment Resource Discussions potential, and reclamation potential. These soil properties are summarized in Table 3-11 and discussed in more detail below. Hydric soils are formed under conditions of saturation, flooding, or ponding long enough during the growing season to develop anaerobic conditions in the upper horizons (NRCS 2017a). The Crowheart, Dobent, and Heapo-like soil components are classified as hydric soils (NRCS 2017a). These four soil components occur within four soil map units and comprise a total of 451.4 acres (7.1 percent) of the analysis area and 28.0 acres (4.0 percent) within the LREP disturbance footprint (Table 3-11). The potential degree of erosion depends upon several factors including runoff probability, slope, soil texture, and soil structure. The NRCS uses Wind Erodibility Groups (WEG) is used to evaluate soils that have the highest potential for wind erosion (NRCS 2017b). Soil components most susceptible to wind erosion include the Baroid and Bankard like components (WEG 2), which comprise a total of 1,429.7 acres (22.4 percent) of the analysis area and that occur in two soil map units that occur in the LREP disturbance footprint and comprise 79.6 acres (11.3 percent) (Table 3-11). Water erosion potential can be classified by the surface runoff potential within the Hydrologic Group (NRCS 2017b). The Bributte, Chipeta, Labou, Mudray, Mudray-like, Oceanet, Persayo, Redarrow, Rekop, Spearfish, Starman, and Travson soil components have Group D ratings and thus the highest surface runoff potential. These soil components are present within 16 of the soil types within the analysis area, and 14 of the soil types within the LREP disturbance footprint (Table 3-11). Combined, these soil types comprise a total 3,769.2 acres (59.0 percent) of the analysis area and comprise 514.7 acres (73.3 percent) within the LREP disturbance footprint. Soil degradation generally occurs following a surface/subsurface disturbance and is measured by a soil’s ability to function without change throughout a disturbance (NRCS 2017b). The Bankard, Baroid, Mudray-like, and Willwood soil components are rated as highly susceptible to soil degradation. These four soil components are present within seven soil units within the analysis are and five soil units within the LREP disturbance footprint (Table 3-11). Combined these soil types comprise a total of 2,524.6 acres (39.5 percent) of the analysis area and 130.0 acres (18.5 percent) within the LREP disturbance footprint. Soil compaction tends to reduce water infiltration which affects plant production and composition, increases runoff with generally increased erosion rates, and affects organisms living within the soil (NRCS 2017b). There are 21 soil components within the analysis area that potentially have low resistance to compaction. These 21 soil components are present within 27 of the soil units in the analysis area and comprise 4,639.5 acres (72.7 percent), including 21 soil units within the LREP disturbance footprint that comprise 599.7 acres (85.4 percent) of it (Table 3-11). Soil restoration potential is the ability of a soil to recover from degradation resulting from surface and subsurface disturbing activities (NRCS 2017b). There are 28 soil components within the analysis area that have a low restoration potential. These 28 soil components are present within 26 of the soil units within the analysis area comprising 4,935.4 acres (77.3 percent), and 19 of the soil units within the LREP disturbance footprint comprising 293.8 acres (41.8 percent) (Table 3-11). 3.10 Transportation The following section generally describes the existing roadway network, approximate traffic volumes on primary roadways serving the LREP site, capacity along key roads, available information about roadway conditions, safety and crash records in the vicinity of the LREP, and maintenance considerations and responsibilities for key roadways. The analysis area for transportation includes regional, local, and on-site roadway networks potentially impacted by construction and post-construction trip generation and related effects. This area was selected because the identified roadways may be subject to slower speeds, additional congestion, and certain safety issues primarily associated with heavy truck movements.

Leavitt Reservoir Expansion Project – Final EIS – 2019 3-15 Chapter 3 – Affected Environment Resource Discussions

The proposed LREP would not involve the use of railroads, airports, transit services, or other transportation means. 3.10.1 Existing Roadway Network Leavitt Reservoir is connected to the interstate system via Interstate 90 (I-90) via US 14. The US 14 intersection in Greybull, Wyoming would be the primary intersection for traffic west of the LREP site. Local access to Leavitt Reservoir from US 14 involves intersections involving Road 36, Lane 32 ½, Road 39, and Lane 31. These roadways connect to Beaver Creek Road. Beaver Creek Road and Bear Creek Road provide access to the LREP site. Local roads and driveways have access to Beaver Creek Road and Bear Creek Road near Leavitt Reservoir. Figure 3-8 presents the local roadway network. 3.10.2 Road Classifications and Conditions US 14, State Highway (SH) 789, US 20, and similar roadways are classified as principal arterials. Beaver Creek Road, Bear Creek Road, and the western most access route between US 14 and Beaver Creek Road are classified as minor collectors. The three other connecting routes are classified as local roads (WYDOT 2017). 3.10.3 Traffic Volumes and Levels of Service The Wyoming Department of Transportation (WYDOT) and Big Horn County report traffic volumes on the regional and local roadway network. Traffic volumes on roads within the regional and local roadway network are below design capacity. A traffic signal controls vehicle movements at the Greybull Avenue/South Sixth Street intersection in downtown Greybull, Wyoming. The intersection is a single lane approach in all directions with no turn pockets. According to the Town Administrator, some turning movements are delayed. The southbound left turn movement to the east towards Shell and the LREP site is occasionally congested. The turning radius in the opposite direction (i.e., left turns from the east to the north) is adequate, but trucks occasionally roll over the curb. WYDOT manages the intersection and traffic signal timing (Thur 2017; Bridges 2017). In general, the local and regional roadways can accommodate traffic increases from new development and incremental annual increases for the foreseeable future. However, large and heavy trucks and farm vehicles often travel at speeds slower than posted limits thereby limiting roadway capacity and the speeds of other vehicles. These factors negatively affect turning vehicles by limiting the number and size of vehicle gaps available for vehicles to enter the traffic stream. All four of the intersections on US 14 that provide access to Beaver Creek Road are uncontrolled (i.e., no stop signs or traffic signals) and no turn lanes are present in either direction. 3.10.4 Traffic Safety WYDOT compiles and reports statewide vehicle crash information. WYDOT’s general crash information for 2016 by county reflects one fatal crash with one fatality, 38 injury crashes with 48 injuries, and 223 property-damage-only crashes in Big Horn County (WYDOT 2016a). Details are provided in WYDOT’s Wyoming Report on Traffic Crashes for 2016. Additional information is available online at http://www.dot.state.wy.us/home/dot_safety/safety_statistics/2016-traffic-crash-information.html (WYDOT 2016b). WYDOT identifies crash “hot spot” locations. These are locations where there have been five or more crashes within a 0.5-mile segment of Wyoming roadways. Along US 14, there is one hot spot in Big Horn County located within Greybull between milepost 0 and 0.5. In this location, there were 13 crashes in 2016 with 2 severe, 2 injuries, and no fatalities. The other nine crashes involved vehicle damage only. 3.10.5 Pavement Conditions Pavement conditions vary on US 14, SH 789 and US 20. Poor pavement conditions are present along portions of SH 14 through Bighorn National Forest east of the LREP site and along a portion of the US 20 route between Worland and Casper.

3-16 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 3 – Affected Environment Resource Discussions

The pavement on Road 32 ½ is relatively new from US 14 to about three miles from the LREP. The paving was completed in 2010 (Bridges 2017). The new pavement is thin and flexible and is not designed for heavy vehicles (which typically include large farm vehicles that occasionally travel on roads and large freight-hauling trucks). The other LREP access roads, upper Beaver Creek Road and Bear Creek Road, have gravel surfaces with widths of approximately 24 to 26 feet. 3.10.6 Road Maintenance WYDOT is responsible for maintenance of US 14, including the US 14 intersection (Greybull Avenue/ 6th Avenue) in Greybull (Janicek 2017). Big Horn County, through the County Engineering Office, is responsible for maintenance of the LREP access routes between US 14 and the LREP site. The Big Horn County Engineer’s office provides road research, design, construction engineering, construction management, road improvements, road access, and ROW permits. 3.11 Vegetation 3.11.1 General Vegetation 3.11.1.1 Overview The LREP area is located on the east side of the Bighorn Basin in the northern part of the Wyoming Basin Ecoregion (Chapman et al. 2004). The Wyoming Basin is described as “a broad arid intermontane basin interrupted by hills and low mountains and dominated by grasslands and shrublands” (Chapman et al. 2004). The Wyoming Basin is nearly surrounded by forested mountains. The ecological subregions in the analysis area include Ecoregion 18d (Foothill Shrublands and Low Mountains) and Ecoregion 18g (Bighorn Salt Desert Shrub Basins). The analysis area for general vegetation includes the LREP disturbance footprint and a one-mile buffer (Figures 3-9 and 3-10). This area was selected to enable comparison of project-specific impacts to the surrounding landscape. 3.11.1.2 General Vegetation in the Analysis Area Vegetation cover data was obtained for the analysis area from the U.S. Geological Survey (USGS) Landfire Data Distribution Site (LANDFIRE 2014), and was clipped to the analysis area. A total of 53 Landfire/Gap Analysis Program land cover types (USGS 2016) were identified in the analysis area, ranging in size from less than 1 acre to 38,000 acres. Cover types were combined based on similarity of composition, structure, and successional status to form 12 vegetation/cover types for analysis (Table 3-12). Seven types are primarily native in composition, including sagebrush, saltbush, native grassland, aspen, conifer woodland, foothill shrub, and barren/sparsely vegetated. Riparian vegetation/wetlands are a native type but the data indicate that most of this vegetation type in the analysis area is dominated by non-native species (see Section 3.15 for more detailed information on riparian vegetation/wetlands). The distribution of vegetation types in the analysis area is shown on Figures 3-9 and 3-10. The vegetation cover shown is based on remote sensing and may not be accurate at a local level. 3.11.2 Noxious Weeds and Invasive Species 3.11.2.1 Overview “Noxious weed” is a legal term for plant species that have been officially designated by a federal or state agency as injurious to public health, agriculture, recreation, wildlife, or property. Noxious weeds are a concern because of their potential to degrade wildlife habitat, adversely affect agricultural production, and impact management of both natural and agricultural systems. There are two categories of noxious weeds in Wyoming. Designated weeds are designated by the Wyoming Weed and Pest Council and apply to the entire state. Declared weeds are identified by counties and apply within the county. Invasive plant species are a broader category of plants that includes both noxious weeds and other species that have been introduced or spread beyond their natural range by human activities, spread aggressively, and may cause economic or environmental harm. The analysis area for noxious weeds includes the LREP disturbance area and an approximate one-mile buffer. This represents the most likely seed source for introduction or spread of noxious weeds during construction

Leavitt Reservoir Expansion Project – Final EIS – 2019 3-17 Chapter 3 – Affected Environment Resource Discussions activities for the LREP. Noxious weeds could potentially be introduced from much further away, even outside the county or state. 3.11.2.2 Noxious Weeds in the Analysis Area Information on the occurrence of noxious and invasive plant species in the analysis area was obtained from Big Horn County Weed and Pest (Big Horn County Weed and Pest 2017). This agency is the lead for management of weeds in Big Horn County and has conducted numerous weed surveys and treatment activities in the analysis area. The data provided for the LREP include more than 7,000 records and 19 plant species or groups of species. A summary of weed data is provided in Table 3-13. Fourteen noxious weeds are designated by the state of Wyoming, one is declared by Big Horn County, and four have no current official status. Additional noxious weeds may be present in the analysis area on private lands not covered by county weed management activities. 3.11.3 Special Status Plant Species 3.11.3.1 Overview Special status plant species applicable to the LREP include species that are federally listed under the Endangered Species Act of 1973 (ESA), species designated as sensitive by the Wyoming BLM, and species identified as a priority for conservation in the state of Wyoming by the Wyoming Natural Diversity Database (WYNDD). Species considered as special status were developed from information in U.S. Fish and Wildlife Service (USFWS) 2018, BLM 2010b, WYNDD 2017a and 2017b. The analysis area for direct and indirect impacts for special status plant species includes the LREP disturbance footprint and a one-mile buffer. 3.11.3.2 Sensitive Species in the Analysis Area The WYNDD lists and township tool (WYNDD 2017a and 2017b) were used to identify BLM sensitive species and WYNDD-tracked species known or potentially present in the vicinity of the LREP. Because the existing reservoir lies near the intersection of four townships, data were reviewed for all four townships, including Township (T) 54 north (N) 92 west (W) (proposed new dam, reservoir, and most of disturbance area), T54N R91W (proposed diversion, pipeline, and borrow area east of reservoir), T53N R91W (proposed transfer pipeline), and T53N R92W (no LREP features). Several species that occur in montane, subalpine, or alpine environments in the Bighorn Mountains in the east side of R91W were excluded because these habitats are very different than the analysis area. One federally listed species, two BLM sensitive species, and eight additional WYNDD species of concern or potential concern were identified for analysis (Table 3-14). The only federally listed species is Ute ladies’-tresses orchid, a perennial forb in the orchid family. Focused surveys were conducted from August 13 to 15, 2017 (WEST 2017). This is within the typical flowering period and was also within the time period that the BLM had verified known Ute’s ladies-tresses populations were blooming in Wyoming. Survey protocols were developed from USFWS 1992, USFWS 1995, and USFWS - Utah Ecological Services Field Office 2007. Discussions with the Wyoming Water Development Commission (WWDC) and BLM identified the habitats to be surveyed, and discussions with USFWS and BLM identified the 2-year survey requirement. To date, no populations have been identified in Big Horn County. Western Ecosystems Technology, Inc. (WEST) conducted surveys within all potential Ute ladies’-tresses habitat in the defined disturbance area identified at the time of the survey. No Ute ladies’-tresses orchids were found and habitat was considered to be marginal in terms of suitability. An additional survey will be conducted in 2018 to satisfy USFWS and BLM survey requirements for this species. A potential BLM sensitive species, Dubois milkvetch (Astragalus gilviflorus var. purpureus), may occur in the analysis area. The nearest known location is about five miles south of Shell Creek (Heidel 2011). Another BLM sensitive species, limber pine (Pinus flexilis), may occur in the analysis area. LANDFIRE vegetation data shows approximately 557 acres of Rocky Mountain foothill limber pine-juniper in the analysis area, which is about 0.8 percent of the total analysis area. 3.12 Visual Resources 3.12.1 Introduction The resource analysis area for visual resources includes lands within a 10-mile buffer of the LREP disturbance footprint (see Figure 3-11). This distance was chosen because a viewshed analysis using the proposed reservoir

3-18 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 3 – Affected Environment Resource Discussions and infrastructure area as the center point shows that 10 miles is the maximum distance from which the LREP would be visible (Figures 3-11 and 3-12). The existing man-made Leavitt Reservoir is approximately 8 miles north of the town of Shell on BLM and private land in Big Horn County, Wyoming. The reservoir is at an elevation of 4,797 feet amsl and is within the semi-arid foothills west of the Bighorn Mountains. The analysis area includes the West Slope SRMA, the Brown-Howe ACEC, and three areas under management to protect lands with wilderness characteristics: 1) the Horse Mountain Unit (7,105 acres); 2) the Painted Hills Unit (7,897 acres); and 3) the Crystal Creek Unit (12,798 acres). See Section 3.7.2, for a discussion of the West Slope SRMA. 3.12.2 VRM System The BLM uses a VRM system to manage and analyze potential impacts on visual resources. The VRM system includes methods and procedures for analyzing potential impacts to visual resources that could be caused by proposed projects and planning efforts, and the system suggests appropriate visual design techniques so that surface-disturbing activities are visually reduced or not obviously visible. 3.12.2.1 Visual Resource Inventory BLM conducted an inventory of visual values, known as a visual resource inventory (VRI), across the CYFO planning area in 2009 in accordance with the BLM’s Manual H-8410-1 Visual Resource Inventory (BLM 1986). The BLM uses the VRI classes to inform management decisions, including assignment of VRM classes, to a given area. VRM classes and their application to the LREP are discussed in Section 3.12.2.2. The VRI process represents the relative values of the visual resources and consists of the following tasks: • A scenic quality evaluation to rate the visual appeal of an area. • An analysis of sensitivity level to assess public concern about an area’s scenic quality and sensitivity to potential changes in the visual setting. • A delineation of distance zones to indicate the relative visibility of the landscape from primary travel routes or observation points. The overlay of the data resulting from these three tasks provides the VRI Class. VRI Classes I and II represent areas with the most value. VRI Class III represents a moderate value, while VRI Class IV represents areas with the least value. Table 3-15 lists the acreage in the visual analysis area by VRI class, as determined from the 2009 inventory. VRI Class II areas are north and east of the LREP area and along the eastern side of the expanded reservoir area. Note that the VRI Class II areas fall on private land (see Figure 3-11). The rest of the LREP area is inventoried as VRI Classes III and IV. 3.12.2.2 VRM Classes and Objectives During the land use planning process, the BLM considers the VRI class of an area along with other management considerations (e.g., oil and gas development, wildlife habitat, prescribed fire) to determine the VRM class. VRM class designations have specific management objectives and specify the degree of permitted changes to the existing visual quality or visual values within a landscape. The objectives for each of the designated VRM classes, with the range of permitted visual resource changes, are: • Class I: The objective of this class is to preserve the existing character of the landscape. The level of change to the characteristic landscape should be very low and must not attract attention. Class I provides for natural ecological changes; however, it does not preclude very limited management activity. • Class II: The objective of this class is to retain the existing character of the landscape. The level of change to the characteristic landscape should be low. Management activities may be seen, but any changes must repeat the basic elements of form, line, color, and texture found in the predominant natural features of the landscape. • Class III: The objective of this class is to partially retain the existing character of the landscape. The level of change to the characteristic landscape should be moderate. Management activities may attract attention but should not dominate the view of the casual observer. Changes to the landscape should repeat the basic elements found in the predominant natural features of the characteristic landscape.

Leavitt Reservoir Expansion Project – Final EIS – 2019 3-19 Chapter 3 – Affected Environment Resource Discussions

• Class IV: The objective of this class is to provide for management activities that require major modifications to the existing character of the landscape. The level of change to the characteristic landscape can be high. Management activities may dominate the view and be a major focus of the viewer’s attention. However, every attempt should be made to minimize the impact of these activities through careful location, minimal disturbance, and repetition of basic elements of form, line, color, and texture found in the predominant natural features of the landscape (BLM 1986). Table 3-16 lists the acreages of each VRM Class in the analysis area as determined from the BLM CYFO Approved RMP (BLM 2015b). VRM Class II areas are northeast of the LREP area, along the eastern side of the expanded reservoir area and south along the Beaver Creek Road corridor. Note that the VRM Class II areas fall on private land. The rest of the LREP is managed by BLM as VRM Classes III and IV (see Figure 3-12). 3.12.2.3 Key Observation Points Key observation points (KOPs) are a series of points on a travel route or at a use area or potential use area, where the view of a project (e.g., the LREP) would be most revealing. KOPs are typically used as viewpoints for assessing potential visual impacts. Four KOPs were selected for the LREP (see Figure 3-12). These four KOPs were chosen because they are on commonly traveled routes or are located on other likely observation points. For the number of viewers at each KOP, “low” indicates 1 to 10 viewers, “moderate” indicates 11 to 30 viewers, and “high” indicates 31 or more viewers are estimated. 3.12.2.4 KOP 1 – Bear Creek Road KOP 1 is located on Bear Creek Road, approximately 9.5 miles north of the town of Shell, Wyoming, and 0.2 mile north of the northern reservoir inundation area (Figure 3-12). KOP 1 lies just outside the West Slope SRMA (Figure 3-12). Information on the West Slope SRMA appears in Section 3.7.2. Land use in the area is predominantly agricultural. The angle of observation from KOP 1 is 0 degrees or eye level. The number of viewers passing the KOP is unknown but is expected to be moderate. The size of the LREP appears relatively large from this KOP in comparison to surrounding landscape features such as Bear Creek Road, agricultural fields, and other topographic features. The season of use is year-round. The light conditions are variable depending on the season, and there are no obstructions from full sunlight. 3.12.2.5 KOP 2 – Beaver Creek Road KOP 2 is located on Beaver Creek Road, approximately 10 miles northeast of the town of Shell, Wyoming; 0.9 mile east of the expanded reservoir inundation area; and 0.2 mile from the easternmost borrow pit. (Figure 3-12). KOP 2 lies within the West Slope SRMA (Figure 3-12). Land use in the area is predominantly agricultural. The angle of observation from KOP 2 is 0 degrees or eye level. The number of viewers passing the KOP is unknown but is expected to be moderate. The size of the LREP appears relatively large from this KOP in comparison to surrounding landscape features such as Beaver Creek Road, agricultural fields, and other topographic features. The season of use is year-round. The light conditions are variable depending on the season, and there are no obstructions from full sunlight. 3.12.2.6 KOP 3 – The “W” Trail The trailhead leading to KOP 3 is located at County Road (CR) 83, approximately 7.3 miles northeast of the town of Shell, Wyoming (Figure 3-12), and approximately 6.0 miles southeast from the expanded reservoir inundation area. From the W trailhead, the KOP is located 0.3 mile along the trail to the north. KOP 3 lies within the West Slope SRMA (see Section 3.7.2). Land use in the area is predominantly agricultural and recreational. With a slope of 11.5 percent, the angle of observation from KOP 3 is superior. The number of viewers is unknown but expected to be moderate. The seasons of use are spring, summer, and fall. The light conditions are variable depending on the season, and there are no obstructions from full sunlight.

3-20 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 3 – Affected Environment Resource Discussions

3.12.2.7 KOP 4 – Sunlight Mesa KOP 4 is located on Forest Service Road 207, 4.75 miles south from its intersection with Hunt Mountain Road and US 14, approximately 19 miles east of the town of Shell, Wyoming (Figure 3-12). KOP 4 is approximately 8.8 miles southeast of the expanded reservoir inundation area. Land use in the area is predominantly recreational and livestock grazing. The angle of observation from this KOP is superior with an elevation difference between the reservoir expansion area and this KOP of 3,300 feet. The number of viewers is unknown but expected to be moderate. The relative size of the LREP from this KOP would be small compared to other landscape features such as agricultural fields and nearby mountains. The light conditions are variable depending on the season, and there are no obstructions from full sunlight. 3.13 Water Resources 3.13.1 Surface Water 3.13.1.1 Analysis Area The analysis area for surface water resources includes the stream and reservoirs in the Beaver Creek Basin below the Bernie Ditch diversion, and Shell Creek Basin, primarily but not limited to the reach from Beaver Creek to Shell Creek at the Bighorn River. 3.13.1.2 Stream Flow in Beaver Creek and Shell Creek The Bighorn River flows generally north, draining a basin bounded by the Absaroka Range on the west and southwest, the Owl Creek Range to the south, the Bighorn Range to the east, and the Sawtooth Range to the northwest (see Figure 3-13). Shell Creek is an east side tributary that begins at 11,500 feet in the Bighorn Mountains and flows westerly for 40 miles to the Bighorn River near Greybull, Wyoming. Elevation of the confluence with the Bighorn River is approximately 3,770 feet. The drainage area is approximately 566 square miles (USGS StreamStats n.d.). Beaver Creek is a tributary of Shell Creek that accounts for 83 square miles or 14.6 percent of the Shell Creek drainage. It rises at an elevation of 10,100 feet near Bald Mountain and flows to the south to join Shell Creek downstream from the town of Shell at an elevation of 4,075 feet (USGS StreamStats n.d.). Mean annual precipitation for the Shell Creek Basin is approximately 20 inches (USGS StreamStats n.d.). The hydrologically productive portion of the basin is the forested high-elevation area where annual precipitation is between 30 to 40 inches (MWH 2010a; PRISM Climate Group 2012). The center of the Bighorn Basin is exceptionally dry, as the surrounding mountains block the flow of moisture laden air from both east and west (WWDC 2010a). The 1971-2000 precipitation normals for Greybull and Basin are 7.54 and 6.77 inches, respectively (National Weather Service n.d.). Beaver Creek, with headwaters at approximately 10,000 feet and terminus near Shell (where the normal precipitation is 10.25 inches [National Weather Service n.d.]), represents conditions between the two extremes. Because of the variation in elevation and precipitation across these drainages, streamflow is snowmelt driven with the majority of runoff occurring from May through July. There are no long-term stream gages on Beaver Creek or Shell Creek below the Beaver Creek confluence. Two temporary gaging stations were installed along Beaver Creek in 2010; the upper gage near Leavitt Reservoir and the lower gage near the confluence with Shell Creek. There are two USGS gages on Shell Creek with complete or seasonal data back to at least 1956. The Shell Creek above Shell Reservoir gage (USGS ID: 06278300) is located high in the basin, above all diversions. The flow measured at this gage is free of the influence of agricultural, industrial, or municipal users in the valley. The Shell Creek near Shell, Wyoming gage (USGS ID: 06278500) is near the midpoint in the basin. The gage is located above nearly all agricultural diversions in the basin but is downstream of Shell and Adelaide reservoirs. Figure 3-13 shows the locations of these four stream gaging stations. Historical and average flow data for the USGS and temporary gages at locations shown on Figure 3.13 are presented and discussed in Appendix 3.15. The historical data start with the first full year available in the records at each site. Table 3-17 provides a summary of the average monthly flow at the gages and model nodes discussed in this section. In general, all the sites show a similar monthly pattern consistent with a snowmelt driven system. Gage sites lower in the basin show higher flow in the later summer and fall months relative to the peak flow during the late spring, highlighting the possible influence of reservoir operations on flows in the basin.

Leavitt Reservoir Expansion Project – Final EIS – 2019 3-21 Chapter 3 – Affected Environment Resource Discussions

3.13.1.3 Reservoirs Reservoirs are a component of the Shell Creek Basin’s surface water resource. Reservoirs increase the supply available for beneficial use because they ensure the water is accessible at the time the demand for water occurs. However, they do not increase the hydrologic supply, and in fact decrease it because of the depletive effect of evaporation. Shell and Adelaide reservoirs, mentioned above, are the two largest reservoirs in the basin. They are on Buck and Adelaide creeks, respectively, headwater tributaries of Shell Creek. The reservoirs are operated to capture spring runoff for later release to downstream irrigators. Releases typically begin in mid- to late-July when the runoff has dropped off. Shell Reservoir has a permitted capacity of 1,949 acre-feet (AF) and Adelaide Reservoir has a permitted capacity of 4,764 AF (MWH 2010b). Leavitt Reservoir is a much smaller structure currently, with a permitted capacity of 643 AF. The water is released for the benefit of both downstream and upstream irrigators, as the upstream irrigators would be called out by senior downstream irrigators if it were not for the reservoir supply. 3.13.1.4 Beneficial Use In the Shell Creek Basin specifically, surface water use is primarily for agricultural, municipal, and domestic use. According to the 2012 USDA, Agricultural Census, the leading crop raised in Big Horn County was alfalfa and grass hay, to support cattle and calf operations. Barley, dry beans, sugar beets, and corn were all represented in significant portions (USDA 2012). Greybull, the largest population center in the Shell Creek Basin at approximately 1,900 residents (U.S. Census Bureau 2011), derives its water supply from deep groundwater wells. 3.13.2 Water Quality 3.13.2.1 Surface Water Quality Analysis Area The spatial analysis area for surface water quality includes the area from the proposed diversion structure on Beaver Creek downstream to the confluence of Shell Creek and the Bighorn River. The area also includes the proposed expanded Leavitt Reservoir and its upstream contributing watershed. 3.13.2.2 Water Quality Standards Section 303(c) of the Clean Water Act (CWA) requires each state to review, establish, and revise water quality standards for all surface waters within the state. To comply with this requirement, Wyoming has developed a beneficial use classification system to describe state-designated use(s). Regulatory programs for water quality standards include default narrative standards, non-degradation provisions, a total maximum daily load (TMDL) regulatory process for impaired waters, and associated minimum water quality requirements for the designated uses of listed surface waterbodies within the state. Wyoming surface water beneficial uses classifications are found within the Wyoming Department of Environmental Quality (WDEQ) Water Quality Division’s (WQD’s) Wyoming Surface Water Classification List (WDEQ 2013a), and the related surface quality standards are detailed within the WDEQ Rules and Regulations Chapter 1 (WDEQ 2013b). Section 303(d) of the CWA requires states to list all streams that do not meet their water use classifications; such streams are considered impaired streams. Wyoming reports the current status of these impairments in WDEQ’s Wyoming’s 2014 Integrated 305(b) and 303(d) Report (WDEQ 2016). 3.13.2.3 Surface Water Classification Streams within the analysis area are classified as Class 2AB (cold water game fisheries supporting and protected for drinking water use, game and non-game fish, fish consumption, other aquatic life, recreation, wildlife, agriculture, industry, and scenic value) (WDEQ 2013a). 3.13.2.4 Surface Water Quality In 2000, the USGS sampled for multiple water quality constituents across the Bighorn Basin, including two sample sites in the analysis area, one each on Shell Creek and Beaver Creek, both below the proposed reservoir site. The results indicated that Escherichia coli (E. coli) and fecal coliform were outside or near the acceptable limits. The South Big Horn Conservation District continued evaluation of water quality from 2002 through 2008, along with several projects aimed at improving water quality. However, reporting indicated continuation of high

3-22 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 3 – Affected Environment Resource Discussions

E. coli concentrations. The average concentrations varied seasonally, with the highest concentrations occurring during the months of June and July, and the lowest occurring in February and March (WDEQ 2013c). WDEQ provided past water quality monitoring data for the impaired reach of Beaver Creek, from the period of May 2002 to October 2010. There were three locations along the impaired reach that streamflow measurements and water quality samples were periodically obtained for E.coli concentration analysis. These locations are all downstream of the proposed LREP outlet, and two of the three are downstream of the proposed transfer pipeline diversion. These baseline data are included in Appendix 4.13.2. Beaver Creek and Shell Creek are two streams within the analysis area that were previously identified as impaired streams; however, in 2014, both received approved TMDLs to control exceedances in fecal coliform. Beaver Creek has a TMDL for a 7.9-mile stretch extending upstream from the confluence with Shell Creek. Shell Creek has a TMDL for a 5.3-mile stretch extending upstream from the confluence with the Bighorn River. The TMDLs target indicator for both streams is E. coli for the primary contact recreation use. Separate summer (May 1 through September 30) and winter (October 1 through April 30) load limits have been identified (WDEQ 2013c). Recent surface water quality monitoring has occurred in the analysis area that was focused on the effects of the existing Leavitt Reservoir operations on water quality in Beaver Creek. Figure 3-14 depicts the locations that water samples were obtained. A summary of the results are included in Table 3-18, and indicate that during the fall release period, the reservoir outflow is a substantial portion of the flow (approximately 50 percent) downstream from the reservoir outflow’s confluence with Beaver Creek. The existing Leavitt Reservoir releases water that is slightly higher in pH and considerably higher in total dissolved solids (TDS) than the water in Beaver Creek slightly upstream from its confluence with discharges from Leavitt Reservoir. The water flowing from the Bighorn Mountains and entering the analysis area from upstream in Beaver Creek has lower TDS and E. coli than downstream reaches on Beaver Creek (Wenck 2017c). Downstream flows on Beaver Creek and the resident water stored in the existing Leavitt Reservoir likely pick up natural salts flowing across the sedimentary rock formations between the Bighorn Mountains and Shell Creek. During the 2017 water quality sampling, conducted as part of the reservoir expansion effort at the locations identified in Figure 3-14, there were no observed exceedances of water quality standards. Although the samples collected by Wenck (2017b) exceeded the USEPA’s secondary drinking water standard for TDS of 500 milligrams per liter (mg/L), these secondary standards are non-enforceable guidelines for contaminants that may cause cosmetic effects only (USEPA 2017). Laboratory testing of the samples listed above did not detect nitrogen, phosphorus, and selenium. Results for total coliform and E. coli were reported as positive/negative (no colony counts or concentrations were provided) which limited determination of water quality standard conformance (Wenck 2017c). Environmental factors that have a large influence on the existing surface water quality include the surficial geology and land uses within the analysis area. The existing environment for these factors are discussed in Sections 3.2 and 3.3, respectively. 3.13.3 Stream Morphology The stream morphology study area for the LREP includes stream reaches impounded and affected from the LREP backwater, as well as stream reaches affected by the alteration of flow and sediment, and in-stream structures associated with the reservoir expansion. The analysis area for geomorphic resources includes the following reaches and areas (Figure 3-15): • Beaver Creek upstream of the LREP to the proposed diversion structure (Reach 1). • Upstream ephemeral and intermittent tributaries impounded within the proposed expanded Leavitt Reservoir within the limits of disturbance. • Beaver Creek from the confluence with Davis Draw to the confluence with Shell Creek (Reaches 2 and 3). • Shell Creek from 1,000 linear feet upstream of the proposed transfer pipeline crossing to the confluence with the Bighorn River. • Davis Draw downstream of the Leavitt Supply Ditch to the confluence with Beaver Creek.

Leavitt Reservoir Expansion Project – Final EIS – 2019 3-23 Chapter 3 – Affected Environment Resource Discussions

3.13.3.1 Geomorphic Setting The proposed LREP lies within the Beaver Creek watershed, which is a sub-watershed to Shell Creek and the greater Bighorn Lake Basin. The study area is within the middle and lower elevations of the watershed where Beaver Creek meanders through a relatively broad valley with several ephemeral and intermittent streams and multiple gully washes contributing sediment and flow. Within the LREP area, Beaver Creek is flanked by sedimentary mesas and valley fill as it cuts through alluvial terraces and agricultural lands. Beaver Creek is a perennial stream where flow is sustained from snowmelt and groundwater originating on Bald Mountain and Little Bald Mountain, within the Bighorn Mountain Range. The study area is in a semi-arid desert, where the adjacent gullies and intermittent streams predominantly flow during rainfall events. Streams within the study area have naturally high sediment loads due to fine-grained geology, highly erodible soils, and relatively steep gradients. The natural character and floodplain functions within the LREP area are more vulnerable to morphological instabilities due to environmental disturbances. Existing stream morphology has been altered by anthropogenic influences associated with agricultural production, roads, bridges, impoundments, and diversions. These hydromodifications have disrupted sediment transport, floodplain connectivity, and altered natural hydrology. Beaver Creek Three reaches along Beaver Creek (Reaches 1, 2, and 3) have been identified for the purpose of evaluating the LREP. Figure 3-15 depicts these reaches and their sub-reaches. The upstream reach (Reach 1) is delineated from the proposed LREP diversion to the confluence with Davis Draw. Beaver Creek flows through the upstream colluvial valley within a slightly more topographically confined valley than the downstream reaches, ranging from 120 to 450 feet wide, respectively. The channel historically meandered across the valley, as evident from land scars, and the channel is currently not confined throughout the meander belt. Agricultural production is less predominant in this upstream reach with localized livestock trail access to the channel. There are no encroachments associated with adjacent roads or irrigation ditch canals. The riparian corridor appears to be robust with an active channel forming point bars and interior floodplains. The lower segment of this reach appears to be steeper, with long riffle-runs and coarser substrate. The middle reach (Reach 2) extends from the confluence with Davis Draw to the proposed transfer pipeline in the lower portion of the watershed. The alluvial channel flows through a transitional valley with natural topographic constraints ranging from approximately 350 to 1,100 feet wide. Relic channels exist throughout the valley, indicating the entire valley width was once an active floodplain. There are localized segments where the stream has been channelized and confined by Beaver Creek Road, residential bridges, and historical alignment. Agricultural production significantly confines the natural meander belt width for approximately 60 percent of Reach 2. There are four different irrigation headgates within Reach 2, but only one diversion structure created a noticeable hydromodification based on aerial imagery review. The Federal Emergency Management Agency (FEMA) designated 100-year (i.e., 1 percent recurrence interval) floodplain map for the reach shows a confined floodplain relative to the historic floodplain (FEMA 2014a). The study area was evaluated in the Flood Insurance Study using approximate methods, as opposed to detailed methods (FEMA 2014b). In general, this means that FEMA performed desktop analysis of the reach using the latest aerial photographs and light detection and ranging (LiDAR) data to delineate the floodplain extents, which shows segments of the channel where the approximated 100-year water surface elevation is approximated at the top of the bank. This indicates these segments are incised and may be actively degrading. Reach 2a is delineated from the confluence with Davis Draw to near the confluence with the proposed spillway channel (Figure 3-15). The upstream segment of this reach has been channelized for 1,000 linear feet, and for 400 linear feet downstream of the Beaver Creek Road crossing. Upstream of the Beaver Creek Road bridge crossing it appears the channel may be degrading, as there are less frequent point bars, compounding meander bends, and evident vertical faces eroded from the overbank terrace. Reach 2a character is similar to Reach 1 character, within an transitional colluvial valley that flows through terraced deposits and is a B4c channel considered moderately entrenched (Rosgen 1994; WWDC 2010b). Reach 2b is located downstream of the intermittent tributary (proposed spillway channel) to just upstream of the intermittent tributary near the confluence with Red Creek. Throughout the upstream segment the channel appears to have an active floodplain with point bars, natural escarpments, woody debris, interior floodplains, and a robust riparian corridor. The channel has been straightened for approximately 455 feet upstream of the diversion where

3-24 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 3 – Affected Environment Resource Discussions agricultural production begins. Aerial imagery reveals riffle-pool complexes through the straighter segments. The lower segment runs though agricultural lands, where the riparian corridor becomes more limited and the channel is encroached and channelized by residential and agricultural developments. The FEMA floodplain mapping delineates the 100-year water surface at the top of the bank, indicating the channel is actively degrading and incised. As the channel flows down the valley, shown as Reach 2c on Figure 3-15, agricultural production significantly minimizes the extents of the riparian corridor and there are fewer point bars and riffles evident from aerial imagery. Red Creek is a lateral perennial tributary that joins Beaver Creek within this reach. From the Red Creek confluence down to the transfer pipeline, there are several segments showing lateral instability and active bank erosion, likely associated with loss of riparian vegetation. Several segments appear to be straightened, likely from a combination of agricultural encroachment and flow alterations. Natural planform shifts may be a result from reduced stream power to mobilize sediment and achieve equilibrium by transitioning to a steeper slope. Upstream of the transfer pipeline, approximately 4,300 linear feet of the stream has been channelized against the west flank of the valley, vertical instability and channel incision are evident from aerial imagery. The lower reach, Reach 3, of Beaver Creek extends from the proposed transfer pipeline diversion downstream to the confluence with Shell Creek. Reach 3 typically loses flow to natural seepage in the alluvium, and/or additional irrigation withdrawals (WWDC 2010b). Reach 3 is considered a losing stream and more susceptible to morphological instabilities with changes in the duration and frequency of bankfull flows. Immediately downstream of the existing diversion at the proposed transfer pipeline, Reach 3a, the channel is vertically and laterally unstable with active channel incision and bank erosion. A narrow riparian corridor exists and the channel planform has been altered to maximize agricultural production, resulting in a reduced sinuosity and associated meander bends and point bars. Along Reach 3b, delineated between the Beaver Creek Road crossing and the LREP transfer pipeline crossing, there are fragments of robust riparian vegetation; however, the majority of the channel flows through agricultural lands with little to no riparian vegetation and active bank erosion is occurring. There are fewer riffles present, a few mid-channel bars, and several large deposits that indicate localized aggradation exacerbated by active bank erosion. As the channel flows down the valley through Reach 3c, there are interior floodplains supporting riparian vegetation; however throughout the majority of this segment, residential and agricultural development has encroached upon the floodplain and thereby altered natural planform adjustments, reduced sinuosity and flood prone width, and increased channel slope. Within this segment, the 100-year water surface elevation is approximated at the top of the bank indicating channel incision (FEMA 2014a). Upstream of the paved Beaver Creek Road crossing, approximately 1,500 feet of the channel is significantly denuded of riparian vegetation and the channel has cut-off meanders forming a more straight homogenous profile. Near the confluence with Shell Creek the channel is classified as a Rosgen E4 type with gravel and sand substrate (Rosgen 1994; WWDC 2010b). Shell Creek Beaver Creek is the largest tributary to Shell Creek (WWDC 2010b). Shell Creek has a historic flood-prone width that varies from over 4,000 feet wide to approximately 1,000 feet wide at the valley pinch point a few miles upstream from the confluence with the Bighorn River. Relic features show numerous abandoned and highly sinuous channels once existed throughout the width of the valley. The meander belt width is now confined by agricultural and residential development, and the floodplain is delineated within Big Horn County and unincorporated areas (FEMA 2014a). Throughout most of the reach the channel exhibits similar sinuosity and radius of curvature to historic relic channels, with hydraulically connected oxbows and active cut-off channels. Several localized segments are channelized from roads, bridges, and streambank protection for agricultural lands and residential structures. Immediately downstream of these channelized reaches, there are larger point bars and braiding caused from the increased sediment loading and increased channel velocities from channel straightening. The substrate is mainly cobbles and gravel, with gravel and sand near the confluence with the Bighorn River (WWDC 2010b). The channel exhibits riffle-pool morphology in this reach. Erosion potential and sediment supply are rated very high for the surveyed stream reach (WWDC 2010b). Sediment loading is naturally high within the lower alluvial valley of Shell Creek, which makes the channel morphology vulnerable to changes in slope and discharge. Stream flows in Shell Creek have been altered from upstream reservoirs (i.e., Adelaide and Shell) and irrigation delivery systems.

