Wyoming State Water Plan, Wyoming Water Development Office
Rafting on Snake River Lake Marie, Snowy Mountains Wyoming Wind River Range picture

Snake/Salt River Basin Water Plan
Final Report



A. Agricultural Water Use

B. Municipal Water Use

C. Domestic Water Use

D. Industrial Water Use

E. Recreational Water Use

F. Environmental Water Use

G. Salmon Recovery Efforts

H. Instream Flows

I. Major Reservoirs

J. Water Quality


Figure II-1. Irrigated Lands

Figure II-2. Irrigated Lands

Figure II-3. Irrigated Lands

Figure II-4. Agricultural Wells

Figure II-5. Municipal Wells

Figure II-6. Domestic Wells

Figure II-7. Grand Teton National Park Snake River & Jackson Lake Private Use Estimates



Agricultural water uses consume more water than any other use in the Snake/Salt River basin. Agricultural uses mainly consist of irrigation of crops by either flood or sprinkler irrigation. The vast majority of irrigation water is diverted from surface water sources, although there are small areas served by groundwater sources.

History of Agriculture in the Basin:

The first homestead was built in Jackson Hole in 1884, and by 1900 the cattle industry dominated the area. Settlement in the Star Valley area began in the late 1870's and 1880's, with many of the early settlers interested in raising beef cattle. Prior to that time, the area had been used as summer range for cattle from the Bear Lake area. The first approved water right in the Star Valley area was on Spring Creek, a tributary of Crow Creek, in 1885. Rights were filed on for many of the tributaries in Star Valley soon afterward. The rise of the dairy industry soon followed, and the first creamery in Star Valley was established in 1900.

Flood irrigation was initially utilized for forage production for farm animals. Initially, water was generally diverted out of the smaller tributaries, as opposed to the main stems of rivers. This was due to the varied locations of the tributaries, as well as the difficulty associated with diverting from a large river.

Irrigated cropland developed more rapidly downstream in Idaho than it did in the Snake/Salt River basin, mainly due to the longer growing season. As a result, conflicts on water use arose between irrigators in the two states. These conflicts resulted in the Roxanna Decree in 1941, which governs the use of Teton Creek and South Leigh Creek on the west side of the Teton Range. Soon afterward in 1950 the Snake River Compact was agreed upon by the two states as well as by federal agencies.

Grand Teton National Park was initially created in 1929, consisting of approximately 100,000 acres. The Park was later enlarged to over 300,000 acres in 1950. While provisions were made to accommodate existing private homesteads located within the Park, much of the land located within the Park that had been irrigated in the past is no longer irrigated or used for agricultural purposes. Also, with the relative lack of land under private ownership in the Jackson Hole area, there is great pressure to convert agricultural lands to residential use. Gravity flow sprinkler systems were established in many areas of Star Valley in the 1960's and 1970's, which increased irrigation application efficiency. This increase in efficiency resulted in an increase in the productivity of the farmland. Several hundred dairy farms were in operation in Star Valley up until the early 1980's, when market prices and new regulations prompted many to sell their cows and leave the business. Presently less than 50 dairies are still in operation, however they tend to have larger herds than the dairies of the past.

Agricultural Water Use Methodology:

While attempting to quantify the use of water for agricultural uses in the Snake/Salt River basin, it was discovered that there are very few diversion records available that quantify the amount of water diverted. Records obtained from the Board of Control as well as various irrigation districts and companies generally consist of spot records on a specific ditch, with sometimes only one spot reading being made in a particular year. Many diversions do not have any records as to the diverted flow. This situation is mainly due to the method of regulation currently used in the basin. Generally, irrigators do not call upon the State to regulate the flow of water in irrigation diversions. In locations where water becomes scarce later in the season (generally the tributaries), canal companies or irrigation districts have been formed in order to run the irrigation facilities more efficiently. These companies or districts regulate the flow of water to the irrigators on the system, and commonly distribute the water equally among all irrigators regardless of priority. In some cases, the irrigation district or company is essentially the only irrigator on a particular tributary.

When regulation is required, flows are read and the water distributed by Water Division IV of the Board of Control. This is the source of the majority of flow records available. However, these readings are generally only made on an as-needed basis, thus the records on regulated streams are very often sparse. The major exception to this is on Teton Creek, which is a tributary to the Teton River. This creek is governed by the Roxanna Decree, and so water must be divided between users in Wyoming and Idaho as part of that ruling.

Irrigated Lands Mapping:

GIS mapping of irrigated lands as well as associated water rights and points of diversion has been completed as part of this study. The process started with irrigated lands mapping previously prepared by States West Water Resources Corporation for the WWDC. States West utilized aerial infra-red photos from 1982-3.

This mapping was overlaid on USGS topographic maps and plotted. Water rights attribution for each identified irrigated polygon was completed. The water right database fields include the permit number, source, ditch or well name, priority date, amount of appropriations (cfs-gpm), number of acres, type of supply (original, additional, supplemental, secondary), and status (adjudicated, unadjudicated, expired, and canceled). The water rights attached to each individual irrigated polygon were abstracted from the original records on file in the office of the Wyoming State Engineer and State Board of Control located in Cheyenne, Wyoming. The irrigated acreage within the Snake/Salt River basin as obtained from the GIS is shown in Table II-1. Irrigated acreage throughout the basin is also shown in Figures II-1 through II-3, and irrigation wells are shown in Figure II-4.

