NOWOOD RIVER STORAGE, LEVEL II STUDY PHASE II EXECUTIVE SUMMARY WYOMING WATER DEVELOPMENT COMMISSION CHEYENNE, WYOMING January 7, 2016 Project #: 06N-002-001 SUBMITTED BY: Trihydro Corporation 1252 Commerce Drive, Laramie, WY 82070 IN ASSOCIATION WITH: Anderson Consulting Engineers, Fort Collins, CO Parsons Water Consulting LLC, Denver, CO Hollingsworth and Associates, Inc., Sheridan, CO LTA, Inc., Laramie, WY SWCA Environmental Consultants, Sheridan, WY Western Ecosystems Technology Inc., Cheyenne, WY Watts and Associates, Laramie, WY Table of Contents 1.0 EXECUTIVE SUMMARY ................................................................................................................ 1-1 1.1 Project Purpose and Scope ..................................................................................................... 1-1 1.2 Project Findings ...................................................................................................................... 1-3 1.2.1 Hydrologic Analyses ................................................................................................ 1-3 1.2.2 Purpose and Need ..................................................................................................... 1-4 1.2.3 Environmental Considerations .................................................................................. 1-4 1.2.3.1 Sage-Grouse ............................................................................................. 1-4 1.2.3.2 Wetland Resources .................................................................................. 1-5 1.2.3.3 Water Quality .......................................................................................... 1-6 1.2.3.4 Other Resources ....................................................................................... 1-6 1.2.4 Cultural and Paleontological Considerations ............................................................ 1-6 1.2.4.1 Class III Cultural Study ........................................................................... 1-6 1.2.4.2 Paleontological Study .............................................................................. 1-7 1.2.5 Geotechnical Investigation ....................................................................................... 1-7 1.2.6 Conceptual Design .................................................................................................... 1-8 1.2.6.1 Conceptual Dam Design .......................................................................... 1-8 1.2.6.2 Conceptual Outlet Works Design ............................................................ 1-9 1.2.6.3 Conceptual Spillway Designs .................................................................. 1-9 1.2.6.4 Conceptual Supply Ditch Design ............................................................. 1-9 1.2.7 Cost Estimate and Economic Analyses................................................................... 1-10 1.2.7.1 Direct and Indirect Benefits ................................................................... 1-10 1.2.7.2 Additional Benefits ................................................................................ 1-10 1.2.7.3 Financing and Willingness to Pay Analysis........................................... 1-10 1.3 Recommendations ................................................................................................................ 1-11 M:\GovState\WyoWaterDvlpComm\ProjectDocs\NowoodRiverWatershed\LevelII_Phase2\Reports\201511_FinalSummary\201601_ExecutiveSummary\201601_NowoodPhIIES_RPT.docx List of Figures ES-1. Nowood Watershed Location and Vicinity ES-2. Alkali Creek Storage Alternative M:\GovState\WyoWaterDvlpComm\ProjectDocs\NowoodRiverWatershed\LevelII_Phase2\Reports\201511_FinalSummary\201601_ExecutiveSummary\201601_NowoodPhIIES_RPT.docx 1.0 EXECUTIVE SUMMARY The Wyoming Water Development Commission (WWDC) is evaluating late-season water shortages in the Nowood River Watershed (Watershed), and identifying and evaluating potential surface water storage alternatives to address these shortages. The WWDC is undertaking these efforts based on concerns with late-season water shortages raised by area landowners. The Nowood River Storage, Level II, Phase II Study (Project or Level II, Phase II Study) expands and refines analyses of the Meadowlark Lake (enlargement) and Alkali Creek (new reservoir) storage alternatives (Figure