4 Water Resources This Chapter Presents the Physical Characteristics (Quantity and Quality) of Surface Water in the Wind- Bighorn Basin

4 Water Resources This chapter presents the physical characteristics (quantity and quality) of surface water in the Wind- Bighorn Basin. Groundwater characteristics are presented in a separate report by the WSGS and the USGS. All information presented in this chapter is historical data. This differs from the simulated streamflow and available flow calculations presented in Chapter 7. In addition, Chapter 7 presents both physically available flow and constrained available flow estimates, which are based on the spreadsheet model analysis.

The basic hydrologic cycle for a typical Wyoming river basin is presented in Figure 10. Precipitation is the source of both groundwater and surface water. Most of the precipitation will evaporate from the surface or be taken up and transpired by local vegetation. Precipitation and snowmelt in excess of immediate demands will either run off (feeding rivers, streams, and lakes) or infiltrate to become groundwater. Groundwater recharge may eventually return to the surface, or be stored in shallow alluvial or deep bedrock aquifers. Surface water will eventually evaporate to the atmosphere, completing the cycle. 5

Figure 10. Hydrologic Cycle

Figure 11 presents a summary of total annual precipitation within each basin in the study area, and the total outflow from the basin at the closest streamflow gaging station(s) to the state line, or in the case of the Wind River Basin, Boysen Reservoir. Average annual precipitation for the Basin produces approximately 18.5 million acre-feet (maf) per year. Headwater drainages for all basins except for the Clarks Fork Basin are completely contained within the state, thus the total basin area within the state generally represents the total contributing area to streamflow at the basin outflow. For the

5 Paragraph and Figure 10 adapted from Framework Plan

Wind-Bighorn Basin Plan Update

Clarks Fork, a small portion of the contributing area to streamflow at the state line outflow point is in Montana.

9.0 8.0 Total Precipitation 7.0 Basin Outflow 6.0 5.0 4.0 3.0 2.0 1.0 Mean Annual Annual Mean Volume (million ac-ft) 0.0 Wind Bighorn Gallatin Madison/ Clarks Fork Clarks Yellowstone

Figure 11. Estimated Mean Annual Basin Precipitation and Outflow

Total estimated annual outflow from the Wind-Bighorn Basin is nearly 6.8 maf, or approximately 37 percent of total precipitation. A portion of this would be available to Wyoming in the Clarks Fork and Bighorn Rivers for future water use under the Yellowstone River Compact.

Of the 11.6 maf that does not leave the state as streamflow, roughly 1.4 maf is consumptively used by crops within the Basin (either through rainfall or irrigation 6), or by other uses documented in Chapter 4.3. Of the remaining 10.3 maf, which comprises nearly 88 percent of the water that does not leave the state, most is evaporated from the surface or transpired by vegetation. A small portion serves to recharge alluvial and bedrock aquifers. A summary of the Basin water resources mass balance is presented in Figure 12.

6 Total crop CU estimated as supply limited CU (see section 5.1) divided by average percent of total CU met by irrigation as calculated from Pochop (1992) data (80 percent). Estimates are for illustrative purposes only.

Wind-Bighorn Basin Plan Update

Total Basin precipitation Leaves State 18.5 maf per year (Available to Wyo) Municipal/Domestic 2.4 /Stock/Industrial 13% 0.015 0.08%

Evaporation Natural ET and Crop CU Current 0.16 Aquifer 1.35 Use 1% Recharge Leaves State 7% 10.1 (Unavailable to Wyo) 55% 4.5 24%

All values are annual consumptive use in maf per year.

Figure 12. Current Basin Water Resources Mass Balance

The remaining portion of this chapter discusses the surface water runoff (or streamflow) component of the hydrologic cycle within the Wind-Bighorn. 4.1 Surface Water Resources The location, timing, quantity and quality of surface water resources within the basin have a significant effect on the ability of those resources to be used for the various water uses described in Chapter 4.3. Historical location, timing and quantity are generally contained in streamflow records, some of which have been collected since the late 1800’s. Historical streamflow estimates are also the basis from which the spreadsheet models discussed in Chapter 7 are developed. Water quality information comes from numerous sources, including raw data that is collected instantaneously at selected streamflow gaging stations and periodically by various entities in certain reaches of rivers. This information is described in the following sub-sections. Additional information on streamflow is presented in Technical Memorandum 4A, while additional information on water quality is presented in Technical Memorandum 6B.

4.1.1 Streamflow Streamflow gages measure the instantaneous discharge of water in a stream segment. There are currently 33 active streamflow gaging stations within the Wind-Bighorn Basin that are operated by the USGS, WSEO Division III, and the USBR. A listing of these gaging stations, a summary of the period-of-record for each station and the average annual flow for the model study period (see Chapter 7) is presented in Table 11. A map of streamflow gaging stations is presented in Figure 13.