Table II-1. Irrigated Acreage By Sub-Basin

Sub-BasinIrrigated Acres

There has been very little use of stored water for irrigation in the basin. The large reservoirs that are located in the basin, such as Jackson Lake and Grassy Lake, serve farmland that is located downstream in Idaho. Palisades Reservoir, which is located partially in Wyoming, also serves Idaho irrigation interests. At this point, there are essentially no storage reservoirs used for irrigation of Wyoming lands located within the Snake/Salt River basin. Because of this fact, flow records from these reservoirs have no bearing on irrigation diversion flows in the basin.

Cropping Patterns in the Basin:

The types of crops grown in the Snake/Salt River basin are greatly influenced by climate. Typical farmland in the basin is located in the high mountain valleys where there is low to moderate precipitation. These valleys have relatively short growing seasons and long winters with significant accumulations of snow. Hard frosts have been observed in every month of the year. Because of these conditions typical crops consist of alfalfa, small grains (mainly barley with some oats), and native hay and grass. In addition to these crops, the portion of the study area that is in the Teton River sub-basin also produces a small amount of potatoes.

As part of the effort to model the surface water features in the basin, the consumptive irrigation requirement for the crops being raised was determined. This requirement for water by the plant varies by crop type as some plants require more water than others. Obtaining a distribution of the various crops in the basin allows for an estimate of the water used during specific conditions of irrigation.

Cropping Patterns Methodology:

Data regarding the types of crops grown in the basin were obtained from various sources such as the USDA Service Center, Wyoming Agricultural Statistics, and the Census of Agriculture. However, this data was difficult to use as it covered all of Lincoln County while the basin covers only the northern portion of the county. Also, agricultural activities tend to be under-reported in these types of reports as many farmers do not respond to surveys and questionnaires regarding their farm activities. The most extensive data was obtained through interviews with those involved with individual irrigation districts and canal companies. It is important to note that in some locations crops are rotated between alfalfa and small grains, and that the acreage of each crop will vary somewhat every season.

In order to estimate the distribution of crops grown in the Snake/Salt River basin, information was obtained from various ditch operators as well as from Water Division IV Hydrographers. These estimates are based on knowledge of the area and of the crops grown by various producers. Other sources of crop information such as crop records or detailed aerial photography were not available for analysis.

Cropping Pattern Conclusions:

In order to determine the crop distribution for the Snake/Salt River drainage, data for each of the major diversions were used. Generally, the determination of crop types as well as the acreage of each crop was obtained from those involved with each ditch, such as water masters, producers, and hydrographers. The assumption was made that the crop distribution in each sub-basin roughly followed the crop distribution of the major ditches combined. In addition to information regarding individual ditches, crop distributions were also estimated by sub-basin in some cases by those with local knowledge of the crops. The crop categories used in this distribution were similar to those used in other previous basin studies and consisted of alfalfa, small grains, pasture grass, and mountain meadow hay. The distinction between pasture grass and mountain meadow hay is essentially based on the method of irrigation as described in “Consumptive Use and Consumptive Irrigation Requirements in Wyoming” by Pochap, et al., 1992, with pasture being sprinkler irrigated and mountain meadow hay being flood irrigated. The resulting distribution of irrigated crops is shown in Table II-2. The determination of consumptive irrigation requirements used as part of the surface water modeling incorporated this crop distribution.

Table II-2. Crop Type Distribution by Sub-Basin

Sub-BasinAlfalfaGrainPastureMtn. Meadow
Upper Salt River49%19%24%8%
Lower Salt River59%25%12%4%
Upper Snake River0%0%0%100%
Lower Snake River0%0%2%98%
Teton River40%30%30%0%

Alfalfa is the most extensive crop grown in the Salt River basin. Much of the alfalfa grown in Star Valley is used to feed local dairy and beef cattle. Small grains such as barley are also grown. There is also a significant amount of acreage used for native hay or pasture. The Snake River portion of the basin produces native hay almost exclusively. Nearly all of this crop is flood irrigated. The Teton River basin has a mix of crops, with alfalfa being the most predominant. Also, a significant amount of small grains are produced, as well as pasture. A small amount of potatoes are grown in the Teton basin.

Consumptive Use:

According to Pochop et al. 1992, Consumptive Use (CU) is the water use of a well-watered crop under optimum growing conditions, and is considered to be the maximum use of water by the specified crop with the given conditions. This consumptive use must be met either through precipitation or irrigation. Consumptive Irrigation Requirement (CIR) is the CU of a crop minus the precipitation. In other words, CIR is the irrigation water required to fulfill the consumptive use of a crop.

Data regarding CU and CIR for this basin study were obtained from the publication Consumptive Use and Consumptive Irrigation Requirements in Wyoming written by Pochop et al., 1992. Background data regarding this report were also collected from the author for use in this basin plan. Data associated with the various data sites within the basin were used. These sites included Afton, Bedford, Jackson, Moran, and Alta. Consumptive use data for alfalfa, grass hay, mountain meadow hay, and grains were collected at the various sites in the Snake/Salt River basin. Indicator gages were selected for the basin plan and used to determine which years to classify as average, wet, or dry for each climate station used for CU/CIR data. Once the years were classified as average, wet, or dry, the results from the CU/CIR study were used to create representative figures for each scenario at each climate station. There were adequate climate stations in the CU/CIR study to enable the various sub-basins in the study to utilize a climate station within its area. For example, Afton was used for the Upper Salt, Moran for Upper Snake, and so forth. The process of obtaining representative CIR information was completed for each crop type. The CIR results for each location, broken into wet, dry, and average years, were then applied to the sub-basin depending upon the distribution of crops grown in that area. The resulting CIR number was weighted based upon the percentage of each crop grown in the sub-basin. This weighted CIR number was used to determine the amount of water consumed by the crops in a particular sub-basin by applying the irrigation requirement over the period of days irrigated.