Leavitt Reservoir Expansion Project – Final EIS – 2019 3-25 Chapter 3 – Affected Environment Resource Discussions

Table 3-19 provides a general summary of the existing conditions of the perennial stream reaches within the study area. Unnamed Tributaries within the Proposed Impoundment Area There are unnamed intermittent and ephemeral drainage channels/tributaries that are within the proposed LREP impoundment area. The existing unnamed tributaries in the LREP include approximately 13,000 linear feet of channel length that have a catchment drainage area greater than 0.1 square mile. An intermittent tributary to Beaver Creek is currently impounded by the existing Leavitt Reservoir for 2,500 linear feet. Downstream of the LREP, this intermittent tributary runs for approximately 7,000 linear feet before the confluence with Beaver Creek. The downstream intermittent segment is proposed as the emergency spillway channel. The channel is slightly sinuous with an active flood prone width ranging from approximately 25 to 110 feet wide. The channel has several connected fingers that support palustrine emergent (PEM) wetland vegetation that span the floor width (WEST 2018a) that are likely a result of elevated groundwater upstream of the existing reservoir. Downstream of the existing reservoir, the channel supports riparian vegetation throughout the belt width as it runs south through colluvium slope wash. The intermittent streams flow only during rain or snow events. These originate from the west flank mesa and have a continuous channel that carry high sediment loads most significantly during high intensity thunderstorms when dry soil conditions exist. These intermittent channels have steep gradients and well drained sand beds. There are no evident intermittent pools or significant riparian vegetation supported. Davis Draw Davis Draw from the proposed LREP supply pipeline downstream to its confluence with Beaver Creek is approximately 3,000 linear feet in length. Davis Draw is a native ephemeral stream that currently operates as an irrigation ditch with augmented flow from diversions further up in the watershed. It is confined by natural topography and with an average flood-prone width of approximately 25 feet. The ephemeral channel is fairly steep with low sinuosity and approximate slope of 2.7 percent. 3.13.4 Groundwater Resources The LREP study area for groundwater resources extends from Beaver Creek near the existing Leavitt Reservoir diversion on the upstream end, to the confluence of Shell Creek and the Bighorn River on the downstream end. The study area encompasses the current Leavitt Reservoir and proposed disturbance footprint, as well as the transfer pipeline that would connect Beaver Creek to the Shell Canal. This area was selected for analysis because it includes the entire disturbance footprint associated with the LREP, and also spans the areas of Beaver Creek and Shell Creek where groundwater-surface water interactions could be affected as a result of changes in the volume and timing of surface water flows. Due to the project location near the eastern edge of the Bighorn Basin, rock layers near the LREP study area generally dip to the west and southwest towards the basin axis. Consequently, the bedrock units present near ground surface decrease in age west of the study area, and increase in age to the east. The geologic formations present beneath Leavitt Reservoir range in age from the Lower Cretaceous Cloverly Formation to the Cambrian Flathead Sandstone (Noggle-Perrin 1989). Unconsolidated to semi-consolidated alluvium and terrace deposits are also present east of the reservoir along the channels of Davis Draw and Beaver Creek. Rocks of the eastern Bighorn Basin can be divided into three main hydro-stratigraphic units, as adapted from Whitehead (1996). From youngest to oldest, these units include the Lower Cretaceous aquifers, a Jurassic to Permian confining unit, and the Paleozoic aquifer system. In Table 3-2, the Lower Cretaceous aquifer corresponds to the Muddy Sandstone, Thermopolis Shale, and the Cloverly Formation; the Jurassic to Permian confining unit spans the Morrison through the Goose Egg formations; and rocks below the Goose Egg Formation represent the Paleozoic aquifer system. Discussions of the local hydrogeology presented throughout this section follow this simplified conceptual model. The discussion focuses on the Lower Cretaceous aquifers, since the deeper Paleozoic aquifer system is hydraulically disconnected from Leavitt Reservoir by low permeability rocks within the Jurassic to Permian confining unit. The Cloverly Formation is the uppermost bedrock unit beneath Leavitt Reservoir and the proposed 3-mile transfer pipeline. In the LREP study area, it is the only formation present that comprises the Lower Cretaceous aquifers. Cloverly Formation ranges from 330 to 447 feet (Manahl 1985; Noggle-Perrin 1989). In Big Horn County, the Cloverly Formation is not an especially productive aquifer. Sandstones in the formation may yield

3-26 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 3 – Affected Environment Resource Discussions enough water for domestic or stock use; however, typical well yields are only about 10 to 15 gallons per minute (gpm) (Plafcan et al. 1993). Beneath the Cloverly Formation lies a thick confining unit comprised of Jurassic, Triassic, and Permian rocks. The strata included in this confining unit, as shown on the stratigraphic column presented on Table 3-2, include the Morrison, Sundance, Gypsum Spring, Chugwater, and Goose Egg formations. These formations consist predominantly of fine-grained rocks such as shale, mudstone, and siltstone that restrict groundwater movement. The Paleozoic aquifer system, present beneath the Jurassic to Permian confining unit, is a broad grouping of formations that spans the Pennsylvanian Tensleep Sandstone through the Cambrian Flathead Sandstone (Table 3-2).The major water-bearing formations within the Paleozoic system include the Tensleep and Flathead units, as well as the Madison-Bighorn aquifer comprised of the Madison Limestone and Bighorn Dolomite. It is not anticipated that the LREP would impact the Paleozoic aquifers due to their depth below the existing reservoir and the hydraulic barrier created by the overlying Jurassic to Permian confining unit. Quaternary alluvium in the LREP study area is also known to contain and transmit groundwater. Groundwater occurs in alluvium deposits associated with Beaver Creek and Shell Creek, and may also be present in Quaternary terrace deposits adjacent to the stream channels. The thickness of the alluvium deposits is generally around 30 feet (Plafcan et al. 1993). The alluvial aquifers receive direct recharge from precipitation, and may also be recharged by surface water seepage during high runoff periods. Yields from wells in Big Horn County completed in the alluvium can range from about 5 to 140 gpm (Plafcan et al. 1993). However, most alluvial wells in the county yield less than 50 gpm. Alluvial well yields near the LREP study area are expected to be similar to or less than this value. Groundwater quality data for the Quaternary alluvium and terrace deposits, Lower Cretaceous aquifer, and Paleozoic aquifer system were obtained from the USGS report entitled Water Resources of Big Horn County, Wyoming (Plafcan et al. 1993). The USGS report contains analytical data and statistics for numerous groundwater quality samples collected in Big Horn County between 1925 and 1988. Table 3-20 summarizes the average pH, major ion, and TDS concentrations for the aquifers that occur in the LREP study area. As shown in the table, groundwater from the Quaternary alluvium, terrace deposits, Cloverly Formation, and Madison-Bighorn aquifer generally exhibits a sodium-sulfate water quality signature. Conversely, the Tensleep Sandstone typically contains calcium-sulfate type water, and the Flathead Sandstone exhibits a sodium- bicarbonate water type. The average groundwater pH appears to increase with aquifer depth, as evidenced by the lower pH values for the Quaternary and Cretaceous formations, and pH values above 8 for the Paleozoic units. The aquifer TDS concentrations vary over a relatively large range, with the lowest average TDS (258 mg/L) occurring in the Flathead Sandstone, and the highest average TDS reported for the Cloverly Formation (1,860 mg/L). Average TDS values also tend to be lower in the deeper Paleozoic aquifers compared to the shallower Quaternary and Cretaceous units. Except for the Flathead Sandstone, the TDS and sulfate values in the aquifers are consistently above the Wyoming Class I groundwater standard for domestic use. Groundwater wells near the study area were queried from a GIS database maintained by the Wyoming State Engineer’s Office (SEO) (2016). Wells with no depth information and records classified as monitoring wells in the database were excluded from this search. Altogether, 34 water supply wells were identified within 0.5 mile of the proposed LREP (Table 3-21). The target aquifer tapped by each well was not available from the Wyoming SEO records; however, each well was assigned to a geologic formation using the well depths, estimated aquifer thicknesses, and bedrock geology maps. The aquifer assignments for the wells are accurate to the extent that the location and depth information for each well is correct in the Wyoming SEO’s database. Results of this analysis indicate that 94 percent of the wells in the study area are completed in either Quaternary alluvium or the Cloverly Formation. Two wells were also identified that tap the Jurassic Morrison Formation. Overall, wells in the study area are mainly permitted for domestic and/or livestock use. Table 3-21 also includes the average well depths, static water level depths, and reported yields for wells completed in each formation. The average depth of wells installed in the Quaternary alluvium is 31 feet, and the average depth of wells installed in the Cretaceous Cloverly aquifer is approximately 165 feet. Wells completed in the Morrison Formation appear to be relatively shallow, with an average depth of just 32 feet. Both the Morrison wells are located in areas where the Morrison represents the uppermost bedrock unit. Therefore, it appears that at least locally, the Morrison Formation is a viable water source in areas where no other shallow aquifer is present.

Leavitt Reservoir Expansion Project – Final EIS – 2019 3-27 Chapter 3 – Affected Environment Resource Discussions

The average static water level depth for wells in the study area ranges from 13 feet below ground surface (bgs) in the alluvium to 35 feet bgs in the Cloverly Formation. The data in Table 3-21 also reveal that the average well yield for wells completed in the alluvium is approximately double that of wells installed in the bedrock units. Overall, the average well yields tabulated in Table 3-21 are in agreement with estimated well yields from Plafcan et al. (1993). According to the Wyoming SEO’s records, there are no springs within 0.5 mile of the study area that have been permitted or adjudicated for beneficial use (Wyoming SEO 2016). Additionally, no mapped groundwater springs were identified within 0.5 mile of the study area in the National Hydrography Dataset (USGS 2013). 3.14 Wildlife and Aquatic Biological Resources 3.14.1 Terrestrial Wildlife The analysis area straddles the transitional zone between two Level IV ecoregions within the Wyoming Basin: the Foothill Shrublands and Low Mountains and the Bighorn Salt Desert Shrub Basins (USEPA 2016). The convergence of these zones results in a variety of habitat types that provide important areas for terrestrial wildlife breeding, birthing, foraging, wintering, and/or migration. Section 3.11 lists the general habitats, categorized by vegetation or cover type, found within the analysis area. Big sagebrush shrubland and steppe is the dominant habitat, covering approximately 60 percent of the analysis area. Agriculture makes up approximately 14.3 percent, and non-native grassland and steppe makes up approximately 9.7 percent. Other habitat types found in the analysis area include wetland/riparian, native grassland, saltbush and greasewood, barren/sparsely vegetated, aspen forest and woodland, developed land and roads, conifer woodland, montane/foothill shrub, and open water. These minor habitats collectively comprise approximately 16 percent of the analysis area. The mammals in the analysis area tend to be generalist species that can be found in other regions of the state. No mammal species’ ranges are restricted to the analysis area or the immediate vicinity. Table 3-22 lists the mammal species observed in the analysis area between 1916 and 2010, which are the earliest and latest occurrence dates for any mammal species in the list (WYNDD 2017c). Big game species in the analysis area could include elk (Cervus canadensis), moose (Alces alces), mule deer (Odocoileus hemionus), white-tailed deer (Odocoileus virginianus), pronghorn (Antilocapra americana). The analysis area overlaps crucial winter range for elk and mule deer; yearlong range for antelope, white-tailed deer, and mule deer; and seasonal range for moose and elk (Figures 3-16, -17, and -18). Additionally, an elk parturition area is approximately 3.4 miles east of the analysis area (Figure 3-18), and a mule deer parturition area is approximately 5.3 miles north of the analysis area. Winter is a crucial and demanding time for ungulates, so crucial winter ranges are often used as criteria for analyzing impacts on big game. Conifer woodlands and montane/foothill shrub near the LREP can support berry-producing shrubs which are important forage for many mammals, such as black bears (Ursus americanus) (WGFD 2017). The patches of trees and rough topography often found in conifer woodlands and montane/foothill shrub provide cover, forage, and nesting substrates for wildlife such as bats and bushy-tailed woodrats (Neotoma cinerea). Aspen forest and woodland, which comprises approximately 1.5 percent of the analysis area and is concentrated along creeks, often supports unique forest wildlife species that otherwise would not occur in these areas (WGFD 2017). Aspen stands typically support high grass and forb production, providing important foraging sites for large and small herbivores such as mule deer, elk, moose, black bear, and chipmunks (Tamias spp.) (WGFD 2017). Aspen and deciduous forests are particularly important to bats, possibly because these habitats are typically close to open water. These woodlands provide cavities for bat roosting. Rock outcrops and cliffs in and near the LREP are important terrestrial habitat for a variety of reptile species because they offer thermally favorable refuges, cover, and hibernacula (WGFD 2017). Reptile species known to occur in the LREP are bullsnake (Pituophis catenifer sayi) and the northern rubber boa (Charina bottae) (WYNDD 2017c). 3.14.2 Terrestrial Special Status Wildlife Species Terrestrial special status species are those listed as threatened or endangered, are proposed for listing, or are candidates for listing under the ESA; those listed by a state implying potential endangerment or extinction (i.e., WGFD’s Species of Greatest Conservation Need [SGCN] rankings); or those designated by the BLM State Director as sensitive. Species designated as sensitive by the BLM State Director include species that are under status review, have small or declining populations, live in unique habitats, or require special management. The

3-28 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 3 – Affected Environment Resource Discussions

BLM Wyoming Sensitive Species Policy and List are provided in a memorandum updated periodically; the latest update occurred in 2010 (BLM 2010b). Special status terrestrial wildlife species that may occur in the analysis area inhabit a variety of habitat types including sagebrush shrublands (e.g., greater sage-grouse, sage thrasher, ferruginous hawk, loggerhead shrike), and grasslands (e.g., burrowing owl, swift fox [Vulpes velox], white-tailed prairie dog). For most terrestrial special status species, comprehensive data on population numbers and distribution within the analysis area are not available. BLM has collected data on raptor nests and prairie dog colonies (BLM 2017b). Twenty-nine terrestrial species (17 bird species, 8 mammal species, and 4 amphibian species) with some kind of special status species designation occur in or near the LREP. There is no known occurrences or potential habitat for USFWS listed threatened or endangered species in the LREP (BLM 2015a). The status, habitat preferences, and potential to occur in the analysis area of these 29 special status wildlife species are summarized in Appendix 3.14. A species was determined to have the potential to occur in the analysis area if 1) WYNDD contained an observation record for the species in the analysis area, 2) the USFWS Information for Planning and Consultation (IPaC) report listed the species as potentially occurring in the analysis area, or 3) NatureServe Explorer showed the species occurring in the watershed (Hydrologic Unit Code [HUC] 12). 3.14.2.1 Migratory Birds (non-raptors) The LREP analysis area supports a diverse range of migratory bird species, including many year-round residents, summer residents/migratory birds, and winter residents/migratory birds. The rolling hills, aspen/deciduous and montane forests, and shrublands provide a variety of habitats that support avian wildlife. Approximately 3.9 percent of the analysis area is composed of wetland/riparian areas. However, riparian areas have a disproportionately high value as wildlife habitat, particularly for bird species (WGFD 2017). In Wyoming, approximately 73 avian species have been identified as using riparian habitats (Nicholoff 2003). Scattered wetlands can provide forage, cover, and nesting habitat for waterfowl. While aspen makes up a small percentage of the analysis area, its high plant diversity and productivity attracts a large number of invertebrates and, consequently, insectivores such as birds. Mature aspen stands are important to cavity nesting birds and usually have greater bird diversity than younger stands (WGFD 2017). Sagebrush and other shrub species provide habitats for sagebrush obligate species, including the greater sage-grouse (Centrocercus urophasianus), sage sparrow (Amphispiza belli), and sage thrasher (Oreoscoptes montanus). Native and non-native grasslands support many ground nesting birds. Table 3-23 lists the migratory bird species observed in the analysis area between 1979 and 2013, which are the earliest and latest occurrence dates for any bird species in the list (WYNDD 2017c), as well as the bird species that may occur in the area according to the USFWS (2016a). The raptor species are discussed in further detail in Section 3.14.2.2. Preferred habitats for the non-raptor migratory bird species that may be found in the analysis area range from sagebrush and grasslands, to marshes and wetlands, to coniferous and deciduous forests. WYNDD and the BLM have little occurrence data for the migratory bird species that may occur in the analysis area. 3.14.2.2 Raptors Nine raptor species are known to occur or may occur in the analysis area: bald eagle, burrowing owl, ferruginous hawk, golden eagle, merlin, northern goshawk, peregrine falcon, short-eared owl, and western screech-owl. All except merlin, short-eared owl, and western screech-owl are BLM sensitive species. The bald eagle is protected under the Bald and Golden Eagle Protection Act of 1940 (BGEPA) and is also a BLM sensitive species. Bald eagles live near rivers, lakes, and marshes where they can obtain fish, their staple food. They breed and winter in forested areas adjacent to large bodies of water (USFWS 2017a). They select large, super-canopy roost trees that are open and accessible for nesting. The Bighorn Basin is predominantly a wintering area for bald eagles. WYNDD (2017c) data include observations of bald eagles throughout the analysis area, though no known bald eagle nests have been documented by the BLM within the analysis area. The burrowing owl is a BLM sensitive species that inhabits prairie dog colonies, opportunistically living in abandoned prairie dog burrows and feeding on rodents that live in and around the colony. There are no

Leavitt Reservoir Expansion Project – Final EIS – 2019 3-29 Chapter 3 – Affected Environment Resource Discussions documented nests or prairie dog colonies that would provide burrowing owl habitat near the LREP (BLM 2015a; BLM 2017b; WYNDD 2017c). The ferruginous hawk is a BLM sensitive species that occurs in grasslands and shrublands during the spring, summer, and fall in Wyoming but is not common in the Bighorn Basin (USFWS 2017b). Ferruginous hawks generally nest on the ground, rock outcrops, topographic high points, or cliffs. WYNDD (2017c) features no documented occurrences of ferruginous hawks in the analysis area, though suitable nesting habitat can be found throughout the area. The BLM has not recorded any known nests near the LREP. The golden eagle is protected under the BGEPA that inhabits open and semi-open country such as prairies, sagebrush steppe, sparse woodlands, or barren areas. The species nests most often on rock ledges of cliffs but sometimes in large, mature trees; on steep hillsides; or on the ground (NatureServe 2017a). WYNDD (2017c) contains numerous observations of golden eagles in and around the LREP. One known golden eagle nest is located near the LREP, approximately 1.42 miles away. The merlin is a small falcon protected under the Migratory Bird Treaty Act (MBTA) that lives in a wide variety of habitats, including marshes, deserts, seacoasts, near coastal lakes and lagoons, open woodlands, and fields (NatureServe 2017b). Merlins nest in conifer woodland or wooded prairies. According to BLM data, there are no previously documented merlin nests in the analysis area. WYNDD (2017c) contains a single documented sighting of merlin within the analysis area. The northern goshawk is a BLM sensitive species that prefers mature or old-growth conifer, mixed hardwood-conifer, birch, or aspen forests for nesting (USFWS 2017c). However, they can also use a variety of forest types (mature or young) for breeding and nesting. They often forage near forest openings or edges (USFWS 2017c). Suitable goshawk habitat occurs near the LREP though WYNDD (2017c) contains no occurrence records for northern goshawk in the analysis area. The peregrine falcon is a BLM sensitive species that is found across western and eastern North America. The subspecies American peregrine falcon was removed from the ESA in 1999. This subspecies is the most often encountered in Wyoming (WGFD 2017). It is uncertain how much of the state may be considered viable winter habitat, and the trend of the winter population is unknown (WGFD 2017). Peregrine falcons are habitat generalists that use a variety of natural and urban habitats for nesting and foraging. Typically in Wyoming, they require cliffs for nest sites and open areas for foraging (WGFD 2017). According to BLM data (2017b), there are no previously documented peregrine falcon nests in the analysis area. WYNDD (2017c) data show multiple documented occurrences of peregrine falcons near the LREP area. The short-eared owl is a medium-sized owl species, protected under the MBTA that prefers native and seeded grasslands, though they may use agricultural fields or surface mines. Short-eared owls require dense horizontal cover for nest concealment and proximity to foraging areas (WGFD 2017). In Wyoming, the species occupies undisturbed open habitats below 6,000 feet amsl, including grasslands, meadows, marshes, and shrub-steppe (WGFD 2017). During the winter they also use large open areas within woodlots, dumps, gravel pits, rock quarries, and shrub thickets. WYNDD (2017c) contains no records of short-eared owls occurring in or near the LREP though USFWS indicates that they have the potential to occur. Suitable habitat exists in LREP grasslands and shrublands habitat. The western screech-owl is a small owl species, protected under the MBTA, that inhabits woodlands, especially broadleaf and riparian woodlands, and scrub (NatureServe 2017c). They nest in tree cavities or abandoned woodpecker holes. According to BLM data (2017b), there are no previously documented western screech-owl nests in the analysis area. WYNDD (2017c) contains documented sightings of western screech-owls near the LREP. There is suitable woodland screech-owl habitat near the LREP. 3.14.2.3 Greater Sage-Grouse In addition to the analysis area, greater sage-grouse leks were assessed within 2 miles of the LREP based on the BLM RMP (BLM 2015b) and state of Wyoming EO 2015-04 (State of Wyoming 2015) regulatory guidelines. The LREP lies within the BLM GHMA. The LREP does not overlap with a BLM PHMA or Sagebrush Focal Area or Wyoming EO core area (BLM 2015a; State of Wyoming 2015). There are two PHMA/core area that occur within 1 mile of the Project area: the Shell Core Area in the northeast, and the Hyattville Core Area in the southeast (Figure 3-19). No known sage-grouse leks are located within the 1-mile analysis area (Figure 3-19). The only portion of the LREP that is within 2 miles of a known grouse lek is approximately 380 feet of the existing CR 39 and its egress onto US 14; the land cover of this LREP portion consists of agriculture, developed,

3-30 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 3 – Affected Environment Resource Discussions and road areas (Figure 3-10). No other areas of the LREP are within 2 miles of a known lek. WYNDD (2017c) contains multiple records of greater sage-grouse observations near the LREP between 1979 and 2014; there are no records of leks in this data. 3.14.2.4 Other BLM Terrestrial Sensitive Species Other BLM terrestrial sensitive species that could occur in the analysis area include: gray wolf, long-eared myotis, spotted bat, Townsend’s big-eared bat, and the white-tailed prairie dog. The LREP area may contain suitable habitat for these species, so they have the potential to occur there. WYNDD (2017c) contains observation records for gray wolf and long-eared myotis near the LREP. 3.14.3 Special Status Aquatic Biological Resources 3.14.3.1 Overview The aquatic groups covered in this section include fish, macroinvertebrates, amphibians, and reptiles. Of these groups, the focus is on game and special status fish and amphibian species due to their management emphasis by the WGFD and federal agencies related to their management of public lands. Special status species are discussed in Section 3.14.4. The analysis area for aquatic biological resources for the LREP includes the current Leavitt Reservoir and proposed expansion footprint to storage capacity of 6,604 AF, as well as Beaver Creek below the existing Leavitt Reservoir diversion downstream to Shell Creek at the Bighorn River confluence (Figure 3-20). This analysis area was chosen to evaluate areas potentially impacted by instream disturbance and flow/water level and water quality changes. The upper and lower ends of the analysis area were determined by surface flow modeling, which showed that flow changes would be small or not even measurable above or below these points (Wenck 2017d). The priority species in the analysis area for aquatic biological resources is Yellowstone cutthroat trout (Oncorhynchus clarkii bouvieri), which is identified by WGFD as having core conservation areas and crucial aquatic and aquatic enhancement habitats. Crucial habitat priority areas are based on the presence of significant biological or ecological values. These areas need to be protected or managed to maintain viable healthy populations of terrestrial and aquatic species. Enhancement habitat priority areas are considered to have realistic potential to address wildlife and aquatic habitat issues to improve, enhance, or restore habitats. Macroinvertebrates are included in the description of aquatic biological resources due to their importance to the trophic level dynamics of aquatic ecosystems and indicators of water quality conditions. 3.14.3.2 Habitat Aquatic habitat located in the LREP analysis area includes Leavitt Reservoir and two perennial streams, Beaver and Shell creeks. These waterbodies are part of the Lower Shell HUC 10 Watershed. The length of perennial stream habitat within the LREP analysis area for these two streams is 12.8 and 16.5 miles, respectively. Information used to characterize habitat within the LREP analysis area is based on habitat priority areas identified by WGFD, the presence of aquatic conservation areas, and the WGFD stream classification system. None of the study area streams are located within watersheds identified as aquatic wildlife conservation areas (WGFD 2010). The portion of Beaver Creek within the LREP analysis area is classified as a yellow ribbon trout stream, meaning it contains 50 to 300 pounds of trout per stream mile with regional importance (Annear et al. 2006; WGFD 2017) (Figure 3-20). Shell Creek is classified as a green ribbon trout stream, which supports less than 50 pounds of trout per mile and is considered to have local importance. The analysis area also contains combined crucial priority and combined enhancement priority habitat, as identified in the Strategic Habitat Plan by WGFD (2015a) (Figure 3-21). In total, the analysis area contains 292 acres of combined crucial priority habitat and 2 acres of combined enhancement priority habitat. The habitat value for combined crucial priority areas is the functioning stream systems that provide habitat for conservation populations of Yellowstone cutthroat trout, habitat connectivity, water quality, and riparian areas (WGFD 2014). The issues for the enhancement priority areas include water quantity, water quality, habitat connectivity, canal entrainment, degraded streams, and degraded riparian areas (WGFD 2014). Based on WGFD habitat surveys conducted in August 2007 at sites shown on Figure 3-20, stream width, depth, substrate, and cover were characterized in Beaver and Shell creeks (Bear 2009). The average wetted stream width varied between approximately 30 and 56 feet in Shell Creek, and an average width of 9 feet in Beaver Creek. The average stream depth in Shell Creek varied from approximately 0.7 to 1 foot and maximum depths ranged from 2.7 to 3.6 feet. In contrast, the average depth in Beaver Creek was 1 foot, with a maximum depth of

Leavitt Reservoir Expansion Project – Final EIS – 2019 3-31 Chapter 3 – Affected Environment Resource Discussions

2.7 feet. The predominant substrate was cobble and coarse gravel or fine gravel in Shell Creek. Cobble and coarse gravel dominated the substrate in Beaver Creek. The percent composition of fine gravel, which represents potential spawning substrate for salmonid (trout) species, varied from 0 to 15 percent in Shell Creek and 7 percent in Beaver Creek. Fish cover consisting of aquatic vegetation, woody debris, overhanging cover, and undercut banks was rated as sparse at all survey locations (Bear 2009). The dominant riparian tree species was Russian olive with cottonwoods as the subdominant species in both streams. A recent survey conducted by WEST (2018a) provided a description of habitat characteristics in Beaver Creek in the proposed diversion structure area, based on surveys in August 2017. Beaver Creek ranged from 10 to 20 feet wide and was surrounded by a forested community. Most of the creek had a well-defined bank, either eroded soil or cobble-lacking wetlands. Aquatic habitat in the LREP analysis area also includes wetlands, which were inventoried by WEST (2018a). In total, approximately 20 acres of wetlands were identified, which were associated with the fringe of Leavitt Reservoir and water features such as ponds, irrigation ditches, streams, and borrow areas. Wetlands identified within the LREP disturbance footprint occurred primarily as fringes along the existing reservoir margins, along the inflow drainage feature, or on the back of the existing dam. Multiple terrace wetlands were identified along Beaver Creek. Detailed descriptions of wetlands are provided in Section 3.15. Water quality in Leavitt Reservoir and Beaver and Shell creeks is discussed in Section 3.13.2.4. Portions of Beaver and Shell creeks (7.9 and 5.3 miles, respectively) have been identified as impaired for E. coli. However, it is important to note that the standard for E. coli is for human health. There is no Wyoming E. coli standard for aquatic life. Water quality sampling conducted in 2017 as part of the reservoir expansion effort reported no exceedances of water quality standards for other constituents (Wenck 2017c). Aquatic invasive species are non-native aquatic species that can adversely affect aquatic species and their habitat. Aquatic invasive species or diseases of concern for the LREP include zebra (Dreissena polymorha) and (Dreissena bugensis) mussels, New Zealand mudsnail (Potamo pyrgus antipodarum), and rusty crayfish (Orconectes rusticus). There are no known zebra or quagga mussel occurrences in Wyoming and rusty crayfish is only known to occur near Casper (Hochhalter 2018). Species or diseases that have been detected in the Cody include New Zealand mudsnail (Hochhalter 2018). No invasive species have been detected in the existing Leavitt Reservoir or Beaver and Shell creeks. However, there is a risk of introduction from watercraft that have been in waters with aquatic invasive species. WGFD has a Wyoming Aquatic Invasive Species Program that focuses on the prevention of the introduction and spread of invasive species through watercraft inspections. Wyoming law requires any watercraft entering the state from March 1 through November 30 each year to have a mandatory inspection by an authorized inspector before launching in Wyoming waters. 3.14.3.3 Fish Leavitt Reservoir, Beaver Creek, and Shell Creek support a coldwater game fishery at higher elevations that transitions to a coldwater/warmwater mixed fishery at lower elevations. The WDEQ classification is 2AB, which is designated as coldwater game fisheries with protection for game and non-game fisheries, fish consumption, aquatic life other than fish, recreation, wildlife, industry, agriculture, and scenic values. Yellowstone cutthroat trout is the fish species of management priority in the LREP analysis area, based on the presence of historical populations in Beaver and Shell creeks (Figure 3-22). No current or core conservation Yellowstone cutthroat trout population occur in the LREP analysis area. Core conservation populations are defined as genetically pure Yellowstone cutthroat trout that have connectivity within their occupied habitat to allow migration and development of all life stages (May et al. 2017). The closest current and core populations are located approximately 2.3 miles upstream of the Leavitt Reservoir diversion in the mainstem of Beaver Creek and South Beaver Creek (Yellowstone Cutthroat Trout Assessment Group 2017). Current populations of game fish species include coldwater species, brook trout, brown trout, mountain whitefish, and rainbow trout; and a warmwater species, channel catfish (Bear 2009; WGFD 2015b). The portions of Beaver and Shell creeks within the LREP analysis area contain native and non-native game and non-game fish species. Studies conducted by WGFD in 2007 and 2010 along with a published report by Bear (2009) indicate that the fish populations are mainly comprised of native non-game species (Table 3-24). The location of the sample sites are shown on Figure 3-22. The number of native fish species reported in these studies included 5 in Beaver Creek and 10 in Shell Creek. The most abundant species in these surveys were fathead minnow, longnose dace, longnose sucker, mountain sucker, and white sucker. Two non-native species,

3-32 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 3 – Affected Environment Resource Discussions carp and brown trout, were collected in Beaver and Shell creeks. Native fish species were more abundant than non-native species (Bear 2009). Limited information is available regarding fish species in Leavitt Reservoir. Trout were stocked in the reservoir in the 1960’s, but subsequent draining by irrigators resulted in the loss of fish (Hochhalter 2017). There has been no fish stocking since the reservoir was refilled. Yellowstone cutthroat trout could potentially occur in the reservoir as a result of diversion of water through canals from upstream stream segments (Hochhalter 2017). Other species potentially occurring in Leavitt Reservoir include fathead minnow, longnose dace, longnose sucker, and white sucker, which have all been collected in Beaver Creek upstream of the reservoir (Bear 2009). 3.14.3.4 Macroinvertebrates Macroinvertebrate information presented here is based on WDEQ data from surveys conducted at three locations in Shell Creek: 1) near the confluences with Granite Creek, 2) Herron Gulch, and 3) Cottonwood Creek (Figure 3-22) (WDEQ 2017). Sampling occurred on September 22, 2010, at the Granite Creek confluence; on August 31, 2005, at the Herron Creek confluence; and on September 16, 1993, at the Cottonwood Creek confluence. The results of sampling indicated a highly diverse macroinvertebrate community at the Herron Creek confluence with a total of 53 taxa. Moderate numbers of taxa were present at the Granite Creek and Cottonwood Creek locations, with 23 and 18 taxa, respectively. Macroinvertebrate groups that were collected in Shell Creek included Coleoptera (beetles), Diptera (true flies), Amphipoda (amphipods), Oligochaeta (aquatic worms), Ephemeroptera (mayflies), Plecoptera (stoneflies), Trichoptera (caddisflies) (EPT). Macroinvertebrate densities ranged from 3,567 to 26,443 individuals per square meter, with the upper number considered to be a relatively high density. The most abundant taxa consisted of mayflies (Baetis tricaudatus, Druneda doddsi, Ephemerella, and Rithrogena sp.), caddisflies (Tricorythodes sp.), and midges (Diptera/Orthocladius sp.). Three macroinvertebrate groups that are considered indicators of water quality conditions (i.e., EPT), were present at all three sampling locations. The total number of taxa for these three groups is referred to as the EPT Index. The EPT Index is calculated by adding the number of taxa represented by these three insect orders. EPT taxa tend to be very sensitive to various forms of pollution. If the EPT Index is 6 or less, then conditions are poor. If the EPT Index is between 7 and 20, then stream conditions are considered to be fair water quality conditions. If the EPT Index is greater than 20, then stream conditions are good quality (NRCS 1999). The EPT Index at the WDEQ sites was 14 at the Herron Gulch confluence, 18 at the Granite Creek confluence, and 23 at the Cottonwood Creek confluence. 3.14.3.5 Amphibians and Reptiles Amphibians that potentially occur in the analysis area include tiger salamander (Ambystoma mavortium), plains spadefoot (Spea bombifrons), Woodhouse’s toad (Anaxyrus woodhousii woodhousii), boreal chorus frog (Pseudacris maculata), and northern leopard frog (Lithobates pipiens) (Orbana et al. 2016). Reptiles that utilize aquatic habitats in the analysis area include the eastern spiny softshell. Tiger salamander, plains spadefoot, northern leopard frog, and boreal chorus frog use permanent waterbodies such as ponds, wetlands, reservoirs, or slow-moving streams to deposit eggs and early life stage development. The other amphibian species use temporary waterbodies for breeding. Wetland habitat in the LREP analysis area was inventoried by WEST (2018a), as summarized in Section 3.15.2. Amphibian surveys were not included as part of WEST’s wetland surveys. 3.14.4 Special Status Aquatic Biological Resources Special status aquatic species in the analysis area include Wyoming SGCN and BLM sensitive species. The BLM sensitive species apply to species occurrence on BLM managed lands. No federally-listed or aquatic species proposed for listing occur in the LREP analysis area. Following Congressional guidelines for State Wildlife Action Plans, each state must identify species with low or declining populations that are indicative of the diversity and health of the state’s wildlife. In Wyoming, these species are termed SGCN (WGFD 2017). In total, two fish, three amphibians, and three mollusks SGCNs are known or potentially occur within the LREP analysis area (Table 3-25). Based on the recent species evaluations in the Wyoming Action Plan (WGFD 2017), the identification of SGCN in the analysis area includes Tier II (moderate priority) and III (lowest priority) ratings. No Tier I (high priority) SGCN is present.

Leavitt Reservoir Expansion Project – Final EIS – 2019 3-33 Chapter 3 – Affected Environment Resource Discussions

3.14.4.1 Fish Based on surveys conducted by Bear (2009), one special status fish species, flathead chub (SGCN Tier III), occurs in Shell Creek. Surveys conducted by WGFD (Bear 2009) identified the habitat associations for flathead chub as using the smallest dominant substrates, deepest water, greatest amount of woody debris, and least amount of undercut banks. Spawning occurs from July through September when stream flows and water levels decrease as indicative of seasonal flow pattern (WGFD 2010). Potential habitat for Yellowstone cutthroat trout (SGCN Tier II) occurs in Beaver and Shell creeks, based on historical occurrence. However, no current Yellowstone cutthroat trout population occurs in the LREP analysis area (Yellowstone Cutthroat Trout Assessment Group 2017). Yellowstone cutthroat trout could be present in Leavitt Reservoir if they enter diversion canals from upstream populations in Beaver and South Beaver creeks (Skorupski 2017). The reservoir occurrence for this species would likely be infrequent and short-term in duration. 3.14.4.2 Amphibians Three special status amphibians occur within the LREP analysis area: northern leopard frog, plains spadefoot, and western tiger salamander. Occurrences for these species are listed in Table 3-25. Habitat for northern leopard frog (BLM Sensitive and SGCN Tier II) consists of marshes, beaver ponds, streams, rivers, lakes, and wet meadows at elevations up to approximately 9,000 feet amsl (Smith and Keinath 2007). The northern leopard frog uses underwater areas as overwinter habitat. Northern leopard frog has been collected in Beaver and Shell creeks (WNHP 2017). Potential habitat also could be present in other wetlands identified in the LREP analysis area by WEST (2018a). The plains spadefoot (SGCN Tier II) prefers loose, well drained soils in plains grasslands and sagebrush communities below 6,000 feet in elevation (WGFD 2010). This species requires aquatic habitat for breeding in May through July, which usually consists of ephemeral pools but permanent waterbodies can be used as well. Western tiger salamander (SGCN Tier III) occurs in terrestrial habitats such as rodent burrows with moisture except for the breeding period in May through July when they use temporary or permanent ponds, streams, lakes, or stock tanks. Mollusks Special status aquatic mollusks (SGCN Tier III) that occur in the LREP analysis area include three snails: ash gyro, tadpole physa, and marsh rams-horn snail. Occurrences for these species are listed in Table 3-25. These snails live in ponds, lakes, and the edges of slower portions of intermittent and perennial streams in shallow pools or protected areas (WGFD 2010). These species were collected in shallow areas of Leavitt Reservoir (WNHP 2017). 3.15 Wetlands/Riparian Vegetation 3.15.1 Overview Wetlands are defined for regulatory purposes as “those areas that are inundated or saturated by surface or groundwater at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions” (33 CFR Part 328.3, 40 CFR Part 230.3). Wetlands are important ecological resources that perform many functions, including providing habitat for plants and animals, groundwater recharge, flood flow attenuation, erosion control, and water quality improvement. Riparian areas are unique vegetation communities that occur adjacent to waterways and wetlands, and that provide habitat for numerous plant and animal species. They generally occupy transitional areas between aquatic and upland habitats, and may function as vegetative buffers for aquatic resources. Riparian areas are generally linear, are more terrestrial and less hydric than wetlands, and are often dependent on a natural disturbance regime relating to flooding and stream dynamics (Naiman et al. 2005). For wetlands/riparian vegetation, the analysis area for direct effects includes the LREP disturbance area (Figure 2-4). The analysis area for indirect and cumulative effects includes areas affected by modifications of stream or ditch flow resulting from the new reservoir, including Shell Creek down to its confluence with the Bighorn River (Figure 4-1). 3.15.2 Wetlands and Riparian Vegetation in the Analysis Area Data on the distribution and characteristics of wetlands and riparian areas for the LREP was developed for the direct effects analysis area using project-specific surveys and analysis (WEST 2016, 2018a, 2018b). Multiple

3-34 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 3 – Affected Environment Resource Discussions aquatic resource inventory (i.e., wetland delineation) field surveys have been conducted for the LREP direct effects analysis area. These occurred in 2012, 2015, and 2017. Each survey included a different survey area but the 2017 report provided data on all previously surveyed areas. Wetlands were delineated in accordance with the 1987 Corps of Engineers Wetlands Delineation Manual (Environmental Laboratory 1987) and the Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Arid West Region (USACE 2008). Wetland survey results for the LREP are summarized in Table 3-26. Three types of wetlands were observed including PEM, palustrine scrub-shrub (PSS), and a mix of PEM and PSS. The palustrine system includes non-tidal wetlands dominated by vegetation, tidal wetlands with low salinity, and small and/or shallow ponds (Cowardin et al. 1979). Emergent wetlands are dominated by herbaceous vegetation such as sedges (Carex spp.) and rushes (Juncus spp.), while scrub-shrub wetlands are dominated by woody shrubs and small trees less than 20 feet tall. Table 3-26 groups wetlands by their locations. Locations of wetlands and other aquatic features are shown on Figures 3-23 and 3-24. Fringe wetlands around the existing Leavitt Reservoir were a mix of PEM and PSS. PEM wetlands were dominated by broad-leaf cattail (Typha latifolia) with outer margins composed of an herbaceous species mixture that included common spike-rush (Eleocharis palustris), soft-stem bulrush (Schoenoplectus tabernaemontani), water sedge (Carex aquatilis), and saltgrass (Distichlis spicata). PSS wetlands were dominated by narrowleaf willow (Salix exigua) and typically located on the outer perimeter of the PEM wetlands. Herbaceous species also had high cover in PSS wetlands and included the same species as in PEM wetlands along the reservoir fringe. The fringe wetlands appear to be hydrologically supported by fluctuating reservoir water levels. Soils were problematic throughout the wetland fringe area due to the presence of a red parent material. Approximately 8.15 acres of PEM and 1.14 acres of PSS were within the OHWM of the existing reservoir. The inflow swale north of the reservoir contained PEM wetlands dominated by sedges (Carex spp.) and rushes (Juncus spp.), with areas of dense broad-leaf cattail and other mixed herbaceous species also present throughout the swale. Common species included water sedge, Baltic rush (Juncus balticus), three-square (Schoenoplectus pungens), fox-tail barley (Hordeum jubatum), and common spike-rush. These wetlands appear to be hydrologically supported by a natural seep at the upper end of the inflow swale and associated with the Leavitt Reservoir supply ditch and adjacent irrigation practices. Soils had a depleted matrix and red parent materials. The four wetlands below the dam are dominated by broadleaf cattail and are supported by seepage through the dam structure. These wetlands extend beyond the survey area. One of the wetlands is located below the west dam abutment. Common species included broadleaf cattail, water sedge, and toad rush (Juncus bufonius). Soils were gleyed and the sample site at a seep had surface water and saturation. One small wetland occurred in the spillway. It had a mix of PEM species including common spike-rush, alkali muhly (Muhlenbergia asperifolia), water sedge, and annual rabbit’s-foot grass (Polypogon monspeliensis). It appears to receive water only during reservoir spilling. A number of mostly small wetlands were delineated in the portions of the analysis area associated with the supply line, borrow areas, pipeline, and transfer pipeline. Wetlands along the supply line included a crossing of Davis Draw, multiple drainages with agricultural runoff and seepage, and an irrigation ditch. The Davis Draw crossing is a fully vegetated PSS wetland dominated by narrowleaf willow and broad-leaf cattail. Several tributaries to David Draw are crossed, including both PEM/PSS and PEM wetlands. Plant species present in these PEM wetlands include broad-leaf cattail, Nebraska sedge (Carex nebrascensis), Field meadow-foxtail (Alopecurus pratensis), creeping bent (Agrostis stolonifera), Baltic rush, and three-square. A small PEM wetland is also located along Beaver Creek along the supply line. One small wetland is located in the east borrow area but no wetlands are in the west borrow area. Two small PEM wetlands are located along the pipeline to Beaver Creek, including one at Beaver Creek and one at a tributary. Wetlands along the transfer pipeline were mostly associated with ditches and portions of Beaver Creek and Shell Creek. The aquatic resource inventory field survey performed by WEST (2018a) also included non-wetland surface waters. Depending on their characteristics and connectivity, cut and fill impacts to these features may need to be addressed in a Section 404 Permit. Surface water features include the existing reservoir, small ponds, streams, ditches, and canals. Because the existing reservoir fills to capacity and spills nearly every year, the OHWM elevation was set to match the spillway crest of 4,797 feet. The existing Leavitt Reservoir occupies 48.1 acres within the OHWM, of which 38.7 acres is open water and the rest is wetlands. Portions of Beaver Creek, Shell Creek, and irrigation ditch canals are also within the aquatic resource inventory field survey area.