In addition to the 33 active gaging stations, there have been nearly 150 other gaging stations that have been operated within the Basin over the years. Some of these gaging stations were operated long ago, while others have been more recently discontinued. These gages can be used within the hydrologic modeling analysis by estimating flows using regression analyses with other gages in the area that have similar flow patterns. More information on the use of these gages in the model and the methods for estimated flows at the gaging stations is presented in Chapter 7 and in Technical Memorandum 4A.

Wind-Bighorn Basin Plan Update

*# 06191500 06207500 *# *# *# #*#* Frannie Bighorn*#*# #* *##* Clarks Fork *# Lake*# # Deaver Cowley * *# Crandall*# Yellowstone# River *# Creek *# * *# *#*#*# *# Lamar Byron Lovell *# River Powell *# #* Shoshone*# River *# *#Yellowstone Park #* *# 06037500 River # *# Madison*# *# *#* River #* # *# * #* *# Shell Creek*# #* Teton *#*# North Fork Shoshone River # *# *# 06278500 *# Yellowstone *# * Cody Dry Creek *# Greybull *# *# Burlington Lake #* #* Buffalo Bill *# *# Big Horn # Reservoir Bighorn#* Basin * River *# Manderson *# *# *# SouthShoshone Fork River Paintrock #* *# *#*# Creek Greybull*# Meeteetse *# Nowood #* *#River Fifteen Mile River Creek #*Tensleep Creek *# Washakie * Gooseberry #*#* *# *# *# *# Worland Ten #* Creek Sleep *# *# *#*# Cottonwood Creek *# Nowater Kirby Creek #* *#*# Owl #* Kirby *# *# Creek *# Creek #**#*#*##**#*# *##* #* Thermopolis *# East Fork # Hot Springs Dubois Wind River * #* Fivemile #* #* Creek Wind *#* River*# Wind River *# Boysen *# *##* Muddy *# Reservoir *# #* Fremont *# Creek #* *# *# *# #**# *# Natrona *#*# Pavillion #* #* *# Shoshoni Bull *# #* *# # #**#*#*####***#*# ##* *# Lake *#*# * * *#*# * Poison Bull Lake *#*# *# Creek Creek Ocean *# #* Lake Fort Riverton Washakie Ethete *# *# *# # *# Arapahoe *# *#*# *# # 06235500 *# *# Popo Agie *#**# #* River *# Hudson Beaver *# *# Creek Lander *#*# Middle Popo #* Agie River *# *#

Legend

Cities *# Active Streamflow Gage Rivers *# Inactive Steamflow Gage Wyoming Water Development Commission County Boundary *# Streamflow Gages highlighted in the text Study Basins 020 40± 80

Scale in Miles

Figure 13. Streamflow Gaging Stations in Wind-Bighorn Basin

Wind-Bighorn Basin Plan Update

Table 11. Summary of Active Stream Gages in Wind-Bighorn Basin

Average Annual Gage Period of Flow (2) Basin Number Gage Name Record (ac-ft) Madison/ 06036905 Firehole River Near West Yellowstone Mt Oct 1983 - Present (1) 232,372 Gallatin 06037500 Madison River Near West Yellowstone Mt Jul 1913 - Present (1) 369,234

06043500 Gallatin River Near Gallatin Gateway Mt Jun 1930 - Present (1) 599,564 Yellow- 06186500 Yellowstone River At Yellowstone Lk Outlet Ynp Oct 1926 - Present (1) 945,587 stone 06187915 Soda Butte Cr At Park Bndry At Silver Gate Oct 1998 - Present 40,887 06187950 Soda Butte Cr Nr Lamar Ranger Station Ynp Oct 1988 - Present 102,382 06188000 Lamar River Nr Tower Falls Ranger Station Ynp May 1923 - Present (1) 642,720 06190540 Hot River At Mammoth Ynp Oct 1988 - Present (1) 19,123 06191000 Gardner River Near Mammoth Ynp Oct 1938 - Present (1) 151,342

06191500 Yellowstone River At Corwin Springs Mt Sep 1910 - Present 2,239,249 Clarks Fork 06207500 Clarks Fork Yellowstone River Nr Belfry Mt Aug 1921 - Present 652,258 (1) Upper 06218500 Wind River Near Dubois, Wyo. Oct 1945 - Present 114,936 (1) Wind 06220800 Wind River Above Red Creek, Near Dubois, Wy Oct 1990 - Present 454,653 (1) 06221400 Dinwoody Creek Above Lakes, Near Burris, Wyo. Oct 1957 - Present 99,177 (1) 06224000 Bull Lake Creek Above Bull Lake, Wy Oct 1941 - Present 198,662 06225000 Bull Lake Creek Near Lenore, Wy Jun 1918 - Present (1) 186,471 06225500 Wind River Near Crowheart, Wy Oct 1945 - Present 803,290 0303WR01 Wind River at Hwy 26 Bridge, near Morton Nov 2001 - Present (1) 393,990 06227600 Wind River Near Kinnear, Wy Apr 1974 - Present (1) 479,409 06228000 Wind River At Riverton, Wy Apr 1912 - Present (1) 364,727 Wind River Ab Boysen Reservoir, Nr Shoshoni, 06236100 Wy May 1990 - Present 815,062 Little Wind 06235500 Little Wind River Near Riverton, Wy Jun 1941 - Present 382,275 Popo Agie River Below The Sinks, Near Lander, Popo Agie 06231600 Wy Oct 1959 - Present 94,901