Irrigation Days:

Consumptive use of crops assumes well watered crops under optimum growing conditions. Field conditions rarely represent optimum growing conditions due to factors such as inefficient irrigation methods, climate, soil conditions, topography, and so forth. Due to this fact, much of the water diverted from the rivers and streams is not consumed by agricultural crops. However, much of this unconsumed water returns to the system through ground water augmentation and return flows. Thus, aside from losses through evaporation and so forth, this water can be used at a later time, and is not depleted from the system.

In order to quantify the water used for crop irrigation, the number of days in which crops are irrigated was determined for each sub-basin. Due to the lack of irrigation water use records in the basin, other methods were used to estimate how many days of each month in the growing season in which irrigation typically occurs. The main source of data for irrigation days was conversations with Water Division IV Hydrographer-Commissioners. Their input was vital in determining the irrigation days to be used for the average, wet, and dry scenarios.

By estimating the number of days in which irrigation is taking place in the basin, the effects of being short of water in a particular sub-basin are taken into account. Also, the period of time in which irrigation is stopped in order to harvest crops is included. For example, fields under flood irrigation must have the water shut off of the field for a number of days in order to let the ground dry up enough to allow harvest. However, areas under sprinkler irrigation experience very little down time, as many will have the sprinklers back on one side of the field before the harvest is completed on the other.

Agricultural Depletion Estimate:

Agricultural depletions consist of the water supplied by artificial means that is consumed by irrigated crops. This is water required by the plants beyond natural precipitation. The determination of agricultural depletions consisted of taking the weighted monthly CIR for each sub-basin, and multiplying that value by the number of irrigated acres. This monthly result was then adjusted based on the number of days irrigated for each month, resulting in the agricultural depletion. This was conducted for average, wet, and dry year scenarios. Agricultural depletion results are included in the surface water modeling portion of this basin plan.


The majority of the population in the basin is located in valleys along the Snake and Salt Rivers, although water used for municipal purposes comes from sources other than those rivers. The following towns, communities, subdivisions, and water systems are considered municipal systems for this study:

Incorporated municipalities with primary groundwater sources:

Other entities with primary groundwater sources:

The following community also obtains water from groundwater sources in Wyoming, however the town itself is located in Idaho:

There are no entities in the basin that obtain water from surface water sources.

Municipal & Domestic Water Use Methodology:

While investigating the use of water for municipal purposes, it was recognized that only four of the communities in the basin are incorporated municipalities. Many other systems serving various unincorporated communities or subdivisions also provide water for municipal type uses, and it was felt that these systems should also be included in the municipal portion of the basin water use profile. In order to have a consistent method of determining whether or not to include a particular system, it was decided that the EPA definition of a Community Public Water System should be used. According to the EPA website, "Public water systems provide water for human consumption through pipes or other constructed conveyances to at least 15 service connections or serves an average of at least 25 people for at least 60 days a year." Public water systems are further defined by EPA as Community, Non-Transient Non-Community, and Transient Non-Community. EPA states that a Community water system "supplies water to the same population year-round." A Non-Transient Non-Community system "supplies water to at least 25 of the same people at least six months per year, but not year-round. Some examples are schools, factories, office buildings, and hospitals which have their own water systems." A Transient Non-Community system "provides water in a place such as a gas station or campground where people do not remain for long periods of time." Using this method of classification ensured that municipal type uses were looked at collectively, while other uses such as schools, restaurants, and dude ranches were included in other portions of the basin water use profile, such as domestic use.

Information regarding municipal use of water in the basin was primarily obtained from the 2002 Water System Survey Report produced by the Wyoming Water Development Commission. Interviews were also held with representatives of some of the water systems to obtain additional information, such as water use records. If information was not available for a particular system in the 2002 Survey Report, the 2000 Survey Report was used, as well as EPA Sanitary Surveys of various dates. Past studies conducted on various water systems were also consulted for additional information. Municipal wells across the basin are shown in Figure II-5.

Many of the water systems in the basin utilize water from spring sources. Were it not for the municipal depletion, this water would enter a stream and flow through the surface water system. Thus, the municipal use in the basin in reality does have an impact on surface water, although water is not diverted from a surface source directly. However, upon further review of this situation, the amount diverted is not significant. For example, the average water use in Afton, which obtains a majority of its water from spring sources, is approximately 1.25 MGD. This corresponds to less than 2 cfs, which is considered minor when compared to other surface water diversions such as irrigation headgates. This is in light of the fact that Afton represents the largest spring source use in the basin, and many other spring users only divert a fraction of the above amount. Due to the fact that the depletion from a major municipal use equates to the depletion of a minor irrigation use, it was determined that the depletions from the various municipal and community systems due to spring sources would not be included in the surface water modeling effort.

Some wastewater treatment systems discharge water to a river or stream following collection and treatment of the wastewater to appropriate standards. A majority of the systems covered in this study utilize individual wastewater disposal systems, such as septic systems. The incorporated municipalities do have wastewater collection and treatment systems, however the majority do not necessitate discharge. Only two systems in the basin have flows that return directly to surface water following the treatment of wastewater. These flows represent a slight increase to the stream flow. Similar to the discussion regarding surface water depletions due to use of springs, the quantity of water discharged and returned to the surface water system is minor, and it was determined that these inflows would not be included in the surface water modeling.


