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 ......................................................................................................................................................