This is a digital document from the collections of the Wyoming Water Resources Data System (WRDS) Library. For additional information about this document and the document conversion process, please contact WRDS at [email protected] and include the phrase “Digital Documents” in your subject heading. To view other documents please visit the WRDS Library online at: http://library.wrds.uwyo.edu Mailing Address: Water Resources Data System University of Wyoming, Dept 3943 1000 E University Avenue Laramie, WY 82071 Physical Address: Wyoming Hall, Room 249 University of Wyoming Laramie, WY 82071 Phone: (307) 766-6651 Fax: (307) 766-3785 Funding for WRDS and the creation of this electronic document was provided by the Wyoming Water Development Commission (http://wwdc.state.wy.us) NOWOOD RIVER STORAGE, LEVEL II STUDY, PHASE I EXECUTIVE SUMMARY WYOMING WATER DEVELOPMENT COMMISSION CHEYENNE, WYOMING December 6, 2013 Project#: 06N-002-001 SUBMITTED BY: Trihydro Corporation 1252 Commerce Drive, Laramie, WY 82070 IN ASSOCIATION WITH: Anderson Consulting Engineers 375 Horsetooth Road, Building #5, Fort Collins, CO 80525 Parsons Water Consulting LLC 4729 W 32 Ave, Denver, CO 80212 Hollingsworth and Associates, Inc. 2875 W. Oxford Ave. #7, Sheridan, CO 80110 ENGINEERING SOLUTIONS . ADVANCING BUSINESS . Home Office I 1252 Commerce Drive I Laramie. WY 82070 I phone 307/745.7474 I fax 307/ 745.7729 I 1vww.trihydro. Table of Contents 1.0 EXECUTIVE SUMMARY ................................................................................................................ 1-1 1.1 Project Purpose and Scope ..................................................................................................... 1-1 1.2 Project Findings ...................................................................................................................... 1-2 1.2.1 Hydrologic Analysis ................................................................................................. 1-2 1.2.2 Purpose and Need ..................................................................................................... 1-2 1.2.3 Potential Storage Alternatives .................................................................................. 1-3 1.2.4 Preferred Alternatives ............................................................................................... 1-5 1.2.4.1 Meadowlark Lake Enlargement ............................................................... 1-5 1.2.4.2 Alkali Creek ............................................................................................. 1-6 1.2.5 Economic Analysis ................................................................................................... 1-6 1.2.5.1 Alkali Creek ............................................................................................. 1-7 1.2.5.2 Meadowlark Lake .................................................................................... 1-7 1.2.5.3 Indirect Irrigation Benefits ...................................................................... 1-8 1.2.5.4 Additional Benefits .................................................................................. 1-8 1.2.5.5 Financing Under WWDC Guidelines ...................................................... 1-8 1.3 Recommendations ................................................................................................................ 1-10 M:\GovState\WyoWaterDvlpComm\ProjectDocs\NowoodRiverWatershed\StorageLevelIIStudy\Reports\201311_FinalSummary_RPT\ExecutiveSummary\201312_NowoodPh1ES_RPT.docx List of Tables ES-1. Summary of Estimated Costs for Top Ranked Alternatives ES-2. Financing under WWDC Guidelines .................................................. ~i ~ro M:\GovState\WyoWaterDvlpComm\ProjectDocs\NowoodRiverWatershed\StorageLevelIIStudy\Reports\201311_FinalSummary_RPT\ExecutiveSummary\201312_NowoodPh1ES_RPT.docx List of Figures ES-1. Nowood Watershed Location and Vicinity ES-2. Level 1 Study Potential Storage Sites ES-3. Meadowlark Lake (Tensleep Reservoir) Enlargement Alternative ES-4. Alkali Creek Storage Alternative M:\GovState\WyoWaterDvlpComm\ProjectDocs\NowoodRiverWatershed\StorageLevelIIStudy\Reports\201311_FinalSummary_RPT\ExecutiveSummary\201312_NowoodPh1ES_RPT.docx 1.0 EXECUTIVE SUMMARY The Nowood River Watershed (Watershed) encompasses approximately 2,012 square miles in north central Wyoming (Figure ES-1). The Watershed experiences substantial spring runoff; however, these flows are not captured and water shortages occur during low-flow periods common in late summer and fall. There are more than 27,000 acres of irrigated land in the Watershed, and the water shortages observed during the late season irrigation period result in fields that cannot be irrigated. The Nowood River Storage, Level II, Phase I Storage Study (Project) was undertaken by the Wyoming Water Development Commission (WWDC) to evaluate opportunities to develop water storage within the Watershed that will benefit Wyoming and its residents by addressing the late season water supply shortages evidenced within the Watershed. This Executive Summary presents the Project purpose, findings, cost estimates, and recommendations. More detail on the Project is included in the Nowood River Storage, Level II Study Phase I Final Summary Report, dated December 6, 2013. 