Domestic water use consists of the water necessary for the function of residences, subdivisions, ranches, commercial establishments, campgrounds, and so forth. Prior to determination of the domestic water use in the basin, a distinction between domestic and municipal water use had to be made. In essence, the use of water for domestic and municipal are the same, consisting of residential, commercial, and any other uses that can be served by a municipal water system. While the use is similar, the source of the water and method of supplying that water to the user are not. Municipal systems generally utilize large water supply sources, such as rivers, lakes, wells, and springs. On the other hand, domestic sources generally consist of a single well or spring that only has one service connection, or possibly a few connections.

The municipal section covered public community water systems, which is defined as a system that serves at least 15 connections or 25 people on a year round basis. Many connections, such as those that serve restaurants or schools, may serve more than this number, but are not considered community systems as they do not serve the same people year round. Non-community systems, as well as those that serve individual residences or businesses, are included as domestic uses.

In order to determine the extent of domestic use in other river basin plans in Wyoming, the population within a particular basin was obtained. The population served by municipal systems were then subtracted, resulting in the population served by rural systems. A daily water use per capita was then used to determine the water use for this population.

Population Estimates:

Nearly 26,000 people reside in just over 10,000 households within the Wyoming portions of the Snake and Salt River basins. Also, roughly 44 percent of the population of the basin lives within the incorporated boundaries of Jackson, Afton, Thayne, and Alpine. The remainder of the basin's population lives within unincorporated areas of Lincoln, Sublette, and Teton Counties. Table II-3 outlines a breakdown of the estimated population in the Snake/Salt River basin. It must be mentioned that this population data represents year-round residents according to census information.

Table II-3. Estimated Snake/Salt River Basin 2000 Population and
Related Political Jurisdictions

Municipal Subtotal2,7098,64711,356
Unicorporated Areas6,6237,97014,593
Basin Total9,33216,61725,949

Data regarding the populations served by various public community water systems was also collected as part of the study, and is summarized in Tables II-4 and II-5.

An interesting observation can be made by looking at the population estimates for Teton County. The number of residents served by public community water systems in the county is nearly equal to the estimated full-time population. However, there are a significant number of residences in the county that are not located within the Town of Jackson or the subdivisions served by the mentioned water systems. There is a missing component that is not accounted for in these numbers, and that component is the population that has second or vacation homes in the area. These people are not included in the full-time residence numbers, however they are included in the population served by the various water systems.

Table II-4. Snake Sub-Basin Municipal and Domestic Use Units

Alta Community Pipeline35
Aspens I/II Water and Sewer District825
Bar-B-Bar Subdivision43
C-V Ranches10
Evans Movile Home Court72
Gros Ventre North Subdivision77
Gros Ventre Butte West (Bar Y Estates)77
High Country Subdivision26
Highland Park Subdivision19
Indian Paintbrush75
Indian Springs25
Gros Ventre Utility Company (Jackson Hole Golf & Tennis)120
J-W Subdivision16
Little Horsethief Canyon17
Melody Ranch430
Millward Trailer Park18
Rafter J Subdivision H.O.A.500
River Meadows H.O.A.55
Saddle Butte Subdivision18
Skyline Ranch Improvement and Service District80
Snake River Mobile Home Park24
South Park Village Subdivision18
Spring Creek Improvement District160
Squaw Creek Water District77
Targhee Towne Water Company30
Targhee village30
Teton Shadows H.O.A.68
Teton Village Water and Sewer District423
Town of Jackson3,861
Wilson Meadows58
Community System Sub-Total7,287
Private System domestic Water Users2,980
Snake Sub-Basin Total10,267

Due to the large number of seasonal residents, use of population figures to determine domestic use would have erroneous results. Some community systems include a significant number of second homes, while others consist of mainly full-time residents. The systems with a significant number of second homes are Jackson, Teton Village, and Aspens. Systems such as Rafter J and Melody Ranch have a small number of second homes. Approximately 30 percent of Teton County's housing inventory is seasonal homes. As a result, it is not possible to simply subtract the number of residents served by the above systems from the total population of the sub-basin to obtain the rural population.

Instead of using population to determine the domestic water use in the Snake River sub-basin, it was decided to use the number of households. This is possible since the census data has information regarding households in the sub-basin as well as the number that were vacant at the time of the census in April. The resulting numbers would generally represent the full time residents, as April is considered off-season in the area. By utilizing this information, it was possible to estimate the number of residences in the Snake River sub-basin that are not obtaining water from community systems. This way, the use of water can be calculated for both tourist season and off season. Also, data regarding commercial establishments not connected to community systems were collected. This covered uses for schools, food establishments, guest ranches, campgrounds, motels, and other uses. These uses were added to the rural residential uses to result in the domestic water use. From this data, approximately 2,980 residences obtain their water from small or individual systems, along with various commercial establishments.

Table II-5. Salt Sub-Basin Municipal and Domestic Use Population

Town of Afton1,640
Town of Alpine288
Bedford Water and Sewer District560
Etna Water & Sewer District85
Fairview Water & Sewer District360
Freedom Water and Sewer District120
Grover Water and Sewer District280
Happy Valley Pipeline Company60
Kennington Springs Pipeline Company63
Nordic Ranches Subdivision180
Osmond Community200
North Alpine special Service District40
Smoot Water & Sewer District500
Star Valley Ranch Association1,800
Star Valley Ranch RV Park/Bridger View Ranches900
Star Valley Trailer Court100
Town of Thayne318
Westview Village70
Willow Creek Pipeline Company50
Community System Sub-Total7,564
Private System Domestic Water Users1,768
Salt Sub-Basin Total9,332

While there are part-time residents in the Salt River sub-basin as well, their impact on water use is not as dramatic as that in the Snake River sub-basin. Many seasonal residents leave only during the winter months, although the time of their absence varies greatly. Some will leave from October to May, while others only leave for January and February. While the number of part-time residents in the Salt River sub-basin is unknown, it is believed that a majority of the seasonal residents that leave for the winter are located in the Star Valley Ranch area, including the Star Valley Ranch RV Park. The number of residents in both summer and winter are known for these areas, so it is possible to use population as a basis to determine domestic water use. As shown in Table II-5 approximately 7,564 of the 9,332 living in the Salt River sub-basin area are served by community systems. That leaves 1,768 people served by domestic use systems.