06233000 Little Popo Agie River Near Lander, Wyo. Apr 1946 - Present (1) 64,682 Lower 06253000 Fivemile Creek Near Shoshoni, Wy Jun 1941 - Present (1) 114,857 Wind 06259000 Wind R Bl Boysen Res Wyo Jun 1951 - Present 953,879 06260000 South Fork Owl Creek Near Anchor, Wy Oct 1940 - Present (1) 23,948 Upper South Fork Owl Creek Below Anchor Reservoir, (1) Bighorn 06260400 Wy May 1959 - Present 15,601 06264000 Owl Creek Near Thermopolis, Wy Mar 1911 - Present (1) 1,696 Cottonwood C At High Island Rnch Nr Hamilton 06265337 Dome Apr 1993 - Present 8,060 06266500 Gooseberry Creek Nr Dickie Wyo Jun 1938 - Present (1) 3,572 Bighorn River near Wyoming Boys School, near 0303BH08 Worland Nov 2003 - Present 374,238 06274300 Bighorn R At Basin Wy Oct 1983 - Present 1,213,695 Nowood No current gages Greybull 06276500 Greybull River At Meeteetse, Wyo. Feb 1921 - Present (1) 208,797 0316MC02 Meeteetse Creek above Joe Moss Ditch Sep 2008 - Present 11,397 0316MC01 Meeteetse Creek below Joe Moss Ditch Jul 2000 - Present (1) 6,633 Bighorn 06278300 Shell Creek Above Shell Creek Reservoir, Wyo. Oct 1956 - Present 22,906 Lake 06278500 Shell Creek Near Shell, Wy Oct 1940 - Present (1) 85,940

06279500 Bighorn River At Kane, Wy Oct 1928 - Present (1) 1,431,787 Shoshone 06279940 North Fork Shoshone River At Wapiti, Wy Oct 1989 - Present 602,993 06280300 South Fork Shoshone River Near Valley, Wy Oct 1956 - Present (1) 282,693 06281000 South Fork Shoshone R Ab Buffalo Bill Res, Wy May 1903 - Present (1) 245,147 06282000 Shoshone River Below Buffalo Bill Reservoir, Wy Jan 1921 - Present 675,903 06285100 Shoshone River Near Lovell, Wy Oct 1966 - Present 595,657 Notes: (1) Incomplete data within period -of -record. (2) Average annual flow for 1973 -2008 study period.

Wind-Bighorn Basin Plan Update

Study Period Selection Because historical data are not available for all gages since the inception of data collection, and to make the model less expansive and easier to use, a representative study period has been selected from the data set. The study period is intended to be representative of the overall long-term gage records and hydrologic conditions. To be consistent within the study period, overall patterns of basin inflows, diversions and storage must remain constant through the study period. Therefore, study periods were selected to minimize the impacts of major new reservoirs or new diversion projects within the period of record. This required examination of reservoir and diversion construction records. Streamflow statistics within each study period were checked against long-term statistics at gages with long-term records to ensure that the data were representative of the long-term period.

Based on the construction of several dams and reservoirs within the Basin and streamflow data available for use, the previous Basin Plan utilized a study period of 1973-2001. Because no additional data has become available prior to 1973, the Basin Plan Update will continue to use 1973 as the start of the study period. However, the study period was extended to include the most recent data available, which is through 2008. Therefore, the Basin Plan Update utilized a study period of 1973-2008. The study period includes drought conditions of the 2000s, which affects the water availability analysis.

Annual Flow Long-term and study period annual flow was compared for one gage with a long-term period-of- record to verify that the study period is reflective of long-term streamflow. In addition, analysis of annual flow presents a general summary of hydrologic conditions, and more importantly for the Basin Plan Update, how the 2000’s drought compares with other historical droughts. The following provides a general summary of these comparisons for each basin. The gages discussed in this section were chosen because they have a long-term period-of-record and are representative of flow conditions within each Basin. Additional information regarding these comparisons is presented in Technical Memorandum 4A.