1.1 PROJECT PURPOSE AND SCOPE Landowners in the area, concerned with late season water shortages, as well as other issues in the Watershed, formed the Proponents of Nowood Drainage Storage (Steering Committee/Project Sponsor) and requested funding from the WWDC for a watershed investigation in the fall of 2007. Their application was successful and the 2008 Wyoming Legislature awarded funding for the Nowood River Storage/Watershed Level I Study (Level I Study). In June 2008, the WWDC contracted Anderson Consulting Engineers (ACE) to complete the Level I Study. The purpose of the Level I Study was to evaluate and describe the Watershed and to develop a Watershed Management Plan. The three primary issues evaluated as part of Level I Study, consistent with other WWDC watershed studies, were: 1) opportunities for surface water storage; 2) the state of, and possible improvements to irrigation infrastructure; and 3) opportunities to enhance upland water resources. Through the course of the Level I Study, ACE and the WWDC developed recommendations for irrigation system conservation and rehabilitation, livestock and/or wildlife upland watering opportunities, grazing management opportunities, other upland management opportunities, and stream rehabilitation. The Level I Study also concluded that, due to the timing of flows in the Watershed, late season water shortages exist, but that water is available for storage during high, spring flows. The Level I Study identified 35 sites that potentially could be developed as storage reservoirs to store available water during the spring and release flows later in the water year. M:\GovState\WyoWaterDvlpComm\ProjectDocs\NowoodRiverWatershed\StorageLevelIIStudy\Reports\201311_FinalSummary_RPT\ExecutiveSummary\201312_NowoodPh1ES_RPT.docx 1-1 Greybull ¤£14 Black Tooth Mountain UV30 Basin Cloud Peak Wild Horse Draw Paint Rock Creek Big Horn County Mather Peaks Manderson Ed Point South Paint Rock Creek 31 Laddie Creek UV Bighorn Peak Hyattville Luman Creek Alkali Creek Medicine Lodge Creek r e v i R n r Loaf Mountain o h g i B West Tensleep Creek UV433 Big Cottonwood Creek East Tensleep Creek ¤£16 ¤£16 Sand Creek Brokenback Creek Little Cottonwood Creek UV435 Tensleep Creek Johnson County ¤£16 Ten Sleep Worland Big Canyon Creek Alkali Creek South Monument Hill ¤£20 UV431 UV432 Bud Kimball Creek Spring Creek Otter Creek South Fork Otter Creek Washakie County North Fork Buffalo Creek Crooked Creek Little Canyon Creek Willow Creek Buffalo Creek Horse Butte Hot Springs County Box Elder Creek Sheridan Hot Springs!. County Cody !. Deep Creek Worland !. 7 Nowood River Battle Mountain NOWOOD WATERSHED Bear Creek Lone Tree Creek Rebedeaux Mountain WYOMING Evanston !. Cheyenne !. Fremont County Natrona County Fremont County EXPLANATION MOUNTAIN PEAKS Copyright:© 2013 National Geographic Society, i-cubed )" CITIES RIVERS & STREAMS FIGURE ES-1 PRIMARY US OR STATE HIGHWAY NOWOOD WATERSHED SECONDARY STATE OR COUNTY HIGHWAY LOCATION AND VICINITY LOCAL OR RURAL ROAD ­ 1252 Commerce Drive NOWOOD RIVER STORAGE LEVEL II STUDY COUNTY BOUNDARY 0 6Miles Laramie, WY 82070 www.trihydro.com WYOMING WATER DEVELOPMENT COMMISSION NOWOOD WATERSHED (P) 307/745.7474 (F) 307/745.7729 TEN SLEEP, WYOMING Drawn By: DRT Checked By: BR Scale: 1" = 6 MI Date: 12/6/13 File: Nowood_Location_ES.mxd Based on the findings of the Level I Study and continued interest by the Project Sponsor, the WWDC contracted with Trihydro Corporation (Trihydro) in June 2010 to provide professional services for the Nowood River Storage, Level II, Phase I Storage Study. The scope of this Project is focused on estimating potential water shortages, estimating flows available for storage, investigating and evaluating potential storage locations, and assessing the capability of the highest-ranked storage locations to meet water shortages and provide other Watershed benefits (e.g., reducing flooding potential or magnitude, reducing stream erosion, increasing late-season stream flows, enhancing habitat, and providing recreational opportunities, among others). 1.2 PROJECT FINDINGS 1.2.1 HYDROLOGIC ANALYSIS A StateMOD watershed hydrologic model was developed to simulate flows in the Watershed. This model incorporates historic