Domestic Water Use:

Water use in the unincorporated portions of the basin can be quite variable. For example, a residence may have a well that provides for indoor use. Additional uses may be lawn and landscape irrigation, which may be many times the indoor use. Some may run water for horses or cattle, which may be constantly running month after month. Faucets may run to prevent freezing during winter. The various uses means that the actual water use may be quite variable from person to person. Also, methods of billing can influence water use, as those billed by water use will likely use less than those with flat rates. Also, people obtaining their water from a well may be more conservative in their water use to reduce power costs compared to those served by a spring. As this is a basin wide study, a daily per capita use has been determined that will likely serve as an average for domestic users in the basin.

Domestic use water rights have been reviewed as part of this basin plan. Generally, domestic water is served by wells, which will be permitted for a particular flow rate in gallons per minute (GPM). In reality, this flow rate is the maximum that will be pumped at any given time, and is only realized when the pump is in use. The pump will sit idle the majority of the time, and will only kick on to serve water needs. Many systems will utilize a tank of some type to minimize the number of starts required for the pump, thus reducing wear and tear on the pump. For example, a pump for a residence may be permitted to run at 5 gpm, which could result in 7,200 gallons per day. However, a typical residence may only use 500 gallons per day. Thus, a compilation of water rights by permitted flow rate is not particularly meaningful. Domestic wells in the basin are shown in Figure II-6, and this data is available in the GIS coverage.

After reviewing the water use on the community systems in the basin, as well as various studies on water use in the basin, it was determined by the project team to use an average daily water use of 450 gallons per residence. This rate appears to be a good average when looking at the factors affecting use described previously. A summary of the average daily domestic water use in the basin is presented in Table II-6.

Table II-6. Average Daily Domestic Water Use by Sub-Basin

Salt800,000Included w/ residential800,000
Basin Total=2,241,000


Compared to other river basins in Wyoming, there is little industrial activity in the Snake/Salt River basin, and the facilities that are present use relatively little water. Some of the industries that are present have origins based in the dairy activity that has been part of the Salt River basin for over a century. The industries and their water sources are:

Food Processing

a) Star Valley Cheese Corporation - Flat Creek Spring (w/ Town of Thayne)
b) Northern Foods - Periodic Spring, Swift Creek (from Town of Afton)
c) Water Star Bottling Company - Periodic Spring, Swift Creek (from Town of Afton)


a) Smoky Canyon Mine (located in Idaho)- Groundwater Well, surface water runoff

Industrial Surface Water Use:

Water for these industries is mainly supplied through or in conjunction with municipal water systems. While much of the water use for these municipalities and industries is covered by surface water rights, the water actually comes from springs that are considered ground water sources. Also, similar to the use of springs for municipal uses discussed previously, the quantity of water involved in industrial uses in the basin is quite small when compared to other surface water uses such as irrigation. Due to the negligible impact that industrial water use would have on the surface water modeling, these uses have not been included in the surface water modeling effort.

The Smoky Canyon Mine obtains much of its water from surface water runoff. This water is not diverted from a stream, but the runoff from the mine area is collected in a pond. The water rights associated with this are unknown, as the mining operation and tailings/collection pond is located in Idaho. Were this runoff not collected, it would eventually flow to Tyghee Creek, which is tributary to Stump Creek, which is tributary to Salt River. The surface water that is collected is used in the milling of the phosphate ore, and much is transported out of the Salt River basin in the phosphate ore slurry, which is piped west toward Pocatello, Idaho. While this is not out of the Snake River basin overall, the water used in the slurry does not travel to the Salt River. There are no interstate compacts on the streams that flow past the Idaho border into the Salt River drainage.

Industrial Groundwater Use:

The Northern Foods plant and the Water Star Bottling Company obtain their water directly from the Town of Afton municipal system, which is supplied by springs and wells. The main source for the Town of Afton is the Periodic Spring, which is tributary to Swift Creek. Northern Foods, whose facility was formerly a cheese processing plant, utilizes water as part of their processing of soy into various products. Water Star Bottling sells bottled water, with added flavors and without, under the Geyser Water label. (Note: At the time of this report, Water Star Bottling has ceased operations. It is believed that other water bottling activities will continue in the future.) The Star Valley Cheese Corporation obtains their water from the same spring source as the Town of Thayne, utilizing the same pipeline. Through an agreement between the two entities in 1948, the transmission pipeline was sized to accommodate both the town and the cheese factory. The Star Valley Cheese Corporation manufactures cheese products, mainly using milk from area dairy operations.

The Smoky Canyon Mine also uses a deep well to provide water for its operation. This well is located in Idaho, and is used to supplement the surface water that is used in the mining operation. As stated above in the Surface Water Use section, the groundwater from the well is used in the milling operation as well as the slurry.

According to the records of the State Engineer's Office, there are groundwater wells classified as industrial use in the Snake/Salt River basin. These wells are used for purposes such as concrete ready mix plants, and do not represent a significant use of water on an annual basis. Because of this, data on these industrial groundwater wells will not be included as part of this report.