Leavitt Reservoir Expansion Project – Final EIS – 2019 3-35 Chapter 3 – Affected Environment Resource Discussions

A survey of non-wetland woody riparian areas was conducted from August 13 to 17, 2017 (WEST 2018b). Non-wetland woody riparian areas were defined as all shrub and forested areas located near aquatic resources that are not identified as wetlands or as upland shrub. The results are summarized in Table 3-27. Reservoir fringe riparian is dominated by narrowleaf willow with small amounts of Russian olive and saltcedar. Both Russian olive and saltcedar are classified as noxious weeds in Wyoming. In many places, the non-wetland woody riparian abutted PSS wetlands. Forested wetlands occurred along Beaver Creek, Shell Creek, and the existing dam outflow. The primary species are plains cottonwood (Populus deltoides) and lanceleaf cottonwood (Populus x acuminata). Other tree species present include Rocky Mountain juniper (Juniperus scopulorum) and river birch (Betula occidentalis), with an understory of river birch, buffaloberry (Shepherdia argentea), and chokecherry (Prunus virginiana). Russian olive, saltcedar, and narrowleaf willow are present in some locations. Other non-wetland riparian vegetation included a mixed narrowleaf willow and Russian olive community along the Leavitt Supply canal, and scattered Russian olives at the transfer diversion dam along Beaver Creek. The aquatic resource inventory field survey (WEST 2018a) did not include one area along the southern portion of the transfer pipeline that was not identified as part of the project area at the time of the survey. Aquatic resources in this area were assessed based on aerial photography. The non-surveyed area has a PEM/PSS wetland and some cottonwoods and Russian olives, but is mostly row crops. WEST’s aquatic resource inventory also did not include survey of most access roads or the areas of potential indirect impacts downstream along Beaver Creek and Shell Creek. Wetland and riparian resources in those areas are expected to be similar to those areas surveyed in the aquatic resource inventory area. National Wetland Inventory (NWI) data (USFWS 2016b) show few wetlands in the Beaver Creek Valley below the reservoir and relatively large areas of wetlands associated in the Shell Creek Valley. PSS wetlands occur mostly along the creek; PEM wetlands occur mostly in oxbows and other depressions in agricultural fields. NWI wetland maps were developed using 1980 and 1981 imagery and may not represent current conditions.

3-36 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 4 – Environmental Impacts

CHAPTER 4 ENVIRONMENTAL IMPACTS

A National Environmental Policy Act (NEPA) impact analysis is a process used to evaluate and describe the cause-and-effect relationships for resources and resource uses that could be affected by a proposed action. Impacts on resources and resource uses are analyzed and discussed in an amount of detail that is commensurate with resource issues and concerns identified throughout the planning process. Geographic information system (GIS) analyses and data from field investigations were used to quantify effects where possible for the Leavitt Reservoir Expansion Project (LREP); however, in the absence of quantitative data, best professional judgment was used. At times, impacts are described using ranges of potential impacts or in qualitative terms. Chapter 4 describes the direct and indirect impacts expected to occur as a result of implementing the No Action Alternative, Proposed Action Alternative, and Operational Alternative for the LREP. The baseline used for determining the potential impacts was the current resource condition described in Chapter 3. The discussion of environmental consequences for each resource topic begins with a brief definition of what is considered an impact for the resource. The parallel organization of Chapter 3 and Chapter 4 allows the reader to compare baseline resource conditions to potential impacts (Chapter 4) for the same resources. An environmental impact is defined as a modification or change in the existing environment as a result of actions taken. Impacts may be beneficial or adverse, may be assessed based on their duration, severity, or relation to the LREP, and may vary in severity. The level of impact is based on regulatory standards, criteria and ordinances, available scientific documentation, and professional judgment of the technical evaluator. The Wyoming Water Development Commission (WWDC) would implement certain environmental protection measures, design features, and procedures to avoid or reduce adverse impacts of the action alternatives that are described in detail in Chapter 2. Based on the impact analyses, mitigation measures to minimize potential adverse impacts are identified in this chapter. Mitigation measures may be included as conditions of the Bureau of Land Management’s (BLM’s) right-of-way (ROW) grant (if issued) and/or the U.S. Army Corps of Engineers (USACE) Section 404 Permit (if issued), or other federal, state, or local permits. An impact analysis was conducted for each resource described in Chapter 3. Within each resource section, a discussion of potential environmental consequences includes: 1) anticipated impacts and issues raised during scoping, 2) impacts analysis, and 3) a summary of unavoidable adverse impacts (i.e., those impacts that are unavoidable and cannot be mitigated). In some cases, where quantitative values may not be applicable to the impacts analysis, the following qualifiers are used to describe potential impacts to resources: • Negligible: Effects to the resource could occur; however, they would be so slight as to not be measurable or distinguishable from natural fluctuations. • Minor: Effects to the resource would occur; however, they would be small and just measurable using normal methods. Effects would be unlikely to affect existing conditions or current uses of the resource. • Moderate: Effects to the resource would occur, would be readily detectable, and could affect the existing conditions and current uses of the resource. • Major: Effects to the resource would be large, measurable, and easily detected. They would substantially change existing conditions and current uses of the resource. Mitigations for the anticipated impacts are discussed in Section 4.16 (Proposed Action) and Section 4.17 (Operational Alternative). Discussions of cumulative impacts, residual impacts, the relationship between local short-term uses of the human environment and maintenance and enhancement of long-term productivity, and irreversible/irretrievable commitment of resources conclude the analysis of each resource topic and can be found in Chapter 5. Refer to Chapter 3 for a discussion of the geographic scope of the analysis areas for the resource impacts discussed in the following sections.

Leavitt Reservoir Expansion Project – Final EIS – 2019 4-1 Chapter 4 – Environmental Impacts

4.1 Cultural Resources and Native American Concerns 4.1.1 Cultural Resources To understand the kinds of cultural resources that could be impacted by the LREP, a literature review of existing information was conducted through the State Historic Preservation Office (SHPO), a review of unpublished Class III reports pertaining to the LREP was performed, and information gathered from recent tribal consultation and a site visit for the LREP was considered. The analysis area for impacts to cultural resources is the direct area of potential effect (APE) which consists of a 200-foot buffer along the proposed normal high water level (NHWL), and 100-foot buffer from the proposed borrow areas, wetlands, and access roads and pipelines centerlines (Section 3.1.1.1). The analysis area for cultural resources’ indirect APE is up to 3 miles from the LREP disturbance footprint or the visual horizon, whichever is closer. The BLM defined the indirect APE for the LREP in order to consider effects on Historic Properties where integrity of the element of setting contributes to significance. To identify Historic Properties within the indirect APE, the BLM conducted a visibility analysis to determine potential changes from the reservoir expansion within a 3-mile radius. The visibility analysis was conducted from a center point within the proposed reservoir expansion at the elevation of the NHWL 4,860 feet (1,481.3 meters) accounting for a 5-foot (1.5-meter) tall observer. The BLM then superimposed all known National Register of Historic Places (NRHP) eligible or unevaluated sites (where integrity of the element of setting could contribute to significance) with results of the visibility analysis. Additional visibility analyses were conducted from the identified sites toward the NHWL to determine if the proposal would be seen from those locations. 4.1.1.1 Impacts to Cultural Resources from the No Action Alternative Current potential impacts to cultural resources based on the most recent Class III Investigation (Wandler 2017) may include surface disturbance due to existing road use and maintenance, recreation on BLM lands, farm and ranch activities, and seasonal flooding and erosion. Additional current potential impacts include unauthorized collecting of surficial materials, and looting of buried sites. However, the magnitude of impacts on cultural resources within the APE from the No Action Alternative is unknown. Under the No Action Alternative, these impacts would remain at existing levels. 4.1.1.2 Impacts to Cultural Resources from the Proposed Action Alternative For cultural resources, any anticipated short-term impacts would eventually become long-term impacts; thus, this section does not distinguish between the two. Known cultural resources within the direct APE consist of 23 historic and pre-historic sites. One site is listed in the NRHP (48BH1269), five are considered eligible for listing in the NRHP (48BH609, 48BH1860, 48BH4242, 48BH4244, and 48BH4245), and two sites are unevaluated (48BH1861 and 48BH1940). The remaining 15 sites are not eligible for listing in the NRHP. The short- and long-term impacts on sites not eligible for listing in the NRHP from the Proposed Action Alternative are expected to be non-existent. The Proposed Action Alternative would have no short- or long-term effects on: Site 48BH1269, Site 48BH609, Site 48BH1860, Site 48BH1861, and Site 48BH1940_1. Site 48BH4242 is a previously unevaluated pre-historic site that is now recommended eligible for listing in the NRHP under Criterion A following tribal on-site visits for the LREP (see Section 3.1.1). Proposed construction activities would be within 10 to 100 feet of this archaeological site. Work under the Proposed Action Alternative would involve the installation of pipe and the outlet works with excavators, compactors, trench boxes, miscellaneous tools, and water trucks. In addition, work along the existing gravel road adjacent to the site would be used to transport equipment, supplies, and personnel. The road may need to be widened for safety concerns, but if widening occurs, it would be to the west, away from the cultural site. While direct effects to the site from construction of the Proposed Action Alternative would not be anticipated, indirect effects would include elevated potential for unauthorized surface collection or disturbance and erosion related to construction. The Proposed Action Alternative would have long-term and permanent effects on the site. Site 48BH4244 is a previously unevaluated pre-historic site. Based on recent investigations by Barron Cultural Resource Consultants (Wandler 2017), the site is recommended eligible for listing in the NRHP under Criterion D. Following tribal on-site visits for the LREP, the site is also recommended eligible under

4-2 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 4 – Environmental Impacts

Criterion A. Construction activities would be within 4 feet of the cultural site boundary. Work would include pipeline installation with excavators, compactors, haulage equipment, trench boxes, miscellaneous tools, and water trucks. Due to the potential for buried cultural materials at 48BH4244 and the proximity of construction to the site under the Proposed Action Alternative, surface disturbing activities would likely result in direct effects to undiscovered cultural materials. Additionally, indirect effects could include elevated potential for unauthorized surface collection or disturbance and erosion related to construction. Considering these impacts, the Proposed Action Alternative would have long-term and permanent effects on the site. Site 48BH4245 is a previously unevaluated pre-historic site. Based on recent investigations by Barron Cultural Resource Consultants (Wandler 2017), the site was recommended not eligible for listing in the NRHP. Following tribal on-site visits for the LREP, the site is also recommended eligible under Criterion A. Work would occur between 50 and 100 feet from the cultural site boundary. Work would involve excavating borrow material for embankment construction and would include scrapers, excavators, haulage equipment, miscellaneous tools, and water trucks. While direct effects to the site by construction would not be anticipated, indirect effects could include elevated potential for unauthorized surface collection or disturbance and erosion related to construction. The Proposed Action Alternative would have long-term and permanent effects on the site. Based on a comparison of previous cultural resource inventories to the cultural resources direct APE for the LREP, approximately 6.4 acres of private land and 1.7 acres of BLM land near the outlet works and from the access road extending north of the outlet works fall outside of previous Class III inventories. An additional 23.6 acres of private land in a temporary disturbance area along the east side of the transfer pipeline also fall outside previous inventories. These areas would have similar impacts to cultural resources as those discussed earlier in this section. In the event that those acres that fall on public land must be disturbed for the LREP to move forward, BLM shall conduct, or cause to have conducted, additional surveys. Direct impacts from the Proposed Action Alternative may include disturbance of known sites or previously undetected buried cultural materials through general construction activities and inundation of cultural sites from the expansion of the reservoir. Under the Proposed Action Alternative, historic properties, known and unknown, within the direct APE may be subject to permanent damage or loss caused by the proposed surface disturbance associated with the LREP. Indirect impacts from the Proposed Action Alternative would include foreseeable impacts that could occur later in time or that are further removed in distance from the proposed action (40 Code of Federal Regulations [CFR] Section 1508.8). Post-construction indirect impacts would include the potential for exposure of previously unexposed sites due to high water episodes and resulting erosion, and increased impacts to cultural resources due to increased human activity in and around resource sites that may result in unauthorized surface collection or surface disturbance. Indirect effects may change the character of the use of the property or degrade the setting, feeling, and association of a resource by introducing visible, audible, or atmospheric elements. The visibility analysis performed by the BLM identified one site, 48BH4293, where integrity of setting would contribute to the significance of the site. The viewshed was reanalyzed from this site and the results indicated that the reservoir would not be visible from 48BH4293. A literature review of all known cultural resources within the 3-mile buffer of the LREP disturbance footprint indicates that 126 cultural sites are previously documented. Five cultural sites within 3 miles of the LREP disturbance footprint, including 48BH4293, may meet the criteria to be considered sites of traditional religious or cultural significance. However, only one of those additional sites (48BH968) falls within the BLM analysis area, and it is not visible from the reservoir expansion (and no visual effects would be anticipated). The remaining sites of traditional religious or cultural significance are over 3 miles from the reservoir expansion. 4.1.1.3 Impacts to Cultural Resources from the Operational Alternative The impacts to cultural resources from the Operational Alternative would be the same as those described for the Proposed Action Alternative. 4.1.2 Native American Concerns Consultation with tribes to identify cultural sites and other cultural values, including contemporary Native American interests, for the LREP was initiated in December 2016 to members and groups in the Native American community in accordance with NEPA policy. Tribal consultation between the BLM and the three resulting Native American tribes that chose to participate in the LREP Environmental Impact Statement (EIS), including Crow Nation, Eastern Shoshone Tribe, and Northern Arapaho Tribe, is continual and on-going during

Leavitt Reservoir Expansion Project – Final EIS – 2019 4-3 Chapter 4 – Environmental Impacts the EIS process. An on-site with the BLM; tribal representatives from Crow Nation, Eastern Shoshone Tribe, and Northern Arapaho Tribe; the manager of the Double Doc Ranch (a private property within the LREP disturbance footprint); and a representative of SWCA Environmental Consultants (SWCA) (part of BLM’s third-party EIS contractor team), took place at an LREP site visit on December 14, 2017. The site visit helped BLM identify resources of Native American concern that could be impacted by the LREP. Through the consultation that occurred during the site visit and shortly following it, BLM determined that three cultural resource sites (48BH4242, 48BH4244, and 48BH4245) that are located within the LREP disturbance footprint hold tribal significance. 4.1.2.1 Impacts to Native American Concerns from the No Action Alternative Current potential impacts to cultural sites of Native American concern located in the LREP disturbance footprint include vehicle use and subsequent road maintenance along portions of existing roads that pass through or are adjacent to the sites. Additional impacts could include the potential for unauthorized surface collection, looting, and surface disturbance to the sites and related cultural features due to increased human exposure, livestock grazing due to trampling and potential displacement of surficial materials, flooding, and periodic erosion. Under the No Action Alternative, these impacts would remain at existing levels. 4.1.2.2 Impacts to Native American Concerns from the Proposed Action Alternative Sites 48BH4242, 48BH4244, and 48BH4245 have been determined to hold tribal significance. These resources are subject to both short- and long-term impacts from construction under the Proposed Action Alternative. Short-term impacts would include lack of access to the sites during construction. Long-term impacts would consist of permanent changes, damage, or loss of portions of these resources. Proposed construction activities consisting of installing pipe and the outlet works would occur within 10 to 100 feet of 48BH4242. The road may need to be widened to the west, away from the cultural site. Construction activities would be within approximately 4 feet of 48BH4244 and include pipeline installation. Construction activities would be within 50 and 100 feet of 48BH4245 and would include excavating borrow material for embankment construction. The Proposed Action Alternative would have short- and long-term/permanent effects on the sites. Native American concerns related to impacts from the Proposed Action Alternative include the following: 1) sites may be disturbed by construction activities, and 2) additional cultural materials may be exposed or destroyed, causing permanent damage to surface and sub-surface materials resulting in loss of integrity and important interpretive data. Following construction, indirect effects to these resources could include soil erosion, recreational use and vehicle traffic. Previously buried materials may become visible which could give rise to looting and increased human impacts to the sites. 4.1.2.3 Impacts to Native American Concerns from the Operational Alternative The impacts to sites of Native American concern from the Operational Alternative would be the same as those described for the Proposed Action Alternative. 4.2 Geology The LREP analysis area for geological resources includes the reservoir inundation area, construction footprint, and existing quarries that would be used to supply concrete and rip rap for the earthen dam embankment. This area was selected for analysis because it encompasses the entire ground disturbance associated with the reservoir expansion. Impacts to geological resources from the Proposed Action and Operational Alternative would generally occur from excavation and surficial disturbance of geologic strata, as well as construction of permanent features such as the expanded reservoir pool that would prevent or limit access to mineral resources present in the underlying geology. Impacts to the LREP are also possible from geologic hazards. 4.2.1 Impacts to Geology from the No Action Alternative Under the No Action Alternative, no ground disturbance would occur because the LREP would not be constructed. The current baseline geology described in Section 3.2 would not change. Consequently, there would be no direct or indirect impacts to geological resources under this alternative.

4-4 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 4 – Environmental Impacts

4.2.2 Impacts to Geology from the Proposed Action Alternative 4.2.2.1 Disturbance-related Impacts Surface disturbance from construction of the LREP would directly impact geological resources under the Proposed Action Alternative. The impacts could be either permanent or temporary depending on the LREP features being built. In general, surface disturbance from newly constructed features, such as the earthen dam embankment and auxiliary spillway, would be permanent because these features would remain in place for the life of the LREP (which is estimated to be 50 years). Conversely, surface disturbance from linear features such as pipelines represent temporary impacts since the disturbance areas would later be reclaimed. This analysis also considers disturbance related to the proposed expansion of the reservoir pool. The total area of permanent, temporary, and reservoir expansion impacts for the Proposed Action Alternative is summarized in Table 4-1 in Appendix 1 by geologic formation. As shown in Table 4-1 in Appendix 1, construction of the earthen dam embankment would directly impact 21.7 acres of the Cloverly Formation. The dam cut-off trench would be excavated into bedrock, permanently altering the original character of the Cloverly Formation where rock is removed. Additional permanent impacts would occur from raising Bear Creek Road and constructing the auxiliary spillway for the expanded reservoir. These features encompass 10.8 acres and would impact both the Cloverly Formation (9.2 acres) and Quaternary terrace deposits (1.5 acres). Excavations, cut and fills, or grading necessary to construct these features could extend into bedrock and permanently alter the character of the affected formations. The new structures would also cover and limit access to the underlying geology for the life of the LREP. Overall, these permanent impacts would be negligible to minor due to their limited areal extent (32.4 acres total). The proposed borrow pits are considered temporary disturbance areas because they would be reclaimed at the conclusion of the LREP. However, impacts to geological resources from the borrow excavations would be permanent. The 520,000 cubic yards (cy) of material removed from the borrow pits would be excavated across an approximate area of 77 acres. Based on data in Table 4-1 in Appendix 1, approximately 93 percent of the fill removed from the pits would be sourced from the unconsolidated Quaternary terrace deposits. The geologic character of the terrace deposits would be permanently altered as the fill material is removed. 4.2.3 Impacts to Geology from the Operational Alternative Impacts to geological resources under the Operational Alternative would be the same as those described for the Proposed Action Alternative. 4.3 Lands and Realty The analysis area for direct and indirect impacts on lands and realty is the LREP disturbance footprint including added wetlands and borrow pits because these areas would be directly affected by the development and operation of the LREP. This analysis considers the two-year construction period and 50-year life of the LREP for direct and indirect impacts. For the purposes of this analysis, the primary indicator of impacts to lands and realty are: predicted increase in the number of visitors, acres of disturbance and inundation, number of acres impacted of each mineral leasing category, and number of acres authorized as ROW. Land use for the LREP includes recreation, special designations, lands with wilderness characteristics, renewable energy, leasable minerals (e.g., oil and gas), and ROWs. 4.3.1 Impacts to Lands and Realty from the No Action Alternative Under the No Action Alternative the LREP would not be implemented. The capacity and operations of the existing Leavitt Reservoir would continue as they currently exist. There would be no changes to lands and realty. Late-season irrigation shortages in the Beaver Creek and Shell Creek drainages and the associated impacts would continue to occur. 4.3.2 Impacts to Lands and Realty from the Proposed Action Alternative 4.3.2.1 Rights-of-Way There would be a minor long-term direct impact to ROWs from the issuance of a new ROW grant under the Proposed Action Alternative. Approximately 178 acres of BLM surface lands would be inundated as part of the

Leavitt Reservoir Expansion Project – Final EIS – 2019 4-5 Chapter 4 – Environmental Impacts

LREP, thereby removing that acreage from other land uses. A new ROW grant would be issued for a portion of the LREP; the remainder would fall under existing ROWs. 4.3.3 Impacts to Land Use from the Operational Alternative Impacts to land use under the Operational Alternative would be the same as those described for the Proposed Action Alternative. 4.4 Noise Noise impacts were evaluated for the analysis area which is a 1-mile buffer around the LREP disturbance footprint (see Figure 3-3). This area was chosen because for most construction projects, noise impacts attenuate to background levels at distances of less than one mile from the noise source. Impacts during construction would result from the use of equipment and vehicles but would be limited to the immediate vicinity of the proposed LREP construction area and along transport access routes. Construction noise would be short-term and sporadic in nature. During operation, reservoir maintenance, noise from the outlet works, and potentially-increased watercraft and recreational traffic would elevate the current ambient noise levels within the immediate vicinity of the Proposed Action area. Impacts to noise are discussed in terms of noise levels expected to be produced by the Proposed Action Alternative and Operational Alternative as compared to baseline conditions (i.e., the No Action Alternative) and relative to applicable laws and regulations. 4.4.1 Methodology and Assumptions 4.4.1.1 Construction The noise levels expected to be generated by construction equipment have been calculated and published in various reference documents. The Federal Highway Administration (FHWA) has published construction noise data for construction projects, which is used to determine construction noise impacts. Projected noise levels from the proposed LREP construction activities, including the expected noise attenuation due to distance from construction activities, are provided in Appendix 4.4. The values presented for estimated construction noise levels at the nearest noise-sensitive receptor (NSR) are the expected maximum noise levels that the nearest NSR would experience during construction. Due to the short-term, temporary, and intermittent nature of construction activities, these values are conservative. 4.4.1.2 Operation The pipelines at the LREP would not generate noise once in operation; however, aboveground facilities and operational activities associated with the reservoir expansion would generate noise. Such noise could include reservoir maintenance, noise from the outlet works, and potentially increased recreation and traffic associated with recreational activities. 4.4.1.3 Impact Threshold For the purposes of this analysis, an impact on noise could result if any of the following were to occur from construction or operation of the proposed LREP: • Exceedance of local or federal noise regulations or guidelines. Because there are no local guidelines, the federal guidelines (the Noise Control Act of 1972) were used; or • Increased noise levels directly or indirectly could affect places of traditional use that are listed or considered eligible for listing in the NRHP, or identified as important to Native American tribes. A minor/negligible impact would occur if the noise environment would retain its existing character and overall baseline conditions would remain unchanged. A no impact designation would result in no obvious changes in baseline conditions of the existing noise environment. Construction impacts would be of limited duration and therefore would not represent substantial impacts to land use restrictions, even if noise levels would be above impact thresholds. 4.4.2 Impacts to Noise from the No Action Alternative Under the No Action Alternative, there would be continued operations and capacity of Leavitt Reservoir as it currently exists. Noise impacts from construction and operation and maintenance of the proposed LREP and

4-6 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 4 – Environmental Impacts associated activities and facilities would not occur. Under the No Action Alternative, noise conditions would likely continue at current levels and trends. 4.4.3 Impacts to Noise from the Proposed Action Alternative Estimates of noise from the construction of the proposed LREP are based on a roster of the maximum amount of construction equipment used at the site on a given day. Table 4-2 in Appendix 1, shows the construction equipment that has been analyzed from the edge of the disturbance footprint to the nearest NSR (for ease of calculation, all equipment is assumed to be operating at this location). FHWA’s Roadway Construction Noise Model (RCNM) has noise levels for various types of equipment pre-programmed into the software; therefore, the noise level associated with the equipment is typical for the equipment type and not based on any specific make or model.

The RCNM assumes that the maximum sound level (Lmax) for a project is the Lmax for the loudest piece of equipment. The nearest NSR to the LREP is a residence located approximately 50 feet from the LREP disturbance footprint along the transfer pipeline route. The Lmax at this residence would be approximately 85 dBA. This noise level is similar to listening to a heavy truck operating 25 feet away. The noise due to construction would be temporary. The approximate noise generated by the construction equipment used at the proposed LREP has been conservatively calculated based on the maximum amount of construction equipment that would be used at the proposed LREP at one time, and does not take into account further attenuation due to atmospheric interference or intervening structures. Results of the RCNM construction noise calculations are provided in Table 4-3 in Appendix 1. Operational noise associated with the Proposed Action Alternative would consist of reservoir maintenance, noise from the outlet works, the operation of pumps, generators, etc., within the outlet control building, and potentially increased recreational activity and recreational traffic. The noise from these operational activities would be substantially less than construction noise. Under the Proposed Action Alternative, there would be no impact to the NSRs located along the supply and transfer pipeline routes after construction is completed. The nearest NSR to the reservoir is located approximately 0.50 mile from the outlet control building. At that distance, noise from the outlet works or reservoir maintenance would have attenuated to below noticeable noise levels. 4.4.4 Impacts to Noise from the Operational Alternative Impacts to noise from the Operational Alternative would be the same as those described for the Proposed Action Alternative. 4.5 Paleontological Resources A summary of the paleontological resource potential and known localities is provided in Section 3.5. The LREP analysis area for direct impacts for paleontological resources includes the LREP disturbance footprint and 100-foot buffer. The analysis area for indirect impacts to paleontological resources includes a 1-mile buffer around the LREP disturbance footprint. 4.5.1 Impacts to Paleontological Resources from the No Action Alternative Under the No Action Alternative, the BLM would not approve the expansion of Leavitt Reservoir and no additional paleontological resources would be affected. Current direct impacts to paleontological resources include inaccessibility to 45 acres of the Cloverly Formation (Potential Fossil Yield Classification [PFYC] Class 5) which is currently inundated. Ongoing direct impacts include erosion from wave action around the edges of the existing Leavitt Reservoir, and fluctuations in water levels from seasonal run off. Human activity along the existing roads and reservoir may cause indirect impacts through unpermitted collection of surface fossils. Under the No Action Alternative, these impacts would remain at existing levels. 4.5.2 Impacts to Paleontological Resources from the Proposed Action Alternative For the Proposed Action Alternative, up to 118 acres of the Cloverly Formation and 2 acres of the Morrison Formation (both have high potential to contain important paleontological resources [PFYC Class 5]), and 14 acres of the Thermopolis Shale (which has moderate potential to contain important paleontological resources [PFYC Class 3]) would be disturbed directly by construction of the dam embankment, spillway, south wetland, access road upgrades, pipelines, borrow areas, and recreational facilities. There is a high potential for vertebrate and scientifically significant paleontological resources to be present in the Cloverly Formation subsurface. An additional approximately 20 acres of the Cloverly Formation could be disturbed for the north and rim wetlands,

Leavitt Reservoir Expansion Project – Final EIS – 2019 4-7 Chapter 4 – Environmental Impacts as there is one paleontological locality within each of those areas. These localities were documented during the LREP surveys (Moses 2017; Moses and Shoup 2012) and contain a highly fragmented fossil tree specimen and several unidentifiable vertebrate bones, respectively. Following construction of the Proposed Action Alternative, 93 acres of the Cloverly Formation (PFYC Class 5) would be under the operational pool and an additional 129 acres would be within the NHWL. This would be nearly five times the acreage inundated under the No Action Alternative. No more than 2 acres of the Thermopolis Formation (PFYC Class 3) would be within the NHWL and would be minimally impacted. Four known paleontological localities (see Section 3.5 for a discussion), and an unknown number of undiscovered localities, are within the operational pool of the Proposed Action Alternative and would be directly inaccessible for the long term. These localities would not be anticipated to be impacted from flooding. As noted in Section 3.5, representative samples of fossils were previously collected from three of these localities. In addition to submergence, direct long-term impacts to paleontological resources would include annual fluctuations of the reservoir water levels which could potentially erode sediment and expose previously unknown paleontological resources. Cloverly Formation has been shown to erode slowly which would limit the impact from increased erosion activities (Oreska et al. 2013). Increased use could indirectly affect paleontological resources for the long term through unauthorized surface collection of paleontological resource or ground disturbance. This could occur at any of the 18 known paleontological localities within 1 mile of the LREP, or at newly exposed localities. 4.5.3 Impacts to Paleontological Resources from the Operational Alternative The impacts to paleontological resources from the Operational Alternative would be the same as those described for the Proposed Action Alternative. 4.6 Range Resources The analysis area for range resources is the boundary of allotments affected by the LREP. 4.6.1 Impacts to Range Resources from the No Action Alternative Under the No Action Alternative there would be no alterations to the allotment management, infrastructure, or available Animal Unit Months (AUMs). Therefore, there would be no impact to range resources from the No Action Alternative. 4.6.2 Impacts to Range Resources from the Proposed Action Alternative Direct and indirect impacts to range resources from the Proposed Action Alternative were assessed within the boundaries of the three BLM livestock grazing allotments that would be impacted by the LREP, as described in Section 3.6. Impacts to range resources include temporary and permanent loss of AUMs and changes to range improvements. There are no anticipated changes to the allotment grazing rotation system that would result in either direct or indirect impacts to allotment management. Livestock fencing is the only range improvement type that would be affected by the Proposed Action Alternative. Temporary removal of livestock fencing may be required during construction, primarily along the areas where there would be road improvements, but also in the reservoir expansion area and transfer pipeline construction area. The livestock fencing that could potentially be temporarily removed during construction, within the Beaver Creek allotment, includes approximately 4,325 feet along Bear Creek Road (including the wing fence and cattleguard crossing the road), approximately 490 feet along the Unnamed Road that goes to the west borrow area and supply pipeline (see Figure 3-3), approximately 230 feet within the primary outlet works footprint, and approximately 1,040 feet along the supply pipeline footprint. The only temporary impacts to fence in the Crandall and Lost allotments would be along the mutual boundary between these allotments where the fence terminates at the existing Leavitt Reservoir, which could result in the temporary removal or impact to approximately 138 feet of fence. The only permanent removal of fence that would occur as part of the LREP would be approximately 126 feet on the western end of the wing fence that starts at the cattleguard on Bear Creek Road, in the Beaver Creek allotment. The permanent removal of the end of the wing fence would not impact the livestock grazing as the new wing fence end would terminate at the expanded Leavitt Reservoir boundary, which would result in the fence continuing to serve as a division fence between pastures. Surface disturbing activities that would remove terrestrial vegetation and disturb soils would impact the availability of livestock forage. These impacts would include the temporary removal of acres available for

4-8 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 4 – Environmental Impacts livestock grazing that would be disturbed during construction, and the permanent removal of acres available for livestock grazing due to the construction of new infrastructure and the expanded reservoir area. Temporary removal of acres available for livestock grazing would include the access road upgrades, reservoir inundation buffer, supply pipeline footprint, and the primary outlet works footprint. Permanent removal of acres available for livestock grazing would include the new earthen dam embankment, expanded inundation area, auxiliary spillway, Bear Creek Road raised footprint, wetland areas, and the western borrow pit. The wetland areas are being considered a permanent removal of available livestock grazing acres due to their function as wetland mitigation areas and the limited livestock access to, and palatability of, forage in wetlands. The number of acres available for livestock grazing that would be temporarily and permanently removed under the Proposed Action Alternative is shown in Table 4-4 in Appendix 1. Available AUMs for the three allotments are based on BLM surface ownership lands only, as outlined in information from the Allotment Management Plans (AMPs) (Section 3.6); therefore, the analysis of AUM reductions is confined to the BLM allotted AUMs only. The number of AUMs that would be temporarily and potentially permanently lost under the Proposed Action Alternative is based on the AMP stocking information for the three allotments that would be impacted by the Proposed Action Alternative (Section 3.6) and the BLM acres impacted (Table 4-4 in Appendix 1). Temporary and potentially permanent AUM reductions from this alternative are shown in Table 4-5 in Appendix 1. Temporary AUM reductions would extend until the disturbed area is restored to pre-disturbance conditions, which is anticipated to be two to five years; and potentially permanent AUM reductions would extend through the life of the LREP (i.e., estimated to be 50 years). The potential for permanent AUM reductions is contingent upon BLM AMP review relative to the Proposed Action Alternative moving forward. The BLM has the discretion to work with permittees to modify management or implement other measures that could result in little to no change to AMP AUMs. Socioeconomic impacts from the potential reduction in AUMs are assessed in Section 4.8. Indirect effects from the Proposed Action Alternative may include an altered pattern of grazing and use by livestock near the LREP due to additional noise, traffic, and human presence with the increased recreational opportunities. During high recreation times the livestock may avoid the LREP area during which could alter how the livestock utilize vegetation in the nearby area. Additionally, increased human activity during calving could increase stress in the livestock. These potential indirect effects would be localized to livestock use near the LREP and would be variable on a year-to-year basis. 4.6.3 Impacts to Range Resources from the Operational Alternative The impacts to range resources from the Operational Alternative would be the same as those described for the Proposed Action Alternative. 4.7 Recreation This section describes the short- and long-term, direct and indirect impacts to recreation from the implementation of the No Action Alternative, the Proposed Action Alternative, and the Operational Alternative as described in Chapter 2. Cumulative impacts for recreation are discussed in Chapter 5. The analysis area for direct and indirect impacts to recreation, consists of the LREP disturbance footprint, including the wetland and borrow pit areas. To assess the impacts to recreational resources and the recreational experience from the implementation of the LREP, the following resource impact indicators were used for this analysis: 1. Changes to recreation setting characteristics (RSCs) (described in Section 3.7); 2. Acres of lost and gained land and water recreation area (e.g., increase in wetlands, gain of flat water surface for water recreation, and miles of trails gained/lost); and 3. Number and type of facilities added. 4.7.1 Impacts to Recreation from the No Action Alternative Under the No Action Alternative, the LREP would not be implemented. The capacity and operations would continue as they currently exist and the recreation opportunities and RSCs would remain the same. There would be no changes to recreation resources or the user experience under this alternative; therefore, there would be no new impacts.

Leavitt Reservoir Expansion Project – Final EIS – 2019 4-9 Chapter 4 – Environmental Impacts

4.7.2 Impacts to Recreation from the Proposed Action Alternative The RSCs within the LREP area would be altered under the Proposed Action Alternative. As stated in Section 3.7, the LREP disturbance footprint consists of two RSC types: rural (171 acres) and semi-primitive motorized (499 acres), as well as approximately 30 acres that are not categorized. Approximately 3,500 visitor days per year to the expanded Leavitt Reservoir would be expected (States West 2013), which equates to 292 more user days per month above current use and 10 more user days per day, most likely with a higher concentration on the weekends. The LREP falls within the West Slope Special Recreation Management Area (SRMA) and as such is assigned recreation settings as outlined in Section 3.7. Approximately 222 acres (44.0 percent) of the total middle country classification within the analysis area would be permanently inundated for the LREP. This could be considered an adverse impact for some recreationists since there would no longer be terrestrial access. However, in general, the addition of flat water surface for swimming and boating would outweigh the loss of terrain and would be considered a beneficial impact for most recreationists. Another 95 acres (19.0 percent) of the middle country classification would be permanently lost to reservoir infrastructure under the Proposed Action Alternative. This would constitute an adverse impact to RSCs. Table 4-6 in Appendix 1 depicts the RSCs by disturbance type. Approximately 43 acres (25 percent) of the rural classification would become the proposed east borrow area and would be considered a long-term adverse impact to the RSCs. The remainder of the rural classification acreage (171 acres or 24 percent) would only have temporary loss of use and therefore a short-term direct impact to RSCs. The physical component of the rural classification would not change from the development of the LREP under the Proposed Action Alternative. The distance from paved/primary roads would remain the same. The LREP would fit as part of the altered landscape and there would be an addition of modern facilities. The social component of the rural classification could be altered by an increase in contacts, group size, and evidence of use -- especially on holidays and weekends. Additionally the operational component of the rural classification would be altered by a change in traffic type. The physical component of the middle country classification would be altered by the development of the LREP under the Proposed Action Alternative because the area would be within 0.5 mile of paved/primary roads instead of four-wheel drive, all-terrain vehicle, and motorcycle routes. The social component for the middle country classification would also be altered by the increase in the number of visitors, individual and in groups, and the sounds of people could be heard more frequently rather than just occasionally, especially on the weekends. The operational component would similarly be changed as automobile and truck traffic would be nearer to the reservoir after the construction of the LREP rather than just four-wheel drive vehicles. Under the Proposed Action Alternative, there would be an increase in recreational opportunities for shoreline and lake fishing and boating due to an increase in the surface acreage of the reservoir. There would be beneficial long-term impacts from the addition of a boat ramp, picnic facilities, restroom and trash facilities, and parking area. The locations and designs of these facilities would be determined through a site-specific recreational analysis; however, it is anticipated that the recreation area would be located on the northeast side of the reservoir. The existing Beaver Creek Road and Bear Creek Road would provide access. The expanded shoreline and addition of wetlands would allow for more hiking opportunities, wildlife watching, and photography. The addition of approximately 3,500 recreational user days is predicted for the expanded reservoir under the Proposed Action Alternative. There could be increased dispersed recreation in the LREP area because of the attraction of the newly expanded reservoir. This would likely have negative direct and indirect impacts on users that are accustomed to solitude. Other changes to recreation in the analysis area would be the loss of 0.5 mile of an unimproved access trail on the northwest side of the reservoir. In all likelihood, wildlife viewing would improve in the newly created wetlands. Opportunities for photography would increase in the wetlands and new surface area of the reservoir. 4.7.3 Impacts to Recreation from the Operational Alternative Impacts from the Operational Alternative would be the same as those described for the Proposed Action Alternative.

4-10 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 4 – Environmental Impacts

4.8 Socioeconomics This section describes the socioeconomic impacts associated with the construction, maintenance, and operations of the Proposed Action Alternative, including the agricultural impacts of the additional water. Socioeconomics impacts are discussed in terms of effects on the Big Horn County economy. For a discussion on the choice of using Big Horn County as the analysis area, see Section 3.8. The economic effects of the Proposed Action and Operational Alternative were estimated using the Impact Analysis for Planning (IMPLAN) regional economic model. IMPLAN is an input/output model originally developed for the U.S. Forest Service and is widely used by both private- and public-sector economists for impact analyses throughout the U.S. The IMPLAN model used in this study incorporated 2016 data for Big Horn County. Construction of the Proposed Action Alternative would create two types of revenue streams that would increase demand for goods and services in the local economy: • Some goods and materials used in construction may be locally sourced within Big Horn County; and • Wages would be paid to local and non-local construction workers who would spend a portion of this income in the economy of the analysis area. Once the proposed reservoir expansion is complete, it would supply agricultural producers in the analysis area with late season irrigation water (or finishing water) to enhance crop yields. This would have two effects on the local economy: • Additional irrigation water would increase the sales of agricultural producers; and • Demand for agricultural inputs would potentially increase for the duration of the life of the expanded reservoir, which is estimated to be 50 years. Both of these effects would stimulate demand for goods and services in the local economy and were included in the IMPLAN analysis of agricultural economic impacts. The Proposed Action Alternative would require annual operations oversight and maintenance. This would increase household income for the employee(s) tasked with fulfilling these duties. The Proposed Action Alternative would also impact recreational and agricultural non-market values. 4.8.1 Impacts to Socioeconomics from the No Action Alternative Under the No Action Alternative, the size and capacity of the existing Leavitt Reservoir would not change and there would be no change in irrigation supplies or recreational opportunities from existing conditions. Consequently, the No Action Alternative would have no effect on socioeconomic conditions. 4.8.2 Impacts to Socioeconomics from the Proposed Action Alternative 4.8.2.1 Short-term Impacts from Construction The Proposed Action Alternative would cost a total of $39.8 million. Approximately $27.9 million is projected for actual construction. The analysis assumes that construction expenditures, which represent income paid to employees and inputs purchased from local businesses, are made in the analysis area. The remaining $11.9 million includes legal fees, permitting, acquisitions of ROWs, design and preparation, engineering, and contingencies (Wenck 2015). These activities would likely take place outside of the analysis area and were not included in the impact analysis. It is possible that the contractor hired to expand the dam would be located outside of the analysis area. In that case, the economic impact of construction activities would be smaller since some employee income would leave the analysis area. The construction phase of the Proposed Action Alternative would take approximately 24 months to complete, corresponding to annual construction expenditures of approximately $14.0 million per year. Construction activities would employ a monthly average of 21 fulltime employees during the 24-month construction period. The number of workers would vary from month to month, and would be highest during the first two months of construction when approximately 40 workers would be employed on site. The average earnings (including benefits) of construction workers in Wyoming between 2014 and 2016 were approximately $48,265 per year (BEA 2017a). Updating to 2017, this analysis assumes total compensation per worker of

Leavitt Reservoir Expansion Project – Final EIS – 2019 4-11 Chapter 4 – Environmental Impacts

$50,000 per year. With an average of 21 workers, annual labor costs for construction would be approximately $1,050,000. As shown in Table 4-7 in Appendix 1, construction of the Proposed Action Alternative is estimated to support approximately 45 short-term jobs. This includes the projected 21 direct jobs associated with construction as well as 24 indirect jobs that would be supported by the local purchases of supplies and materials for construction, household expenditures by the locally hired workers, and local expenditures of non-local workers during the construction period. In addition to the $1.8 million in annual compensation anticipated to be paid to local and non-local construction workers and proprietors, construction of the proposed LREP is estimated to indirectly produce an additional $662,437 in annual labor earnings during the two-year construction period (Table 4-7 in Appendix 1). Overall, construction of the Proposed Action Alternative is estimated to increase economic output in the analysis area by $16.2 million during the two-year construction period. As discussed above, the Proposed Action Alternative would require an annual average of approximately 21 construction workers to report to the reservoir site during the construction phase. Some of the construction workers may come from inside the analysis area (i.e., Big Horn County), but others may not. Workers from outside of the analysis area would most likely seek accommodation in nearby towns based on the commuting distance to the reservoir site, the availability of temporary accommodations, rental costs, and other factors. There are several towns within 40 miles of the reservoir site (e.g., Greybull, Basin, and Lovell), but all of the towns are relatively small with populations of 2,500 or less. The temporary construction force could create short-term shortages of temporary housing depending on which community(ies) the workers sought accommodation in. According to the 2010 Census, Greybull had 23 units available for rent in 2009, which represented about 20 percent of the town’s vacant housing stock. More recent information from the American Community survey suggests that Greybull has approximately 26 short-term units, Basin has roughly 14 short-term units, and Lovell has approximately 37 short-term units for a total of 77 short-term units in the four closest communities to the proposed LREP site. These estimates were developed assuming roughly 20 percent of each town’s vacant housing stock is composed of properties available as short-term rentals. If the temporary work force sought accommodation across all four towns, the effects on short- and long-term housing prices and availability would be minimal. The economic impacts created by construction, operations and maintenance, and agricultural activities would also generate additional tax revenues for state and local governments. The largest sources of new state and local taxes would be sales taxes and property taxes1. Based on the IMPLAN analysis of regional economic effects, construction of the proposed LREP would produce approximately $389,490 in additional state and local tax revenues over the two-year construction phase. 4.8.2.2 Short-term Impacts on Livestock Grazing Construction activities would be expected to lead to the temporary loss of about 80 acres of BLM grazing land, corresponding to approximately 3 AUMs. The direct economic impact of this reduction could vary between $0 and $228 depending on whether or not the permittee is utilizing 100 percent of the forage authorized under the grazing permit. If the loss of grazing land does not cause a change in the number of cattle grazed by the permittee or the amount of forage the livestock consume, then there would be no economic impact from the temporary loss of grazing land. If the loss of grazing land negatively affected either the number of livestock grazed by the permittee or the amount of forage available to each individual livestock, it would result in a temporary direct economic impact of $228, based on the average Wyoming economic return of $76 per AUM (University of Wyoming Extension 2018). 4.8.3 Long-term Impacts from Operations Once construction was completed, the operation of the proposed LREP would require a half-time position to fulfill duties taking approximately 100 hours per month for 6 months. During the other 6 months of each year, duties to sustain the operations of the expanded reservoir would require 20 hours of labor per month. Routine maintenance is expected to require approximately two weeks of labor from a three-person crew each year.