In both the Madison and Gallatin River Basins, because there are no major storage reservoirs or significant surface water diversions in the area, there have been few man-made changes in river regime. Figure 14 presents a summary of the period-of-record and the study period for the Madison River near West Yellowstone (06037500). The average flow during the study period is approximately 2.7 percent higher than the long-term average. The study period average is closer to the long-term average than in the previous Basin Plan, which had an average 5.6 percent higher. The addition of 2002-2008 data in the study period has resulted in the study period being more closely representative of the long-term gage data than the previous Basin Plan. However, the drought years in the 2000’s do not approach the low flow years that occurred in the 1930s. Because the general trend in the Basin in river flows since 1950 is slightly greater than the long-term average (even during drought conditions), the period-of-record used is deemed adequate. However, if drought studies are conducted for downstream water users in the Basin (downstream of Wyoming), a longer period-of-record that accounts for the lower flow conditions earlier in the 20 th century should be used.

Wind-Bighorn Basin Plan Update

600,000 600,000

500,000 400,000

200,000 400,000 0

300,000 -200,000

-400,000

Annual Discharge Discharge Annual (ac-ft) 200,000 Cum Dep From Mean -600,000 Annual Flow Cumulative Departure from Mean (ac-ft) 100,000 Period-of-Record Mean -800,000 Study Period Mean

0 -1,000,000 1900 1905 1910 1915 1920 1925 1930 1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 Water Year Figure 14. Annual Flow for Madison River near West Yellowstone (06037500)

In the Yellowstone River Basin, because there are no major storage reservoirs or significant surface water diversions in the area, there have been few man-made changes in river regime. In addition, data are available in part for several gages since the mid-1920s. Figure 15 presents a summary of the period-of-record and the study period for the Yellowstone River at Corwin Springs. The average flow during the study period is approximately 0.4 percent lower than the long-term average. This represents a slight change from the previous Basin Plan, which showed a 1.1 percent higher average annual flow for the study period. In general, the model is slightly conservative regarding water supply.

Annual flow for the Clarks Fork Yellowstone River near Belfry gage is shown in Figure 16. The average flow during the study period is approximately 7.6 percent less than the long-term average. This is drier than the previous Basin Plan study period, which showed an average annual flow during the study period 2.0 percent less than the long-term average. The average annual flow for the updated study period is approximately 1.8 percent less than the average annual flow in the previous study period. The study period contains the most prolonged period of sustained high flows (1969- 1976) as well as a prolonged period of sustained low flows (1982-1994). The study period also contains the five lowest flows on record at this gage. The 2000s drought years show similar flow patterns as the 1930s drought, although the 2000s drought was shorter in duration. In general, the comparison with long-term data indicates that the period-of-record is conservatively representative of the long term data from a water supply perspective.

Wind-Bighorn Basin Plan Update

4,000,000 2,500,000

3,500,000

1,500,000 3,000,000

2,500,000 500,000

2,000,000 -500,000

1,500,000

Annual Discharge Discharge Annual (ac-ft) -1,500,000 Cum Dep From Mean 1,000,000

Annual Flow Cumulative Departure from Mean (ac-ft) Period-of-Record Mean -2,500,000 500,000 Study Period Mean

0 -3,500,000 1900 1905 1910 1915 1920 1925 1930 1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 Water Year Figure 15. Annual Flow for Yellowstone River at Corwin Springs (06191500)

1,200,000 1,500,000

1,000,000 1,000,000

500,000 800,000

0 600,000

-500,000

Annual Discharge Discharge Annual (ac-ft) 400,000 Cum Dep From Mean -1,000,000

Annual Flow Cumulative Departure from Mean (ac-ft) 200,000 Period-of-Record Mean -1,500,000 Study Period Mean

0 -2,000,000 1900 1905 1910 1915 1920 1925 1930 1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 Water Year Figure 16. Annual Flow for Clarks Fork Yellowstone River near Belfry (06207500)

Wind-Bighorn Basin Plan Update

Annual flow for the Little Wind River near Riverton gage is shown in Figure 17. The average flow during the study period is approximately 5.1 percent less than the long-term average. The study period is drier than in the previous Basin Plan study. The addition of 2002 through 2008 to the study period and adjusting the hydrologic classification to accommodate the additional years (dry, average or wet years; see section 7.1 for hydrologic classifications) resulted in inclusion of lower flow years in both of these categories. The study period contains a prolonged period of generally sustained low flows (1986-1994) as well as a prolonged period of generally sustained high flows (1994-1999), and a period of drought condition flows (2000-2008). In addition, the study period contains the three highest high flows and five of the six lowest flows in the period-of-record. These statistics all indicate that the period-of-record is conservatively representative of the long term data from a water supply perspective. It should be noted that this gage is heavily influenced by irrigation diversions and return flows (most of which have been in operation since the early 1900s). However, if it is assumed that these demands and return flows are relatively constant through the study period and long-term period-of-record, then the diversions and return flows do not influence the relative comparisons.