The use of water for industrial purposes is very limited in the Snake/Salt River Basin. Typical industries from other parts of Wyoming such as coal mines, trona mines, and natural gas and oil wells are not found in the basin, and the communities in the basin are relatively small and do not have large industrial facilities. The facilities that do exist are generally related to food processing and production, with most of the use having its roots in the dairy industry. A summary of the industrial water use in the basin is presented in Table II-7, which compares the larger industrial uses.

Table II-7. Industrial Water Users Ground Water Sources
Hydropower Generation:

Star Valley Cheese Corporation20138Star Valley Cheese CorporationFlat Creek36.4
Northern FoodsVariousTown of AftonVarious7.8
Water Star Bottling CompanyVariousTown of AftonVarious2.7
Smoky Canyon MineOut of StateSmoky Canyon MineVarious283.8

There are many places in the West where the energy of water is harnessed to produce electricity. However, there has been relatively little development of hydropower in the Snake/Salt River basin. Table II-8 lists the projects in the basin with Federal Energy Regulatory Commission (FERC) licenses.

Table II-8. Current Snake/Salt River Basin FERC Licensed Projects

Swift Creek1500Swift CreekSwift Creek Power Co. Inc.
Strawberry Creek1500Strawberry CreekLower Valley Power & Light
Salt River1100Salt RiverHeiner, Scott D.

Please note that the power generation facilities at Swift Creek and Salt River described above are currently not active. Also, in addition to these listed facilities within the basin, electricity is generated at Palisades Dam on the Snake River immediately downstream of Wyoming in Idaho.


Recreation is generally considered a non-consumptive use of water. There is a significant amount of recreational activity within the Snake/Salt River basin. People travel from around the world in order to boat, fish, ski, camp, and hike in this part of Wyoming. Tourism has a major impact on the economies of the communities in the basin, with much of the tourism being linked to Grand Teton and Yellowstone National Parks. Many of the draws of these parks are water related, with the most notable water features within the basin being Jackson Lake and the Snake River. The Snake River is also a major draw throughout the Jackson Hole area as well as through the Snake River Canyon toward Alpine, sometimes referred to as the Grand Canyon of the Snake River. Thousands visit the river each year for rafting, kayaking, fishing, and other activities. In addition to the Snake River and Jackson Lake, there are numerous rivers, streams, and lakes throughout the basin that are used for recreation. Other activities that utilize or require water in some form include waterfowl hunting and winter sports such as skiing.

Grand Teton National Park:

Grand Teton National Park is the largest tourist destination located entirely within the basin. There are many water-based recreational activities that draw people to the park. The main focus of recreational water use in the park is divided between Jackson Lake and the Snake River.

Most of the use of Jackson Lake is by private individuals participating in various activities, such as motorboating, pontoon boating, canoeing, kayaking, camping, and fishing. In the winter, activities such as ice fishing, cross country skiing, and snowshoeing are common. Many ice fisherman have used snowmobiles or snow planes for transportation across the frozen lake. The Park Service has concessioners that provide services such as boat rentals, scenic lake tours, guided fishing trips, and marina services. Data obtained from Grand Teton National Park outlining visitors using park concessioners for water-related recreation are shown in Table II-9.

Table II-9. Grand Teton National Park Visitors by Use (Concessionaire Use)

YearRiver Float
River Fishing
Lake Fishing
Scenic Lake
199175,8092,187 2,864 24,641 24,129 76,170
1992 82,321 2,758 1,724 15,441 11,253 83,292
1993 77,230 2,920 2,503 20,761 18,571 79,502
1994 84,976 3,542 2,750 18,389 16,879 86,277
1995 82,753 2,700 2,570 26,014 18,791 90,209
1996 79,583 3,228 3,588 27,940 25,917 93,187
1997 71,969 2,836 2,331 24,179 20,980 83,342
1998 68,160 2,476 2,581 28,489 18,023 90,123
1999 70,553 2,322 4,458 23,295 20,506 88,035
2000 63,456 3,227 3,070 24,069 23,028 84,085
2001 59,431 2,685 1,869 17,471 9,547 70,526

The National Park Service has estimated private users on the Snake River for both floating and angling activities. A graph indicating the number of private users for these recreational activities is shown in Figure II-7. In addition to estimating the number of floaters and anglers in the park, the National Park Service has also estimated the number of snowplane users on Jackson Lake during the winter months. Snowplanes are used as a mode of transportation on the lake when it is frozen over, much like snowmachines. It must be noted that recent decisions by the National Park Service have resulted in the banning of snowplanes from the park beginning in the winter of 2002-2003.

Bridger-Teton National Forest:

Snake River

There is significant use of the Snake River within the Bridger-Teton National Forest. A majority of the use consists of rafting, boating, and kayaking in Snake River Canyon between Hoback Junction and Alpine. In this area, there are also six campgrounds maintained by the Forest Service. Many commercial rafting outfitters use this area as part of their rafting business. Statistics regarding the use of the river by rafters, both commercial and non-commercial, are kept by the Forest Service and are shown in Table II-10.

Table II-10. Snake River Rafting Use - Bridger Teton National Forest

1973 3100 21200 24300
1974 3,900 24,100 28,000
1975 4,900 35,300 40,200
1976 5,900 45,700 51,600
1977 5,300 51,000 56,300
1978 5,200 58,700 63,900
1979 7,000 59,700 66,700
1980 8,000 58,500 66,500
1981 19,900 62,700 82,600
1982 22,700 59,300 82,000
1983 24,500 64,100 88,600
1984 28,400 70,800 99,200
1985 28,100 69,300 97,400
1986 29,000 69,200 98,200
1987 29,700 67,100 96,800
1988 32,700 73,700 106,400
1989 32,700 76,200 108,900
1990 33,600 90,400 124,000
1991 34,600 92,300 126,900
1992 35,600 104,400 140,000
1993 34,600 98,100 132,700
1994 39,300 117,300 156,600
1995 38,000 121,200 159,200
1996 37,200 118,500 155,700
1997 37,000 99,400 136,400
1998 37,000 109,000 146,000
1999 46,000 102,000 148,000
2000 57,000 98,000 155,000
2001 52,000** 91,000 143,000

* Non-outfitted numbers reflect number of persons coming to the river, and not the number of times those persons ran the river in a given visit. Noncommercial users average 2-3 trips down the river in a given day of use. Noncommercial numbers are estimates based on periodic counts, reviews of river photographs and group permit numbers.