1 The general sales tax rate in Wyoming is 4 percent. Cities and towns in Wyoming do not have a city sales tax.

4-12 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 4 – Environmental Impacts

In total, these annual operations and maintenance costs are anticipated to be around $28,600 per year and result in the direct creation of approximately one full-time equivalent local job. The recirculation of the wages paid to the operations and maintenance staff would produce modest ongoing economic impacts in the analysis area. 4.8.3.1 Long-term Impacts Associated with Irrigation Agricultural producers in the analysis area would be impacted directly from the proposed LREP by using the additional water to increase crop production. Crop production could be enhanced by distributing the additional water to the existing allocation of crops in the analysis area, or by allocating more acreage to high value crops and reducing the acreage devoted to low value crops like hay and alfalfa. This analysis assumes that agricultural producers in the analysis area would adapt to having additional irrigation water by applying it to the current allocation of crops, thus avoiding conversion costs and limiting agricultural producer’s financial exposure to uncertain conditions in the future. The Shell Valley Storage Level II, Phase II Study (Wenck 2015) published crop-water production functions for alfalfa, corn, and dry beans, the most commonly grown crops in the analysis area. The functions indicate that an acre-foot of consumptively used water would increase dry bean gross revenues by $549.23; $453.32 for corn; and $236.09 for alfalfa. According to the Shell Valley Storage Level II, Phase II Study, 2,540 acre-feet (AF) of additional water supplies would be available for use as finishing water after accounting for system and on-farm water use efficiency (Wenck 2015). Under the water allocation discussed above, the 2,540 AF of additional water supplies would increase farm gross revenues by $1,118,861 under the Proposed Action Alternative if additional irrigation water supplies are used to finish relatively high value crops like corn and beans, and to a lesser extent, alfalfa. As shown in Table 4-8 in Appendix 1, the gross revenue generated by the additional irrigation water would be likely to support approximately 14 direct, indirect, and induced jobs per year during the operational life of the proposed LREP. This includes nine direct jobs on local farms as well as five indirect jobs supported by local purchases of supplies and materials for agricultural producers, and household expenditures by farm owners and workers. In addition to the $1.20 million in additional annual agricultural output expected to be produced in the analysis area as a result of the Proposed Action Alternative, the direct, indirect, and induced economic activity associated with growth in agricultural output would be expected to produce $311,414 in additional annual labor income in the analysis area. Overall, the additional irrigation water stored by the proposed LREP would be expected to increase Big Horn County’s economic output by $1.52 million per year. This total includes the projected $1.20 million increase in direct output due to higher crop yields, as well as $0.3 million in additional economic output due to recirculation of wages and expenditures in the analysis area. Following the proposed Leavitt Reservoir expansion, the agricultural sector would contribute an additional $46,045 to state and local tax revenues each year. Under the WWDC Dam and Reservoir Program, WWDC may recommend a loan/grant finance package to pay for the expansion based on the reservoir sponsor’s ability to pay a portion of the LREP costs and all of the operation, maintenance, and replacement costs (WWDC 2017). It is common for the WWDC to offer a loan/grant package that covers 67 percent of a project’s costs and that requires the sponsor to pay back the remaining 33 percent. Under the Proposed Action Alternative, this would require the irrigators to repay approximately $13.1 million to finance their share of the costs. WWDC finances loans at an annual interest rate of 4 percent. This analysis assumes this amount would be paid back for the 50-year life of the expanded Leavitt Reservoir as a surcharge on each acre-foot of water. Based on the foregoing assumptions, the annual payment required of LREP irrigators would be approximately $611,000, or $170 per acre-foot of firm yield. The projected $170 per acre-foot cost for LREP irrigators may be perceived as an unusually expensive irrigation supply, and could make it difficult to obtain local financial support for the Proposed Action Alternative. The average cost of irrigation supplies in Wyoming was approximately $8 per acre-foot in 2013 (USDA 2013). Over the 2012-2017 period, the average value of irrigation supplies in Wyoming, based on the difference in rental rates between irrigated cropland and dry cropland, was about $74 per acre, or approximately $50 per acre-foot (USDA 2017). 4.8.3.2 Long-term Impacts on Livestock Grazing The operation of the Proposed Action Alterative would lead to the permanent loss of about 210 acres of BLM grazing land, corresponding to approximately 10 AUMs. The direct economic impact of this reduction could

Leavitt Reservoir Expansion Project – Final EIS – 2019 4-13 Chapter 4 – Environmental Impacts vary between $0 and $760 depending on whether or not the permittee is utilizing 100 percent of the forage authorized under the grazing permit. If the loss of grazing land does not cause a change in the number of cattle grazed by the permittee or the amount of forage the livestock consume, then there would be no economic impact from the temporary loss of grazing land. If the loss of grazing land negatively affected either the number of livestock grazed by the permittee or the amount of forage available to each individual livestock, it would result in a temporary direct economic impact of $760, based on the average Wyoming economic return of $76 per AUM (University of Wyoming Extension 2018). 4.8.3.3 Long-term Impacts on Recreation Economy The Proposed Action Alternative would create a recreation and environmental pool with a minimum surface area of 93 acres. On average, the reservoir would cover an area of approximately 175 acres with the proposed expansion. The LREP would also add a boat ramp, picnic facilities, restrooms, trash facilities, and parking areas to the site. The additional surface area and recreation facilities would provide opportunities for flat-water recreation, including boating and fishing. 4.8.3.4 Long-term Impacts on Non-Market Values The Proposed Action Alternative would impact non-market values held by recreationists, farmers, and other residents in the analysis area. In terms of recreation, the Proposed Action Alternative would improve non-market recreation values for some users of the site and reduce them for others. The expanded reservoir would include new and enhanced recreation amenities, but it would also permanently inundate several hundred acres of land with recreation value. New and current reservoir users would benefit from the amenities by being able to participate in existing recreation activities more easily and having an overall wider choice of activities to participate in. However, the Proposed Action Alternative would alter the landscape and introduce more modern facilities, potentially reducing non-market values for residents who value remote settings and limited contact with other groups. The Proposed Action Alternative would improve non-market values of farmers. Farmers are dependent on supplies of irrigation water to grow crops and earn a living. Creating new water supplies would enhance the existence, option, and bequest values of farmers. All else equal, new water supplies would make farmers more certain that their enterprise and the agricultural lifestyle would continue to exist in the analysis area or that they at least had the option to continue to work in agriculture. The additional water supplies would also give farmers a stronger sense that their farm and the agricultural lifestyle could be passed down to future generations. 4.8.4 Impacts to Socioeconomics from the Operational Alternative The socioeconomic effects of the Operational Alternative would be the same as the effects described for the Proposed Action Alternative. 4.8.5 Impacts to Environmental Justice from the Proposed Action Alternative As described in Section 3.8, there are six communities in the Big Horn County analysis area that could be considered environmental justice populations based on the proportions of minority residents or residents living below the poverty level and/or based on the proportions of minority residents – Byron, Burlington, Deaver, Frannie, Greybull, and Lovell. The environmental justice populations are located throughout Big Horn County, but are not proximate to the location of the proposed LREP. Block 1 of Census Tract 9627, which contains the LREP analysis area, does not contain any environmental justice populations. If there were any adverse short- or long-term environmental consequences from the Proposed Action Alternative, they would not fall disproportionately on environmental justice populations in the analysis area. 4.8.6 Impacts to Environmental Justice from the Operational Alternative The environmental justice effects of the Operational Alternative would be the same as the effects described for the Proposed Action Alternative. 4.9 Soils The analysis area for direct impacts to soils is the LREP disturbance footprint. This analysis area was chosen because direct impacts would only occur where soils are disturbed by the LREP. The analysis area for indirect impacts to soils is a 0.25-mile buffer of the LREP disturbance footprint for. This area was chosen to provide an

4-14 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 4 – Environmental Impacts adequate area outside the LREP disturbance footprint for determining indirect impacts, particularly those that are downstream from the LREP disturbance footprint. 4.9.1 Impacts to Soils from the No Action Alternative Under the No Action Alternative, no surface disturbing activities would occur; therefore, no impacts would occur to soils. Baseline levels of erosion would likely continue at current levels in soil types that are susceptible to wind erosion and surface runoff, including some degradation of the soil resource following loss of topsoil from erosive forces. 4.9.2 Impacts to Soils from the Proposed Action Alternative The construction for the Proposed Action Alternative would result in impacts to approximately 702 acres of soils. Direct impacts to the soils would occur from surface disturbing activities such as excavating and expanding the reservoir, earthwork and construction of ancillary reservoir infrastructure and facilities, and the upgrading of access roads and raising of 0.87 mile of Bear Creek Road. Approximately 284.6 acres of soils (40.5 percent of total impacts) would be permanently impacted from development of the reservoir and ancillary infrastructure including the recreation areas, new earthen dam embankment, reservoir expansion, constructed wetlands, and 0.87-mile raise of Bear Creek Ranch Road (Table 4-9 in Appendix 1). Permanent impacts associated with these areas would include but not be limited to, the removal of vegetation and topsoil, compaction of high use areas, and construction of permanent infrastructure. Potential impacts would also include short-term, temporary impacts to the soil resource. Approximately 417.6 acres of soils (49.6 percent of total impacts) would be temporarily impacted from access road improvement and use, development of the reservoir inundation buffer, supply pipeline, transfer pipeline, primary outlet works footprint, and other general construction disturbance (Table 4-9 in Appendix 1). Temporary impacts to these areas would include but not be limited to, the removal of top soil and vegetation, compaction in high use areas, and construction of temporary infrastructure. Following temporary activities, areas that are no longer needed for construction would be reclaimed, as necessary. Temporary impacts could potentially occur in soil types that have limiting factors, such as soil strength or chemistry, and/or sensitive soils, such as hydric soils, that may impact the soil resource. Permanent impacts to soil types that have limiting factors are not expected to occur based on the existing soil series. It should be noted that the Soil Survey Geographic Database (SSURGO) did not cover the entire LREP analysis area; therefore, generalized soils from the State Soil Geographic Database (STATSGO) were pulled to fill in the data gaps for the SSURGO soils. The permanent impacts for the LREP analysis area would be within the Spearfish-Rekop- Neville-Gystrum STATSGO soil unit. 4.9.3 Impacts to Soils from the Operational Alternative The impacts to soils from the Operational Alternative would be the same as those described for the Proposed Action Alternative. 4.10 Transportation The analysis area for transportation impacts from the LREP includes regional, local, and on-site roadway networks potentially impacted by construction and post-construction trip generation. 4.10.1 Impacts to Transportation from the No Action Alternative The No Action Alternative would not include any roadway network changes or facility improvements so there would be no changes or effects to travel patterns, mobility, accessibility, accident rates or pavement conditions. The No Action Alternative would not generate additional traffic so traffic volumes would not change. Incremental annual increases in traffic and associated congestion caused by new development, population growth, and economic growth would occur over time at rates associated with anticipated local, regional, and statewide trends.

Leavitt Reservoir Expansion Project – Final EIS – 2019 4-15 Chapter 4 – Environmental Impacts

4.10.2 Impacts to Transportation from the Proposed Action Alternative 4.10.2.1 Roadway Network: Facility Changes, Travel Patterns, Mobility and Accessibility The proposed roadway upgrades prior to construction would improve the existing roadway network conditions by creating a modified road segment along the reservoir and by improving public accessibility to the expanded Leavitt Reservoir and associated recreation facilities. These roadway changes would be designed to comply with applicable engineering design requirements and would have beneficial impacts on the roadway network. Road rehabilitation at the end of the construction period would include repairs to address typical construction activity impacts along primary construction corridor routes. The construction activity required to raise 0.87 mile of Bear Creek Road would temporarily disrupt travel. Traffic on this segment of Bear Creek Road is relatively low and primarily involves private property access. The anticipated disruption would be expected to occur over a period of 22 months and would require a temporary route and traffic control measures to provide motorists with safe travel around the roadway re-construction site. Anticipated traffic control measures would be in compliance with applicable engineering design requirements and standards. 4.10.2.2 Traffic Volume and Levels of Service: Congestion Construction Phase Trip Generation and Distribution versus Capacity Construction trips to and from the LREP site would be distributed over the regional and local roadway network during the anticipated 23-month construction period. These trips would be generated by workers in personal vehicles and by construction vehicles (e.g., light and heavy trucks). Additional trips involving personal vehicles, light and heavy trucks, and other construction equipment (e.g., scrapers, loaders, excavators, and graders) would also be generated with origins and destinations within the construction area. The focus of the effects analysis is on new trips that would be distributed beyond the boundaries of planned construction areas on primary routes used by the various types of construction vehicles (i.e., U.S. Highway 14 [US 14]), Bear Creek Road, and County Road [CR] 39). I-90 would handle some LREP traffic, but would not be expected to have effects on capacity, safety, or maintenance. Table 4-10 in Appendix 1 outlines the number of personnel and equipment vehicles that would be needed daily during each month of the construction period. This information and related assumptions provided the basis for the calculation of construction-phase trip generation for the LREP. Table 4-11 in Appendix 1 presents a summary of estimated construction period trips per day. The highest number of trips generated was estimated to occur during the first two months of construction mobilization, and when excavation and other earthwork activities would be initiated. The origins and destinations of the construction trips were estimated based on the size of the towns surrounding the LREP site (i.e., Buffalo, Cody, Dayton, Greybull, Sheridan, and Worland) and their proximity to major transportation facilities. The LREP construction-related traffic was added to existing and future estimated average annual daily traffic (AADT) and peak-hour traffic to evaluate the direct impacts of the Proposed Action Alternative on traffic volumes. The anticipated impacts are summarized below. US 14, East and West of CR 39: The total number of trips on US 14 would remain well below the capacity of the roadway. Trips to the east along US 14, at the US 14/I-90 interchange, and along I-90 would be accommodated by the existing capacity of these facilities. Trips to the north would also be accommodated by the capacity of existing facilities. Intersection of US 14 and CR 39: There is limited data on turning movements at this intersection, but it is assumed that the number of movements is relatively low during the peak hour relative to capacity. The additional peak period trips that would make left turns into (16 trips in the morning peak hour) and left turns out of (23 trips in the evening peak hour) the LREP site could be delayed by traffic resulting from the Proposed Action Alternative on US 14, especially when the turns are made by heavy trucks that move slowly through the intersection.

4-16 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 4 – Environmental Impacts

Intersection control and/or left turn storage could be needed to provide safe turning movements during the peak period. Intersection of US 14 and 6th Street: The additional trips generated under the Proposed Action Alternative during the morning and evening peak hours that would travel on US 14 through Greybull (maximum of 16 trips – left turns) would have an incremental adverse effect on the capacity of the intersection. With limited data on existing and future turning movements at this intersection, it is possible that the additional trips that would be generated under the Proposed Action Alternative could cause some additional delay at this intersection during the morning and evening peak hours. This delay could be addressed by signal timing adjustments, if deemed necessary by Wyoming Department of Transportation (WYDOT). Bear Creek Road: The addition of 39 peak-hour trips on Bear Creek Road under the Proposed Action Alternative is slightly over one trip every two minutes, which would be substantially higher than existing traffic. Bear Creek Road and intersections along Bear Creek Road (cross streets and driveways) could handle this capacity, but it would be an increase noticeable by residents and other road users. Potential impacts to Bear Creek Road from heavy trucks under the Proposed Action Alternative are addressed in the following discussion on operational phase trip generation versus capacity. Operational Phase Trip Generation and Distribution versus Capacity Operational phase trip generation to and from the LREP site under the Proposed Action Alternative would occur after construction is completed and would be distributed over the regional and local roadway network. Under the Proposed Action Alternative, less than 10 trips would be anticipated per day from worker and recreation sources. Operational phase traffic would be distributed annually with most of the recreation traffic occurring in the summer months when water-oriented activities would occur at the reservoir recreation facility. The combination of vehicles associated with facility operations and recreation vehicles expected under the Proposed Action Alternative would not create substantial traffic issues. There are multiple routes connecting US 14 to Bear Creek Road so traffic on these routes could be distributed rather than concentrated on CR 39. Permanent signage and turning lanes at any of the route connections to US 14 should be evaluated as part of the recreational analysis if the “visitor days” estimate of 3,500 is revised upward or the referenced assumptions are not considered accurate for anticipated users of the final set of facilities that are constructed. 4.10.2.3 Traffic Safety: Conditions and Accident Rates Construction-phase vehicle travel under the Proposed Action Alternative would incrementally increase the potential for accidents by adding more vehicles to local roadways and by introducing slow-moving vehicles, which would potentially add delay and queuing to the local roadway network. The associated effects on safety would be addressed by roadway improvements and could be addressed with standard and customized construction driver awareness efforts and site-specific construction period intersection control measures, where appropriate. Intersection control measures would include adjusted signal timings, temporary signing, and traffic control devices at key locations, as well as flaggers in some instances. Operational-phase vehicle travel would incrementally increase the potential for accidents by adding more vehicles to local roadways resulting in a minor adverse effect. 4.10.2.4 Pavement and Maintenance Conditions Construction phase traffic increases, especially heavy trucks on local roads, would incrementally impact existing pavement that is not designed for heavy truck travel. The construction of the LREP may necessitate the re-assessment of pavement deterioration rates and planned timing for pavement upgrades. Turning movement limitations for large trucks may incrementally contribute to maintenance needs in Greybull, where the wheels of large trucks sometimes pass over curbs and sidewalks. Operational-phase traffic increases would also incrementally impact existing pavement, pavement deterioration rates, and reduce the anticipated time prior to pavement upgrades. These impacts would be minor. 4.10.3 Impacts to Transportation from the Operational Alternative The impacts to transportation from the Operational Alternative would be the same as those described for the Proposed Action Alternative.

Leavitt Reservoir Expansion Project – Final EIS – 2019 4-17 Chapter 4 – Environmental Impacts

4.11 Vegetation Potential impacts to vegetation from the proposed LREP include permanent loss of vegetation, temporary disturbance of vegetation during construction followed by revegetation, introduction or spread of noxious or invasive plant species resulting from construction activities or operational procedures, loss or disturbance of individuals or populations of Ute ladies’-tresses (federally listed), and loss or disturbance of populations of BLM sensitive plant species or Wyoming Natural Diversity Database (WYNDD) tracked species. The analysis area for vegetation is the LREP disturbance footprint, including areas of permanent or temporary ground surface disturbance. The analysis area for threatened and endangered plant species is the LREP disturbance footprint and one-mile buffer. The analysis area for noxious weeds is the LREP disturbance footprint plus one-mile buffer (this represents the most likely seed source for introduction or spread of noxious weeds during construction activities). 4.11.1 Impacts to Vegetation from the No Action Alternative The No Action Alternative does not involve any new construction. Operation of the existing Leavitt Reservoir would continue as is, including the existing timing of diversion. As such, no changes resulting in impacts to vegetation would be expected under this alternative. 4.11.2 Impacts to Vegetation from the Proposed Action Alternative 4.11.2.1 General Vegetation Acres of permanent and temporary disturbance of vegetation under the Proposed Action Alternative are provided in Table 4-12 in Appendix 1, and impacts by LREP component are provided in Table 4-13 in Appendix 1. The Proposed Action alternative would have permanent impacts to 364 acres of vegetation and temporary impacts to 338 acres. Permanent impacts would occur in the reservoir inundation area, at the dam area (spillway, embankment, Bear Creek Road raise), and borrow areas, all of which would involve permanent changes to the existing ground surface. Impacts from proposed wetland mitigation and recreation areas were also considered to be permanent. Most of the permanent impacts would occur from reservoir inundation. About 77 percent of permanent impacts would occur in big sagebrush shrubland and steppe and non-native grassland and steppe. Temporary impacts would occur in the temporary construction disturbance areas and the pipeline and road disturbance areas. Construction in these areas would be of short-term duration and require less modification to the existing ground surface. The extent of roadway modification is not currently known and it is possible that there may be some areas of permanent disturbance from widening or from upgrading of culverts at stream or ditch crossings. However, the majority of roadway impacts are expected to be temporary. The reservoir inundation buffer would also be a temporary impact. Due to the fact that the reservoir is designed to fully contain the PMF, the likelihood of discharge over the spillway would be extremely remote. Therefore, impacts to the existing natural channel downstream of the spillway would not be anticipated. Most of the temporary impacts would result from pipeline installation and road improvements. About 77 percent of temporary impacts would occur in big sagebrush shrubland and steppe, agriculture, and developed and roads vegetation/cover types. Impacts to the different vegetation/cover types would generally be proportionate to their abundance in the analysis area, and average about 1 percent of their occurrence in the analysis area. Most of the impacts to “Developed” and “Roads” would occur along the access roads. Most of the impacts to “Open Water” would be within the vicinity of the existing Leavitt Reservoir, which would be affected by construction of the new dam and expanded reservoir, as well as the South Mitigation Wetland. Areas disturbed during construction under the Proposed Action Alternative, except the reservoir and reservoir buffer, would be revegetated. Specific restoration and revegetation plans have not been developed, but would likely consist of seeding native grass, forb, and shrub species that would be appropriate for the post-construction conditions. Other techniques could include topsoil salvage, mulching, and use of soil amendments. A revegetation plan including seed mixes and other specifications would need to be developed by the applicant and approved by the BLM prior to any surface-disturbing activities. Interim revegetation could be required to stabilize areas during construction, and permanent restoration would be installed at the end of construction for the various LREP features. Separate seed mixes and planting procedures would be developed for upland, wetland, and riparian habitats. Monitoring would be performed to evaluate the success of reclamation; remedial measures would need to be implemented where revegetation goals were not achieved. Successful revegetation

4-18 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 4 – Environmental Impacts would require vegetation cover to equal or exceed pre-disturbance conditions. Control of wind and water erosion would be addressed by the construction contractor in the stormwater management plan and fugitive dust control plan that would be developed for the LREP. Non-BLM landowners may have individual requirements for revegetation, especially in agricultural areas. With implementation of revegetation, areas dominated by herbaceous vegetation would be expected to reach pre-disturbance cover in two to five years. Revegetated areas would typically be dominated by herbaceous species for the first 15 to 20 or more years because dryland shrubs would take longer to establish and grow. 4.11.2.2 Noxious Weeds and Invasive Species Potential impacts under the Proposed Action Alternative would include introduction or spread of noxious or invasive plant species as a result of construction activities and operational procedures. Construction could contribute to the spread of noxious weeds in several ways, including removal of existing vegetation cover; movement of seeds and propagules during grading and earth moving; potential import of noxious weed seeds or other propagules by vehicles and construction equipment travelling from areas that contain invasive species; by seeding of disturbed areas by airborne seeds from nearby established populations; and/or by import of construction materials that may contain weed seeds. Operation of the reservoir could also provide favorable conditions for establishment of some invasive species, including salt cedar and Russian olive. A number of noxious weeds are already established in the analysis area. Species that are common in all areas include cheatgrass, Canada thistle, field bindweed, Russian olive, and whitetop. A number of species are common in the Shell Creek Valley but not reported in the north or central parts of the analysis area, including houndstongue, ox-eye daisy, and perennial pepperweed. Several others are much more common in the Shell Creek Valley than elsewhere, including bull thistle, common burdock, musk thistle, Russian knapweed, and field bindweed. Several species are currently rare or uncommon in the analysis area but have the potential to spread, including black henbane, ox-eye daisy, Scotch thistle, spotted knapweed, and Swainson pea. Development of a noxious weed management plan would be required prior to ground-disturbing activities. The plan would need to be consistent with BLM invasive and noxious weed management policies and procedures, and comply with Big Horn County Weed and Pest requirements. Big Horn County Weed and Pest is the local lead agency for weed management in Big Horn County. With development and implementation of a noxious and invasive species management plan, impacts from noxious weeds and invasive species would be minor. 4.11.2.3 Special Status Plant Species Potential impacts to special status plant species under the Proposed Action Alternative include loss or disturbance of individuals or populations of Ute ladies’-tresses (federally listed) and loss or disturbance of populations of BLM sensitive plant species or WYNDD tracked species. There are no previously recorded occurrences of listed, sensitive, or tracked species within the analysis area. Five species are potentially present, based on overall range and general habitat suitability. Federally Listed Species Ute ladies’-tresses orchid was not found during focused field surveys for the LREP in 2017, and the habitat in the survey area was considered to be marginal. An additional field survey will be conducted in 2018 because Ute ladies’-tresses does not necessarily flower every year. Based on the marginal habitat and the negative survey results, the Proposed Action Alternative would have no effect to this species. BLM Sensitive Species No surveys have been conducted to date. Dubois milkvetch is a local endemic of the Dubois Badlands in the northeastern Wind River Basin. Similar plants from the eastern Bighorn Basin may be this or a related taxon. There are nine known occurrences of unresolved taxonomic status in the Bighorn Basin (Heidel 2011; Heidel 2018). The closest recorded occurrences to Leavitt Reservoir are 5 to 6 miles south of Shell Creek and not within the analysis area. The Proposed Action Alternative would have no effect to known populations of Dubois milkvetch and it is unlikely that new populations will be found within the analysis area. Pre-construction surveys will be conducted to identity and avoid any occurrences of this species. The closest recorded occurrence of limber pine is about 1 mile upstream of the diversion on Beaver Creek, along a creek (University of Wyoming 2018). Landfire vegetation mapping (Landfire 2014) identifies a Rocky Mountain Foothill Limber Pine –Juniper Woodland that occupies about 0.8 percent (556.7 acres) of the analysis

Leavitt Reservoir Expansion Project – Final EIS – 2019 4-19 Chapter 4 – Environmental Impacts area, and 9.3 acres of the LREP disturbance footprint. This was used as an approximation of potential impacts, because vegetation type may not be accurately characterized at specific locations, and limber pine may not be present at all locations. Surveys have not been conducted in the analysis area and the actual area of impact is not known; impacts may be minor or moderate. The 9.3 acres of potential impacts represent 1.7 percent of this cover type in the analysis area, indicating that the vast majority of this vegetation type would not be affected under the Proposed Action Alternative. Pre-construction surveys will be conducted to identify and avoid occurrences of this species. 4.11.3 Impacts to Vegetation from the Operational Alternative Direct and indirect impacts to vegetation from the Operational Alternative would be the same as those discussed for the Proposed Action Alternative. 4.12 Visual Resources This section describes the short-term, long-term, direct, and indirect impacts to visual resources from the implementation of the No Action Alternative, the Proposed Action Alternative, and the Operational Alternative as described in Chapter 2. Cumulative impacts for visual resources are discussed in Chapter 5. The analysis area for direct and indirect visual impacts is the 10-mile buffer around the LREP disturbance footprint. This distance was used because a reverse viewshed analysis shows that 10 miles is the maximum distance from which the LREP would be visible. The analysis considers a 50-year life of the LREP for direct and indirect impacts. For the purposes of this analysis, the primary indicators of impacts to visual resources are: • Degree of visual contrast created by the LREP (i.e., line, form, color, texture) which is determined through the contrast rating process as outlined below; • Increase or decrease in visual values as measured by the visual resource inventory (VRI) scenic quality ratings; and • Amount of land in acres that would have visual changes. The LREP must meet the analysis area Visual Resource Management (VRM) Class Objectives as outlined in Section 3.12. The BLM Contrast Rating Process is used to determine impacts to visual resources and includes a combination of field surveys, visual simulations using GIS analysis, and contrast ratings. Contrast ratings are conducted from critical viewpoints, known as key observation points (KOPs), which are usually found along commonly traveled routes such as highways, access roads, or trails. A KOP can be a single point of view that an observer/evaluator uses to rate an area or panorama, or a KOP can describe a series of sequential views from a linear feature (e.g., along a roadway, trail, or river corridor). Four KOPs were selected for the LREP (SWCA 2017). Factors considered in selecting the KOPs were the angle of observation or slope of the proposed LREP area in relation to the KOP; the estimated number of viewers of the LREP area at the KOP; the length of time that the LREP would be in view from the KOP; the relative size of the LREP from the KOP; the season of use; and light conditions. Section 3.12 describes the KOPs that were chosen for visual simulations. Photographs were taken from each KOP and descriptors of the line, form, color, and texture of the land, water, vegetation, and structures in the existing landscape were recorded. Subsequent to the collection of field data and the creation of photographic panoramas, visual simulations of the LREP after construction were completed for each KOP. The same descriptors noted for the existing landscape were noted for the visual simulations (see Section 3.12). The degree of visual contrast between the two was rated by a visual resource specialist as a contrast rating. The contrast ratings, recorded on BLM Contrast Rating Worksheets (i.e., BLM Form 8400-4) were used to determine whether the level of disturbance associated with the proposed LREP would exceed the VRM objectives for that area (BLM 1986). Results of the contrast ratings for each KOP are described in the following sections.

4-20 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 4 – Environmental Impacts

4.12.1 Impacts to Visual Resources from the No Action Alternative Under the No Action Alternative, the LREP would not be implemented. The capacity and operations of the existing Leavitt Reservoir would continue as they currently exist and the viewshed would remain the same. There would be no impacts on visual resources. 4.12.2 Impacts to Visual Resources from the Proposed Action Alternative There would be short-term direct and indirect impacts to visual resources within the approximate 702 acres of the disturbance footprint during the approximate two-year LREP construction period under the Proposed Action Alternative. Dust and particulates created from earth-moving activities, surface disturbance, and increased vehicle use would impair visibility and cause a temporary adverse impact to visual resources. The entire disturbance area would experience these temporary and permanent impacts to the following VRM class types: 32 percent of VRM Class II lands, 57 percent of VRM Class III lands, and 11 percent of VRM Class IV lands. Since the management objectives for VRM Class II are to retain the existing character of the landscape and keep the level of change to the landscape low, impacts would be more adverse in VRM Class II areas as compared to VRM Class III and Class IV areas where change can be moderate or dominant. After construction, earth-moving activities and construction vehicle use would cease, thereby reducing or eliminating the fugitive dust. Table 4-14 in Appendix 1 shows the number of acres of temporary and permanent disturbance that would occur under the Proposed Action Alternative within the analysis area by VRM Class. For visual analysis, “disturbance” equates to changes in the landscape which can be beneficial or adverse. Over the long term, there would be direct beneficial impacts to visual resources under the Proposed Action Alternative because of the addition of more water surface (approximately 197 acres) and wetlands (approximately 25 to 30 acres total) to the analysis area. As per BLM’s Manual H-8410-1 Visual Resource Inventory, water adds visual value and ranks high as an aesthetically pleasing element especially in arid environments (BLM 1986). In areas where there would be new infrastructure, there would be long-term adverse impacts to visual resources because man-made buildings and structures would create contrasts in line, form, color, and texture to the existing landscape. However, these impacts would be minor in comparison to the overall beneficial impact of additional water surface. It is likely that lands classified as VRI III and IV would have an increase in visual value due to the increase in water surface. Whether the addition of water to the VRI values would increase the existing VRI classification to the next highest classification (e.g., VRI III to VRI II) would depend on other factors such as color, vegetation, and adjacent scenery. A new VRI would need to be conducted during the next BLM Cody Field Office (CYFO) Approved Resource Management Plan (RMP) revision to determine if a class change was warranted. Lands classified as VRI II would retain their visual value from the implementation of the LREP after construction. Impacts from the Proposed Action Alternative that would result to the viewshed from each of the KOPs are described in detail in the sections below. 4.12.2.1 KOP 1 – Bear Creek Road There would be moderate visual contrasts created from the construction of the LREP from KOP 1 as depicted in the visual simulation (see Appendix 4.12). The reservoir would add moderate contrasts to the view from the horizontal form at KOP 1. Lines created by the reservoir would be bold and straight rather than undulating and would create a moderate contrast. There would be strong contrasts created from the white, tan, and rust colors of the land changing to blue from the reflection of the water. The texture of would change from coarse land to smooth water creating a moderate contrast. The newly created wetlands would also add contrast in all the elements (form, line, color and texture). The dam and raised road add moderate contrasts in line and form and especially color, but from KOP 1 the distance mitigates these structural elements, see Appendix 4.12 for more details on the contrast ratings. The LREP falls within a VRM Class III management area. While there would be visual impacts the project would still meet visual resource management objectives because the objectives for VRM Class III are to partially retain the existing character of the landscape. The change to the existing landscape should be moderate. While the reservoir and dam occupy and change the foreground and middle ground views most of the foreground view is retained because there are no changes to the road or vegetation and the middle ground and background mesas and buttes remain the same. Additionally as noted in Chapter 3 water has high visual value and can offset the impacts of moderate and strong contrasts.

Leavitt Reservoir Expansion Project – Final EIS – 2019 4-21 Chapter 4 – Environmental Impacts

4.12.2.2 KOP 2 – Beaver Creek Road There would be weak and moderate visual contrasts created from the construction of the LREP from KOP 2 as depicted in the visual simulation (see Appendix 4.12). The LREP from this KOP adds a narrow smooth blue band in the foreground replacing the white soil of the badlands and inundating a portion of the rust and tan hills. The LREP from this KOP only creates moderate contrasts in color, the remainder of the elements for land/water, vegetation and structures have weak or no contrasts (see Appendix 4.12). This KOP falls within VRM Class III. The management objectives for VRM Class III are to partially retain the existing character of the landscape. The change to the landscape within VRM Class III can be moderate. Therefore the LREP would meet VRM Class III objectives at this KOP because the change to the landscape is low. 4.12.2.3 KOP 3 – The “W” Trail There would be no visual contrasts created from the construction of the LREP from KOP 3 as depicted in the visual simulation (see Appendix 4.12). The distance from the KOP to the LREP is approximately six miles. The distance and the fact that there is a bluff in the foreground that partially blocks the LREP and draws the eye to the foreground viewscape makes it so that the LREP is barely visible in the upper right portion of the visual simulation. Since the analysis is based on the contrasts visible to the human eye, none are created at this distance. Therefore, the LREP would meet VRM Class III objectives at this KOP because the change to the landscape is virtually non-existent. 4.12.2.4 KOP 4 – Sunlight Mesa Visual simulations for KOP 4 were not completed due to access issues from winter snow. KOP 4 is approximately nine miles from the LREP. Although the view from KOP 4 is superior to (higher than) the LREP making it likely that it would be visible from KOP 4, the distance would keep any potential visual contrasts in line, color, form or texture weak. The potential for visual contrasts would come from the reflection of the lake during particular times of the day. The LREP would meet VRM Class III objectives at this KOP because the change to the landscape would be low. 4.12.3 Impacts to Visual Resources from the Operational Alternative Impacts from the Operational Alternative would be the same as those discussed for the Proposed Action Alternative. 4.13 Water Resources 4.13.1 Surface Water The analysis area for surface water is Beaver Creek from the Bernie Ditch diversion to Shell Creek at the Bighorn River. This is the reach of the surface water system that would be affected by diversions to and releases from storage by the LREP. 4.13.1.1 Anticipated Impacts and Issues Expanding Leavitt Reservoir would change the flow regime in Beaver and Shell creeks. Water would be diverted at a different, more downstream location than it is currently, and diversions to the expanded reservoir could both be greater and last longer than diversions to the existing reservoir. Thus spring and early summer flows below the proposed diversion point would be lower than they are currently. On the other hand, the purpose of the reservoir is to re-time streamflow, saving it during the runoff season and making it available through reservoir releases when irrigation demand exceeds the natural supply. In the late irrigation season, water would be released from the expanded reservoir, resulting in flows that are higher than they are currently, in the section of Beaver Creek below the confluence with Davis Draw. In the Shell Creek Basin below Beaver Creek, streamflow would be affected due to increased irrigation return flows. Because LREP will afford downstream irrigators larger diversions in late summer, greater return flows would accrue to the stream in late summer and into the fall. In summary, streamflow would change, but the nature of the change would depend on the location (e.g., above or below the reservoir supply diversion, above or below the transfer pipeline, etc.) and time of year. The expanded Leavitt Reservoir would have a capacity to 6,604 AF, compared with the capacity of the existing Leavitt Reservoir of 643 AF. The LREP represents a more than nine-fold increase in impounded water.

4-22 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 4 – Environmental Impacts

Impacts to surface water use would consist of increased consumption of irrigation water because the reservoir supports water availability when it is most needed by crops. Current users with water rights would not be deprived of supply by the expanded Leavitt Reservoir, because the reservoir would capture only unappropriated water that would otherwise flow downstream and into the Bighorn River. In other words, Wyoming’s water rights administration would allow the expanded Leavitt Reservoir to fill only after downstream senior users were satisfied. Section 4.13.1.2 describes the approach taken to identify and summarize changes in streamflow associated with each action alternative. Sections 4.13.1.4 and 4.13.1.5 describe results of the impact analysis for the action alternatives which is supported by comprehensive data reported in Appendices 4.13.1-A and 4.13.1-B. 4.13.1.2 Approach for Action Alternatives Wenck Associates, Inc. (Wenck) developed a surface water allocation model of the Shell Valley Watershed that represents the native water supply in Shell Creek and its tributaries, and administration of the water under Wyoming’s water rights and historical water using practices. The model is a node network model, with numerous individual nodes at points where water is removed from or added to a stream, such as ditches, reservoirs, and tributary confluences. The Wenck Shell Valley Model operates from 1971 through 2016. Two future conditions were analyzed for the LREP: the Proposed Action Alternative and the Operational Alternative. The general approach to the impact analysis for each alternative was to analyze “side-by-side” model runs, one with the existing 643-AF Leavitt Reservoir (“the baseline run”), and the second with the expanded 6,604-AF Leavitt Reservoir in place (either the ”Proposed Action Alternative” or the “Operational Alternative” run, as appropriate). The impact to surface water flow due to the LREP at any modeled location was then determined by differencing the time series of streamflow at that node from the baseline model and the time series of streamflow at that same node from the respective alternative model. This modeling approach generates a huge number of data points for each side-by-side pair of model runs: flow at scores of nodes for over 400 time steps for two scenarios. To create a summarized characterization of flow change, eleven locations were selected as points of interest, as shown on Figure 4-1 in Appendix 2. Annual virgin flow in Beaver Creek below the confluence of North and South Beaver creeks was analyzed to categorize each year of the study period as dry, normal, or wet using a 20/60/20 percentile delineation. For each point of interest and each hydrologic condition, average flow and median flow by month were calculated. Absolute and percent differences in these monthly values were calculated. Complete results of this analysis are presented in Appendices 4.13.1-A and 4.13.1-B. 4.13.1.3 Impacts to Surface Water from the No Action Alternative The No Action Alternative reflects continuation of historical practices with the currently sized Leavitt Reservoir. There would be no difference between baseline conditions and the No Action Alternative, so there would be no additional impact to the surface water resource. 4.13.1.4 Impacts to Surface Water from the Proposed Action Alternative Because the reservoir would be designed to fully contain the probable maximum flood (PMF), the likelihood of discharge over the spillway would be extremely remote. Therefore, impacts to the existing natural channel downstream of the spillway would not be anticipated. Long-term Impact Long-term impacts are changes in surface water flow, relative to existing flows, from the time the reservoir begins to operate as an irrigation supply reservoir until the reservoir is abandoned or modified in the future. The Proposed Action Alternative was modeled with the additional 5,961 AF of storage capacity that is filled with a junior water right from a new diversion point (downstream from the prior diversion) on Beaver Creek. There was also a provision that the junior reservoir fill water right would be subject to a 5 cubic feet per second (cfs) minimum bypass requirement. That is, only streamflow above 5 cfs would be diverted to storage, and no storage diversions could be made if streamflow was less than 5 cfs. Furthermore, the reservoir would release to enable an upstream diversion by exchange only if more than 5 cfs was flowing in the intervening stream reach. The streamflow resulting from these proposed operating parameters for the expanded Leavitt Reservoir was compared to the baseline streamflow dataset (see baseline description above) for normal, wet, and dry conditions.