800,000

700,000 1,000,000

600,000

500,000 500,000

400,000 0

300,000

Annual Discharge Discharge Annual (ac-ft) -500,000 Cum Dep From Mean 200,000

Annual Flow Cumulative Departure from Mean (ac-ft) -1,000,000 Period-of-Record Mean 100,000 Study Period Mean

0 -1,500,000 1900 1905 1910 1915 1920 1925 1930 1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 Water Year Figure 17. Annual Flow for Little Wind at Riverton (06235500)

Annual flow for Shell Creek near Shell, which is representative of the eastern portion of this part of the Bighorn Basin, is presented in Figure 18. The average flow during the study period is nearly identical to the long-term average. The study period contains both the driest year (2001) and wettest year (1978) in the period-of-record. Overall, this study period at this gage is very representative of the long-term average.

Wind-Bighorn Basin Plan Update

140,000

100,000 120,000

50,000 100,000

0 80,000

-50,000 60,000 Annual Discharge Discharge Annual (ac-ft) -100,000 40,000 Cum Dep From Mean

Annual Flow Cumulative Departure from Mean (ac-ft) 20,000 Period-of-Record Mean -150,000 Study Period Mean

0 -200,000 1900 1905 1910 1915 1920 1925 1930 1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 Water Year Figure 18. Annual Flow for Shell Creek Near Shell (06278500)

Monthly Streamflow In addition to annual streamflow, the timing of streamflow is an important component in estimated available flow. Figure 19 and Figure 20 present estimated monthly streamflow for several selected gages within the study area. Most of the gages presented in the figures are downstream of reservoirs or irrigation diversions and return flows, thus the streamflow does not represent a “natural flow.” Comparison of hydrographs that are better estimates of natural flow conditions (such as the Wind River at Dubois, South Fork Shoshone River and North Fork Shoshone River) with gages that are downstream of major reservoirs (such as the Bull Lake Creek near Lenore, Wind River below Boysen Reservoir, Greybull River at Meeteetse, and Shoshone River below Buffalo Bill Reservoir) gages show the effect that reservoir operations and releases have on flows within the river.

The Framework Water Plan had originally developed a methodology to roughly calculate physically available flow for the Basin as a whole by simply adding the quantity of surface water leaving the state to estimates of surface water depletions. Rather than repeat this methodology in this section, a more comprehensive method is presented and developed in Chapter 7 that accounts for other factors that influence available supply, such as location, timing and needs for downstream demands.

Wind-Bighorn Basin Plan Update

Yellowstone River At Corwin Springs MT Clarks Fork Yellowstone River Near Belfry MT

12,000 4,500 4,000 10,000 3,500 8,000 3,000 2,500 6,000 2,000 4,000 1,500 1,000 2,000 500 Average Monthly Flow (cfs) MonthlyAverage Flow (cfs) MonthlyAverage Flow 0 0 Jul Jul Jan Jan Jun Jun Oct Oct Feb Apr Sep Feb Apr Sep Aug Aug Dec Dec Nov Nov Mar Mar May May

Wind River Near Dubois Bull Lake Creek Near Lenore

600 800 700 500 600 400 500 300 400 300 200 200 100 100 Average Monthly Flow (cfs) AverageMonthly Flow (cfs) AverageMonthly Flow 0 0 Jul Jul Jan Jan Jun Jun Apr Oct Apr Oct Feb Sep Feb Sep Aug Aug Dec Dec Nov Nov Mar Mar May May

Wind River At Riverton Popo Agie River Below The Sinks, Near Lander

1,800 600 1,600 500 1,400 1,200 400 1,000 300 800 600 200 400 100 200 Average Monthly Flow (cfs) MonthlyAverage Flow (cfs) MonthlyAverage Flow 0 0 Jul Jul Jan Jan Jun Jun Apr Oct Apr Oct Feb Sep Feb Sep Aug Aug Dec Dec Nov Nov Mar Mar May May

Little Wind River Near Riverton, Wy Wind River Below Boysen Reservoir

2,500 2,500

2,000 2,000

1,500 1,500

1,000 1,000

500 500 Average Monthly Flow (cfs) MonthlyAverage Flow Average Monthly Flow (cfs) AverageMonthly Flow 0 0 Jul Jul Jan Jun Jan Apr Oct Feb Sep Aug Jun Apr Oct Dec Feb Sep Aug Nov Mar Dec May Mar Nov May

Figure 19. Average Monthly Streamflow – Yellowstone, Clarks Fork and Wind River Basins

Wind-Bighorn Basin Plan Update

South Fork Owl Creek Below Anchor Reservoir Cottonwood Ck At High Island Ranch Near Hamilton Dome 100 90 50 80 45 70 40 60 35 50 30 25 40 20 30 15 20 10