**The decrease in noncommercial use in 2001 is a result of enforcement of the large group permit system required by the Snake River Management Plan.

Other Recreational Uses

There are many other water-based recreational opportunities in the Bridger-Teton National Forest besides rafting the Snake River. According to the Greys River Ranger District of the BTNF, other activities include canoeing and other watercraft use, fishing, and to a lesser extent ice fishing, waterfowl hunting, and swimming. Recreational Visitor Days (RVD's) for the Greys River Ranger District and Jackson Ranger District as estimated by the Forest Service for 1994 are shown in the following Table II-11.

Table II-11. Bridger-Teton National Forest Recreational Visitor Days (1994)

UseRVD (Thousands)
Greys River (District 3)Jackson (District 4)
Swimming & Water Play1.33.96
Water Skiing & Other Water Sports0.80.11
Boat, Powered1.10.31
Other Watercraft1.570.06
Hunting, Waterfowl0.90.94
Fishing, Cold Water13.67.47
Fishing, Ice0.10.11

The above mentioned recreational activities take place throughout the forest, which has numerous rivers, streams, lakes, and ponds.

Ski Areas & Winter Sports:

There are three major ski resorts located in the Snake/Salt River basin. Snow King Resort is located in the Town of Jackson, and has 400 skiable acres. The resort has a base elevation of 6,237 feet and a top elevation of 7,808 feet, for a vertical rise of 1,571 feet. Tubing and ice skating are also available at Snow King. Grand Targhee Resort is located 5 miles east of Alta, and has 2,000 lift-served skiable acres and 1,000 snowcat served skiable acres. The resort has a top elevation of 10,000 feet, and a vertical rise of 2,395 feet. They also have 15 kilometers of groomed cross country trails. Jackson Hole Mountain Resort is located at Teton Village and has 2,500 skiable acres. The resort has a base elevation of 6,311 feet and a top elevation of 10,450 feet, for a vertical rise of 4,139 feet. Over 17 kilometers of groomed cross country trails are also available, as well as sleigh rides and dog sledding. All three resorts have incorporated snowmaking facilities into their resorts. For the 1998-99 ski season, the three resorts combined for nearly 550,000 skier days. Skier days for the ski areas in the basin are shown in Table II-12. In addition to the resorts described above, there are also companies that provide heli-skiing in the mountain ranges throughout the basin.

Table II-12. Skier Days

SeasonSkier Days
Jackson HoleGrand TargheeSnow KingTotal

The three ski areas utilize snowmaking during the early season, which can be from mid-October through January. Snow King snowmaking typically starts in October to accommodate World Cup race training prior to the season opening. Ground water is typically utilized for snowmaking operations. While all three resorts have installed snowmaking facilities on portions of their ski areas, the success of the ski season is dependent upon natural snowfall. Typical snowfall amounts for the resorts are 500 inches per year at Grand Targhee, 400 inches per year at Jackson Hole Mountain Resort, and 150 inches per year at Snow King.

There is generally adequate snowfall across the basin to support winter sports at locations other that the ski areas. Other activities such as cross-country skiing, snowshoeing, and snowmobiling are popular, and miles of trails are groomed throughout the basin for use by snowmachiners and skiers. Also, the annual World Championship Snowmobile Hill Climb has been held at Snow King for over 25 years.


Fishing is a significant recreational activity throughout the Snake/Salt River basin. Fly fishing dominates on the Snake River, and the significant game fish in the basin are shown in Table II-13.

Table II-13. Gamefish of the Snake/Salt River Basin

Common Gamefish NameScientific Name
Snake River Cutthroat TroutOncorhynchus clarki ssp.
Yellowstone Cutthroat TroutOncorhynchus clarki bouvieri
Mountain WhitefishProsopium williamsoni
Lake TroutSalvelinus namaycush
Brook TroutSalvelinus fontinalis
Rainbow TroutOncorhynchus mykiss
Golden troutOncorhynchus aguabonita
Kokanee SalmonOncorhynchus nerka
Brown TroutSalmo trutta
Arctic GraylingThymallus arcticus
Rainbow-Cutthroat Trout Hybrid

According to the Wyoming Game and Fish Department, many of the streams and lakes in the basin are managed to preserve the indigenous Snake River Cutthroat Trout as well as to preserve wild trout fisheries. Maintaining the supply and increasing the diversity of sport fishing in the basin is also a management goal of the department. There are also trophy fish in the area, as evidenced by two state record fish. A 50 pound lake trout was caught in Jackson Lake, and a mountain whitefish over 4 pounds was caught in the Snake River.

There is a variety of lakes and streams in the basin that provide a wide range of fishing experiences, from small wilderness streams and lakes to the Snake River and Jackson Lake. Some areas, such as Jackson Lake, see a considerable amount of ice fishing in the winter. A document produced by the Game and Fish Department entitled "Jackson Fish Management - Sub-basin Management Plans" in 1995 contains data on fishing in the Snake/Salt River basin. In this report, the basin has been broken into various sub-basins, with information on the existing fishery and future management plans outlined for each sub-basin. Table II-14 provides a summary of selected data from this report from each sub-basin.