Leavitt Reservoir Expansion Project – Final EIS – 2019 4-23 Chapter 4 – Environmental Impacts

Relocation of the reservoir feeder to a downstream point in the LREP would result in greater flow in the reach between the former diversion and the proposed LREP diversion during the fall and early winter. This is the period when the existing Leavitt Reservoir fills. The average increase in monthly flow rate would be generally 5 cfs or less. The reach below the proposed LREP diversion point would be impacted in the spring runoff months, generally April, May, and in some years, June, when LREP would fill. These decreases in flow rate are on the order of approximately 10 cfs. Differences in both cases are related to diversions at the respective diversion sites. The Beaver Creek reach from the LREP release point to the proposed transfer pipeline would be impacted during April, May, and June as the impacts described above for Beaver Creek below the proposed LREP diversion point would be translated downstream. However, this reach would be most affected during the months that LREP would release to irrigators. In July of dry years, the average difference in flows would be approximately 30 cfs. Differences are less pronounced in average years and there is little difference in flows in wet years. Since much of the reservoir release would be taken in to the transfer pipeline, Beaver Creek flow below the transfer pipeline would be affected only slightly in July and August, as small amounts of the reservoir release would be delivered to irrigators below the transfer pipeline. These impacts would be greater in dry years than average years, and there would be virtually no difference in flows in wet years. Shell Creek below the Beaver Creek confluence would be affected in April, May, and June as the impacts of filling LREP translate downstream. The impact in terms of flow rate would be virtually the same as it would be for Beaver Creek below the proposed LREP diversion, but as a percentage of Shell Creek’s flow, the impact is much smaller. Immediately below the Beaver Creek confluence, July through September flows are virtually the same except for dry years when average monthly flows are lower by approximately 1 or 2 cfs. At the mouth of Shell Creek, flows would increase slightly in July, August, and September, due to irrigation return flow from lands served by LREP. The difference is greater for dry and average years than it is for wet years. Charts and tables showing average monthly flows at eleven locations by hydrologic condition, for baseline and Proposed Action Alternative are included in Appendix 4.13.1-A. The locations are shown in Figure 4-1 in Appendix 2. Appendix 4.13.1-B is a similar presentation but shows median rather than average flows. Short -term Impact There would be short-term impacts on streamflow from the LREP due to disruption of historical streamflow patterns during dam construction. Wenck has estimated that construction will take nearly two years, so it is expected that two irrigation seasons would be affected by construction. During these two seasons users would presumably be able to divert under their direct flow rights but they would not get any benefit from either the existing Leavitt Reservoir or the LREP. The existing Leavitt Reservoir fills during fall and winter months at a rate of no more than 15 cfs, and typically at 5 cfs more or less. Accordingly, fall and winter flows in Beaver Creek below the existing Leavitt Reservoir diversion would be expected to be slightly higher during two non-irrigation seasons affected by construction. Conversely, late summer flows below Leavitt Reservoir would be slightly lower than they have been historically as there would be no releases to support irrigation. Water use would be affected during two irrigation seasons within the construction period, since there would be no storage under either the existing Leavitt Reservoir or the expanded Leavitt Reservoir during this time. Late summer irrigation supply would be reduced. 4.13.1.5 Impacts to Surface Water from the Operational Alternative Long-term Impact Long-term impacts are changes in surface water flow, relative to existing flows, from the time the reservoir begins to operate as an irrigation supply reservoir until the reservoir is abandoned or modified in the future. The Operational Alternative for the LREP differs from the Proposed Action Alternative in that there would be no minimum stream bypass of 5 cfs at the pipeline diversion to fill the expanded Leavitt Reservoir. Under this scenario, Beaver Creek below the reservoir supply pipeline would be dried up frequently during any month from October through March. In the Proposed Action Alternative model (with the 5 cfs bypass in place), Beaver Creek would be dewatered in approximately half the Octobers, a quarter of Novembers, Decembers, and Januarys, and only a few of the remaining winter months. The dewatering is due to operation of Leavitt Reservoir’s existing senior fill right which is not subject to the bypass requirement. In the Operational Alternative, any flow available

4-24 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 4 – Environmental Impacts after the senior fill right is satisfied would be diverted to Leavitt Reservoir. This results in dewatering in most months of October through March. However, the time required to fill the expanded Leavitt Reservoir would be slightly reduced, relative to the Proposed Action Alternative, as the change could allow up to approximately 10 additional acre-feet of water to be placed in storage each day that diversions occur. Accordingly, April and May flow rates are at times higher in the Operational Alternative than in the Proposed Alternative because Leavitt Reservoir is done filling during these months. Charts and tables showing average monthly flows at the eleven sites described above, by hydrologic condition, for baseline and the Operational Alternative are included in Appendix 4.13.1-A. Appendix 4.13.1-B is a similar presentation but shows median rather than average flows. Short -term Impact Short-term impacts of the Operational Alternative would be the same as the short-term impacts for the Proposed Action Alternative. Wenck has estimated that construction will take nearly two years, so it is expected that two irrigation seasons would be affected by construction. During these two seasons users would presumably be able to divert under their direct flow rights but they would not get any benefit from either the existing Leavitt Reservoir or the LREP. 4.13.2 Water Quality The analysis area for water quality extends from the proposed diversion structure on Beaver Creek, downstream to the confluence of Shell Creek and the Bighorn River. The area also includes the proposed expanded Leavitt Reservoir and its upstream contributing watershed. Impacts to water quality from the LREP would occur as a result of changes to stream flow rates and timing. Because the stream flow changes would be the catalyst of the water quality impacts, they have been used as the impact indicator. The average values representing the predicted magnitude of stream flow changes were used as the specific indicator because these values appear more sensitive to the modelled changes than the median values during normal and wet years, and generally showed a higher magnitude of impact (greater change in stream flow) throughout the year. Four specific locations that were modelled for changes to stream flow were analyzed to illustrate the changes relevant to water quality impacts, including Beaver Creek above the proposed diversion, Beaver Creek below the proposed diversion, Beaver Creek below the release point, and Beaver Creek below the transfer pipeline. Additionally, because limited and qualitative water quality monitoring data is available, no quantified changes to water quality from the LREP were estimated, and the analysis relied upon extrapolation of the existing condition across the modelled flow changes for a qualitative assessment of water quality changes. 4.13.2.1 Impacts to Water Quality from the No Action Alternative Continued operation of the existing Leavitt Reservoir would result in continuation of the current water quality. The streams would be managed to fall within total maximum daily loads (TMDLs) for Escherichia Coli (E. coli), and the streams would continue to meet the designated uses. No impacts to water quality or the designated beneficial uses would occur from the development or operation of the LREP under the No Action Alternative. 4.13.2.2 Impacts to Water Quality from the Proposed Action Alternative Under the Proposed Action Alternative, bare ground caused by construction disturbance could erode, causing an increase to sediment loading in Beaver Creek during periods of surface runoff from snowmelt or precipitation events. To avoid or minimize this impact, the LREP would be required by the Wyoming Department of Environmental Quality (WDEQ) to obtain a Construction Stormwater Permit and employ erosion control measures as detailed through the preparation and implementation of a Stormwater Pollution Prevention Plan (SPPP). Operation of construction equipment and related activities would pose an increased risk of water contamination from spills or releases of hazardous materials. If the LREP construction contractor requires 1,320 gallons or more of above ground hazardous liquids storage (e.g., fuel, motor oil, hydraulic fluid), the U.S. Environmental Protection Agency (USEPA) regulations require that a spill prevention, control, and countermeasures (SPCC) Plan be prepared and implemented to avoid or minimize the risk and plan the actions to be taken in the event of an unanticipated release. Diversion of additional water from Beaver Creek during spring runoff for early-irrigation season (May and June) storage in the LREP would decrease the volume of water in the creek, and create potential downstream effects on

Leavitt Reservoir Expansion Project – Final EIS – 2019 4-25 Chapter 4 – Environmental Impacts temperature, dissolved oxygen, suspended sediment, and other factors dependent on quantity of water. The new diversion would decrease flow that would normally dilute constituents downstream from the diversion point. Likewise, water released from LREP during the late-irrigation season (July and August) and then diverted into the transfer pipeline could also decrease dilution of constituents downstream from the diversion point. Storage of additional water in the expanded Leavitt Reservoir could alter the quality of water through increases in water temperature from solar heating, which in turn can cause stratification and may raise total dissolved solid (TDS) levels, promote E. coli and coliform growth and decrease dissolved oxygen levels as evidenced from recent monitoring (see Section 3.13) (Wenck 2017a); however, the short storage period of just a few months from diversion during spring runoff until release to meet late summer irrigation water shortage demands would minimize these changes. The geology of the reservoir site is not anticipated to affect the water quality in the reservoir or downstream reaches based on water quality data collected from the existing Leavitt Reservoir. Fencing to exclude livestock would reduce the effects of grazing on the LREP from the existing condition, reducing a direct source of fecal coliform and E. coli to the reservoir. Wetlands have been shown to improve water quality, with a high percentage of bacterial pathogens being removed from water as it passes through a wetland, with removal efficiencies of E. coli may approach 90 percent (Diaz et al. 2010; Karim et al. 2008), indicating their use in improvement in water quality is an effective measure. The North and Rim wetlands that are proposed at the inlet to the reservoir will increase water quality before its storage. Additionally, the South Wetland proposed at the outlet of the reservoir will have a similar effect on water released from storage when the water is released above and passes through the wetland. Release of stored water from the expanded Leavitt Reservoir under the Proposed Action Alternative would transfer the changed water quality to the receiving Beaver Creek, affecting the reaches between the reservoir outlet and the diversions for irrigation use. These releases would also increase the stream flows during late-season irrigation, affecting the timing of the existing hydrologic processes. Additionally, suspended sediment levels would likely increase temporarily in the immediate area downstream of the release point to Beaver Creek each year with the start of the increased flows. Modelled flow changes indicate that additional diversion of water for reservoir storage would occur during spring runoff, when the limited available water quality monitoring data appear to indicate water quality is generally shifting from its best during the late winter and early spring (e.g., high dissolved oxygen, low TDS, sampling occurrences with no E. coli detected per Wenck 2017a) to a more degraded state during the early summer months of June and July (WDEQ 2013c), presumably from mobilization of pollutants from surface runoff. By capturing and storing the better-quality early season water for release at later points in the year, it is anticipated that reservoir releases would increase water quality in the receiving reaches of Beaver Creek through the release of that water during low-flow periods when E. coli and higher TDS water is found in the creek. However, diversion of water for reservoir storage will reduce the streamflow in downstream reaches and potentially increase concentrations of E. coli from reduced flows for dilution. Additionally, water diverted with degraded water quality and higher E. coli concentrations could lead to water quality issues in the reservoir, and subsequent releases would be largely affected by factors such as the reservoir’s preexisting E. coli concentration, the time the water is stored in the reservoir and the E. coli growth rate. These uncertainties limit the ability to predict decreases or increases to water quality. The dry year scenario shows the largest increase in flows during the month of July, which has the potential to create the largest effect to water quality, whether beneficial or adverse. Due to the fact that the reservoir is designed to fully contain the PMF, the likelihood of discharge over the spillway would be extremely remote. Therefore, impacts to the existing natural channel downstream of the spillway would not be anticipated. Land uses in the area would not experience major changes from baseline conditions under the Proposed Action Alternative; the minor areas that would change would be the proposed inundation and recreation areas shifting from current grazing uses. This would be a negligible shift resulting in little to no change from the current water quality conditions. The designated beneficial use of recreation may be affected as noted in the discussion of E. coli above. Measures to minimize and mitigate these effects are contained in Section 4.16. Effects to other beneficial uses of these Class 2AB waters are not anticipated to be major or to impair the uses.

4-26 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 4 – Environmental Impacts

4.13.2.3 Impacts to Water Quality from the Operational Alternative Impacts to water quality under the Operational Alternative would be the same as those described under the Proposed Action Alternative with exceptions related to the lack of bypass flows. This alternative would decrease the ability of Beaver Creek to dilute flows high in TDS or E. coli below the LREP diversion during the winter months when flows are nearly zero. However, because the magnitude of flows measured during these months in the existing condition are minimal (e.g., 2 cfs or less), the overall effect of flows nearing zero would not be substantial. 4.13.3 Stream Morphology The existing stream morphological conditions have been altered and impacted by the operation of the current Leavitt Reservoir, numerous irrigation diversions, agricultural uses, and developments associated with channel realignment, roads, bridges, and other structures in the analysis area as described in Section 3.13.3. The predicted morphological response from the alternatives is described in the context of expected hydrological conditions to move sediment and water, coupled with proposed operational changes to existing flows. 4.13.3.1 Impacts to Stream Morphology from the No Action Alternative The No Action Alternative would have no impact on the ephemeral, intermittent, and Davis Draw tributaries. The effects of the No Action Alternative on Beaver Creek and Shell Creek stream morphology would be a continued trend towards reduced cross-sectional geometry and a change in channel form. Current channel geometry is vertically and horizontally unstable due to a loss of riparian vegetation, agriculture, irrigation diversions, and road encroachments. Habitat features are homogenized by an increase in fine sediment load (bank erosion) and decreased hydraulic capacity to move it (reduced flow). 4.13.3.2 Impacts to Stream Morphology from the Proposed Action Alternative Hydrologic alterations are complex and impact different facets of the natural flow regime in respect to wet/dry/normal water years flow duration and volume. The Proposed Action Alternative would result in a greater reduction to peak flows during wet water years as compared to normal years. Wet water year flows are important for a deeper profile in bed material movement, uplifting imbricated sediments, transporting larger size sediments, and re-sorting of depositional features (Schmidt 2004). The Proposed Action Alternative would incrementally impact the magnitude of these events, exacerbating existing channel contraction and homogenization of habitat complexes. Similarly, during dry water years, the Proposed Action Alternative would reduce peak flows. During dry water years, especially those occurring in consecutive years, channel aggradation would likely be an issue leading to localized bank erosion. More predominately in the lower Reach 3, where the alluvial channel is a losing stream. The Proposed Action Alternative would reduce the average stream flow in Beaver Creek during normal water years by 30 percent (Reach 1), 31 percent (Reach 2), and 32 percent (Reach 3) in May (B&C 2018). Bankfull flows typically occur mid-May to mid-June, for approximately a 21 day period. Streamflow measurements within the LREP reach were obtained to provide operational flow data (Wenck 2017a). The available streamflow baseline information is limited for making a deterministic analysis to approximate channel-forming discharge (bankfull flows), or other morphological event flows important for maintaining floodplain dynamics. Single high magnitude flows of varying magnitude are more important than frequent small to medium flows for providing floodplain aquifer recharge, riparian plant composition, replenishing channel features, and causing floodplain profile shifts relative to the water table. The LREP would have an effect on bankfull flows, and other flow events that occur during wet water years (i.e., the 5-year and 10-year return interval), with a compounding consequence proceeding dry periods. Annual peak flows within Beaver Creek are in response to snowmelt, whereas the ephemeral and intermittent tributaries peak flows are in response to individual events, such as high intensity rainfall events, or rapid snowmelt events. Regional curves are useful aids for estimating bankfull discharge at ungagged sites, particularly where field indicators of bankfull stage are not apparent, such as actively incising or degrading stream channels (Foster 2009). Regional curves developed for the Rocky Mountain Hydrologic Region in Wyoming with below 25 inches mean annual precipitation were used to relate drainage area to bankfull discharge and bankfull width (Foster 2009). 0.73 2 Bankfull Discharge Qbkf (cfs) = 24.55 x Drainage Area (sqMi) R = 0.77

Leavitt Reservoir Expansion Project – Final EIS – 2019 4-27 Chapter 4 – Environmental Impacts

0.44 2 Bankfull Width Wbkf (ft) = 8.22 x Drainage Area(sqMi) R = 0.80 Table 4-15 in Appendix 1 is the summary of existing and predicted regional curve bankfull width and discharge. The Proposed Action Alternative would include a supply structure with a 75-cfs capacity, which reduces the bankfull flow by 20 percent in Reach 1, 13 percent in Reach 2, 12 percent in Reach 3 and 3 percent in Shell Creek. The capacity to reduce bankfull flows by 75 cfs would include the existing hydrological alteration to fill Leavitt Reservoir. The Proposed Action Alternative would incrementally reduce the magnitude and duration of bankfull flows, which would consequently affect the frequency of these events. The incremental reduction to bankfull flows from the Proposed Action Alternative would have the potential to exacerbate the current trend in channel narrowing and shift the channel form as described through the channel evolution process (Rosgen 1994). Table 4-16 in Appendix 1 provides a summary of the predicted stream morphological impacts due to decreased bankfull flows. The Proposed Action Alternative would increase average normal year flows by up to 65 percent in Reach 2a and 83 percent in Reach 2c, during the irrigation period in July and August (B&C 2018). These flows are not of sufficient magnitude to be a channel forming discharge, however they could negatively impact channel stability by eroding bank materials at the lower level of the bank, at exposed roots, and sparsely vegetated bank faces, exacerbating channel incision. Within Reaches 2a and 2c, where the channel is already incised, and areas that lack riparian vegetation, the channel is not stable. The increase in average normal year stream flows during July and August under the Proposed Action Alternative would further destabilize these areas. The modified diversion structure for the proposed transfer pipeline could create localized impacts. In summary, the Proposed Action Alternative would impact Beaver Creek by an incremental reduction in the cross-sectional geometry, perpetuating the shift in the channel evolution process. The Proposed Action Alternative would add to the current trend in channel narrowing, incision, vegetation encroachment, reduced sediment transport capacity, and associated changes in the channel profile, planform, and substrate. The incremental reduction to flood flows would result in a corresponding reduction in overbanking flows, floodplain form, associated infiltration, and the riparian water table. The Proposed Action Alternative would incrementally reduce the habitat complexity and add to simplification of the channel. Shell Creek: The Proposed Action Alternative would reduce the average stream flows during the peak runoff period by 4 percent (B&C 2018), and a capacity to reduce bankfull flows by approximately 3 percent. The reduction to stream flows would be negligible in terms of other stream morphology impacts. Davis Draw: No hydrological data was evaluated to predict the proposed changes in flow regime to Davis Draw under the Proposed Action Alternative. Under current operations, flows are diverted from two ditches that then deliver flows through Davis Draw before being diverted to fill Leavitt Reservoir. Under the Proposed Action Alternative, flows from Davis Draw would no longer be diverted, and there would be a reduction in flows within the segment used to fill the current Leavitt Reservoir. Davis Draw would likely contract back to its original form prior to being used for water delivery. Intermittent Channels: The effects from the Proposed Action Alternative on the channel morphology of intermittent channels would be the complete loss of the resource throughout the entire length (14,528.5 linear feet) of the channels inundated by the backwater of the proposed reservoir expansion. This total length includes the channel that would be changed into a wetland marsh at the upstream end. Sediment supplied to Beaver Creek from these channels is already captured by the existing reservoir. Due to the fact that the reservoir would be designed to fully contain the PMF, the likelihood of discharge over the spillway would be extremely remote. Therefore, impacts to the existing natural channel downstream of the spillway would not be anticipated. 4.13.3.3 Impacts to Stream Morphology from the Operational Alternative Impacts to stream morphology under the Operational Alternative would be the same as those described under the Proposed Action Alternative. The Proposed Action Alternative bypass flow of 5 cfs would have benefits associated with surficial fine sediment transport to reduce accumulation, and maintain low-flow pool depths and water depths for aquatic passage over structures; however, this bypass flow would not be of sufficient magnitude to cause negative or positive impacts to stream morphology.

4-28 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 4 – Environmental Impacts

4.13.4 Groundwater Resources The LREP analysis area for groundwater resources extends from Beaver Creek near the existing Leavitt Reservoir diversion on the upstream end, to the confluence of Shell Creek and the Bighorn River on the downstream end. The analysis area encompasses the current Leavitt Reservoir and proposed disturbance footprint, which includes the transfer pipeline that would connect Beaver Creek to Shell Canal. This area was selected for analysis because it includes the entire disturbance footprint associated with the LREP, and also spans the areas of Beaver Creek and Shell Creek where groundwater-surface water interactions could be affected by changes in the volume and timing of surface water flows. 4.13.4.1 Impacts to Groundwater Resources from the No Action Alternative No direct impacts to groundwater resources would occur from the No Action Alternative. The existing Leavitt Reservoir would continue to function under current operational protocols, with reservoir storage supplied by surface water diversions from Beaver Creek and Davis Draw. Indirectly, the No Action Alternative could increase reliance on groundwater pumping as a way to offset irrigation shortages. A previous study for the LREP ruled out a groundwater supply alternative due to the impracticality of installing enough wells to provide the same firm yield that would be achieved by expanding Leavitt Reservoir. The study estimated that 60 deep aquifer wells would be needed to provide the same average July dry period shortage reduction as the LREP, with an average installation cost of $1.4 million per well (Wenck 2017e). Still, under the No Action Alternative, some landowners affected by irrigation shortages could have no choice but to permit and drill additional wells to augment irrigation supplies when their surface water rights are out of priority. This could result in a dispersed but long-term impact throughout the LREP analysis area, with numerous low-yield irrigation wells installed in the Quaternary or Lower Cretaceous aquifers. The net effect of these actions would be to irreversibly deplete non-renewable groundwater from the aquifers targeted by the new water supply wells. Indirect impacts to the Paleozoic aquifer system from the No Action Alternative would likely be negligible. As discussed in Chapter 3, the Paleozoic aquifers are separated from the Lower Cretaceous aquifers by a thick confining layer. Consequently, drilling a deep well into the Paleozoic system would likely prove cost-prohibitive for most landowners in the analysis area. 4.13.4.2 Impacts to Groundwater Resources from the Proposed Action Alternative Construction Impacts Under the Proposed Action Alternative, construction of the earthen dam embankment would remove approximately 1.4 million cy of rock from Quaternary terrace deposits and the Cloverly Formation. The terrace deposits would be excavated across an area of 70.9 acres as part of borrow areas 1 and 2 (Table 4-1 in Appendix 1). The Cloverly Formation would be excavated for fill material from within the expanded reservoir pool. The exact dimensions of the reservoir pool excavation have not been quantified, but would not exceed the limits of the NHWL of the expanded reservoir. Both the terrace deposits and Cloverly Formation are considered viable aquifers in the analysis area. Water-bearing zones within these units would be permanently impacted under the Proposed Action Alternative as geologic material that transmits groundwater is removed. Since both aquifers are present at or near ground surface, groundwater in these formations is assumed to exist under unconfined conditions. The likelihood of encountering water-bearing zones in the borrow areas therefore depends on the depth of the planned excavations and the static water level depth within each geologic unit. In the vicinity of the LREP, static water level information is not available for the Quaternary terrace deposits; however, for the Cloverly Formation, the depth to water is expected to range from about 31 to 44 feet below ground surface (bgs) (Wyoming State Engineer’s Office [SEO] 2016). The depth to water beneath the expanded reservoir area is likely even shallower because portions of the Cloverly Formation in this area are already submerged by the existing reservoir, and seepage from the reservoir provides a continuous source of groundwater recharge. Thus, excavations for the Proposed Action Alternative could intercept groundwater in the Cloverly Formation (and possibly the terrace deposits), which may require dewatering for the excavations to continue below the water table. The proposed earthen dam embankment could also impact groundwater since the dam cut-off trench would be excavated into bedrock. Construction of the dam embankment would directly impact 21.7 acres of the Cloverly aquifer (Table 4-1 in Appendix 1). Possible foundation treatments for the dam include a triple row grout curtain

Leavitt Reservoir Expansion Project – Final EIS – 2019 4-29 Chapter 4 – Environmental Impacts or a barrier wall that extends through the Cloverly Formation Unit V mudstone and sandstone. If a grout curtain is used, injection of grout into the underlying formation could impact groundwater chemistry. Studies in the literature suggest that these impacts would likely be negligible, and may include increased groundwater pH, as well as short-term variations in alkalinity, calcium, sodium, and potassium concentrations (Gascoyne 2002; Eiswirth et al. 1999). Other constructed features of the LREP would have little direct impact on groundwater aquifers, because the required excavations would be limited to soil horizons and shallow bedrock above the saturated zone. This applies to the 0.87-mile Bear Creek Road raise, auxiliary spillway, and temporary disturbance areas associated with the primary outlet works, water supply pipeline, and transfer pipeline. Groundwater supply effects from constructing the LREP would be limited to depletions from potential dewatering of the excavation borrow areas (if necessary). Water requirements for embankment compaction, dust control, and vehicle washing would be supplied entirely from surface water sources. Accidental leaks or spills of chemicals used during construction could potentially impact shallow groundwater quality without prompt action to clean up the spill and contaminated soil material. Construction of the LREP could impact existing groundwater wells. Well records from the Wyoming SEO (2016) indicate that there are two wells (permit numbers P109355.0W and P174689.0W) in the LREP disturbance footprint. Both wells fall within the proposed borrow pits east of Bear Creek Road. No other wells were identified within approximately 0.5 mile of the proposed borrow pit locations. Other groundwater wells outside of the LREP disturbance footprint could be impacted if the wells are close to the construction area and blend in with the surrounding landscape. Appurtenant well piping could also be damaged by subsurface excavations if buried piping associated with the wells extends beneath the construction footprint. In addition to the two wells that plot inside the proposed borrow pits, there are three other permitted wells within 150 feet of the LREP (Table 4-17 in Appendix 1). The three wells are located along access roads and the proposed transfer pipeline alignment in the southern portion of the LREP disturbance footprint. These wells could potentially be damaged by vehicle traffic or heavy equipment during construction if mitigation measures are not implemented. As discussed in Chapter 3, there are no mapped springs within 0.5 mile of the LREP. Consequently, the Proposed Action Alternative would have no impact on groundwater springs. Operational Impacts The expansion of Leavitt Reservoir could affect groundwater supplies by changing the location, timing, and amount of groundwater recharge. A quantitative analysis of groundwater recharge impacts is not possible due to the lack of published recharge rates for the analysis area, and the overall difficulty of obtaining reliable recharge estimates. From a qualitative standpoint, the LREP could indirectly impact groundwater recharge in the Beaver Creek and Shell Creek alluvial aquifers because recharge of these aquifers is heavily dependent on stream flow and surface water-groundwater interactions. In the Beaver Creek alluvial aquifer, groundwater recharge is likely concentrated in the spring and early summer months when the creek stage is above the water table in the adjacent alluvium. The difference in hydraulic potential between the creek stage and the water table creates a gradient which causes surface water to seep through the stream bed into the alluvial aquifer. The volumetric seepage rate is directly proportional to the hydraulic gradient; thus, as stream flow decreases over the summer and the stream stage drops, recharge from seepage gradually declines until the creek changes from a losing to gaining condition. This situation reflects the existing condition of groundwater-surface water interactions in Beaver Creek. A stream flow analysis of the Proposed Action Alternative indicates that Beaver Creek would experience an overall decline in flow during the May through July peak flow period when seepage and aquifer recharge are highest. At Beaver Creek below the proposed Leavitt Expansion diversion, average May through July stream flow in normal water years would decrease by 19.1 cfs, or 16 percent (B&C 2018). These flow changes would likely cause groundwater levels in the alluvial aquifer to decline between the proposed diversion and the reservoir release point to Beaver Creek. Below the release point, average stream flows from May to July are predicted to decrease by 7.9 cfs, or 6 percent, in normal water years (B&C 2018). The smaller flow decrease below the release point would be due to planned discharges from the reservoir in July to offset irrigation shortages. Overall, the decrease in groundwater recharge along these segments would lead to a long-term groundwater level decline within the alluvium downstream from the proposed Leavitt Reservoir diversion.

4-30 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 4 – Environmental Impacts

It should be noted that groundwater level impacts would not be uniform across the entire Beaver Creek alluvial aquifer. Because the proposed Leavitt Expansion diversion is downstream of the existing diversion, aquifer recharge and groundwater levels would likely increase upstream of the proposed diversion as perennial flow is restored to this segment of the creek. During normal water years, average stream flows between the existing and proposed diversions would remain largely the same during the May through July peak flow period, but are predicted to increase by as much as 600 percent during the autumn and winter dry season (B&C 2018). The dry season flow increases would help maintain higher alluvial groundwater levels year-round above the proposed Leavitt Expansion diversion. In Shell Creek, stream flows are predicted to decrease below the Beaver Creek confluence. The predicted decrease in the May to July timeframe during a normal water year would be around 20.0 cfs (B&C 2018). Although this decrease would be similar to predicted flow decreases in Beaver Creek, it would represent a smaller proportion of the total flow because Shell Creek is a much larger stream. Any reduction in recharge or groundwater levels in the Shell Creek alluvial aquifer from these flow changes would likely be negligible. The decreases in stream flow, seepage, and alluvial groundwater recharge essentially represent water that would be “captured” by diversion into the expanded Leavitt Reservoir. The diverted water would not be entirely lost from the groundwater system if some of it seeps through the dam abutments or through geologic strata underlying the reservoir pool. On the east side of the proposed reservoir expansion (i.e., left abutment), the Cloverly Formation contains layers of high permeability sandstone interbedded with low permeability mudstone. The existing Leavitt Reservoir has experienced significant seepage through the sandstones in this area. The sandstones also pose a seepage risk under the Proposed Action Alternative, with potential seepage rates through the left abutment estimated to be as high as 100 acre-feet per year (AF/yr) (Wenck 2015). The final LREP design would incorporate control measures to limit seepage losses. As shown on Figures 3-1 and 3-2 and in Table 4-18 in Appendix 1, the Cloverly Formation would be the uppermost geologic unit beneath the vast majority of the expanded reservoir pool. As the Cloverly is submerged, groundwater recharge would increase through weathered or fractured zones in the formation, or through permeable sandstone layers exposed near ground surface. The total seepage flux into the Cloverly Formation could increase by a factor of four since the expanded reservoir surface area would be approximately four times larger than the existing reservoir. A four-fold increase in the recharge flux would increase the saturated thickness of the Cloverly aquifer immediately below and adjacent to the reservoir. This increase in saturated thickness would not likely extend to nearby groundwater supply wells since so few wells have been installed in the vicinity of the existing reservoir. Groundwater quality impacts from mixing of different water types may also be possible as water discharges from the expanded reservoir through seepage or planned releases. As discussed above, seepage through the reservoir bottom could cause reservoir water to mix with native groundwater in the Cloverly Formation. Mixing could also occur between reservoir water and Beaver Creek alluvial groundwater due to releases from the primary outlet works. Table 4-18 in Appendix 1 compares average groundwater quality in the Cloverly and Quaternary aquifers to surface water quality in Beaver Creek and the existing Leavitt Reservoir. A review of the table reveals that pH is higher and TDS concentrations are lower in the surface water samples compared to native groundwater. This finding suggests that infiltration of reservoir water into the Cloverly Formation or Beaver Creek alluvium would likely decrease groundwater TDS concentrations through dilution, while also raising the groundwater pH. Any reduction in TDS would help make the affected groundwater more suitable for domestic and agricultural uses, as long as the groundwater pH remained below the domestic (i.e., Class I) groundwater standard of 8.5 pH units. 4.13.4.3 Impacts to Groundwater Resources from the Operational Alternative Construction Impacts Groundwater impacts from construction of the Operational Alternative would be the same as the Proposed Action Alternative. Operational Impacts The Operational Alternative would distribute diversions more evenly throughout the year because no minimum bypass flow would have to remain in Beaver Creek (the minimum bypass flow for the Proposed Action Alternative would be 5 cfs). Fall and winter months when the average creek flow is typically less than 5 cfs would therefore supply a greater share of annual diversions under this alternative. As a result, flow would be

Leavitt Reservoir Expansion Project – Final EIS – 2019 4-31 Chapter 4 – Environmental Impacts maintained at a higher level in Beaver Creek during the peak flow period from May to July. Stream flow analysis for the Operational Alternative indicates that the flow in Beaver Creek below the proposed Leavitt Reservoir diversion would decrease by 14.8 cfs, or 12 percent, during a normal water year. Likewise, the normal water year stream flow below the release point to Beaver Creek would decrease by 2.5 cfs, or 2 percent, during the same period (B&C 2018). These numbers compare favorably to the Proposed Action Alternative where a greater decrease in flow is predicted during the May to July timeframe. The stream flow differences between the Proposed Action Alternative and Operational Alternative are summarized in Table 4-19 in Appendix 1. The lower reduction in stream flow under the Operational Alternative would promote more favorable conditions for groundwater recharge by maintaining a higher stream stage in Beaver Creek during the peak flow period. Thus, long-term groundwater levels in the Beaver Creek alluvium would likely be higher under the Operational Alternative than the Proposed Action Alternative. However, the No Action Alternative would still have the smallest impact on the alluvial aquifer, with no new reservoir-related changes occurring to long-term stream flows, stream seepage, or groundwater levels. Similar to the Proposed Action Alternative, the Operational Alternative would have a negligible impact on stream seepage and groundwater levels in the Shell Creek alluvial aquifer. The average normal water year peak flow reduction in Shell Creek below the Beaver Creek confluence is predicted to be 14.5 cfs, or 1.6 percent of the total creek flow (Table 4-19 in Appendix 1) (B&C 2018). Other recharge and groundwater quality impacts from the Operational Alternative would be the same as those described for the Proposed Action Alternative. 4.14 Wildlife and Aquatic Biological Resources 4.14.1 Terrestrial Wildlife The analysis area for terrestrial wildlife is the 1-mile buffer around the LREP disturbance footprint. The analysis area extends beyond the LREP disturbance footprint because of wildlife migration and the ability of construction activities to extend to a habitat-level effect. One mile is considered the general line-of-sight/audible distance where wildlife species could be impacted by the LREP. The temporal analysis period includes recent past and present conditions as well as the anticipated 50-year life of the LREP. 4.14.1.1 Impacts to Terrestrial Wildlife from the No Action Alternative Under the No Action Alternative, the BLM would not approve the expansion of Leavitt Reservoir and terrestrial wildlife would not be affected. Existing terrestrial wildlife habitats would not be removed, replaced, or converted in the LREP analysis area. Any effects on wildlife would result from possible agricultural, residential, or other development in the area. 4.14.1.2 Impacts to Terrestrial Wildlife from the Proposed Action Alternative Direct and indirect impacts from construction and operation activities of the Proposed Action Alternative were assessed within the LREP disturbance footprint and within 1 mile of it (this was considered the analysis area). Construction-related impacts are typically short-term or temporary in nature, while operation-related impacts are generally considered long-term because they last at least as long as a project is in operation and maintenance activities are conducted (for the LREP, that period is estimated at 50 years). Terrestrial wildlife-related issues addressed by this impact assessment were determined through the public scoping process and in consultation with the BLM and the Wyoming Game and Fish Department (WGFD). Under the Proposed Action Alternative, the primary impact issues for terrestrial wildlife would include: • Habitat loss, alteration, degradation, and fragmentation. o Direct wildlife habitat loss due to construction of LREP components (i.e., dam embankment, recreation area, and upgrades to access roads). o Habitat alteration though conversion of terrestrial wildlife habitat to aquatic habitat in the expanded Leavitt Reservoir area. o Habitat fragmentation by increasing the dam footprint and reducing connectivity for smaller wildlife species.

4-32 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 4 – Environmental Impacts

• Injury or loss of a species, displacement of individuals, and loss of reproductive success from exposure to increased human activity. o Direct mortality of wildlife due to collisions with vehicles and equipment. o Noise, dust, and visual intrusions during construction could cause wildlife to avoid suitable breeding habitat near human activity. Direct, long-term loss of terrestrial habitat would occur from the surface disturbance associated with the reservoir expansion and construction of the dam embankment, auxiliary spillway, support facilities, 0.87-mile raise of Bear Creek Road, and recreational facilities. These areas would be unavailable for typical terrestrial wildlife use during the operation of the LREP, though wildlife may still be able to traverse those areas. Flooding of the reservoir expansion area would convert approximately 197 acres of terrestrial habitat to open water lacustrine habitat. Conversion of terrestrial habitat to aquatic habitat would result in the loss and long-term alteration of existing habitat types, creating direct and permanent impacts to terrestrial species and changing local wildlife species assemblages. The expansion area would be unavailable to terrestrial wildlife species, such as small mammals, sagebrush or grassland obligate birds, and reptiles, except as a water source. The greatest short-term and long-term adverse effects (from mortality and habitat loss) would occur with reptiles, amphibians, and small mammals because these groups have smaller home ranges that could be eliminated through actions occurring under the Proposed Action Alternative. Most snake species in the area would be negatively affected by the LREP due to habitat loss. Potential direct impacts to big game species would include reduction of potential forage and increase of noxious weeds and habitat fragmentation caused by vegetation removal. However, the Proposed Action Alternative would create more wetland and riparian habitats along the edges of the reservoir area. The diversity and abundance of migratory game birds, waterfowl, shorebirds, and wading birds (e.g., western grebe, common loon) would increase due to the increased availability of such aquatic, wetland, and riparian habitats. Direct, short-term loss of terrestrial habitat would occur from the construction of pipelines, access road upgrades, borrow areas, and staging areas. These areas would be used for construction only and would be reclaimed to their existing conditions after construction was completed. However, these areas would be temporarily unavailable for wildlife use during the construction phase of the LREP. Loss of habitat would decrease forage availability, cover availability, and the number of breeding and nesting locations for bird, mammal, and reptile species that use the shrublands and grasslands in the analysis area. Habitat loss or alteration could result in direct losses of smaller, less mobile wildlife species, such as small mammals and reptiles, and the displacement of more mobile species into adjacent habitats. Surface-disturbing activities that remove vegetation and disturb soils can impact habitat quality. Temporarily or permanently removing wildlife habitats can also degrade the quality of adjacent habitats. Erosion or runoff from the surface disturbance (e.g., access roads, dam embankment) could enter adjacent habitats and cause additional soil erosion or reduce the quality of vegetation in the adjacent habitat. Because the 0.87-mile segment of Bear Creek Road what would be raised, recreational facilities, and outlet works would be void of vegetation and contain impervious surfaces, surface runoff near those components would increase and could lead to soil erosion and potential transport of pollutants to nearby habitats, including wetlands or riparian areas. Noxious weeds that often colonize along the edges of surface disturbance could spread to non-disturbed adjacent habitats, degrading habitat quality and decreasing the amount of native forage. Another indirect impact would be wildlife avoidance of otherwise suitable habitat in and around the surface disturbance. Small mammals or birds may avoid adjacent habitat due to increased exposure to predators, noise, and human presence around the LREP components during construction and maintenance activities. Project components like the 0.87-mile raise of Bear Creek Road, dam embankment, and auxiliary spillway could create wildlife barriers and alter migration patterns or species dispersal, particularly of small wildlife species like rabbits, prairie dogs, and squirrels. Habitat fragmentation from the larger dam footprint could reduce habitat connectivity and restrict animal movement for smaller, less mobile species. Fragmentation causes a reduction in usable ranges and potential isolation of smaller wildlife species. While the LREP analysis area is located within crucial winter range for elk and mule deer, the relatively small size of the LREP area compared to the size of elk and mule deer crucial winter habitats (i.e., less than 0.1 percent) makes it unlikely that actions under the Proposed Action Alternative would restrict big game movement. Big game may temporarily avoid traveling near the LREP during construction. The location of the LREP analysis area is on the western edge of elk and mule deer crucial winter range rather than in the middle of the range; this may mitigate impacts to elk and mule deer movement.