Average Monthly Flow (cfs) AverageMonthly Flow 10 5 0 (cfs) MonthlyAverage Flow 0 Jul Jul Jan Jan Jun Oct Apr Jun Apr Oct Feb Sep Feb Sep Aug Aug Dec Nov Dec Mar Nov Mar May May

Shell Creek Near Shell Bighorn River At Kane

500 5,000 450 4,500 400 4,000 350 3,500 300 3,000 250 2,500 200 2,000 150 1,500 100 1,000

Average Monthly Flow (cfs) AverageMonthly Flow 50 (cfs) AverageMonthly Flow 500 0 0 Jul Jul Jan Jan Jun Jun Apr Oct Apr Oct Feb Sep Feb Sep Aug Aug Dec Dec Nov Nov Mar Mar May May

Greybull River At Meeteetse North Fork Shoshone River At Wapiti

900 4,000 800 3,500 700 3,000 600 2,500 500 2,000 400 1,500 300 200 1,000 100 500 Average Monthly Flow (cfs) AverageMonthly Flow (cfs) AverageMonthly Flow 0 0 Jul Jul Jan Jan Jun Jun Apr Oct Apr Oct Feb Sep Feb Sep Aug Aug Dec Dec Mar Nov Mar Nov May May

South Fork Shoshone Rriver Above Buffalo Bill Shoshone River Below Buffalo Bill Reservoir Reservoir 2,500 1,800 1,600 2,000 1,400 1,200 1,500 1,000 800 1,000 600 400 500 200 Average Monthly Flow (cfs) AverageMonthlyFlow Average Monthly Flow (cfs) AverageMonthly Flow 0 0 Jul Jul Jan Jun Apr Oct Jan Feb Sep Aug Dec Jun Oct Nov Feb Apr Sep Mar Aug Dec May Nov Mar May

Figure 20. Average Monthly Flow - Bighorn Basin

Wind-Bighorn Basin Plan Update

4.1.2 Reservoirs Water is stored within the Basin for irrigation, municipal, industrial, recreation, fisheries, and flood control purposes. Total storage capacity, for reservoirs with capacity of at least 500 acre-feet, is about 3 million acre-feet. Table 12 lists all reservoirs within the Basin that have a permitted capacity of more than 500 acre-feet of storage and includes permitted capacities and main reservoir uses.

The largest reservoirs in the Basin are owned and operated by the USBR to supply federal irrigation projects. Most of the USBR storage facilities and associated irrigation projects were developed as part of the Pick-Sloan Missouri Basin Program. These federally constructed facilities have unique operational opportunities and constraints that differ from privately developed facilities. This section briefly describes the Pick-Sloan Program and the federal facilities that were constructed either as part of the Pick-Sloan Program or under separate USBR programs.

The "Pick-Sloan Plan" was created in 1944 to coordinate planned reservoir projects within the Missouri Basin by the USBR and U.S. Army Corps of Engineers. The original plan called for almost 100 reservoirs to be built on the Missouri River and its tributaries. The program has been modified and expanded over the years and has been integrated with other projects for the region. The USBR portion of the Pick-Sloan program consists of about 150 “units” in Colorado, Iowa, Kansas, Minnesota, Missouri, Montana, Nebraska, North Dakota, South Dakota, and Wyoming. Units can consist of groups of storage (dams and reservoirs), conveyance facilities and hydroelectric power generation components. Several reservoirs and irrigation projects in the Wind-Bighorn Basin are part of USBR’s Pick-Sloan Missouri Basin Program, including the Owl Creek Unit (Anchor Reservoir), the Boysen Unit (Boysen Reservoir), the Shoshone Project (Buffalo Bill Reservoir and Deaver Reservoir) and Riverton Unit (Bull Lake and Pilot Butte Reservoir).

In addition to the USBR project, the Wind River Irrigation Project (WRIP) is a federal project on the Wind River Indian Reservation. The WRIP is owned and operated by the Bureau of Indian Affairs (BIA) of the United States Department of the Interior. The Eastern Shoshone and Northern Arapaho Tribes assist the BIA in operation and maintenance of the project, which has an assessed acreage of 39,400 acres.

The WRIP consists of four units: the Little Wind Unit, Upper Wind Unit, Johnstown Unit and the Lefthand Unit. The Little Wind Unit diverts water from the Little Wind River. The remaining three units divert from the Wind River and tributaries to the Wind River. The Little Wind Unit includes Ray Lake, Washakie Reservoir, and three major canals. The Little Wind Unit comprises approximately 25,000 assessed acres (NRCE 1994). The Upper Wind Unit diverts water from the Wind River, Dinwoody Creek, Dry Creek, Meadow Creek and Willow Creek. The unit includes Dinwoody Lakes and 6 major canals, and has approximately 11,400 assessed acres (NRCE 1994). The Johnstown and Lefthand Units divert from the Wind River downstream of the Upper Wind Unit. There is one major canal in each of these units, with 1,100 and 1,900 assessed acres, respectively (NRCE 1994).