ES-1). These two sites, which largely service geographically different areas and are considered independent alternatives, were identified as the top-ranked storage alternatives during the Nowood River Storage Level II, Phase I Study (Level II, Phase I Study). The Project and this report focus on the Alkali Creek alternative; although, some Project activities (e.g., temporary stream gauging, wetland delineations, and agency coordination) also encompass the Meadowlark Lake alternative. Specific information pertaining to Meadowlark Lake will be presented in a separate Level II, Phase II Study report. The proposed Alkali Creek reservoir is sited on Alkali Creek, an intermittent tributary to Paint Rock Creek in the lower Watershed (Figure ES-2). The reservoir, as currently designed, would store 7,994 acre-feet, and would be filled with flow from Alkali Creek and flow diverted from Paint Rock Creek and Medicine Lodge Creek via enlargements to the Anita Supplemental Ditch and the Anita Ditch (Figure ES-2). This proposed reservoir could reduce late-season shortages in the lower Watershed by 58%. 1.1 PROJECT PURPOSE AND SCOPE Landowners in the Watershed, concerned with late season water shortages, as well as other Watershed issues, formed the Proponents of Nowood Drainage Storage (Steering Committee/Project Sponsor) and requested WWDC funding for a watershed investigation in the fall of 2007. Their application was successful and the 2008 Wyoming Legislature awarded funding for the Nowood River Watershed Level I Study (Level I Study). The purpose of the Level I Study was to evaluate and describe the Watershed and to develop a Watershed Management Plan. Through the course of the Level I Study, Anderson Consulting Engineers (ACE) and the Wyoming Water Development Office (Office) 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 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. M:\GovState\WyoWaterDvlpComm\ProjectDocs\NowoodRiverWatershed\LevelII_Phase2\Reports\201511_FinalSummary\201601_ExecutiveSummary\201601_NowoodPhIIES_RPT.docx 1-1 Greybull Black Tooth Mountain Basin Cloud Peak W k e i e l r d C ALKALI CREEK H i o l r a SITE k Big Horn County k e s l e e A r D C r k Mather Peaks a c w o R t in ek a Manderson re P C L Ed Point um ge S d an o o C ut L r L h ne e a P i ek d ai k Bighorn Peak ic d nt e d i R e e Hyattville e r C oc r M C e k v r C i e r p R e k ee e k e n l Creek s t Tensleep r Eas n o e T Loaf Mountain h t g s i e B W ek re C ck ba en ok S r MEADOWB LARK LAKE ek a re n C d p e C e sl r n e e e T k k e e r C Johnson County d o Ten Sleep o ek w re n C Worland o t n t yo o n C a C g i ig B B Monument Hill k ree ll C ek ba re im C d K ng Bu ri Sp S o u th F o N r orth k Fo O rk t Washakie County Bu te ffal r o C C ree k re e k C roo ked Cr eek k e e r C o l a f f u k B e Horse Butte e r Hot Springs County C B o w x o l E l i l d W e r C r e e k Sheridan Hot Sp.!rings County Cody .! Worland .! 7 Battle Mountain k e e er r v C i R e d e o r NOWOOD WATERSHED o B T ow e N e a n r o C L r e e k Rebedeaux Mountain W Y O M I N G 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 NOWOOD RIVER STORAGE LEVEL II PHASE II STUDY ­ 1252 Commerce Drive COUNTY BOUNDARY Laramie, WY 82070 0 6Miles 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: 1/4/16 File: Nowood_Location_FigES-1.mxd AMERICAN COLLOID COMPANY AMERICAN k HAMILTON COLLOID e e COMPANY r RANCH, INC C i al lk A MONTANA MINERALS AMERICAN DEVELOPMENT CO COLLOID COMPANY NEGUS, GREER, KEVIN TYLER & EVA WILLIAM & GREER, H ig CASEY T. & h land D KATHERINE A. itc GREER LAND h GREER, DAVE L & LIVESTOCK DIAMOND S & LORETTO M HYATTVILLE RANCH, LLC CEMETERY BARRER, STEVEN JON BOOTH, JUNE & DIANE R R. & HARLEY PAINT ROCK CAINES, GLEN PHILIP T PAINT ROCK ANGUS SEARFOSS, RANCH INC & CATHERINE B ANGUS KENNETH H BOOTH, JUNE RANCH INC SYLVESTER, & REBECCA R. & ZIEROLF, MILAN KENT SHIRRAN, LOIS A NANCY BOOTH REVOCABLE TRUST h Anita Supplemental Ditc SHIRRAN, Anita BOWERS, Ditch PAINTROCK FRANK & GEORGE T ANGUS JONES, CONNIE C. TRUST RANCH, INC O'BRIEN, TODD W CAINES LAND MICHAEL A & NANCY J ock Creek & LIVESTOCK LP t R ALM, in PAINT ROCK itch a JOHN R ita D P ANGUS An TRI-CO RANCH INC TELEPHONE ASSOC, INC PAINTROCK PAINTROCK ANGUS ANGUS RANCH, INC RANCH, INC WEDEL, THARP, LARRY & DOYLE, GEORGIA ALM, PATRICIA GAY LIN & GAY JOHN R MARYLOU PAINTROCK ALM, Hyattville ANGUS JOHN R DEHONY, JO ALM, rge & Ba ch ")