Leavitt Reservoir Expansion Project – Final EIS – 2019 4-33 Chapter 4 – Environmental Impacts

Direct wildlife mortality or injury may occur from increased traffic during construction or maintenance activities. Destruction of active nests from construction activity would also negatively impact migratory birds. Noise, light pollution, and visual intrusions during construction may cause short-term abandonment of habitat near the human activity. After construction, some species may be able to repopulate reclaimed disturbance areas and adjacent habitats. The construction phase would have short-term, localized adverse effects on wildlife from noise, light pollution, dust, and general disturbance. For example, noise pollution can harm the health, reproduction, survivorship, and abundance of wildlife species. Noise can also lead to changes in behavior, including avoidance behavior. Short-term construction effects would mainly involve displacement of individuals from disturbed areas and adjacent habitats (wildlife avoidance). Displaced individuals would be forced into neighboring territories where they would compete with already established individuals for limited food supplies and other resources. Potential temporary impacts from construction could also include nest or burrow abandonment or loss of eggs or young. This would result in a decrease in reproductive success for certain species. BLM’s CYFO Approved RMP timing limitation stipulations between November 15 and April 30 for big game crucial winter range (BLM 2015b) will reduce the active construction impacts to big game during the winter period. The project does not impact parturition areas for big game. 4.14.1.3 Impacts to Terrestrial Wildlife from the Operational Alternative The impacts to terrestrial wildlife from the Operational Alternative would be the same as those described for the Proposed Action Alternative. 4.14.2 Terrestrial Special Status Wildlife Species The analysis area for terrestrial special status wildlife is the 1-mile buffer around the LREP disturbance footprint. The analysis area extends beyond the LREP disturbance footprint because of wildlife migration and the ability of construction activities to extend to a habitat-level effect. One mile is considered the general line-of-sight/audible distance where wildlife species could be impacted by the LREP. The temporal analysis period includes recent past and present conditions as well as the anticipated 50-year life of the LREP. 4.14.2.1 Impacts to Special Status Wildlife Species from the No Action Alternative Under the No Action Alternative, the BLM would not approve the expansion of Leavitt Reservoir and special status wildlife species would not be affected. Existing terrestrial wildlife habitats would not be removed, replaced, or converted in the LREP area. Any changes to wildlife would result from possible agricultural, residential, or other development in the area. 4.14.2.2 Impacts to Special Status Wildlife Species from the Proposed Action Alternative Impacts to special status wildlife species from the Proposed Action Alternative would be the same as those described for terrestrial wildlife under the Proposed Action Alternative. However, there may be additional taxon-specific or species-specific impacts that are assessed below. The methodology for evaluating impacts to special status wildlife species focuses on those species that were identified as potentially occurring within the analysis area (see Appendix 3.14). Special status wildlife species included in this analysis include 5 mammal, 14 bird (not including migratory birds without BLM sensitive species designation), and 1 amphibian species. Under the Proposed Action Alternative, threatened and endangered species would not be affected because no threatened and endangered wildlife species have the potential to occur in the analysis area (see Appendix 3.14). The Proposed Action Alternative would have both beneficial and adverse impacts on migratory birds. The species that may occur in the analysis area use a variety of habitats (e.g., sagebrush steppe to wetlands to deciduous and coniferous forests), so LREP impacts would be species-specific. However, little data exist on occurrence, population numbers, or habitat use of specific species in the analysis area. In general, the conversion of terrestrial habitat to aquatic habitat (via flooding of the expanded reservoir area) would lead to direct habitat loss for some migratory bird species, such as sagebrush obligates and grassland obligates, and direct habitat creation for other migratory bird species, such as waterfowl and shorebirds. The effect on migratory waterfowl (e.g., ducks and geese) would likely be positive due to those species’ ability to take advantage of open water for foraging and resting. The effect on shorebirds may be neutral or positive due to an increase in shallow flooded areas and mudflats around the reservoir. Conversion to open water habitat may lead to an increase in food source

4-34 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 4 – Environmental Impacts for birds such as swallows and swifts that feed on insects over open water. The effect on forest-dependent, shrubland-dependent, and grassland-dependent songbirds would likely be negative due to loss of those terrestrial habitats. Almost all of the migratory birds designated as BLM sensitive species that may potentially occur in the analysis area (e.g., Baird’s sparrow, Brewer’s sparrow, loggerhead shrike, mountain plover, sage sparrow, and sage thrasher) rely on terrestrial habitat for food, shelter, and breeding. Therefore, the Proposed Action Alternative would result in a negative impact on those species through habitat loss or habitat degradation. The long-billed curlew would likely experience a neutral or positive impact due to habitat creation through the reservoir expansion. The increase in open aquatic habitat would likely have a positive impact on bald eagles, which live near rivers and lakes and primarily feed on fish. No bald or golden eagle nests are known to occur in the analysis area, so there would be no direct take of eagle nests. Construction of the Proposed Action Alternative could remove potential raptor nesting substrate and habitat (e.g., trees and grasslands) and negatively impact tree nesters (e.g., golden eagles, merlins, red-tailed hawks, and American kestrel) and ground nesters (e.g., ferruginous hawks, burrowing owls, and short-eared owls). The Proposed Action Alternative would remove suitable foraging habitat for golden eagles, owls, and hawks. Conversion to open water habitat could potentially negatively impact burrowing owls, which rely on prairie dog colonies in grasslands for shelter and nesting sites. Human activity during construction and operation could cause raptors to avoid otherwise suitable habitat. For example, noise and disturbance associated with the recreational facilities could make potential nesting habitat unsuitable for raptors. The human disturbance may cause nest abandonment, make a nest site less productive, or prevent a suitable nest site from being used. Indirect negative impacts on raptors may result from decreasing the prey base (which generally consists of small mammals, reptiles, and songbirds) in the LREP area due to habitat loss. The analysis area overlaps two greater sage-grouse core areas. The WGFD commented during the scoping process that while sage-grouse may come into irrigated hayfields in the late summer during late brood-rearing, they do not typically use the LREP area during breeding, nesting, and early brood-rearing. Therefore, critical breeding, nesting, and brood-rearing habitat would not be impacted under the Proposed Action Alternative. Under the Proposed Action Alternative, impacts to greater sage-grouse would be similar to those described for migratory birds and raptors. Under the Proposed Action Alternative, impacts to other BLM sensitive species would be the same as those described for terrestrial wildlife species. 4.14.2.3 Impacts to Terrestrial Special Status Wildlife Species from the Operational Alternative The impacts to terrestrial special status wildlife species from the Operational Alternative would be the same as those described for the Proposed Action Alternative. 4.14.3 Aquatic Biological Resources The analysis area for aquatic biological resources consists of the current Leavitt Reservoir and proposed disturbance footprint to storage capacity of 6,604 AF, as well as Beaver Creek below the existing Leavitt Reservoir diversion downstream to Shell Creek at the Bighorn River confluence (Figure 3-20). The analysis area includes perennial stream habitat in Beaver Creek (15.4 miles) and Shell Creek (20.7 miles), as well as approximately 222 surface acres in the expansion footprint of Leavitt Reservoir at the NHWL. Potential impacts to aquatic biological resources were identified based on feedback from federal and state agency biologists, public scoping, and literature related to the impact issues for aquatic biological resources. Impact issues and the analysis considerations for aquatic biological resources are listed in Table 4-20 in Appendix 1. Identification of aquatic habitat potentially affected by LREP activities focused on waterbodies that support aquatic species on a persistent basis throughout the year (i.e., perennial streams and Leavitt Reservoir). Impact parameters were used in combination with effects information for the purpose of quantifying impacts. The impact parameters also allow comparisons among alternatives. Additional information regarding impact assessment methods and parameters is provided in the impact discussions for the Proposed Action Alternative.

Leavitt Reservoir Expansion Project – Final EIS – 2019 4-35 Chapter 4 – Environmental Impacts

The effects of the No Action and action alternatives on aquatic species and habitat are described in the following sections. The discussions for the Proposed Action Alternative and Operational Alternative are organized by impact issues. The impact discussion for the Operational Alternative focuses on differences in effects compared to the Proposed Action Alternative. 4.14.3.1 Impacts to Aquatic Biological Resources from the No Action Alternative Under the No Action Alternative, Leavitt Reservoir would not be expanded and current operation and releases from the reservoir would continue to support irrigation uses. The current 643-AF storage capacity would continue to exist along with water level fluctuations related to diversion input and releases to Beaver Creek. Fish composition would continue to be comprised of mainly non-game species such as fathead minnow, longnose dace, longnose sucker, and white sucker. Game fish species, brook trout, brown trout, and mountain whitefish would continue to be present. Impacts to aquatic habitat and species in Beaver and Shell creeks would continue at present levels as a result of current Leavitt Reservoir operations and natural conditions (e.g., annual fluctuations in stream flow due to reservoir releases, varying precipitation, downstream diversions for irrigation, etc.) and existing development in drainages within the analysis area. Aquatic habitat in Beaver and Shell creeks would continue to coincide with flow patterns, which consist of peak flows in late May to mid-June and relatively low flows in September through early April. There is minimal or no flow in Beaver Creek from January through March in normal and dry years. The low flow patterns provide limited aquatic habitat especially during the overwintering period for fish species. No stocking or development of a game fishery would occur as part of the No Action Alternative based on the management history of the reservoir the past 10 years. Under the No Action Alternative, the reservoir levels would fluctuate during the year with full capacity in the spring and low levels from late summer through the winter. The reservoir fills to capacity every year. Under full capacity conditions, there is an abundance of shallow nearshore areas with vegetation consisting of fringe palustrine and shrub-scrub wetlands. Trout species occurrence including Yellowstone cutthroat trout would continue to occasionally be present in the reservoir from input of diversion water from Beaver Creek. Fish cover and relatively shallow nearshore areas are lacking during the low water levels in late summer through the winter (WEST 2018a). The conditions during low water levels would be considered low quality fish habitat. Issues with the existing diversion structure (Bernie Ditch) on Beaver Creek would continue, which would allow passage of brook trout and other species from downstream areas into the Yellowstone cutthroat trout population in North Beaver Creek. Water quality in Leavitt Reservoir, Beaver Creek, and Shell Creek would continue under the current conditions, as discussed in Sections 3.13.2.4 and 4.13.2.1. Beaver Creek and Shell Creek downstream of Leavitt Reservoir would continue to be impaired by E. coli bacteria from rangeland operations. 4.14.3.2 Impacts to Aquatic Biological Resources from the Proposed Action Alternative Habitat Alteration and Water Quality Effects from Surface Disturbance and Water Input on Habitat and Aquatic Species Construction within or near Leavitt Reservoir and Beaver and Shell creeks would alter aquatic habitat in the analysis area. Construction activities that would occur under the Proposed Action Alternative in Beaver Creek include access road upgrades, transfer pipeline crossings, and relocation of the existing diversion structure. The linear distance of direct disturbance would include 1,678 feet in Beaver Creek and 307 feet in Shell Creek, which is related to the proposed access road upgrades and transfer pipeline. There also could be disturbance from the widening or upgrading of culverts at stream crossings. Aquatic habitat that is disturbed would recover within several months to previous conditions after the construction is completed (Waters 1995). There would be a permanent loss of habitat within the instream footprint of the diversion structure. Construction disturbance also would increase sediment input to Leavitt Reservoir and Beaver and Shell creeks. In addition to direct disturbance in Beaver and Shell creeks, soil disturbance in construction areas that parallel the streams could result in sediment input. The linear distance of access roads that would parallel and be within 100 feet of the streams in the analysis area includes 2,485 feet for Beaver Creek and 434 feet for Shell Creek. Changes in water quality from surface disturbance within or near waterbodies would include an increase in suspended sediment concentrations. Sediment that is suspended from direct disturbance or that enters the stream from adjacent areas would be re-deposited in downstream areas. The extent of the sedimentation effect would depend on the flow conditions, substrate composition, stream configuration, and types of aquatic communities

4-36 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 4 – Environmental Impacts located within the affected areas. The duration of sediment effects would be short-term and coincide with the construction period. Fish and macroinvertebrate species could be affected by sedimentation in portions of the perennial streams within the analysis area. To avoid or minimize this impact, the LREP would be required by the WDEQ to obtain a Construction Stormwater Permit and employ erosion control measures as detailed through the preparation and implementation of a SPPP. The reservoir expansion would include approximately 197 acres within the NHWL footprint as the reservoir fills with water. As discussed in Section 4.13.2, the short-term storage of water and the geology of the reservoir and downstream areas would be expected to minimally affect water quality parameters such as suspended sediment, temperature, dissolved oxygen, or bacteria levels in the reservoir or downstream reaches. However, water discharge from the pipeline below the dam and transfer pipeline into Shell Creek would increase stream flows in the fall. These discharges could increase suspended solids by resuspending fine sediments from the stream bottom in stream segments located immediately downstream of the discharge points. The effects of sedimentation could range from potential short-term adverse effects on species behavior, physiological functions, or spawning (Waters 1995). In general, salmonid (trout) species are more sensitive to increased turbidity compared to many of the warmwater fish species. Sediment deposition in substrates used for spawning could affect successful egg development. The impact level would be determined by fish species presence, the timing of the construction in relation to spawning periods, and the closest spawning areas to the disturbance area. The duration of sediment impacts could last for several months depending on the timing of construction in relation to spring flows and other precipitation events that would flush sediments. The recovery period for biological communities would be several months for macroinvertebrates and fish, based on the short-term duration of disturbance (Waters 1995). Mitigation measures WQ-1 (South Big Horn District Water Quality Monitoring) and WQ-2 (Selective Withdrawal System) would be implemented to avoid or minimize water quality effects from reservoir operation. Vehicle and equipment use within or near waterbodies would pose a risk to aquatic biota from fuel or lubricant spills. If fuel reached a waterbody, aquatic species could be exposed to toxic conditions. Spills could result in chemical residues within or on substrate in waterbodies. Impacts could include direct mortalities or reduced health of aquatic organisms. The magnitude of impacts would depend on the volume of spilled fuel, flow conditions, channel configuration, and presence of aquatic species. Impacts from fuel spills would be avoided or minimized through implementation of best management practices (BMPs) and LREP design features. As specified in mitigation measure WQ-3, impacts from fuel spills will be avoided or minimized by restricting refueling within 100 feet of wetlands and streams. The construction contractor will be required to implement SPCCs in the event that a spill occurs during construction. In conclusion, the implementation of BMPs, design features related to erosion control and fuel spills, and mitigation measures WQ-1, -2, and -3, impacts to aquatic habitat and species would be minor or low magnitude. Impacts on aquatic habitat and species would be temporary and at a level that would not detrimentally affect fish and other aquatic species population viability. Based on the impact discussion in Section 4.13.2.2, there would be minor effects on other water quality parameters such as temperature, dissolved oxygen, and bacteria levels in Leavitt Reservoir and Beaver and Shell creeks. However, reservoir operation involving a short storage period of two months and the late-season release of high-quality water diverted and stored during the spring runoff period would minimize changes in water quality. Bacteria levels in Leavitt Reservoir and Beaver and Shell creeks would be reduced by the addition of wetlands at the inlet and outlet areas and fencing around the reservoir to restrict livestock grazing. The attainment of beneficial uses in the Beaver and Shell creeks related to non-game and game fish species, other aquatic life such as macroinvertebrates, and fish consumption would not be changed as a result of the Proposed Action, as discussed in Section 4.13.2.2. The designated beneficial use of recreation may be affected due to E. coli. Additional mitigation measures are recommended in Section 4.16.10 to reduce water quality effects. Fish Movement/Effects of Diversion Relocation The new diversion structure would be constructed for water diversion from Beaver Creek. The structure would include a concrete barrier wall, a headgate (a gate for controlling the water flowing into the pipeline/channel/ irrigation ditch), a diversion intake overflow wall, and a sluice gate. The new structure would be located approximately 0.8 mile from the existing diversion. The proposed design of the diversion structure does not include a barrier that would restrict upstream movement by fish. Therefore, unrestricted fish movement would

Leavitt Reservoir Expansion Project – Final EIS – 2019 4-37 Chapter 4 – Environmental Impacts continue under the Proposed Action Alternative. The upstream movement of one species, brook trout, has caused issues with the Yellowstone cutthroat trout population in North Beaver Creek due to competition. Yellowstone cutthroat trout is a special status aquatic species which is discussed in Section 4.14.3. Potential Spread of Aquatic Invasive Species If recreational boating is allowed in Leavitt Reservoir, there would be a risk of introducing aquatic invasive species. Wyoming law requires any watercraft entering the state from March 1 through November 30 each year to have a mandatory inspection by an authorized inspector before launching in Wyoming waters. In addition, construction activities associated with pipeline and road crossings and the intake structure would represent a risk for transfer and spread of invasive aquatic species. It is assumed that aquatic invasive species could be present in Beaver and Shell creeks. In total, there would be three disturbance areas each in Beaver and Shell creeks. No BMPs or design features have been defined to require equipment or vehicle washings prior to crossing waterbodies. Effects of Water Diversions and Flow Changes on Aquatic Species in Beaver and Shell Creeks The effects of water diversions and reservoir operation on stream flows in Beaver and Shell creeks are discussed in Section 4.13.1. Due to the fact that the reservoir would be designed to fully contain the PMF, the likelihood of discharge over the spillway would be extremely remote. Therefore, impacts to the existing natural channel downstream of the spillway would not be anticipated. The effects of flow changes on stream morphology are discussed in Section 4.13.3. The Proposed Action Alternative would add to the current trend in channel narrowing, incision, vegetation encroachment, reduced sediment transport capacity, and associated changes in the channel profile, planform, and substrate. The Proposed Action Alternative would incrementally reduce the habitat complexity and add to simplification of the channel. These changes would reduce the habitat diversity for aquatic species. Stream morphology would not be affected in Shell Creek. For the purpose of evaluating the effect of flow changes on aquatic habitat, the magnitude of the percent flow change was used as an impact indicator. Month in which the percent flow change would be greater than 10 percent (increase or decrease) over baseline flow was the impact indicator. This percent flow change is a level that exceeds the difference that could occur as a result of flow measurement error or uncertainty. The first step in this analysis was to summarize where and when percent flow changes would exceed 10 percent, based on flow analyses at eight points in Beaver Creek and three points in Shell Creek. Based on the period or record from 1971 through 2016, modeling was done to estimate average and median flows at the sites for normal, dry, and wet years. Definitions for average, median, and normal flows are provided in Section 4.13.1. Flow analysis results are provided in Appendices 4.13.1-A and 4.13.1-B. The flow analysis for aquatic biological resources used average flow data, since average data show a wider range of months under normal, dry, and wet years when flow changes exceeded 10 percent compared to median flow data. The following information summarizes the flow changes by groups of sites that showed similar patterns under the Proposed Action Alternative. A map of the analysis points is included as Figure 4-1 in Appendix 2. • Site 1, Beaver Creek above Existing Leavitt Reservoir Diversion – There would be no flow changes in Beaver Creek above the existing Leavitt Diversion. • Site 2, Beaver Creek below Existing Leavitt Reservoir Diversion, and Site 3, Beaver Creek above Proposed Leavitt Reservoir Expansion Diversion – Percent flow increases exceeding 10 percent would occur in October through February in normal years (22 to over 400 percent) and October through March in dry years (22 to 621 percent). There would be no flow reductions exceeding 10 percent at these sites. • Site 4, Beaver Creek below Proposed Leavitt Reservoir Expansion Diversion, and Site 5, Beaver Creek above Proposed Release Point to Beaver Creek – Percent flow changes at these sites would be dominated by reductions in two to six months depending on the type of year. At Site 4 in normal and wet years, flow reductions would occur in April through June with changes ranging from 10 to 58 percent in relation to base flows of approximately 4 to 108 cfs. Flow reductions exceeding 10 percent at Site 5 would consist of one fewer month in each type of year (i.e., two months in normal and wet years and five months in dry years). The time frame of these reductions would be April and May in normal years, April through July and November in dry years, and May and June in wet years. There would be no flow increases exceeding 10 percent at sites 4 and 5. • Site 6, Beaver Creek below Proposed Release Point to Beaver Creek, and Site 7, Beaver Creek above Proposed Transfer Pipeline – Flow changes at these Beaver Creek sites would include both increases

4-38 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 4 – Environmental Impacts

and reductions. Flow reductions exceeding 10 percent would occur in April through June in all types of years. Additional reductions would also occur in November at Site 6, and in September and November Site 7. Reductions would range from 10 to 57 percent in relation to base flows of approximately 1 to 110 cfs. Flow increases exceeding 10 percent would occur in July and August in normal and dry years and August in wet years. Increases would range from 25 to over 200 percent over base flows from approximately 5 to 20 cfs. • Site 8, Beaver Creek below Proposed Transfer Pipeline – The pattern of flow changes at Site 8 would be similar to the sites 6 and 7 except that there would be only one month with a flow increase exceeding 10 percent. Flow increases exceeding 10 percent would occur in August in a dry year, with a change of 43 percent over a base flow of approximately 3 cfs. In normal and wet years, flow reductions would occur in April through June with changes ranging from 10 to 69 percent. Base flows during these years would range from approximately 4 to 110 cfs. Flow reductions in a dry year would occur in April through June and in September and November with changes of 12 to 41 percent from base flows of approximately 1 to 33 cfs. • Site 9, Shell Creek above Beaver Creek Confluence; Site 10, Shell Creek below Beaver Creek Confluence; and Site 11, Shell Creek at Confluence with Bighorn River – Flow changes at these sites that would exceed 10 percent would occur in July during dry years. Flow reductions at sites 9 and 10 would be changes of 20 and 12 percent, respectively, from base flows of approximately 12 and 22 cfs. There would be no flow reductions exceeding 10 percent at Site 11. The only flow increase exceeding 10 percent would occur at Site 11, which would be an 11 percent increase from a base flow of approximately 64 cfs. The next step in this impact assessment was to relate these flow changes to aquatic habitat and species in Beaver and Shell creeks. The importance of a stream’s flow regime for sustaining the biodiversity and ecological integrity of aquatic environment is well established (Poff and Zimmerman 2010). Flow regime is considered the primary determinant regarding the structure and function of aquatic and riparian ecosystems for streams and rivers. When evaluating the effects of flow reductions on aquatic species, it is important to consider the magnitude of flow change in relation to the base flow and the time of year. As summarized above, the majority of the flow increases exceeding 10 percent under the Proposed Action Alternative would occur mainly below the existing and proposed Leavitt diversions in Beaver Creek. In particular, aquatic habitat in Beaver Creek below the existing diversion downstream to the proposed diversion would be enhanced due to increased flow. Current conditions in this segment do not contain consistent habitat for aquatic species throughout the year due to the intermittent flows. Flow increases also would occur in the remaining downstream portion of Beaver Creek during one or two months in the summer. Flow increases exceeding 10 percent in Beaver Creek would be beneficial to aquatic species, since additional habitat would be available during the low flow periods in late summer through the winter months. Flow increases would provide additional wetted area and increased depths in the stream. For example, increased flow, especially in the winter months, could increase overwintering habitat due to increased pool depths. Flow increases could also increase fish cover such as woody debris, undercut banks, and overhanging vegetation, if water levels coincided with such types of cover. Adverse effects could include habitat changes from channel instability and increased bank erosion, loss of riparian vegetation, and alteration of spawning cues and fish recruitment. Flow reductions exceeding 10 percent under the Proposed Action Alternative would mainly occur in April through June in the segment of Beaver Creek below the proposed Leavitt Reservoir diversion to the area below the proposed transfer pipeline. The magnitude of these flow reductions would range from approximately 10 to 60 percent. Additional flow reductions exceeding 10 percent would occur in dry years in September and November. The effects of flow changes on stream morphology are discussed in Section 4.13.3.2. The potential effects of flow reductions on fish habitat are listed below. • Continued trend of channel narrowing; • Reduced water velocity, water depth, and wetted channel areas; • Reduced sediment transport; • Reduced depths and velocities over spawning and rearing areas; • Reduced depths in overwintering pools; • Potential restrictions in fish movement or migration due to reduced stream depths;

Leavitt Reservoir Expansion Project – Final EIS – 2019 4-39 Chapter 4 – Environmental Impacts

• Changes in the quantity and types of cover (e.g., undercut banks, woody debris, substrate, turbulence) as depths are reduced; and • Potential loss of riparian vegetation and overhanging cover for fish. These effects are mainly related to changes in Beaver Creek. Riffle, run, and pool habitat would continue to be present in Beaver Creek, although depths and flow velocity would decrease. Species composition would continue to be comprised mainly of non-game species such as fathead minnow, longnose dace, longnose sucker, and white sucker along with game fish species such as brown trout and mountain whitefish. There could be a shift is spatial occurrence of fish species to coincide with their preferences for depth, flow, and cover (Poff and Zimmerman 2010). As a result of the larger channel in relation to flow reductions in Shell Creek, effects on stream morphology and habitat would be negligible. Because most of the flow reductions under the Proposed Action Alternative would occur during the high flow period in the spring, adverse effects would be considered moderate. Base flows would provide sufficient flow and habitat during this period but because high flows create habitat through scouring streambanks and beds, creating and maintaining bars and riffle-pool complexes and importing organic matter from floodplains, less spawning habitat would be available. The impact magnitude would be higher during dry years when base flows are relatively low. However, the duration of flow changes in the low flow period would consist of one or two months. As a result of the short-term duration of flow reductions, effects on aquatic species in dry years would be moderate. The response of macroinvertebrate communities to flow changes has been the subject of reviews by Poff and Zimmerman (2010) and Dewson et al. (2007). Studies that involved relatively large flow reductions (approximately 60 to 100 percent) indicated that macroinvertebrate abundance and diversity declined. However, results varied for smaller flow changes in terms of effects on macroinvertebrate communities. Regarding the flow reductions related to the Proposed Action Alternative, there would be no expected adverse effect on macroinvertebrate communities during the spring high flow period, since adequate wetted area would be available during this time. There could be short-term adverse effects on macroinvertebrate communities during dry years for one or two months when less wetted area is present. However, any short-term reduction in macroinvertebrate abundance or diversity would recover in subsequent months when flows would be similar to base flow conditions. There could be beneficial effects to macroinvertebrate communities during periods of flow increases, as additional wetted area would be present. Operation of the expanded Leavitt Reservoir would result in just one month per type of year with flow changes that would exceed 10 percent in Shell Creek. The magnitude of these flow changes would range from 10 to 20 percent. Therefore, the effects of flow changes on aquatic habitat and species in Shell Creek would be considered minor. Effects of Expanding Leavitt Reservoir on Aquatic Species The expansion of Leavitt Reservoir would convert approximately 2.8 miles of intermittent stream habitat to reservoir habitat. Intermittent streams (as well as ephemeral streams) can and often do support important aquatic habitat. Intermittent streams can be important seasonal feeding areas for some fish species, and can provide habitat for early fish life stages as well as different species that thrive in them due to lack of predators. Intermittent streams are also important for processing of nutrients, therefore protecting downstream water quality. The reservoir surface area would increase by approximately 197 acres, based on the footprint of the NHWL. The loss of intermittent stream habitat would negatively affect macroinvertebrate communities and fish species that could be present on a seasonal basis when water is present. To assess the effects of water volume increases in Leavitt Reservoir from additional water storage on aquatic species requires information on the reservoir morphology such as increased water depths and wetted area. In general terms, the expansion of Leavitt Reservoir would increase the water volume and depths. The current NHWL elevation would increase as a result of additional water storage. The most notable change on aquatic habitat would be increased depth and surface area in the existing bays (reservoir inlet). This would be beneficial to fish species, since bays are used as feeding areas and the development of young fish. There would be an estimated 44 acres of bay habitat created from the expansion of Leavitt Reservoir, which is an increase of 30 acres compared to the existing reservoir bay acreage. 4.14.3.3 Impacts to Aquatic Biological Resources from the Operational Alternative The effects of the Operational Alternative on aquatic habitat and species would be the same as those described for the Proposed Action Alternative except for water diversions and flow changes related to no bypass flow.

4-40 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 4 – Environmental Impacts

Flow changes and effects on aquatic habitat and species in Beaver Creek below the existing Leavitt Reservoir diversion, proposed Leavitt Reservoir expansion diversion, and Shell Creek below the Beaver Creek confluence would be the same as discussed for the Proposed Action Alternative. The following information describes differences of flow effects under the Operational Alternative compared to the Proposed Action Alternative. Effects of Water Diversions and Flow Changes on Aquatic Species in Beaver and Shell Creeks Flow reductions in the segment of Beaver Creek below the proposed Leavitt Reservoir expansion diversion to below the proposed transfer pipeline would be more frequent and include higher percent reductions under the Operational Alternative compared to the Proposed Action Alternative. Modeling results showed the following differences between the Operational Alternative and the Proposed Action Alternative. Detailed results are provided in Appendices 4.13.1-A and 4.13.1-B. • Site 3, Beaver Creek above Proposed Leavitt Reservoir Expansion Diversion – One or two additional months with flow reductions exceeding 10 percent in normal and dry years. • Site 4, Beaver Creek below Proposed Leavitt Reservoir Expansion Diversion, and Site 5, Beaver Creek above Proposed Release Point to Beaver Creek – Five or six additional months with flow reductions exceeding 10 percent in normal and wet years, and decreased flow the entire year in dry years; and almost no flow in November through March. • Site 6, Beaver Creek below Proposed Release Point to Beaver Creek – Five additional months with flow reductions exceeding 10 percent in all types of years; and almost no flow in November through March. • Site 7, Beaver Creek above Proposed Transfer Pipeline – Five additional months with flow reductions exceeding 10 percent in all types of years; almost no flow in November through March in normal and wet years; and no flow in December through March in wet years. • Site 8, Beaver Creek below Proposed Transfer Pipeline – Four or five additional months with flow reductions exceeding 10 percent in all types of years; almost no flow in November through March in normal and wet years; and no flow in December through March in wet years. The effect of the frequent flow reductions and high magnitude of change (many greater than 70 percent) would be a loss of aquatic habitat on a consistent basis in Beaver Creek. This loss of habitat would result in adverse effects that would likely reduce the abundance and diversity of fish and macroinvertebrates in Beaver Creek. The predominance of flow reductions exceeding 10 percent in all types of years would indicate a long-term effect on aquatic habitat and species. 4.14.4 Special Status Aquatic Biological Resources The analysis area for special status aquatic species consists of the current Leavitt Reservoir and proposed expansion footprint to storage capacity of 6,604 AF, as well as Beaver Creek below the existing Leavitt Reservoir diversion downstream to Shell Creek at the Bighorn River confluence (Figure 3-28). The analysis area includes perennial stream habitat in Beaver Creek (15.4 miles) and Shell Creek (20.7 miles), as well as approximately 49 surface acres in Leavitt Reservoir at the NHWL. Potential impacts to special status aquatic species were identified based on feedback from federal and state agency biologists, public scoping, and literature related to the impact issues, which are the same issues listed for aquatic biological resources in Table 4-20 in Appendix 1. Identification of aquatic habitat potentially affected by activities from the LREP focused on waterbodies that support special status aquatic species on a persistent basis throughout the year (i.e., perennial streams and Leavitt Reservoir). The following special status aquatic species are analyzed for the LREP. The status of the species is also noted. The special status species consist of BLM Sensitive and Species in Greatest Conservation Need (SGCN). As defined in the Wyoming Action Plan (WGFD 2017), the identification of SGCN in the analysis area includes Tier II (moderate priority) and III (lowest priority) ratings. • Fish – Yellowstone cutthroat trout (BLM Sensitive, SGCN Tier III) and flathead chub (SGCN Tier II); • Amphibians – Northern leopard frog (BLM Sensitive, SGCN Tier II), plains spadefoot (SGCN Tier II), and western tiger salamander (SGCN Tier III); and • Mollusks – Ash gyro (SGCN Tier III), tadpole physa (SGCN Tier III), and marsh rams-horn snail (SGCN Tier III).

Leavitt Reservoir Expansion Project – Final EIS – 2019 4-41 Chapter 4 – Environmental Impacts

Impact parameters were used in combination with effects information for the purpose of quantifying impacts. The impact parameters also allow comparisons among alternatives. Additional information regarding impacts methods and parameters is provided in the impact discussions for the Proposed Action Alternative. 4.14.4.1 Impacts to Special Status Aquatic Biological Resources from the No Action Alternative Under the No Action Alternative, Leavitt Reservoir would not be expanded and current operation and releases from the reservoir would continue to support irrigation uses. The current 643-AF storage capacity would continue to exist along with water level fluctuations related to diversion input and releases to Beaver Creek. Yellowstone cutthroat trout would continue to occasionally be present in the reservoir from input of diversion water from Beaver Creek. The current operation of the Leavitt Reservoir would continue to affect flows from diversions, which results in flow and habitat reductions. Historic habitat for Yellowstone cutthroat trout in Beaver and Shell creeks and flathead chub would continue to be affected by flow changes. Flow changes would also continue to affect northern leopard frog in Beaver and Shell creeks. Aquatic habitat in Beaver and Shell creeks would continue to coincide with flow patterns, which consist of peak flows in late May to mid-June, and relatively low flows in September through early April. There is minimal or no flow in Beaver Creek from January through March. Under the No Action Alternative, the reservoir levels would continue to fluctuate during the year with full capacity in the spring and low levels from late summer through the winter. The reservoir typically fills to capacity every year. Leavitt Reservoir would continue to represent low quality habitat for Yellowstone cutthroat trout. Water level fluctuations in Leavitt Reservoir would continue under the No Action Alternative, which could limit the further development of special status mollusk species (e.g., ash gyro, tadpole physa, and marsh rams-horn snail). Issues with the existing diversion structure (Bernie Ditch) on Beaver Creek would continue, which would allow passage of brook trout and other species from downstream areas into the Yellowstone cutthroat trout population in North Beaver Creek. 4.14.4.2 Impacts to Special Status Aquatic Biological Resources from the Proposed Action Alternative Due to the fact that the reservoir would be designed to fully contain the PMF, the likelihood of discharge over the spillway would be extremely remote. Therefore, impacts to the existing natural channel downstream of the spillway would not be anticipated. BLM Sensitive Species (Yellowstone Cutthroat Trout and Northern Leopard Frog) Potential impacts to Yellowstone cutthroat trout and northern leopard frog would involve the same types of issues discussed for aquatic biological resources in Section 4.14.3, which include habitat alteration, erosion and sedimentation from existing surface disturbance, risk of potential leaks or spills of contaminants from facilities or activities within or near perennial waterbodies, flow changes in Beaver and Shell creeks, and the increased reservoir habitat in Leavitt Reservoir from expansion. It is important to note that effects to Yellowstone cutthroat trout would involve historic habitat, which is considered potential habitat for the species. There would be no effects on individual fish, since current populations are not present in the analysis area. The following summary of effects is provided for the impact issues. • Habitat Alteration – Instream disturbance would alter habitat at crossings associated with access road upgrades, the diversion structure, and transfer pipeline. The number of disturbance areas would include three in Beaver Creek and one in Shell Creek. Habitat would recover to previous conditions after construction was completed. • Water Quality Effects from Surface Disturbance and Water Input – Disturbance within or near Leavitt Reservoir and Beaver and Shell creeks would result in short-term sedimentation. In addition to the disturbance areas listed for habitat alteration, access road upgrades that are within 100 feet and parallel to Beaver and Shell creeks would contribute short-term sedimentation effects. Water releases from the supply pipeline and transfer pipeline also would increase sediment levels in a short segment near the discharge points. This effect would be more evident during low flow periods. • Fish Movement/Leavitt Reservoir Expansion Diversion – The design of the proposed diversion structure does not include a barrier to restrict upstream movement of fish. Issues with the absence of an

4-42 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 4 – Environmental Impacts

upstream fish barrier would continue, which would allow passage of brook trout and other species from downstream areas into the Yellowstone cutthroat trout population in North Beaver Creek. • Water Diversions and Flow Changes – Flow reductions exceeding 10 percent would occur in Beaver Creek below the proposed Levitt Reservoir expansion diversion downstream to the confluence with Shell Creek. These reductions would occur mainly during the high flow period from May through June during all types of years. There also would be reductions in a few months during low flow periods in the summer or fall of dry years. The effect of the flow reductions on historic Yellowstone cutthroat trout habitat and existing northern leopard frog habitat would be minor during May through June, since sufficient flows and habitat would be available to support these species. However, there could be a shift in the spatial occurrence of the riffle and pool habitat used by these species due to reduced depths and wetted areas. There would be a moderate level effect on habitat in the few scattered months in dry years with flow reductions exceeding 10 percent. • Expansion of Leavitt Reservoir – The additional volume of water and increase of surface area of approximately 197 acres would provide additional habitat for Yellowstone cutthroat trout and northern leopard frog. In particular, the new wetland area located in the north portion of the reservoir would represent quality habitat for northern leopard frog. The reservoir expansion would provide additional inlet habitat, which would be beneficial to Yellowstone cutthroat trout. When considering the potential effects of the Proposed Action on BLM sensitive species, species protection is required as part of BLM Manual 6840 and the Cody RMP. The BLM Manual requires that BLM activities affecting BLM sensitive species be carried out in a way that is consistent with its objectives for managing those species and their habitats at the appropriate spatial scale. In addition, stipulation 4135 in the Cody RMP requires the following: (1) appropriate management guidance identified in Pilliod and Wind (2008) be applied to amphibian and reptiles; and (2) when cleaning or removing sediment from wet reservoirs, where feasible, retain riparian vegetation for wildlife habitat values and avoid reservoir work during amphibian mating and metamorphosis periods (April – July). SGCN (Flathead Chub, Plains Spadefoot, Western Tiger Salamander, Ash Gyro, Tadpole Physa, and Marsh Rams-horn Snail) The effects of the Proposed Action Alternative on flathead chub would be similar to the BLM species in terms of habitat alteration and water quality issues except that flathead cub occurs only in Shell Creek. The effects of flow changes on flathead chub in Shell Creek would be minor, since flow reductions or increases would only occur in July of all types of years. As discussed in Section 4.13.3.2, the effects of flow changes on stream morphology would be negligible in Shell Creek. The Proposed Action Alternative would not affect plains spadefoot and western tiger salamander, since these species use upland areas. The expansion of Leavitt Reservoir would provide additional potential habitat for ash gyro, tadpole physa, and marsh rams-horn snail. The expansion would create additional protected wetted areas around the perimeter of the reservoir, which represents potential habitat for these mollusks. 4.14.4.3 Impacts to Special Status Aquatic Biological Resources from the Operational Alternative The effects of the Operational Alternative on special status aquatic species would be the same as those described for the Proposed Action Alternative except for water diversions and flow changes related to no bypass flow. Flow changes and effects on aquatic habitat and species in Beaver Creek below the existing Leavitt Reservoir diversion, and Shell Creek below the Beaver Creek confluence would be the same as discussed for the Proposed Action Alternative. Under the Operational Alternative, flow reductions exceeding 10 percent would occur in Beaver Creek below the proposed Leavitt Reservoir diversion in 8 to 12 months with changes ranging from 10 to 100 percent. In dry years, flow reductions exceeding 10 percent would occur throughout the year. Minimal or low flow would exist in the period from October to March. The effect of the frequent flow reductions and high magnitude of change (many greater than 70 percent) would be a loss of historic Yellowstone cutthroat trout habitat and existing northern leopard frog habitat on a consistent basis in Beaver Creek. This loss of habitat would result in adverse effects that would reduce the quality of habitat for special status aquatic species in Beaver Creek. The

Leavitt Reservoir Expansion Project – Final EIS – 2019 4-43 Chapter 4 – Environmental Impacts predominance of flow reductions exceeding 10 percent in all types of years would indicate a long-term effect on historic Yellowstone cutthroat trout habitat and existing northern leopard frog habitat. 4.15 Wetlands/Riparian Vegetation Potential impacts to wetlands/riparian vegetation from the LREP include permanent or temporary loss of wetlands, other waters, or woody riparian from construction and operation of the LREP. Evaluation of impacts to wetlands and surface waters is required for USACE Section 404 permits. Woody riparian areas are usually adjacent to either wetlands or other waters and strongly influence the integrity and functions of the wetlands and surface waters. The analysis area for direct impacts to wetlands and riparian vegetation is the LREP disturbance footprint, including all areas of ground disturbance. This represents the area within which direct LREP impacts would need to be addressed for Section 404 permitting. The analysis area for indirect impacts to wetlands and riparian vegetation is the valleys downstream from LREP area, including the Beaver Creek and Shell Creek valleys to the confluence with the Bighorn River. This area was selected to be consistent with the surface water and groundwater analyses and includes the areas where wetlands and riparian areas could be affected by changes in groundwater-surface water interactions and/or changes in the volume and timing of surface flows. 4.15.1 Impacts to Wetlands/Riparian Vegetation from the No Action Alternative Under the No Action Alternative, there would be no construction and operation of the existing reservoir would continue the same. No changes to wetlands or woody riparian vegetation would occur under this alternative. 4.15.2 Impacts to Wetlands/Riparian Vegetation from the Proposed Action Alternative 4.15.2.1 Direct Effects Acres of direct permanent and temporary loss of wetlands, woody riparian habitat, and surface waters under the Proposed Action Alternative are provided in Table 4-21 in Appendix 1, and impacts by LREP component are provided in Table 4-22 in Appendix 1. These tables do not include impacts from roadway disturbance, which are discussed separately below. Permanent impacts under the Proposed Action Alternative would occur in the reservoir inundation area and at the dam area (spillway, embankment, 0.87-mile Bear Creek Road raise), and borrow areas, all of which would involve extensive modification of the existing ground surface that would continue for the life of the LREP (i.e., 50 years) or beyond. Impacts from proposed wetland mitigation and recreation areas were also considered to be permanent, although not all of these areas may be affected depending on final mitigation wetland design. All of the wetlands and riparian habitat on the edge of the existing reservoir downstream from the new embankment would be permanently impacted either by construction or loss of water that supports the wetland. The areas of pipeline disturbance (transfer, supply, and primary outlet works) and temporary construction area (other than losses considered permanent) would be considered temporary impacts. Areas disturbed by pipeline construction would generally recover within 1-5 years for herbaceous and shrub vegetation, although trees would take longer to re-establish. Wetland and riparian vegetation within the temporary construction area would have a similar time frame for recovery for areas where existing hydrology will still be present after construction. The reservoir inundation buffer would not affect any existing wetland or riparian areas. The extent of roadway modification is not currently known and it is possible that there could be some areas of permanent disturbance from widening or upgrading of culverts at stream or ditch crossings. However, the majority of roadway impacts would be expected to be temporary. Most of the wetland impacts under the Proposed Action Alternative would occur from inundation by the expanded Leavitt Reservoir, and would occur in wetlands fringing the existing reservoir and in reservoir inflow swales. Permanent impacts would also occur in the dam area, wetland mitigation areas, and shoreline wetlands in areas of within the temporary construction disturbance around the reservoir. Temporary wetland impacts would mostly occur along the pipelines. The open water within the existing reservoir would be affected by construction of the new embankment and construction of mitigation wetlands. Less than half of the open water in the existing reservoir (16.8 of 38.7 acres) would also be open water in the expanded reservoir. Most areas of willow and mixed shrub around the existing reservoir would be affected by dam construction or inundation, while cottonwood forest would primarily be affected by pipeline construction. For purposes of this analysis, existing wetlands within the proposed wetland mitigation areas were assumed to be impacted by construction but could potentially be preserved.

4-44 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 4 – Environmental Impacts

About half of the wetland impacts would occur within the ordinary high water mark (OHWM) (the USACE’s term for the NHWL) of the existing reservoir (Table 4-23 in Appendix 1). Similar wetlands are likely to develop near the OHWM of the expanded reservoir, but are not considered part of wetland mitigation. Most of the roadway disturbance area was not surveyed and reported in the WEST Aquatic Resources Inventory Report (West 2018a), and there were no wetlands, streams, ditches, or woody riparian habitat within the roadway disturbance areas that WEST did survey. The existing access roads involve seven crossings of Beaver Creek, two crossings of Shell Creek, and at least eight ditch crossings. Potential wetlands are present at some of the Beaver Creek and ditch crossings, and at a few other locations. Upgrades to the existing access roads, if required, could affect wetlands or riparian vegetation, depending on location and type of upgrade. Roadway construction disturbance would likely be a temporary impact, but there could be some areas of permanent disturbance from widening or upgrading of culverts at stream or ditch crossings or at wetlands. Aquatic resource inventory and Section 404 permitting could be required as part of roadway upgrades that affect wetlands or surface waters, but would most likely be handled by a nationwide permit. Impacts to wetlands and woody riparian areas would be avoided or minimized during construction in the roadway and pipeline disturbance areas. All areas of temporary impact would be reclaimed following construction. WWDC would develop a reclamation plan prior to construction in these areas, including upland, wetland, and riparian seeds mixes and planting, topsoil salvage, soil amendments, and other procedures. 4.15.2.2 Indirect Effects Indirect impacts to wetlands/riparian vegetation under the Proposed Action Alternative could potentially result from LREP-induced flow changes in ditches and streams in the analysis area. The analysis area for indirect effects includes the valleys downstream from the LREP area, including Beaver Creek and Shell Creek valleys to the confluence with the Bighorn River (Figure 4-1 in Appendix 2). This area was selected to be consistent with the surface water and groundwater analyses and because it includes the areas where wetlands and riparian areas could be affected by changes in groundwater-surface water interactions and/or changes in the volume and timing of surface flows. The following analysis is based on hydrological modeling presented in Section 4.13.1 for eleven sites, including eight on Beaver Creek and three on Shell Creek, for normal, dry, and wet years. Under the Proposed Action Alternative, changes in stream flows could potentially affect downstream wetlands by the lowering of alluvial groundwater tables, or by changes in the width of bank area that is regularly inundated. Surface water and groundwater are linked in river corridors, forming a single hydrological system across the valley fill (Naiman et al. 2005). Water is continually exchanged between the river, riparian aquifer, and regional aquifer. Lowering of alluvial groundwater could affect wetlands across the valley floor. Changes in inundation patterns are primarily concerned with changes in peak flows, which could result in channel encroachment and changes in streamside vegetation. Natural stream flows may vary within and between years, so that wetlands and riparian vegetation could have considerable resiliency to the effects of changes in stream flows. Section 4.13 contains the impact analysis for surface water flows, stream geomorphology, and alluvial groundwater. Decreases in peak flows could result in reduced bankfull flows and less recharge of the alluvial aquifer in the Beaver Creek Valley. Flow reductions would be greater in wet years than in normal years, resulting in smaller areas of overbank inundation during floods. The Beaver Creek Valley below the existing Leavitt Reservoir has relatively few wetlands that appear to be primarily associated with an alluvial aquifer, based on a review of National Wetland Inventory (NWI) mapping and aerial photographs. NWI scrub-shrub wetlands occur along portions of the stream channel above in the upper portions of the valley (Reaches 1, 2, 2b on Figure 3-23 in Appendix 2). Reductions in the alluvial groundwater may affect the size or quality of these wetlands except where they are associated with irrigation return flows. Riparian vegetation is well developed in upper Beaver Creek but becomes narrower downstream or absent along much of lower Beaver Creek because of agricultural development, channelization and previous reductions in stream flows. Reduced wet and normal year flows would result in a decline in the alluvial groundwater table, destabilization of stream channels, and reduced overbank flooding, all of which would contribute to further reductions in the area and quality of riparian vegetation in the Beaver Creek Valley. Wetlands occur along some portions of Beaver Creek, but many sections of the creek appear to have limited, if any, wetlands. Changes in flows along Beaver Creek would be unlikely to lead to the loss of any wetlands, but could result in small changes in the water table and wetted surface, especially in dry years, causing some shifts in vegetation.