Wind-Bighorn Basin Plan Update

Table 12. Reservoirs with More Than 500 acre-feet Permitted Storage Capacity

Permitted Capacity Sub Basin Reservoir Name Source Use (1) (ac-ft) Clarks Fork Luce Reservoir Paint Creek irr 645.25 Upper Wind Bull Lake Reservoir Bull Lake Creek dom-irr-mfg-pwr 151,951 Pilot Butte Reservoir Big Wind River irr–pwr-mun 34,600 Teapot Reservoir Dry Creek irr 1,578 Little Wind Dinwoody Lakes Dinwoody Creek irr 3,900 Ray Lake Little Wind River irr 6,980 Washakie Reservoir Little Wind River irr 7940 Popo Agie Christina Reservoir Little Popo Agie River mine-mil-irr-sto-dom 3,860 Enterprise Reservoir Roaring Fork irr-dom-sto 1,698 Shoshone Reservoir Shoshone Creek irr-sto 9,740 Worthen Meadows Res. Roaring Fork mun-irr 1,504 Lower Wind Boysen Reservoir Big Horn River dom-irr-mun-pwr-ind 757,851 Cameahwait Reservoir Cottonwood Drain Draw fis-wil-irr-sto-rec 6,683 Debatable Reservoir Willow Creek irr 582 Jack Pot Reservoir Alkali Creek irr-RR 772 Middle Cottonwood Res. Cottonwood Drain Draw irr-sto-fis-wil-rec 612 Prairie (Barquin) Reservoir Dry Muddy Creek irr 578 Shell Reservoir Shell Creek irr 1,949 Upper Bighorn Lake Creek Reservoir Lake Creek irr 1,373 Owl Creek Anchor Reservoir S.F. Owl Creek irr 17,412 Thompson No.1 Reservoir Owl Creek irr 920 Nowood Ten Sleep Reservoir Ten Sleep Creek irr-dom-fire-rec-sto 3,509 Lower Bighorn Adelaide Reservoir Adelaide Creek irr-fis 4,764 Bighorn Lake Big Horn River irr-rec 1,116,000 Leavitt Reservoir Beaver Creek irr 644 Greybull Corral Reservoir Corral Draw rec-sto-irr 1,026.8 Fairview Reservoir Manny Draw irr-dom-sto 1,411 Greybull Valley Reservoir Red Clay Draw irr-rec 33,169 Harrington Reservoir Manny/Wardell Draw irr 1,201.85 Lower Sunshine Reservoir Sunshine Creek pow-sto-ind-irr-dom 58,748 Thomas Reservoir North Rawhide Creek irr 864 Upper Sunshine Reservoir Sunshine Creek irr-ind-sto-dom 52,988 Shoshone Beck Lake S.F. Shoshone River irr-dom 623 Buffalo Bill Reservoir Shoshone River dom-irr-mun-pwr-ind 456,600 Deaver Reservoir Short Draw fish-irr-mun-rec 720 Diamond Creek Dike Reservoir Diamond Creek flo-fis-wil 18,378 Foster No.1 Reservoir Sage Creek irr 573 Shoshone Newton Reservoir Trail Creek irr 4,525 Perkins & Kinney Reservoir South Sage Creek irr 1202.3 Sage Creek Reservoir Sage Creek irr 2,785 Wiley Reservoir Sage Creek irr 1,020 Notes: (1) dom - domestic, fis - fish propagation, flo - flood control. Ind - industry, irr - irrigation, mfg - manufacturing, mil - milling, mun - municipal, pwr - power, rec - recreation, RR - railroad purposes , sto - stock, wil - wildlife

4.1.3 Water Quality Water quality in the Wind-Bighorn Basin is strongly influenced by the geology and terrain of the Wind River Range and Bighorn Mountains (WDEQ 2008). Natural water quality is generally good in the mountain ranges, but gradually changes as streams flow across the Basin into the main river

Wind-Bighorn Basin Plan Update channels where runoff from irrigation, discharge from oil and gas development and other human activities has the potential to degrade the water quality further (WDEQ 2008).

The 2008 303(d) listing includes 27 reaches of impaired streams and one impaired lake (Ocean Lake) within the Wind-Bighorn Basin (WDEQ 2008). Locations of the 303(d) impaired streams are illustrated in Figure 21. With one exception, all impairment listings are due to bacteria that affects water bodies with recreation beneficial uses. Ocean Lake is impaired for aquatic life due to sediment.