Leavitt Reservoir Expansion Project – Final EIS – 2019 4-45 Chapter 4 – Environmental Impacts

Flow reductions in the Shell Creek Valley would be very small (4 percent during peak flows in average years) and would be unlikely to have any discernible effect on wetlands along Shell Creek or in the Shell Creek Valley. 4.15.3 Impacts to Wetlands/Riparian Vegetation from the Operational Alternative Direct effects of the Operational Alternative would be the same as those described for the Proposed Action Alternative. This alternative would not have minimum bypass flows in Beaver Creek. Stream flows would be reduced to very low amounts during fall and winter (0.5 cfs or less), but flows from April to July would be roughly the same as for the Proposed Action Alternative. The reduced flows in fall and winter would not have adverse effects on wetlands or riparian vegetation because flows are normally low during this period. Flows during the growing season would be about the same as the Proposed Action Alternative and impacts would be the same. 4.16 Mitigation and Mitigation Effectiveness for the Proposed Action Alternative There is no mitigation recommended under the Proposed Action Alternative beyond what is listed in the BLM CYFO Approved RMP for the following resources: • Air Quality and Climate • Geology • Land Use • Hazardous Materials and Waste • Recreation • Environmental Justice • Soils • Terrestrial Wildlife and Special Status Wildlife For the remaining resources, recommended mitigation measures are described below. 4.16.1 Cultural Resources and Native American Concerns 4.16.1.1 Cultural Resources Under the Proposed Action Alternative, it is assumed impacts to cultural resources would be avoided, minimized, and/or mitigated under existing stipulations in the BLM’s CYFO Approved RMP (BLM 2015a), the Wyoming State Protocol (BLM and SHPO 2014), and other applicable laws and regulations noted in Sections 3.1 and 3.1.3. The recommended avoidance area for historic properties within the direct APE where construction activities are proposed is 100 feet. Due to the proximity of the construction activities associated with the Proposed Action Alternative to sites, adverse effects may occur either during construction or during maintenance and use. In such cases, appropriate mitigation will be implemented. Following standard conditions of approval for BLM ROWs, during construction, the LREP proponent is required to report unanticipated finds. In the event of an unanticipated discovery, measures to avoid adverse effects outlined in Appendix K of the Wyoming State Protocol between the BLM and SHPO (2014) will be followed. Adherence to those measures will minimize or alleviate any direct impacts to unanticipated cultural resource finds. The following additional mitigation measures will be implemented to minimize impacts to cultural resources. CUL-01: For the affected properties (i.e., sites 48BH4242, 48BH4244, and 48BH4245), the LREP proponent will use construction fence and silt fence so that personnel and sediment will not encroach on the sites. Additionally, due to the sensitive nature of some historic properties, tribal concerns will need to be addressed (see Section 4.16.1.2 concerning proposed mitigation for tribally sensitive sites). CUL-02: As an avoidance measure, existing improved roads will not be expanded at or near the noted NRHP-listed properties, NRHP-eligible properties, and unevaluated sites so that those sites will not be impacted from such activities.

4-46 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 4 – Environmental Impacts

The LREP will not create an adverse impact to the integrity of setting for known historic properties so no mitigation is proposed for such effects. In the event that areas of the LREP disturbance footprint that fall outside of existing Class III inventories on public lands must be disturbed for the LREP to move forward, BLM may conduct additional surveys. 4.16.1.2 Native American Concerns NAT AMER-01: Based on input from tribal consultation, attended by representatives from Crow, Eastern Shoshone, Northern Arapahoe, Double Doc Ranch, and subcontractors of WWDC; agency, proponent, and landowner mutually agreed re-design for avoidance of all eligible sites (including sites of Tribal concern [i.e., 48BH4242, 48BH4244, and 48BH4245], was technically feasible (schematics submitted by RJH Consultants, Inc.). Re-design would minimize potential for direct impacts to sites of Tribal concern. Additionally, for the sites of Tribal concern (i.e., 48BH4242, 48BH4244, and 48BH4245), RJH Consultants, Inc. indicated use of construction fence and silt fence by LREP proponent would ensure personnel and sediment will not encroach on the sites. Furthermore, at the request of the tribes, tribal monitors will be present during any and all construction activities that occur in or around sites 48BH4242, 48BH4244, and 48BH4245. Due to the proposed proximity of construction activities to these sites, adverse effects may occur either during construction or during maintenance and use and appropriate response will be implemented based on consultation with the landowner, tribes, BLM, and SHPO. 4.16.2 Noise The Proposed Action Alternative could generate temporary noise increases due to the use of heavy-duty construction equipment. These noise increases would be temporary. To help offset these impacts, the following mitigation measures will be implemented to reduce construction noise: NOISE-01: All stationary noise-generating equipment will be located as far as possible from nearby NSRs. NOISE-02: Construction equipment with internal combustion engines will have sound control devices at least as effective as those provided by the original equipment manufacturer. No equipment shall be permitted to have an unmuffled exhaust. 4.16.3 Paleontology Under the Proposed Action Alternative, it is assumed impacts to paleontological resources would be avoided, minimized, and/or mitigated under existing stipulations in the BLM’s RMP (BLM 2015b) and other applicable guidance noted in Section 3.5. The following additional mitigation measures will be implemented to minimize impacts to paleontological resources: PALEO-01: Prior to construction, LREP personnel will be instructed that it is unlawful to damage, alter, excavate, or remove vertebrate fossils or other scientifically significant paleontological resources from the LREP area. PALEO-02: Monitoring for paleontological resources during construction will be conducted by a BLM permitted paleontologist for disturbance of PFYC Class 5 geologic units (e.g., Cloverly Formation). These activities include construction of the dam embankment, spillway, wetlands, recreational facilities, and portions of the access road upgrades and supply pipeline. Paleontological resource mitigation methods will follow agency guidance as summarized in Section 3.5, and mitigation paleontology best practices outlined in Moses et al. (2014) and Murphey et al. (2014). PALEO-03: A Paleontological Discovery Plan will be developed and submitted to the BLM for review and approval prior to any ground disturbance occurring. Paleontological discoveries will be reported per the Paleontological Discovery Plan. LREP operations will avoid any scientifically important paleontological resource discovery by at least 100 feet until the discovery is fully evaluated, and the BLM field manager has issued written authorization to proceed (BLM 2015b). Following these measures will minimize or alleviate any direct impacts to paleontological resources.

Leavitt Reservoir Expansion Project – Final EIS – 2019 4-47 Chapter 4 – Environmental Impacts

4.16.4 Public Health and Safety PUBLIC H&S-01: Signage and/or gates will be provided at LREP construction area entrances to limit access and promote on-site security. 4.16.5 Range Resources RANGE RESOURCES-01: In areas where livestock would be removed for construction, temporary fencing will be provided during the time that the construction coincides with livestock grazing in the impacted allotment. After construction is completed, livestock fence required for the management of the allotments will be replaced. Areas with temporary construction impacts will be restored to their approximate pre-disturbance conditions following construction. 4.16.6 Socioeconomics SOCIO-01: The potential for short-term adverse impacts on the availability of temporary housing and the demand for local services will be mitigated by encouraging construction firms to utilize local labor wherever feasible. SOCIO-02: The minor short- and long-term adverse impact from the loss of a small amount of grazing land and a small number of AUMs will be mitigated by offering additional grazing leases to the affected rancher(s), if available. 4.16.7 Transportation The following mitigation measures are recommended to address the transportation effects described in this section. The effectiveness of the mitigation measures is characterized after the mitigation descriptions. TRANS-01: The final design plans for the LREP will comply with applicable federal, state, and local engineering design requirements and should include engineering drawings and specifications that clarify design details for Maintenance of Traffic (MOT) during the construction period along the area involving the Bear Creek Road raise, at key intersections used by heavy vehicles, and at the main intersection with US 14 (south of the LREP site). Temporary intersection control and/or left-turn storage will likely be needed to provide safe turning movements during the peak period. Signal timing adjustments at the US 14/6th Street intersection may also be deemed necessary by WYDOT. TRANS-02: A Safety Program will be developed that includes driver safety reminders involving on- and off-site travel, designated travel routes from US 14 to the LREP site, and recommendations for drivers of large trucks making turns to and from Bear Creek Road and US 14 in Greybull, and south of the LREP site. Most safety effects will be addressed by roadway improvements, with standard and customized construction driver awareness efforts, and site-specific construction period intersection control measures, where appropriate. Intersection safety measures will include temporary signing and traffic control devices at key locations, as well as flaggers in some instances. Risks of collisions with wildlife and livestock will be highlighted in the Safety Program along with speed limits on individual roadway segments. Construction workers will be directed to use the US 14/CR 39 intersection and avoid the other US 14 intersections. TRANS-03: Roadway ROW permits from Big Horn County and private property access agreements will be secured to address construction period access, safety, traffic control, and maintenance issues prior to initiation of the Bear Creek Road raise, and prior to use of Bear Creek Road and other roads by construction vehicles. TRANS-04: A recreational analysis will be performed to re-evaluate the need for permanent improvements to the intersection of US 14 and CR 39. Permanent signage and turning lanes at any of the route connections to US 14 will be evaluated as part of the recreational analysis. Approval of the MOT, Safety Plan, and local government agreements and corresponding construction phase compliance will effectively address access, safety, and maintenance impacts associated with construction vehicle movements, including heavy truck operations. Securing access agreements and the corresponding construction phase compliance will effectively address local access, mobility, and safety issues for local property owners.

4-48 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 4 – Environmental Impacts

4.16.8 Vegetation The BLM ROW grant will include requirements to develop and implement an LREP reclamation plan and a noxious weed management plan. Reclamation and revegetation will restore vegetative cover within a few years, but plant species diversity and shrub cover will take longer to recover. Specific analysis of wetland loss and compensatory mitigation is discussed in Section 4.15. The following mitigation measures are recommended for the Proposed Action Alternative to help restore vegetation disturbed during construction: VEG-01: WWDC will apply the provisions in their BLM-required reclamation and noxious weed management plans on both BLM and non-BLM lands, except where directed otherwise by individual landowners. VEG-02: Surveys for limber pine will be conducted in all areas of planned temporary disturbance, and impacts will be avoided or minimized through design or minor route modifications. More than half of the potential LREP impacts could be avoidable by minor re-routes or other avoidance measures during siting of pipelines and access road improvements, and development of borrow areas. 4.16.9 Visual Mitigation will be as directed under the BLM CYFO Approved RMP for visual resources. Additional mitigation will include: VIS-01: The new proposed infrastructure will be painted a color that blends with the existing landscape to reduce contrast. 4.16.10 Water Resources 4.16.10.1 Water Quality Under the Proposed Action Alternative, the following mitigation measures for water quality are proposed: WQ-1: An LREP Monitoring and Adaptive Management Plan (MAMP) will be developed to address the water quality issues identified in the Section 4.13.2. The Water Quality LREP Monitoring and Adaptive Management Plan is made of four components: 1) Identifying issues, 2) Setting thresholds, 3) Completing monitoring, and 4) a suite of potential corrective actions. The project proponent, WWDC, will develop the MAMP in consultation with the BLM, WDEQ and the Shell Valley Watershed Improvement District (SVWID). Support of secondary recreational designated use in Beaver Creek downstream of the reservoir is the primary issue. The LREP MAMP will establish thresholds to determine whether water quality conditions in the reservoir and Beaver Creek downstream of the reservoir are meeting the desired conditions set forth in Table 4.24 in Appendix 1. Thresholds must be measurable and based on existing water quality standards and the established TMDLs for E. coli concentrations in Beaver Creek downstream of the reservoir. These thresholds will ultimately define the monitoring needs identified in the MAMP. In addition, the MAMP will establish mitigation measures to be implemented so that the desired conditions are met. Actions considered may include both operational adjustments (e.g., utilization of selective withdrawal system from the reservoir, adjustment to management of the LREP transfer pipeline) and off-site BMPs that correspond to the regional watershed study (e.g., livestock exclusion fencing around waterbodies [reservoir and stream]), off-channel stock water tanks, removal/replacement of leaking septic systems in the watershed). Water quality issues, desired conditions and recommended mitigation measures to be considered in the finalized LREP MAMP are discussed in Table 4-24 in Appendix 1. The final LREP MAMP must be completed and signed by WDEQ, BLM, WWDC, and SVWID prior to the BLM signing a Record of Decision (ROD) and issuing a ROW for LREP. Effectiveness: This measure will maintain a record of the water quality as an indicator of stream health and will provide a framework for the development of the necessary adaptive management plan. In the event that established TMDLs are not met downstream of the expanded Levitt Reservoir or other water quality standards are not met as an effect of the Project, adaptive management will proceed as outlined in the final plan. WQ-2: A selective withdrawal system will be installed as part of the outlet works for future use to selectively release water from several levels within a stratified reservoir water column.

Leavitt Reservoir Expansion Project – Final EIS – 2019 4-49 Chapter 4 – Environmental Impacts

Effectiveness: Implementation of this measure will provide options for selective releases from different elevations in the stored water as future adaptive management without the need for retrofitting of the outlet works. Selective withdrawal has been shown to effectively encourage reservoir turnover (Vonins and Jackson 2017) and reduce the likelihood of water quality issues in stored water. WQ-3: The construction contractor will develop and implement a SPCC Plan for construction of the LREP, regardless of the amount of hazardous liquids storage during construction. Impacts from fuel spills will be avoided or minimized by restricting refueling within 100 feet of wetlands and streams. Effectiveness: SPCC Plan implementation will establish best practices related to hazardous liquids handling and will facilitate quick and efficient responses in the event of unintentional releases, thus avoiding or minimizing effects to water quality and other resources. 4.16.10.2 Stream Morphology It is difficult to attribute how much incremental impact from the Proposed Action Alternative will require mitigation. Active mitigation measures may need to be implemented in Beaver Creek Reach 2 to stabilize areas that are channelized, actively incised, and lack sufficient vegetation. The increased volume and duration of Proposed Action Alternative delivery flows would increase erosion potential and instability issues in these areas. These impacts will be mitigated per requirements outlined in the BLM CYFO Approved RMP (BLM 2015a). A MAMP will be developed to address the potential issues associated with channel stability in Beaver Creek (Table 4-24 in Appendix 1). The plan will include surveys to monitor channel stability and establish corrective measures to address observed deviations from the desired condition of a stable channel form for Beaver Creek. STREAM MORPH-01: Impacts from in-stream structures to divert and control water flows will be mitigated with a natural channel design that maintains dimension, pattern, and profile for fluvial systems (NRCS 2007). 4.16.10.3 Groundwater Groundwater mitigation measures for the Proposed Action Alternative will include the following: GW-01: A pre-construction reconnaissance survey to confirm the existing water well locations listed in Table 4-17 in Appendix 1. Wells identified within 150 feet of the construction area will be staked and marked with high-visibility flagging to avoid damage and potential collisions with the wells during construction activity. GW-02: Any well identified within a proposed borrow area will be plugged, abandoned, and re-drilled at an alternate location in accordance with applicable regulations. These measures should prevent damage to existing wells, and provide in-kind compensation to affected landowners whose well requires abandonment. 4.16.10.4 Wildlife and Aquatic Biological Resources Terrestrial Wildlife and Special Status Wildlife Species The following mitigation measures will be implemented for the Proposed Action. WILDLIFE-01: Areas with temporary construction impacts will be restored to their approximate pre-disturbance conditions following construction. A native seed mix will be used for reclamation seeding of disturbed areas. Aquatic Biological Resources and Special Status Aquatic Biological Resources The following mitigation measures are recommended for aquatic biological resources under the Proposed Action Alternative. ABR-01: If culverts are widened or upgraded in streams with game and special status fish populations, flow will be maintained in a portion of the stream to allow unrestricted fish passage. Any plan for dewatering the stream at the culvert site will be approved by the appropriate federal and state agencies prior to dewatering. Culvert size and type will be selected to facilitate the continued and long-term connectivity and movement of target aquatic species. ABR-02: If vehicles and equipment come in contact with stream water and sediments and are moved across multiple streams, they will be cleaned with a spraying device that uses an uncontaminated water source (i.e., a potable water source with no aquatic invasive species present).

4-50 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 4 – Environmental Impacts

ABR-03: The diversion structure in Beaver Creek will be designed to restrict upstream movement of fish. The benefit of this measure is that it will prevent brook trout from moving upstream and accessing North Beaver Creek, which contains a native population of Yellowstone cutthroat trout. Brook trout cause adverse effects on Yellowstone cutthroat trout as a result of competition. Additional mitigation measures discussed for surface water in Section 4.16.10.1 such as WQ-1 (water quality monitoring), WQ-2 (selective withdrawal system), and WQ-3 (SPCC Plan) also would protect aquatic habitat and species. 4.16.10.5 Wetland/Riparian Vegetation The USACE will require compensatory mitigation for permanent wetland losses resulting from the LREP. WWDC has identified three potential areas (North, South, and Rim wetland areas) and an additional area that may be used for either wetland mitigation or recreation. The combined area is likely to be more than sufficient to mitigate for wetland impacts. The final areas and configurations will depend on mitigation requirements determined by the USACE and site design considerations. The north mitigation wetland could provide up to 18.3 acres in mitigation and would be located north of the proposed reservoir in an area that is now upland vegetation. Creation of the wetland would require construction of an embankment on the lower end and grading of the area above the embankment to desired elevations. The source of water would be the reservoir water supply system. Water elevations in the wetland would be maintained using an overflow structure and pipeline. The outflow from the north wetland would discharge to the rim wetland. The rim wetland mitigation area could provide up to 23.9 acres in mitigation as currently mapped, which includes 15.6 acres of overlap with the expanded Leavitt Reservoir. It would be located on the northeast edge of the expanded reservoir. About 0.48 acre of existing wetlands are located within this potential mitigation area. This wetland would be constructed at the NHWL of the reservoir, and berms would be used to maintain water in the wetland when the reservoir pool was lower, and grading to create appropriate water depths. The water supply for the rim mitigation wetland would be the reservoir supply pipeline, which would be routed on the east side of the wetland. It could deliver flow to the wetland at multiple locations. Multiple outlets from the wetland to the reservoir would be constructed to control the water elevation, and provide sufficient capacity to discharge the maximum supply pipeline design flow of 75 cfs. WWDC would use the north and rim wetlands to remove sediment from the water diverted from Beaver Creek. Final design of these wetlands would include consideration of the sediment, including estimated volumes of sediment accumulation, horizontal flow velocities, detention time (based on sediment size), and distribution of the sediment deposition within the wetlands. The south wetland could provide up to 10.8 acres for mitigation and would be constructed in the lower portion of the existing Leavitt Reservoir pool and a portion of the drainage below the existing dam. This area currently has about 0.15 acre of wetlands and 0.33 acre of riparian woodland, mostly located below the existing dam. The elevation of the new wetlands would be established based on the elevation of the embankment drains. The wetland bottom would be graded to support the desired wetland species. The existing dam embankment would be lowered to serve as the berm for the wetlands, and outlet structures and pipes would be installed to control the wetland water elevation. Water for the downstream wetland would be provided by flow from the embankment drains. The volume of the drain flow would not be known until the reservoir was built and operated, and the outlet works had been preliminarily designed with the capability of delivering flow to the wetlands with a pipeline for successful mitigation. A pipeline could also be used to maintain the existing wetlands and riparian areas below the existing dam. Conceptual design for the potential recreation or wetland area would be the same as the rim wetland; this area is located just south of the rim wetland. This area is 14.4 acres in size, of which 11.2 acres would be within the expanded Leavitt Reservoir. The proposed operation of the reservoir, which involves storing spring runoff for release in late summer, would probably result in development of wetlands around the perimeter of the reservoir similar to those present for the existing reservoir. These potential wetlands are not being considered as part of the compensatory mitigation requirements except where they would be part of an engineered design (e.g., the Rim wetland).

Leavitt Reservoir Expansion Project – Final EIS – 2019 4-51 Chapter 4 – Environmental Impacts

Section 404 of the Clean Water Act requires that impacts to wetlands and other waters of the U.S. be avoided, minimized, or mitigated. Based on the nature of the LREP, impacts to wetlands at the reservoir site cannot be avoided or minimized. WWDC has identified multiple compensatory mitigation sites around the new reservoir to provide sufficient area for compensatory mitigation. WETLAND-01: The north and rim wetlands will have water provided by the reservoir water supply system, which will discharge to and flow through the constructed wetlands prior to entering the main body of the expanded Leavitt Reservoir. Wetlands will be constructed around the OHWM of the reservoir, with berms to extend the duration of suitable wetland hydrology. These sites will be very suitable for development of wetlands, particularly with the large supply of water. Discharge of sediment into the proposed wetlands could affect them in the long-term; that will be addressed in final design. WETLAND-02: The south wetland will be supported by flows from the embankment drains, which are currently unknown in quantity; therefore, the effective size of this wetland is difficult to predict and is likely smaller than the available area. Detailed designs of wetland mitigation areas will be required for Section 404 permitting, including grading and planting plans and operational procedures. WETLAND-03: Wetland impacts along the pipelines and roadway improvements will be avoided or minimized during final alignment of the pipelines and design of roadway improvements, in accordance with Section 404 Permit conditions. Impacts to woody riparian vegetation will also be avoided or minimized. All wetlands and riparian areas that would be temporarily disturbed during construction will be revegetated and reclaimed to pre-construction levels. WETLAND-04: Various BMPs will be required during construction, such as implementation of stormwater controls, fencing of the edge of construction areas where such areas are adjacent to wetlands and riparian areas that are being protected, and construction in waterways during low or no flow where possible. 4.17 Mitigation and Mitigation Effectiveness for the Operational Alternative Mitigation for all resources analyzed under the Proposed Action Alternative will be the same under the Operational Alternative.

4-52 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 5 – Cumulative Impacts

CHAPTER 5 CUMULATIVE IMPACTS

5.0 Cumulative Impacts Introduction This chapter describes the potential cumulative effects that would result from the Leavitt Reservoir Expansion Project (LREP). The regulations for implementing the National Environmental Policy Act (NEPA), define cumulative impacts as “the impact on the environment which results from the incremental impact of the action when added to other past, present, and reasonably foreseeable future actions (RFFAs) and regardless of what agency (federal or non-federal) or person undertakes such other actions. Cumulative impacts can result from individually minor but collectively significant actions taking place over a period of time” (40 Code of Federal Regulations [CFR] 1508.7). This regulation refers only to the cumulative impact of direct and indirect effects of the Proposed Action and its alternatives when added to the aggregate effects of past, present, and RFFAs. Cumulative impacts, then, consider total environmental effects from a proposed action. The U.S. Army Corps of Engineers’ (USACE’s) Section 404(b)(1) Guidelines state that “cumulative impacts are the changes in an aquatic ecosystem that are attributable to the collective effect of a number of individual discharges of dredged or fill material. Although the impact of a particular discharge may constitute a minor change in itself, the cumulative effect of numerous such piecemeal changes can result in a major impairment of the water resources and interfere with the productivity and water quality of existing aquatic ecosystems” (40 CFR 230.11(g)(1)). 5.0.1 Past, Present, and Reasonably Foreseeable Future Actions The cumulative effects analysis for the LREP evaluates past, present, and RFFAs that continue to or that can influence existing environmental conditions, including the existing operation of Leavitt Reservoir, when combined with the Proposed Action and its alternatives that may result in a cumulative effect on the environment. The identification of the effects of past and present actions is critical to understanding the environmental condition of an area. See Chapter 2 of this Environmental Impact Statement (EIS) for a description of the No Action Alternative, which reflects the existing Leavitt Reservoir, associated ditches, and service area. The other primary waterbodies in the Shell Creek watershed include Shell Reservoir, Adelaide Reservoir, and Moraine Lake, as well as several smaller unnamed reservoirs for irrigation and/or stock water. Recent guidance on the consideration of past actions in cumulative effects analysis states that “…it is not practical to analyze how the cumulative effects of an action interact with the universe; the analysis of environmental effects must focus on the aggregate effects of past, present and RFFAs that are truly meaningful” (CEQ 2005). Bentonite-bearing strata are located to the southwest of the LREP area in the Thermopolis and Mowry shales (BLM 2009b). Several of these bentonite beds are mined within an area designated as the Eastern Bighorn Basin District (Sutherland 2014). According to the Bureau of Land Management (BLM) Cody Field Office (CYFO), there are approximately 1,430 acres of active or un-reclaimed bentonite mines in the Shell Creek watershed, along with an additional 1,290 acres of planned mining and 730 acres of mines that have already been reclaimed. The nearest planned or active mining area is located approximately 1.75 miles southwest of the current Leavitt Reservoir (BLM 2017b). 5.1 Cumulative Impacts 5.1.1 Cultural Resources and Native American Concerns 5.1.1.1 Cultural Resources The cumulative analysis area for cultural resources consists of the direct and indirect area of potential effect (APE) for the LREP described in Section 4.1. The analysis period includes recent past and present conditions as well as the anticipated 50-year life of the LREP. Past development and other actions in the analysis area have likely changed the archaeological record. Construction of the original Leavitt Reservoir, rural residential areas, agricultural fields, and roads have likely resulted in the loss of cultural data. Operation of the Leavitt Reservoir and dam, bentonite mining activities,

Leavitt Reservoir Expansion Project – Final EIS – 2019 5-1 Chapter 5 – Cumulative Impacts grazing, irrigation, and agricultural activities may have destroyed or altered cultural resources in the analysis area. Rural agricultural and residential developments are anticipated to gradually increase. One planned or active bentonite mine is within the indirect APE for cultural resources and its operation may pose future impacts to cultural resources in the area of analysis. The cumulative impacts of all RFFAs would generally be adverse for cultural resources as those areas are developed. The LREP would have a relatively small cumulative impact on cultural resources compared to other activities in the region. 5.1.1.2 Native American Concerns Pre-historic cultural resources are an integral part to maintaining tribal identity. Contemporary Native American interests can include traditional cultural properties such as sacred sites, sites that hold ceremonial significance and places on the landscape that are rooted in tribal history. The cumulative effects on three cultural sites in the analysis area (which is the same as the direct and indirect APE for the LREP described in Section 4.1) holding tribal significance were assessed for the LREP. The analysis period includes recent past and present conditions as well as the anticipated 50-year life of the LREP. Sites 48BH4242, 48BH4244, and 48BH4245 have been identified as cultural properties that hold tribal significance. Past development and other actions have altered these resources and may have removed other sites of tribal significance within the LREP. Construction of the original Leavitt Reservoir, rural residential areas, agricultural fields, and roads have likely resulted in the loss materials of Native American concern. Rural agricultural and residential developments are anticipated to gradually increase. The cumulative impacts of RFFAs regarding sites of Native American concern can only be ascertained through further consultation with the participating tribes. 5.1.2 Geology The cumulative impact analysis area for geological resources is the Shell Creek watershed. This area was selected for analysis because it includes other past, present, and reasonably foreseeable future mining activity that could contribute to cumulative impacts from the LREP. Bentonite within the Bighorn Basin is common throughout a stratigraphic section of approximately 1,500 feet (Pierce and Andrews 1941). The thickest, most important bentonite deposits for commercial development are contained within the Frontier and Mowry formations (BLM 2009a). Geographic Information Systems (GIS) data provided by the BLM CYFO show that bentonite mining is concentrated southwest of the LREP within the approximate mapped extent of the Frontier Formation (BLM 2017b). Historical and recent bentonite mining has contributed to the excavation and removal of in situ geologic strata within the Shell Creek watershed. The total impact of past, present, and reasonably foreseeable future bentonite mining in the watershed is expected to reach 3,450 acres (BLM 2017b). Under the Proposed Action and Operational alternatives, geologic material would also be “mined” from two borrow areas to construct the earthen dam embankment, with a total disturbance footprint of approximately 77 acres. This number is a small fraction of the anticipated disturbance associated with bentonite mining; thus, cumulative geologic impacts from the Proposed Action Alternative or Operational Alternative would likely be negligible to minor. Both alternatives would increase the cumulative area of bedrock excavation/mining in the Shell Creek watershed by about 2 percent. 5.1.3 Land Use The cumulative impacts analysis area considered for land use is the LREP disturbance footprint including the added wetlands and borrow pits. Past and present actions that have impacted land use include agriculture, livestock grazing, off-highway vehicle (OHV) recreation designations, an exploratory oil and gas well (now plugged and abandoned), a utility corridor, and road development. These activities have cumulatively contributed to changes in land use. These actions are described in detail in Section 3.3 and have, in general, created visually intrusive forms, lines, colors, and textures on the natural landscape. Because land use authorizations are based on programmatic decisions, past and present actions that have impacted such authorizations are limited to past resource management planning wherein areas of avoidance,

5-2 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 5 – Cumulative Impacts exclusion, or withdrawal from the rights-of-way (ROW) were designated. Individual past and present projects do not contribute to these impacts. As such, the cumulative effects of past actions on land use authorizations are reflected in the No Action Alternative currently under consideration. RFFAs such as bentonite mining would all require issuance of land use authorizations. Future development of lands surrounding the analysis area is likely to also prompt requests for ROW authorizations across BLM-administered lands to serve and access those developments. Under the Proposed Action Alternative and Operational Alternative, a ROW would have to be granted for the LREP and that could reduce the routing options for ROW facilities such as utilities and roads but that would be unlikely due to the distance between the proposed mining and the LREP. As such, this would not add to cumulative impacts. For agriculture and recreation, the LREP would present an incremental cumulative impact but of a beneficial nature. There would not be an incremental addition to cumulative impacts of the special designation (i.e., the Brown/Howe Dinosaur area of critical environmental concern [ACEC]) because the land use within that area would not change. 5.1.4 Noise Noise impacts due to construction of the LREP would be localized and short-term. For this reason, the cumulative impacts analysis area for noise is a 1-mile buffer around the LREP disturbance footprint. Construction noise from RFFAs in the analysis area, when combined with the proposed LREP construction and operation and maintenance that may cumulatively impact ambient noise levels includes bentonite mining in the Shell Creek watershed. The nearest planned or active mining area is located approximately 1.75 miles southwest of the current Leavitt Reservoir which is outside the cumulative impact analysis area. Noise generated by the construction of the LREP would have attenuated to ambient noise levels at the active mining area southwest of the expanded Leavitt Reservoir. Therefore, cumulative noise impacts from mining and any overlapping noise generated from construction of the LREP would be minimal. 5.1.5 Paleontological Resources The cumulative impacts analysis area for paleontological resources consists of the exposures of the Cloverly Formation (the primary geologic unit underlying the LREP) along the eastern edge of the Bighorn Basin from Shell Creek north following Beaver Creek to Bear Creek, east to the Bighorn Mountains, and southeast to Horse Creek. Construction of the original Leavitt Reservoir dam and associated roads may have resulted in the loss of important paleontological resources, and filling of the reservoir may have caused some other resources to be buried for the long term. In addition to these negative impacts, the roads and reservoir may have allowed access to an area that was otherwise inaccessible, providing for the collection and preservation of paleontological resources not immediately destroyed by these activities. Other disturbance in the cumulative analysis area includes past, present, and future rural agricultural and residential developments. These developments would be anticipated to gradually increase; however, since such development would typically be concentrated on flat, vegetated areas, immediately underlain by younger (Quaternary) geological units, they would be unlikely to impact paleontological resources. Within the cumulative effects analysis area, there are numerous previously active, active, and potentially undiscovered paleontological vertebrate quarries. In those areas, the Cloverly and Morrison formations are being excavated and fossils are being documented and removed from portions of those formations that would not be accessible due to the LREP. For exposures of the Cloverly and Morrison formations immediately east of the LREP, the Brown-Howe ACEC offers some additional protection for paleontological resources (BLM 2015b) like those that may be impacted by the LREP. The contribution to cumulative impacts from the LREP would be minimal because the LREP would impact less than 5 percent of the cumulative impact analysis area for paleontological resources. 5.1.6 Range Resources The cumulative impacts analysis area for range resources is the boundary of the allotments that would be affected by the LREP for the anticipated life of the LREP (i.e., approximately 50 years). The majority of the analysis area is comprised of native rangeland vegetation. The primary past and present development and impacts are the existing Leavitt Reservoir, county and local access roads, and bentonite mining. The only past or

Leavitt Reservoir Expansion Project – Final EIS – 2019 5-3 Chapter 5 – Cumulative Impacts present bentonite mining in the analysis area is in the southern portion of the Lost allotment. Construction of the original reservoir eliminated approximately 45 acres of land with available livestock forage. In addition to the original construction of Leavitt Reservoir reducing available livestock forage, it also provided a new livestock water source that increased the available use area of the Beaver Creek, Crandall, and Lost allotments. The only new development, other than the development associated with the proposed action alternatives that is a RFFA, would be new bentonite mining areas. New bentonite mining areas could further reduce Animal Unit Months (AUMs) in the Lost allotment. The cumulative impacts of all past, present, and RFFAs would be the potential for continued reduction in available livestock forage through the disturbance of rangeland vegetation and the continued availability of Leavitt Reservoir as a livestock water source. 5.1.7 Recreation The cumulative impacts analysis area for recreation is the LREP disturbance footprint, including wetland and borrow pit areas. Past and present actions that have impacted recreational resources include OHV recreation designations, an exploratory oil and gas well (now plugged and abandoned), and utility corridor and road development. These activities have cumulatively contributed a change in recreation use patterns and user experience in the analysis area. There are no known RFFAs in the analysis area that would create surface disturbances or visual contrasts on the landscape would have an effect on recreational resources and the user experience. The LREP would add to cumulative impacts but the impacts for recreational resources would mostly be beneficial as described in Section 4.7. However, there would be a minor adverse impact from the disturbance associated with construction of the LREP infrastructure that would contribute to the cumulative impacts. 5.1.8 Socioeconomics The cumulative impacts analysis area for socioeconomics is the same as that for direct and indirect effects of the LREP and includes all of Big Horn County. Past and present projects and activities have largely defined the socioeconomic setting described in Section 3.8. Farming remains the largest non-government employment sector in the analysis area, followed by mining, quarrying, and oil and gas extraction; retail trade; and construction (BEA 2017b). The potential for bentonite mining near the expanded Leavitt Reservoir is the only RFFA identified for this EIS. Since the nearest planned or active mining area is located approximately 1.75 miles southwest of Leavitt Reservoir, the expansion of the reservoir under the Proposed Action Alternative or Operational Alternative would not be likely to affect the prospects for future bentonite mining. However, additional bentonite mining could further contribute to the long-term increase in local economic activity from enhanced irrigation supplies. Wyoming is the largest producer of bentonite in the U.S. and accounts for almost 50 percent of the world bentonite production (WSGS 2014). The average bentonite mine in Wyoming produces about $10 million per year, and employs approximately 27 people with a payroll of about $1.2 million per year (Census Bureau 2015). It is not known whether the extent of bentonite resources in the Shell Creek watershed would be sufficient to support a mine of this scale. 5.1.9 Soils The cumulative effects analysis area for soils is a 0.25-mile buffer of the LREP disturbance footprint over the life of the LREP (50 years). There has been minimal past development or other actions in the analysis area. The primary past and present development and impacts are the existing Leavitt Reservoir, county and local access roads, and general recreation activity within the West Slope Special Recreation Management Area. Construction of the original reservoir permanently impacted approximately 49 acres of soils. RFFAs (bentonite mining) would occur outside of the analysis area for soils. Therefore, the soil impact of approximately 284.6 acres (4.4 percent of the cumulative impacts analysis area for soils) from the Proposed Action Alternative or the Operational Alternative would be the major contributor to cumulative effects to soils.

5-4 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 5 – Cumulative Impacts

5.1.10 Transportation The cumulative impacts analysis area for transportation includes the regional, local, and on-site roadway networks potentially impacted by construction and post-construction trip generation. The temporal limits for the transportation cumulative impacts analysis are generally bounded the 50-year life of the LREP. Past activities that caused transportation effects represented by current conditions within the spatial and temporal limits for the transportation cumulative effects analysis. Present activities and related projects of these types are ongoing. The current pace of this activity is similar to past trends. There are no major ongoing or imminent projects that are or will create impacts similar to those of the Proposed Action and Operational alternatives. Given past trends, the contribution of the LREP to long-term cumulative effects would be minor and inconsequential. Future rural, agricultural, and industrial activities, including bentonite mining, are anticipated. These activities along with past and present activities would add to the incremental impacts of the LREP. 5.1.11 Vegetation 5.1.11.1 General Vegetation The cumulative impacts analysis area for general vegetation is the LREP disturbance footprint plus a one-mile buffer. Potential bentonite mining would not occur within the vegetation cumulative impacts analysis area. There would be no cumulative effects to vegetation. 5.1.11.2 Noxious Weeds and Invasive Species The cumulative impacts analysis area for noxious weeds and invasive species is the LREP disturbance footprint plus a one-mile buffer. Potential bentonite mining would not occur within the LREP analysis area, and would not result in cumulative impacts for noxious weeds and invasive species. 5.1.11.3 Special Status Plant Species The cumulative impacts analysis area special status plant species is the LREP disturbance footprint plus a one- mile buffer. Planned or active bentonite mining is not located within the LREP analysis area. Outside of the analysis area, cumulative impacts to special status plant species could potentially occur if the LREP and bentonite mining would affect the same species. Other than limber pine, the LREP would not affect sensitive or listed plant species. Limber pine is widely distributed and the combined effects of the LREP and bentonite mining would be unlikely to adversely affect overall distribution or abundance of this species. 5.1.12 Visual Resources The cumulative impacts analysis area for visual resources is a 10-mile buffer around the LREP disturbance footprint. Past and present actions that have impacted visual resources include OHV recreation designations, an exploratory oil and gas well (now plugged and abandoned), a utility corridor, and road development. These activities have cumulatively contributed to an adverse loss of scenic quality. These impacts have, in general, created visually intrusive forms, lines, colors, and textures on the natural landscape in the analysis area. Any RFFAs that would create surface disturbances or visual contrasts on the landscape would have an effect on visual resources. Within the analysis area, such actions would be bentonite mining. Bentonite mining would create surface disturbances and visual contrasts with the surrounding landscape and adversely contribute to the existing scenic quality impacts on the analysis area landscape. There are no planned, disturbed, or reclaimed bentonite areas in the LREP disturbance footprint; however, there are 1,433 acres of disturbed area, 1,290 acres of planned development, and 3,636 acres of previously developed areas that have been reclaimed. Both the disturbed and planned areas would add cumulatively to the changes in line, color, form, and texture on the landscape and therefore the quality of visual resources. There could also be a reduction in the acres of cumulative impact as areas of current and planned disturbance are reclaimed. The LREP would add to cumulative impacts but the impacts for visual resources would mostly be beneficial as described in Section 4.12 (i.e., the addition of more water surface). However, there would be a minor adverse impact from the LREP infrastructure that would contribute to the cumulative impacts.

Leavitt Reservoir Expansion Project – Final EIS – 2019 5-5 Chapter 5 – Cumulative Impacts

5.1.13 Water Resources 5.1.13.1 Surface Water The cumulative impacts analysis area for surface water is Beaver Creek from the Bernie Ditch diversion to Shell Creek at the Bighorn River. Surface water impacts associated with bentonite mining for the LREP would be related to modifications of runoff patterns and additional use of the resource. The BLM CYFO has identified 1,290 acres within the Shell Creek Basin, on which bentonite mining is planned. Current water needs for bentonite mining are for dust suppression. Revegetation is accomplished without irrigation as pre-mining vegetative varieties suitable to the native non-irrigated condition are used (BLM 2018, 2011b). Given the constraints of water law, water for dust suppression could need to be leased which means that use of surface water for dust suppression would displace other uses as opposed to adding to the consumptive use on a watershed or basin-wide basis. BLM has identified, in addition to planned mining areas, active or un-reclaimed areas and fully reclaimed areas. The amount of land currently reclaimed indicates that the baseline hydrology described in Section 4.13 reflects some amount of bentonite mining in the past. Thus, there would be a cumulative effect on surface water only to the extent that future bentonite mining operations would require more water than such operations required in the past. Based on low water needs for bentonite mining, the likelihood of leased water sources, and the nature of local mining and reclamation, the cumulative effects of surface water consumptive use would be very similar to the LREP effects described in Section 4.13 for the Proposed Action Alternative. 5.1.13.2 Water Quality The cumulative impacts analysis area for water quality is the same as the direct and indirect effects analysis area, and consists of the LREP footprint as well as Beaver and Shell creeks from the LREP proposed diversion point to the confluence of the Bighorn River. Past, present, and RFFAs in the cumulative effects analysis area include bentonite mining. Past mining has disturbed approximately 3,636 acres in the Shell Creek watershed, which has been reclaimed. Additional future demands placed on the water sources of Beaver Creek through the bentonite mining, along with additional future surface disturbance and associated potential erosion/ sedimentation could negatively affect water quality in the analysis area. However, future developments of the mines in the area that may discharge water to Beaver Creek would be subject to regulation under the Clean Water Act (CWA) National Pollutant Discharge Elimination System (which includes regulation of discharges from stormwater runoff), and said developments would have to account for effects and plan to avoid, minimize, or mitigate additional impacts at that time. Based on the application of requirements from the CWA and the jurisdiction afforded the state of Wyoming, the cumulative impacts to water quality would be minimal. 5.1.13.3 Stream Morphology This analysis considers the anticipated life of the LREP (i.e., approximately 50 years). The cumulative effects analysis area for stream morphology is described in Section 3.13.3. Future bentonite mining is outside of the analysis area for stream morphology, and any flow and sediment issues associated with tributaries to Beaver Creek would be mitigated. In general, existing morphological conditions have been historically impacted from hydromodifications as described in Section 3.13.3. The existing conditions of several segments along Beaver Creek show instability and morphological degradations predominantly associated with channel realignment, agricultural encroachment, and hydrological alteration. The majority of cumulative impacts to stream morphology would be attributed to the hydrological alterations associated with the No Action, Proposed Action, and Operational alternatives. The LREP would result in approximately 3 percent reduction to bankfull flows in the Shell Creek (see Section 4.13.3). The estimated changes to stream morphology in Shell Creek by the implementation of the LREP would be negligible compared to other cumulative flow depletions.

5-6 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 5 – Cumulative Impacts

5.1.13.4 Groundwater Resources The cumulative impact analysis area for groundwater resources extends from Beaver Creek near the existing Leavitt Reservoir diversion on the upstream end, to the confluence of Shell Creek and the Bighorn River on the downstream end. Under the Proposed Action Alternative and Operational Alternative, unconsolidated alluvial material would also be mined from Quaternary terrace deposits to construct the earthen dam embankment, with a total disturbance footprint of approximately 77 acres; thus, the cumulative removal of alluvial material under the Proposed Action Alternative or Operational Alternative would represent a negligible to minor impact. Approximately 930,000 cubic yards (cy) of native bedrock material would also be excavated from the Cloverly Formation within the expanded reservoir footprint. The Cloverly Formation and Quaternary terrace deposits may also need to be dewatered in the LREP borrow areas if the pit excavations extend into the saturated zone. Thus, both the Proposed Action Alternative and Operational Alternative could increase cumulative groundwater losses from dewatering in the analysis area. 5.1.14 Wildlife and Aquatic Biological Resources 5.1.14.1 Terrestrial Wildlife The cumulative analysis area for terrestrial wildlife resources is a 1-mile buffer around the LREP disturbance footprint. The analysis area extends beyond the LREP area because of wildlife migration and the potential for activities to extend to a habitat-level effect. The temporal analysis period includes recent past and present conditions as well as the anticipated 50-year life of the LREP. Past development and other actions in the analysis area have changed the availability and quality of wildlife habitat. Construction of the original reservoir eliminated approximately 46 acres of upland wildlife habitat, while simultaneously providing waterfowl and shorebird habitat and a consistent water source in the uplands not previously present at this location. Other developments in the analysis area include rural residential areas, agricultural fields, and roads. Other past actions that have affected availability and quality of wildlife habitat include operation of the Leavitt dam and reservoir, grazing, irrigation, and agricultural activities. These activities have changed water availability, altered wildlife habitats, and changed species distribution in the analysis area. Agricultural, residential, and other development are anticipated to follow historic patterns and continue to gradually increase, regardless of whether the Proposed Action Alternative or Operational Alternative is implemented. If either alternative is implemented, there would likely be a short-term loss in species abundance as a result of construction and habitat loss. The analysis area is located within a watershed that contains active bentonite mining. While no planned or active mines are situated in the analysis area itself, bentonite mining could indirectly impact wildlife resources in the analysis area. Habitat loss from mining in nearby areas could force more wildlife species into the analysis area, resulting in an overall decrease in forage, cover, and breeding site availability. This would lower habitat quality and increase competition and predation in the analysis area. The cumulative impacts of RFFAs would generally be adverse for native wildlife as terrestrial habitats would be converted into aquatic habitat and developed areas. Species distribution within the area would change as some wildlife species will avoid or move away from disturbed areas and increased human activity where others that are more adapted to human development would move into these areas. 5.1.14.2 Special Status Wildlife Species The cumulative impacts of the Proposed Action Alternative, the Operational Action Alternative, and other RFFAs on special status wildlife species would be the same as those described for terrestrial wildlife. 5.1.14.3 Aquatic Biological Resources The cumulative effects analysis area for aquatic biological resources consists of the existing Leavitt Reservoir and proposed expansion footprint to storage capacity of 6,604 acre-feet (AF), as well as Beaver Creek below the existing Leavitt Reservoir diversion downstream to Shell Creek at the Bighorn River confluence. The analysis period includes recent past and present conditions as well as the 50-year life of the LREP to account for RFFAs that could affect aquatic communities.

Leavitt Reservoir Expansion Project – Final EIS – 2019 5-7 Chapter 5 – Cumulative Impacts

As described in Sections 4.14, the effects of the Proposed Action Alternative and Operational Alternative would contribute to the effects from past, present, and RFFAs in the analysis area. These effects on aquatic habitat and species would include habitat loss, water quality and quantity changes, and the potential spread of aquatic invasive species. Best management practices (BMPs), LREP design features, adherence to water quality regulations, and recommended mitigation measures would reduce effects on aquatic habitat and species to minor. One notable exception is the moderate level of effects of the Operational Alternative on aquatic habitat from flow reductions in all types of years. Past development and other actions in the analysis area have affected the quality and quantity of aquatic habitat in Beaver and Shell creeks and Leavitt Reservoir. Other developments in the analysis area include water withdrawals for irrigation of agricultural land and development of agricultural land, roads, and scattered residential areas. The effects of past irrigation use are discussed as part of the No Action analysis in Section 4.13.3.1. The operation of Leavitt Reservoir and other water use in the watershed in combination with natural conditions have affected the flow patterns and amount of aquatic habitat. Aquatic habitats in Beaver and Shell creeks have coincided with flow patterns, which consist of peak flows in late May to mid-June, and relatively low flows in September through early April. There is minimal or no flow in Beaver Creek from January through March in normal and dry years. Past and present actions within the analysis area also have contributed to effects on water quality parameters such as bacteria levels. Past, present, and RFFAs in the cumulative effects analysis area also include bentonite mining. Past mining has disturbed approximately 3,636 acres in the Shell Creek watershed, which has been reclaimed. Current bentonite mining has disturbed approximately 1,433 acres, with the closest areas in Herron and Porter Gulches, which are approximately 0.1 mile and 1 mile, respectively from Shell Creek. Future bentonite mining development is proposed for 1,290 acres. Current and future bentonite mining would include soil disturbance in intermittent drainages to Shell Creek. However, mining development would be required to follow sediment control measures to avoid effects to Shell Creek as part of the mine permits. Bentonite mining uses well and stock pond water for dust suppression on access roads. Groundwater used for the wells is not linked to surface water in the analysis area. In addition, there is no produced water from bentonite mining, as mining depths are shallower than the water table. 5.1.14.4 Special Status Aquatic Biological Resources The cumulative effects analysis area and analysis timeframe for special status aquatic biological resources is the same as aquatic biological resources. As described in Section 4.14, the effects of the Proposed Action Alternative and Operational Alternative would contribute to the effects from past, present, and RFFAs in the analysis area. These effects on special status species and their habitat include habitat loss, water quality and quantity changes, potential spread of invasive aquatic species, and movement of undesirable species (brook trout) into North Beaver Creek that contains Yellowstone cutthroat trout. Species that would be affected include BLM sensitive species, Yellowstone cutthroat trout (historic habitat only), and northern leopard frog in Beaver and Shell creeks. Species of Greatest Conservation Need affected species would include flathead chub in Shell Creek and three mollusks (i.e., ash gyro, tadpole physa, and marsh rams-horn snail) in Leavitt Reservoir. Past and present cumulative actions that have affected special status aquatic species are the same as those described for aquatic biological resources in Section 5.4.11. Water quality and quantity have been affected in Beaver and Shell creeks, which contains historic habitat for Yellowstone cutthroat trout and existing habitat for northern leopard frog and flathead chub. Although cumulative actions also have reduced the quantity of wetland habitat in the analysis area, the proposed LREP would add additional wetlands above the reservoir, which would be beneficial to northern leopard frog. Past and present cumulative actions in Leavitt Reservoir have contributed to current conditions consisting of fluctuating water levels with low volumes during the irrigation season. The contribution of the proposed LREP would add habitat for the special status mollusk species. Future bentonite mining would disturb soils in Shell Creek tributaries. By following required sediment control measures, effects on water quality parameters and historic Yellowstone cutthroat trout habitat would be minor. 5.1.15 Wetlands/Riparian Vegetation The cumulative impacts analysis area for wetlands and riparian vegetation is the LREP disturbance footprint plus a one-mile buffer. Potential bentonite mining would not occur within the cumulative impacts analysis area. The

5-8 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 5 – Cumulative Impacts action alternatives combined with bentonite mining would not result in cumulative impacts to wetlands/riparian vegetation. 5.2 Residual Impacts This section discusses the residual impacts that would be experienced under the action alternatives. Resources that are not anticipated to experience residual impacts include Geology, Recreation, and Environmental Justice. Resources with residual impacts that would remain the same as impacts from the Proposed Action Alternative include Land Use and Surface Water. For all resources, except Aquatic and Special Status Aquatic Biological resources, residual impacts from the Operational Alternative would be the same as those for the Proposed Action Alternative. 5.2.1 Cultural Resources and Native American Concerns The Proposed Action Alternative may have an operational residual impact on cultural resources from increased use of the area which could in turn increase the potential for unauthorized surface collection and looting. Cultural resource sites that are not eligible for the National Register of Historic Places (NRHP) could be lost due to construction. Although impacts to eligible resources would be avoided, minimized, or mitigated, the loss of some eligible resources through mitigation (e.g., data recovery, if required) or the accidental disturbance during construction, and impacts to the surrounding landscapes would create some residual impacts to eligible resources. The Proposed Action Alternative may have an operational residual impact on significant tribal resources by increasing use of the area which may in turn increase the potential for looting and additional impacts to these sites. 5.2.2 Noise Short-term, localized, and intermittent increases in noise levels would occur during construction. There would be both short- and long-term minor operational noise impacts. Operation of the facilities included in the LREP would not require extensive operation or maintenance activities. Operational noise levels resulting from mobile sources such as employee commute trips or material haul trips would not be expected to increase ambient noise levels in the vicinity of the LREP. 5.2.3 Paleontology Residual impacts to paleontological resources from the Proposed Action Alternative could occur from increased unsupervised human activity through unauthorized collection or damage of paleontological resources. Erosion from increased wave action around the expanded reservoir could also create residual impacts to paleontological resources if the resources eroded completely prior to collection. 5.2.4 Range Resources Residual indirect impacts from increased recreation use would result under the Proposed Action Alternative. No other residual impacts would occur. 5.2.5 Socioeconomics The Wyoming Water Development Commission (WWDC) will continue to require some level of local funding participation under the Proposed Action Alternative, so repayment of the alternative would lead to increased water service charges for participating irrigators. Additional agricultural revenues from the increased water supply would be expected to exceed the increase in water service charges. 5.2.6 Soils Some portion of the soil resource would be lost as a result of erosion and compaction in soil types that are susceptible to wind erosion or surface runoff, including the degradation of the soil resource following loss of topsoil from erosive forces. Increased casual use of pedestrians in designated recreation areas could potentially result in removal of vegetation and compaction of topsoil.

Leavitt Reservoir Expansion Project – Final EIS – 2019 5-9 Chapter 5 – Cumulative Impacts

5.2.7 Transportation The residual transportation impacts from the Proposed Action Alternative would be minor and would include temporary disruption of access along public and private roads involving delays due to traffic controls and slow-moving construction vehicles, incremental impacts on roadway safety associated with increased vehicle travel, and incremental impacts on roadway use and associated deterioration rates and maintenance. 5.2.8 Vegetation Residual impacts would include loss of hundreds of acres of native vegetation from inundation and construction. The Proposed Action Alternative would also temporarily disturb vegetation in areas of temporary construction impacts until fully restored. Despite revegetation efforts, much of the post-revegetation communities would remain different for years following the completion of construction. The Proposed Action Alternative would unavoidably create favorable conditions for establishment of noxious weeds. 5.2.9 Visual There would be residual impacts under the Proposed Action Alternative because the visual impacts created by the permanent infrastructure from the LREP could not be mitigated. The spillway and other infrastructure would remain throughout the life of the LREP and as such contrasts in color, texture, line, and form would also remain. 5.2.10 Water Resources Residual impacts include temporary increase of TSS in Beaver Creek directly below the LREP outlet to the creek at the time releases begin, as well as the increased late season flows increasing the water quality by diluting the flows that historically contain E. coli and fecal coliform. The incremental water use under the Proposed Action Alternative would reduce bankfull flows which could impact channel form in the channel evolution process. The proposed mitigation would address most of the impact to stream channel morphology so that the residual impact would be minimal. Residual impacts for groundwater resources would include rising groundwater levels in the Cloverly Formation beneath and adjacent to the expanded reservoir pool. The higher groundwater levels in this this area would persist for the life of the LREP. 5.2.11 Terrestrial and Special Status Wildlife The Proposed Action Alternative would have an operational residual impact on terrestrial and special status wildlife species by decreasing the amount of wildlife habitat and increasing human activity in the analysis area over the long-term. 5.2.12 Aquatic and Special Status Aquatic Biological Resources Implementation of BMPs, BLM stipulations, and additional mitigation would reduce impacts to aquatic and special status aquatic biological resources. Residual impacts that would remain after implementation of these measures would include: • Loss or alteration of aquatic, historic Yellowstone cutthroat trout, and existing northern leopard frog habitats in streams and a small portion of Beaver Creek from the diversion structure. • Loss of aquatic, historic Yellowstone cutthroat trout, and existing northern leopard frog habitats due to flow reductions in Beaver Creek from the operation of the LREP. The habitat loss would occur in 3 to 6 months with reductions ranging from 10 to 60 percent. Most of the reductions would occur in the high flow period from May through June. • Addition of aquatic habitat in Beaver Creek downstream of the proposed Leavitt Reservoir expansion diversion due to flow increases from the operation of the LREP. Habitat increases would mainly occur in the low flow periods in one or two months during late summer and winter below the proposed diversion, and the summer months in the remaining downstream portion of Beaver Creek. • Addition of aquatic habitat in Beaver Creek due to flow increases from the operation of the LREP. Habitat increases for aquatic habitat would occur in five to seven months during the low flow period from October through March, and for special status aquatic species during July, September, or November below the proposed Leavitt Reservoir diversion.

5-10 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 5 – Cumulative Impacts

5.2.13 Wetlands/Riparian Vegetation Residual impacts would include loss of existing wetlands and riparian areas, but USACE requirements for compensatory mitigation would restore wetland areas and functions at new locations. Compensatory mitigation may also cover losses of riparian vegetation. The Proposed Action Alternative would also temporarily disturb wetlands and riparian vegetation in areas of temporary construction impacts until fully restored. 5.3 Relationship between Local Short-term Use of the Human Environment and Maintenance and Enhancement of Long-term Productivity This section discusses whether construction and operation of the LREP could cause short-term uses of the environment that would affect, either positively or negatively, the long-term productivity of the environment. 5.3.1 Cultural Resources and Native American Concerns Short-term effects to the environment associated with the alternatives include the construction activity and the possibility of inadvertent or accidental damage of cultural resources from use of an area during construction. Short-term effects also include potential impeded access to sites of Native American concern by Native Americans. The short-term use and long-term productivity of cultural resources not eligible for listing in the NRHP and within the proposed LREP disturbance areas would be lost. Long-term changes would include the potential for direct loss and disturbance of four NRHP-eligible sites from construction and of the sites holding tribal significance in the LREP disturbance footprint. Mitigation measures such as data recovery, if data recovery is required, would cause loss of short-term use but there would be a long-term benefit from the increase in knowledge of the past and the distribution of this knowledge to the public. 5.3.2 Geology Although uranium and oil and gas deposits exist near the LREP, the development potential for these resources is low. As such, implementation of either the Proposed Action Alternative or Operational Alternative would not affect the long-term productivity or recovery of hydrocarbons or uranium. Under both action alternatives, 1.7 acres of Thermopolis Shale could be submerged by the expanded reservoir pool and the reservoir inundation buffer (Table 4-1 in Appendix 1), which would effectively restrict access to economic bentonite deposits that may be present within the shale. However, due to the small size of the affected parcel, impacts to long-term productivity of bentonite resources would be negligible. 5.3.3 Land Use Short-term uses of the environment associated with the action alternatives would include changes to the physical and social environment during the construction of the LREP. Construction would involve increased traffic, detours, access issues, noise, and changes in land use. These impacts would not have an impact on the long-term productivity of special designations, lands with wilderness characteristics, or leasable minerals-oil and gas. The LREP would enhance long-term productivity through long-term reduction of water shortages for agriculture and an increase in the number of recreation user days, along with an increase in user satisfaction. 5.3.4 Noise Noise associated with construction activities and recreational traffic would result in short-term increases in the ambient noise environment. Sources of noise associated with long-term operations would increase as a result of reservoir maintenance and noise from the outlet works. However, the long-term productivity of operations would not be affected by this increase in noise. 5.3.5 Paleontology Short-term effects to the environment associated with the action alternatives would include the construction activity and the possibility of inadvertent or accidental damage to paleontological resources from use of the area during construction. Long-term change would occur from the inundation of a minimum of 93 acres of the highly fossiliferous Cloverly Formation, including three known localities, and could result in new localities being uncovered through increased erosion.

Leavitt Reservoir Expansion Project – Final EIS – 2019 5-11 Chapter 5 – Cumulative Impacts

5.3.6 Range Available AUMs would be impacted during the short-term use of temporary construction areas. The short-term use impacts would end after the temporary construction areas are restored. Long-term impacts would include the permanent reduction of AUMs, if enacted, if acreage is taken out of forage production from the permanent above ground infrastructure and expanded reservoir area and alterations to how to livestock use the area. 5.3.7 Recreation Short-term uses of the environment associated with the action alternatives include changes to the physical and social environment during the construction of the LREP. Short-term uses would include the construction of the LREP which would involve increased traffic, dust, detours, lack of access, and temporary deterioration of the recreational experience due to construction activities. These impacts would not have an impact on the long-term productivity of recreation. Long-term productivity would be improved as the expanded reservoir would add more opportunities for recreation. 5.3.8 Socioeconomics Short-term uses of the environment would generally be those associated with the construction of the proposed LREP. During construction, the short-term use of resources would be required including land, labor, materials, and housing. Like most construction projects, the use of these resources would create temporary disturbances. Disturbances could include temporary construction noise, visual impacts, disruption of local traffic, increased competition for short-term accommodation, and disruption of local recreation amenities. The negative short-term effects mentioned above are necessary to secure the long-term benefits of the action alternatives. The long-term effects of the action alternatives would be to create a larger supply of late-season irrigation water that would allow irrigators in the analysis area to grow high value crops like dry beans and corn. These effects would enhance agricultural productivity and household income, which would create additional employment in other economic sectors in the analysis area. The additional economic activity would increase the economic output of the analysis area and create the potential for state and local governments to collect additional tax revenues. 5.3.9 Soils Under the action alternatives, overall site productivity would depend on revegetation success following the implementation of reclamation practices. Productivity would vary for each impacted vegetation community based on land management actions and land uses. Long-term soil health would be dependent on the mitigation measures implemented to increase aeration and permeability, maintain soil structure, control soil chemistry, conserve soil fertility, and promote other soil characteristics that would facilitate successful reclamation of temporarily impacted areas. Although there would be permanent impacts to the long-term productivity related to soil resources, short-term impacts in temporary use areas and access road upgrades, and other temporary disturbances for development of the Proposed Action and Operational Alternative would be mitigated following the successful revegetation of areas and facilitate long-term enhancement and maintenance of the overall site productivity. 5.3.10 Transportation The action alternatives would include raising a 0.89-mile segment of Bear Creek Road and improving the existing roads to the planned recreation facilities. These short- and long-term investments would be productive because they would incrementally improve the local roadway network through increased accessibility to private property, public lands, and recreation area resources. 5.3.11 Vegetation The action alternatives are would have an adverse effect on long-term productivity by disturbing and removing vegetation. Areas of temporary disturbance would be restored, which would make some of the impacts short term. The expanded reservoir would be a long-term use of the human environment. 5.3.12 Visual Short-term uses of the environment associated with the action alternatives would include changes to the physical and social environment during the construction of the LREP. Construction would involve increased traffic, dust,

5-12 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 5 – Cumulative Impacts and temporary deterioration of the viewshed due to construction equipment. These impacts would not have an impact on the long-term productivity of visual resources. Long-term productivity would be improved for visual resources as the expanded reservoir would add visual value to the landscape. 5.3.13 Water Resources During construction of the expanded Leavitt Reservoir, the existing impoundment would be breached or dismantled, returning Beaver Creek temporarily to a more natural flow condition. The winter flows that have historically been diverted into the existing Leavitt Reservoir would stay in the channel. While Beaver Creek water users would be able to divert for irrigation use pursuant to their direct flow water rights during the construction period, the summer reservoir releases that have historically helped irrigators finish a crop would be unavailable. No mitigation for this effect is planned on a LREP level. Individual farmers may temporarily reduce irrigated acreage, adjust cropping, or otherwise modify practices to accommodate low water supply. In the long term, the LREP would presumably directly benefit farmers by increasing water availability to better match crop irrigation requirement, raising crop yield, reducing vulnerability for the farmer, and improving productivity and profit for as long as the reservoir expansion is in place (i.e., 50 years is the anticipated life of the LREP). The parties that will be directly impacted by short-term construction-related impacts to surface water would be the same parties that would reap the benefits of long-term future improvements in water supply. Local short-term use of water during construction could have minor effects on water quality. However, required measures (e.g., implementation of spill prevention, control, and countermeasures [SPCCs] Stormwater Construction Discharge Permit) would minimize their extent. No long-term effects are anticipated. Stream channels would be impacted from short-term construction activities; however, the short-term impacts would end after temporary construction areas are restored. Long-term effects would result from the incremental change to the natural hydrograph which would impact downstream reaches of Beaver Creek. Long-term effects would also occur to stream reaches inundated by the expanded Leavitt Reservoir. Both the action alternatives would result in long-term changes to the groundwater flow regime. In general, the LREP would shift some groundwater recharge from the Beaver Creek alluvial aquifer to the Cloverly Formation beneath the expanded reservoir pool. The shift in recharge would likely decrease groundwater levels in the Beaver Creek alluvium, while simultaneously creating a localized mounding effect in the Cloverly aquifer. These changes would result in the following impacts to long-term resource productivity: • Water levels in alluvial aquifer wells would generally be reduced, potentially resulting in reduced well yields. • Accessing rising groundwater levels in the Cloverly aquifer through new well installations in an area immediately below and adjacent to the expanded reservoir may not be feasible due to access challenges. However, from an overall water supply standpoint, these effects to long-term groundwater productivity would be outweighed by the stabilization of surface water supplies resulting from either action alternative. Thus, any degradation of long-term groundwater productivity would be a negligible impact. 5.3.14 Terrestrial and Special Status Wildlife Short-term uses of the environment include construction activities that would increase noise, dust, light pollution, and general human disturbance in the LREP analysis area, resulting in wildlife avoidance of habitats, direct mortalities/injuries, and wildlife displacement. Areas like the outlet works, pipelines, and construction staging areas would be temporarily unavailable for use by terrestrial wildlife species during construction. Long-term impacts would include the permanent removal of wildlife habitat in the expanded Leavitt Reservoir area, auxiliary spillway, 0.89-mile segment of the Bear Creek Road raise, and recreational facilities. Long-term uses of the environment include operation of the reservoir and recreational activities that would generally affect terrestrial wildlife species through decreased habitat quality. The long-term productivity of terrestrial wildlife resources may be compromised. 5.3.15 Aquatic and Special Status Aquatic Biological Resources Surface disturbance to perennial streams would result in short-term effects to aquatic habitat and species, historic Yellowstone cutthroat trout, and existing northern leopard frog habitats, but these impacts would not affect the long-term productivity of their populations. Stream diversions and operation of the LREP would result in flow

Leavitt Reservoir Expansion Project – Final EIS – 2019 5-13 Chapter 5 – Cumulative Impacts reductions and increases that would affect habitat and species on a long-term basis but the changes would vary depending on the type of year (i.e., wet, dry, or normal) and time of year. Impacts resulting from the Proposed Action Alternative would not affect the long-term productivity of aquatic populations, Yellowstone cutthroat trout, or northern leopard frog because the majority of the flow reductions would occur during the high flow period in the spring. Flow additions in Beaver Creek could increase the productivity in the section just above and below the existing Leavitt Reservoir diversion where additional habitat would be available in the low flow periods from fall through the winter. However, flow additions in the remaining downstream portion of Beaver Creek below the proposed Leavitt Reservoir diversion would be limited to one or two months, which would not be expected to affect the long-term productivity. In contrast, flow reductions from the Operational Alternative would result in habitat reductions in 8 to 12 months in all types of years in Beaver Creek from below the proposed Leavitt Reservoir diversion to the confluence with Shell Creek. These flow reductions would affect the long-term productivity in Beaver Creek due to the frequent and relatively high magnitude of percent reductions. 5.3.16 Wetlands/Riparian Vegetation The action alternatives would have short-term impacts to wetlands, but would not have an adverse effect on long-term productivity. Wetlands would be replaced through compensatory mitigation. The expanded Leavitt Reservoir would be a long-term use of the human environment that could support more wetlands than the existing Leavitt Reservoir. 5.4 Irreversible and Irretrievable Commitment of Resources This section discusses the irreversible and irretrievable commitment of resources for resources under the action alternatives. There is no irreversible or irretrievable commitment of resources anticipated for Land Use, Noise, Recreation, Environmental Justice, or Visual resources. 5.4.1 Cultural Resources & Native American Concerns The LREP would result in an irreversible and irretrievable loss to cultural resources that are not eligible for listing in the NRHP that are within the disturbance areas. Eligible sites or portions of eligible sites may be destroyed if proper avoidance measures are not implemented, which would lead to an irreversible and irretrievable loss of those sites. If proper avoidance measures are implemented, there would be no irreversible or irretrievable loss of eligible sites. Sites of Native American concern may be altered or destroyed if proper avoidance measures are not implemented, which would lead to an irreversible and irretrievable loss. If proper avoidance measures are implemented, there would be no irreversible or irretrievable loss to such sites. 5.4.2 Geology The 925,000 cy of rock that would be excavated from the expanded reservoir pool area and 500,000 cy that would be removed from the borrow areas represent an irreversible commitment of resources. The rock would be crushed and processed as it is used to construct the earthen dam embankment, and would not be available for other purposes in the future. Some additional geologic materials needed for dam construction may be obtained from outside the LREP area, including 2,000 cy of concrete transported from Greybull, Wyoming, and 10,000 cy of rip rap imported from existing quarries potentially in Carbon County, Montana. The imported concrete and rip rap also represent an irreversible commitment of geological resources. 5.4.3 Paleontology Paleontological resources could be destroyed if proper mitigation measures are not implemented, which would lead to an irretrievable loss. If proper mitigation measures are implemented, there would be no or limited irretrievable loss to important paleontological resources. 5.4.4 Range If AUMs are permanently removed and livestock use is altered under either action alternative, the impact would be irretrievable during reservoir operation, but not irreversible (i.e., the impact could be reversed if the LREP was removed and the area reclaimed).

5-14 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 5 – Cumulative Impacts

5.4.5 Socioeconomics The LREP would involve an irreversible use of many irretrievable socioeconomic resources. Resources like land, labor, and materials used in the construction of the LREP would be irretrievable once they were used. The construction of the proposed LREP would also require the permanent and irreversible removal of a recreation trail that is currently located at what would be the north end of the expanded Leavitt Reservoir. 5.4.6 Soils An irretrievable commitment of the soil resource would result from temporary impacts. Through the implementation of required and recommended BMPs, temporary impacts will be mitigated to the extent practicable. Temporary impacts are expected to be fully mitigated following the implementation of reclamation activities; however, soil resources will be temporarily lost during temporary impacts from construction and improvement activities. Through the construction of the permanent infrastructure, there would be an irreversible commitment of approximately 364 acres of permanent disturbance from the implementation of the Proposed Action Alternative and Operational Alternative. 5.4.7 Transportation The action alternatives would not involve an irreversible or irretrievable commitment of transportation resources, but would involve an irreversible and irretrievable commitment of energy (primarily fossil fuels) and materials necessary to raise a 0.89-mile segment of Bear Creek Road and improve the access roads to the planned recreation facilities along the shore of the expanded Leavitt Reservoir. While some of the materials used for road work could be recycled or reused, much of this material would be permanently used/consumed or committed. 5.4.8 Vegetation The action alternatives would result in an irretrievable loss of existing natural vegetation in the inundation and other disturbance areas. Some of the losses may be irreversible because vegetation communities that would establish after removal of the LREP could be likely to be different than those now present. Reclamation would reverse the loss of vegetation in areas of temporary disturbance. 5.4.9 Water Resources Irreversible and irretrievable impacts to the commitment of surface water would be experienced through the short-term loss of late season irrigation supply during two irrigation seasons out of the construction period is an unavoidable adverse impact on water use. The severity of the impact would depend on natural supply (i.e., late summer precipitation during the construction years). Irrigators affected in the short term would most likely be beneficiaries of the LREP (or would have had the opportunity to participate in the LREP) and would be motivated to accept the short-term impacts for long-term improved water supply. While minor effects to water quality would be irretrievable during the life of the LREP (i.e., 50 years), the effects would be reversible through adjustments to the management of the water resources and surrounding land uses. The construction of permanent infrastructure would result in irretrievable impacts to stream channels due to reduction in bankfull flows, which would be irreversible during operation of the LREP. Impacts to intermittent and ephemeral streams would be reversible upon removal and reclamation of the LREP and return of natural hydrologic conditions in Beaver Creek. Irretrievable commitments of groundwater resources would likely occur under both the Proposed Action Alternative and Operational Alternative. Groundwater recharge in the form of seepage from Beaver Creek that is “captured” through diversions into Leavitt Reservoir would represent an irretrievable commitment of alluvial groundwater. These losses would be higher under the Proposed Action Alternative than the Operational Alternative since a greater share of diversions would occur during the peak groundwater recharge months of May, June, and July. Groundwater could also be irretrievably depleted from the Quaternary terrace deposits and Cloverly Formation if dewatering is required during excavation of the proposed borrow pits.

Leavitt Reservoir Expansion Project – Final EIS – 2019 5-15 Chapter 5 – Cumulative Impacts

5.4.10 Terrestrial and Special Status Wildlife Both the Proposed Action Alternative and the Operational Alternative would result in an irretrievable commitment of terrestrial and special status species wildlife habitats in the LREP area. Those habitats would be unavailable for use by wildlife species during the life of the LREP (estimated at 50 years). 5.4.11 Aquatic and Special Status Aquatic Biological Resources The potential loss of aquatic, historic Yellowstone cutthroat trout, and existing northern leopard frog habitats in Beaver Creek due to the diversion structure at the Beaver Creek transfer pipeline crossing would be irretrievable; however, the habitat loss would be reversible if the culvert was removed at a later time. The construction of other permanent infrastructure and expansion of the reservoir would result in irretrievable impacts to aquatic habitat due to stream channel loss and alteration, which would be irreversible during operation of the LREP. Impacts would be reversible if the structures were removed after the life of the project. The reduction in aquatic habitat in Beaver Creek during spring months from the operation of the LREP would be irretrievable; however, habitat would be reversible to natural hydrologic conditions if the LREP operations ceased. 5.4.12 Wetlands/Riparian Vegetation The action alternatives would have an irretrievable loss of existing wetland and riparian areas. Losses of wetland functions may be irretrievable during the period between loss of existing wetlands and successful establishment of the compensatory mitigation wetlands, but the USACE may factor this into the compensatory mitigation requirements. The USACE follows a no net loss policy, and wetland losses would be reversible.

5-16 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 6 – Consultation and Coordination

CHAPTER 6 CONSULTATION AND COORDINATION

The Council on Environmental Quality (CEQ) regulations (40 Code of Federal Regulations [CFR] Parts 1500– 1508) require public involvement and interagency consultation and coordination to determine the issues related to a proposed action and alternatives that an environmental impact statement (EIS) should address. The purpose of this process is to actively acquire input from interested parties to identify important issues, concerns, and potential impacts that require analysis in the EIS as well as to eliminate issues of no concern and alternatives from detailed analysis. 6.1 Agency Participation/Coordination Because Leavitt Reservoir is on federal (i.e., Bureau of Land Management [BLM]) land, the proposed Leavitt Reservoir Expansion Project (LREP) requires a right-of-way (ROW) grant from the BLM, Cody Field Office (CYFO). BLM is the lead federal agency for the LREP. The LREP also requires a Section 404 Permit from the U.S. Army Corps of Engineers (USACE), Omaha District, because the project is anticipated to involve the discharge of dredged or fill material into waters of the U.S. as defined in 40 CFR 230.3. The USACE is a Cooperating Agency on the LREP. The Wyoming Water Development Commission (WWDC) intends to apply for a Department of the Army Permit (Section 404 Permit), pursuant to Section 404 of the Clean Water Act (CWA). This EIS is intended to serve BLM’s ROW grant decision and the USACE’s Section 404 Permit decision. Specific regulations require the BLM to consult with federal, state, and local agencies about the potential of the LREP and alternatives to affect sensitive environmental and human resources. The BLM initiated these consultation activities through the scoping process and has maintained them through regular meetings regarding key topics (e.g., alternatives development) with Cooperating Agencies throughout the National Environmental Policy Act (NEPA) process. The BLM conducted an LREP kick-off meeting on November 17, 2016, at the BLM CYFO. The kick-off meeting included the key BLM resource specialists, representatives from the USACE and WWDC, and the third-party contractor (AECOM Technical Services, Inc. [AECOM]) project management team and resource coordinator. The other Cooperators were invited to attend or participate by conference call but did not do so. The BLM conducted a Cooperating Agency scoping meeting at its CYFO on October 26, 2017, and a public scoping meeting at the Shell Community Hall in Shell, Wyoming, from 6:00 to 8:00 p.m. on October 26, 2017, to solicit input and identify environmental issues and concerns associated with the LREP. The BLM invited interested federal, state, and local agencies as well as tribes to participate as Cooperating Agencies for preparation of the EIS. Based on positive agency responses, the following agencies are Cooperators on the LREP EIS: • USACE, Omaha District • Wyoming State Engineer’s Office (SEO) • U.S. Environmental Protection Agency • Wyoming Department of Environmental Quality, (USEPA), Region 8 Water Quality Division (WDEQ, WQD) • Wyoming Water Development Commission • Wyoming Department of Agriculture • Wyoming Governor’s Office • South Big Horn Conservation District • Wyoming Office of State Lands and Investments • Big Horn County Board of Commissioners • Wyoming Game and Fish Department (WGFD) The Leavitt Reservoir Expansion Project, Environmental Impact Statement, Final Scoping Report (AECOM 2017) provides an overview of the public scoping process and a summary of the scoping comments, issues, and concerns identified during public scoping for the LREP. Although the BLM encourages commenting on the LREP throughout the preparation of the LREP EIS, the range of issues summarized in the Leavitt Reservoir Expansion Project, Environmental Impact Statement, Final Scoping Report reflects the comments received during the public scoping period.

Leavitt Reservoir Expansion Project – Final EIS – 2019 6-1 Chapter 6 – Consultation and Coordination

6.2 List of Preparers and Reviewers Under the direction of and as the third-party contractor for the BLM, AECOM prepared the EIS with assistance from three subcontractors (BBC Research and Consulting, Brown and Caldwell, and SWCA Environmental Consultants). Appendix 5 provides the names and educational background of the individuals who were principally involved with preparing this EIS. 6.3 Consultation Federal laws require the lead federal agency (i.e., BLM) on a project to consult with certain other federal and state agencies and entities, and Native American tribes during the NEPA decision-making process (40 CFR 1502.25). The following section discusses activities conducted during the NEPA process to meet these requirements. 6.3.1 Tribal Consultation Federal agencies are directed by the National Historic Preservation Act (NHPA) to consult with any Indian tribe that attaches religious and cultural importance to historic properties that may be affected by an undertaking. Tribal consultation is a government-to-government relationship and is the active, affirmative process of: 1) identifying and seeking input from appropriate Native American governing bodies, community groups, and individuals; and 2) considering their interests as a necessary and integral part of the BLM’s decision making process. Under the auspices of the American Indian Religious Freedom Act (AIRFA), Executive Order (EO) 13007, the Native American Graves Protection and Repatriation Act of 1990 (NAGPRA), the NHPA, NEPA, and the Federal Land Policy Management Act of 1976 (FLPMA), the BLM must take into account the effects of land use decisions on places (i.e., physical locations) of cultural value to American Indian groups. For the LREP, the BLM and USACE worked in joint cooperation with American Indian tribes to coordinate and consult before making decisions or approving actions for the proposed LREP. Federal programs are required to be carried out in a manner sensitive to American Indian concerns and tribal government planning and resource management programs. In December 2016, the BLM CYFO initiated consultation with the following tribes regarding the LREP and sought input and assistance from the tribes in identifying any potential cultural concerns regarding the project: • Shoshone-Bannock • Northern Cheyenne • Blackfeet • Eastern Shoshone • Crow • Northern Arapahoe BLM requested that the tribes refer BLM to any available information that would help BLM to understand the significance and nature of traditional cultural concerns at the proposed location for the LREP. BLM included a form and a stamped, return-addressed reply envelope in its December 2016 mailing to the tribes to aid the tribes in submitting responses. BLM requested the tribes provide the names and addresses of any other contacts they felt should be involved, or who they may have missed. In addition to the reply envelope, BLM followed up with phone calls to facilitate communications. No responses were received to this mailing or the subsequent calls. On October 13, 2017, BLM mailed a letter to these same tribes to notify them of BLM’s publication of a Notice of Intent to prepare an EIS in the Federal Register on September 29, 2017. The letter communicated the 45-day scoping period and reminded tribes of the three Class III Cultural Resource Inventory Reports the BLM CYFO had authorized for the proposed LREP and the findings of those reports. The letter included an LREP overview map, figures from the previous site inventories, and a site summary table as attachments. The BLM again solicited the tribe’s input and assistance in identifying any potential cultural concerns regarding the LREP, and indicated the BLM sought to consider the views of the tribe. The BLM requested any available information that would help it to understand the significance and nature of traditional cultural concerns at the proposed location of the LREP. BLM offered to arrange for a meeting to understand tribal concerns sufficiently to take into account the effects that the LREP might have on historic properties and sites of traditional religious or cultural significance. No comments were received from Native American tribes during the scoping period.

6-2 Leavitt Reservoir Expansion Project – Final EIS – 2019 Chapter 6 – Consultation and Coordination

Nine cultural resource investigations that overlap with the LREP cultural resource direct area of potential effects (APE) took place between 1980 and 2017. The findings of the previous investigations indicate that 23 cultural sites are within the LREP cultural resources direct APE (as discussed in Section 3.1). Following BLM’s outreach to the Native American tribes regarding the LREP scoping period: • Josh Mann, Eastern Shoshone Tribal Historic Preservation Officer (THPO), confirmed via email on December 6, 2017, that the Eastern Shoshone would send Tribal Elder John Pingree for the tribal on-site. • Devin Old Man with the Northern Arapaho THPO confirmed via email on December 11, 2017, that Brian Soundingsides from the Northern Arapaho THPO would attend the tribal on-site. • William Big Day with the Crow THPO confirmed via email on December 8, 2017, that he would attend the tribal on-site. The tribal on-site occurred on December 14, 2017. Any and all specific information provided by tribal members concerning resources of Native American concern for the LREP is and will remain confidential. 6.3.2 Other Consultation On January 10, 2018, the BLM hosted Cooperators at its CYFO for an LREP alternatives development workshop. The purpose of the workshop was to develop a reasonable range of alternatives for analysis and consideration in the LREP EIS, with a goal of developing an EIS that meets both the BLM's and the USACE’s decision making needs. Representatives from BLM, WWDC, the Wyoming SEO, the USACE, Big Horn County, USEPA, WDEQ, SWCA, Senator Enzi’s Office, South Big Horn Conservation District, WGFD Habitat Protection Program, Wenck (WWDC’s project engineer), and AECOM participated in this workshop. 6.3.3 Draft EIS Public Review and Comment The BLM, with input from the USACE and other Cooperating Agencies, developed a Draft EIS and made it available to interested parties for public review and comment on August 31, 2018. Following a 45-day public comment period, all comments received were compiled and responses prepared for incorporation as an appendix to this Final EIS. The Draft EIS was then modified, clarified, and/or corrected as appropriate in coordination with the BLM, USACE, and other Cooperating Agencies. The Final EIS will be made available to interested parties for a 30-day public availability period. Following the 30-day public availability period, the BLM and USACE will each develop separate Records of Decision (ROD) and if appropriate, issue the applicable ROW grant and Section 404 Permit, respectively. 6.4 Public Involvement The BLM received 16 unique comment letters during the public comment period. Table 6-1 in Appendix 1 includes a list of the unique written comment letters. Appendix 6.3 presents all of the comments that were received on the Draft EIS. The table in Appendix 6.3 includes the commenter’s affiliation, comment letter ID, the comment number, the specific comment, and the BLM’s response to the comment. In responding to comments, every effort was made to address all questions, concerns, and other points presented by the commenter. Two primary principles of NEPA are full disclosure of potential environmental effects and open public participation throughout the decision-making process. Through the public involvement process, the public is able to participate in the NEPA process. NEPA requirements for public involvement are set forth by the CEQ at 40 CFR 1500-1508. The USACE will evaluate WWDC’s application under a public interest review, as well as the environmental criteria set forth in the Section 404(b)(1) Guidelines (40 CFR 230), regulations promulgated by the USEPA, as well as the USACE regulations for implementing NEPA (33 CFR 325). The BLM will accept comments throughout all stages of the NEPA process for the LREP.

Leavitt Reservoir Expansion Project – Final EIS – 2019 6-3 Chapter 6 – Consultation and Coordination

This page intentionally left blank

6-4 Leavitt Reservoir Expansion Project – Final EIS – 2019