Currently, in the Basin, there are some groundwater concerns over potential contamination from oil and gas operations. In August 2009, the USEPA reported that, based on water analysis studies earlier this year, 11 of 39 domestic wells tested near the town of Pavillion showed traces of methane gas, hydrocarbons, lead and copper, among other substances (USEPA 2009a). A large oil and gas company owns wells near the domestic wells that were tested. A spokesman from that company reports that there has not been any drilling in that area since 2007 (Colson 2009). The USEPA report states that more tests are needed before any conclusions can be drawn as to whether nearby gas wells have caused the contamination. No other groundwater or surface water concerns have been identified in the Basin. 4.2 Groundwater Resources Groundwater resources were investigated as part of the previous Basin Plan (LA 2003). The report identified 13 principal aquifers in the Basin that have historically been the major groundwater sources for development. The two aquifers primarily developed for high capacity municipal supply are the Wind River and Madison Aquifers. The Wind River Aquifer is composed of saturated and permeable sandstone and conglomerate of the Wind River formation. The aquifer is the major source of drinking water for domestic and water supply purposes in the vicinity of Riverton and Shoshoni. The Madison Aquifer is composed of saturated and permeable portions of the Madison Limestone, Darby Formation, and Bighorn Dolomite. The aquifer is the primary source of drinking water for several municipalities in the Bighorn Basin. The Madison Aquifer is locally hydraulically connected to the overlying Tensleep Aquifer. Generally, water quality in each aquifer varies based on physical properties of the aquifer.

The WSGS is currently completing the Wind-Bighorn River Basin Plan Update Groundwater Level I Study. Tasks in this study related to the identification of groundwater resources include identification of extent, properties, recharge areas, and recharge rates. In addition, the WSGS will identify existing models that might be available for the Basin and the validity of each model. All work will be presented in the Wind-Bighorn Groundwater Basin Planning Report.

Wind-Bighorn Basin Plan Update

Figure 21. Locations of the 303(d) Impaired Streams and Lakes for the Wind-Bighorn Basin

Wind-Bighorn Basin Plan Update

4.3 Water Resources Summary This chapter summarizes historical hydrology within the Wind-Bighorn Basin. The previous Basin Plan study period of 1973-2001 was extended to 1973-2008. Throughout the study area, 2001- 2008 hydrologic conditions were considered drought conditions. Low flows were significant from both the magnitude of low flow conditions during single years and the duration and extent of drought conditions throughout the basin. 2001-2008 conditions were the driest conditions within the 1973- 2008 study period and approached the magnitude of drought conditions in the 1930’s and the 1950’s.

The inclusion of additional data in the study period resulted in changes in average streamflow for dry, average and wet year hydrologic conditions. A summary of average annual streamflow for representative gages within each sub-basin in the study area is presented in Table 13. The difference between this streamflow and that calculated in the previous Basin Plan is presented in Figure 22. In general, inclusion of the additional data resulted in higher to slightly lower streamflow during dry years, and lower streamflow for average and wet years. Higher streamflow in dry years occurred because the additional years included as dry years in the Basin Plan Update had slightly higher streamflow than the previous group of years. Additionally, some of the years previously classified as dry years were reclassified as average years, reducing streamflow during average years. Similarly, years previously classified as average years were reclassified as wet years, reducing average flow during wet years. Streamflow at these gages, as well as other active and inactive gages, is used in the hydrologic modeling discussed in Chapter 7 to determine surface water availability.

Table 13. Summary of Average Annual Flows for Hydrologic Conditions at Selected Gages

Gaged Annual Flow USGS (ac-ft) Sub-Basin Gage No. Site Name Dry Average Wet Yellowstone 06191500 Yellowstone River At Corwin Springs 1,746,622 2,237,284 2,736,788 Clarks Fork 06207500 Clarks Fork Yellowstone River Nr Belfry 506,542 659,039 781,021 Upper Wind 06220800 Wind River Above Red Creek, Near Dubois 331,314 453,951 579,746 Little Wind 06235500 Little Wind River Near Riverton 222,680 382,295 541,818 Lower Wind 06259000 Wind River Below Boysen Res 687,627 929,413 1,281,296 Upper Bighorn 06260000 South Fork Owl Creek Near Anchor 14,567 23,862 33,542 Greybull 06276500 Greybull River At Meeteetse 154,117 209,160 262,572 Bighorn Lake 06279500 Bighorn River At Kane 971,988 1,411,342 1,942,700 Shoshone 06282000 Shoshone River Below Buffalo Bill Reservoir 492,252 675,726 859,996

Wind-Bighorn Basin Plan Update

20% 15% Dry Average 10% Wet 5% 0% -5% -10% -15% -20% Difference From PreviousBasin Plan Yellowstone Clarks Fork Wind River Little Wind Wind River South Fork Greybull Bighorn Shoshone River At Yellowstone Above Red River Near Below Owl Creek River At River At River Below Corwin River Nr Creek, Near Riverton Boysen Res Near Anchor Meeteetse Kane Buffalo Bill Springs MT Belfry Dubois Reservoir

Figure 22. Difference in Average Annual Streamflow From Previous Basin Plan at Selected Gages, by Type of Hydrologic Year