The Wyoming Game and Fish Department has developed a stream classification system for the rivers and streams in the State of Wyoming. This classification system is based on the aesthetics, availability, and productivity of the stream. Aesthetics includes the characteristics of the stream channel, water quality, development, and landscape. Availability looks into the quantity and ease of access. Productivity is the pounds of trout per mile in the stream. This classification system is for trout only. The classifications are as follows:

In the Snake/Salt River basin, the Snake River is the only Class 1 or blue stream. The Salt and Greys Rivers are Class 2 or red streams. The stream classifications are presented as a GIS theme as part of this basin plan.

Table II-14. Fishery Management Data by Sub-Basin

Lake Surface
Pressure (d/yr)
Snake River (below Jackson Lake Dam)3115,23247,453
Snake River (above Jackson Lake Dam)9117,96625,764
Snake River Basin (wilderness waters)6730518
Hoback River Basin224417,690
Gros Ventre River Basin1671,3344,270
Fish Creek Basin903503,711
Spread Creek Basin4823912
Buffalo Fork Basin57281,378
North Buffalo Fork Basin39123344
South Buffalo Fork Basin4560620
Cub Creek Basin1538297
Pacific Creek Basin682282,426
Palisades Basin110336
Teton River Basin1353382,333
Lower Salt River Basin155189,577
Upper Salt River Basin42411,805
Greys River Basin133695,845
Little Greys River Basin452688

Source: Jackson Fish Management - Sub-Basin Management Plans, WGFD, 1995.

Waterfowl Hunting:

Waterfowl hunting is another recreational activity that is possible due to water features in the basin. The Snake/Salt River basin is located between the Central and Pacific Flyways, which are major routes for migratory birds between Canada and Mexico. While the basin is not directly in a major flyway route, there are a significant number of birds that migrate through the area, and there are numerous locations that attract waterfowl as well as hunters.

Estimates on waterfowl hunting activity in various sub-basins in Wyoming are made by the Wyoming Game and Fish Department, and are also included in their annual report. These estimates cover the number of hunters, the number of days they hunted, and the harvest of waterfowl. This data for the 2000 hunting season is presented in Table II-15 for ducks and Table II-16 for geese.

Table II-15. Duck Hunting Estimates for 2000

DrainageHuntersHunter DaysHarvest
Snake River2211,4101,393
Salt River2481,2201,572

Table II-16. Goose Hunting Estimates for 2000

DrainageHuntersHunter DaysHarvest
Snake River191940475
Salt River131533118

Other waterfowl included in this report, though they are hunted in much smaller numbers, include coots and mergansers. Migratory game birds included in the report include sandhill cranes, mourning doves, rail, and snipe. Data regarding various other birds are included in the Game and Fish report as well, however they will not be included in this river basin plan.

Recreational Water Use Conclusions:

While recreation is generally a non-consumptive use of water, it is a very important part of life in the Snake/Salt River basin. A large portion of the economy is driven by tourist activity, most of which is due to the recreational opportunities in the area. Different forms of recreation are enjoyed each season of the year. These opportunities are available due to the water resources in the basin, which are renewed annually through the hydrologic cycle. Recreation also contributes greatly to the quality of life for those who live in the basin.


Water features such as rivers, streams, and lakes are an integral part of the landscape and environment in the Snake/Salt River basin. Among the various uses of water studied as part of the Snake/Salt River basin plan, this report also looks at the use of water for environmental purposes. Many of these uses are controlled by man to maintain or improve existing conditions, while others, such as wetlands, may occur naturally and are subject to management by various means.

Maintenance Flows:

The construction of the Jackson Lake Dam in 1911 allowed for control of the flow of Snake River below Jackson Lake. This control was generally exercised to the benefit of farmers located downstream in Idaho. Peak flows that would have spilled from the lake were held back for use later in the growing season. However, management of the flow for optimal use by farmers does not necessarily mean that the flow will be suited for fish in the river. Frequent or large adjustments in releases from the lake that may be desired by downstream users tend to be detrimental to the fish population. Also, very low flows during the winter when the reservoir is filling can have a negative effect on fish.

Drought in the basin in the late 1980's brought concern for the fish in Snake River. Farmers wanted to save as much water as possible during the winter in order to have adequate water for irrigation the following summer. However this would compound the problem of stream flows already low due to drought. During this time, it was determined that there was storage space available to the State of Wyoming in Palisades Reservoir. This storage space was later purchased by the State. Purchase of this storage space enabled interests upstream of Idaho in Wyoming to be heard. Since all Bureau of Reclamation water contracts in Palisades Reservoir and Jackson Lake were for uses downstream in Idaho, it did not matter to the downstream users in which reservoir the water controlled by Wyoming was located. As a result, Wyoming is able to exchange water in Palisades for water in Jackson Lake. This water can then be used to augment fish flows if needed, without impact to irrigators in Idaho. According to the Wyoming Game and Fish Department, a minimum winter release of 280 cfs from Jackson Lake is desired for the Snake River fishery.

In addition to the use of water in Jackson Lake, the State of Wyoming also had opportunity for input regarding the operation of the water storage facilities at Jackson Lake and Palisades Reservoir, similar to any other space holder in these facilities. As a result, the State Engineer's Office and Wyoming Game and Fish Department now have semi-annual meetings with the U.S. Bureau of Reclamation regarding operations of the reservoir facilities.

Wetlands Mapping:

According to their website, the National Wetlands Inventory (NWI) of the U.S. Fish & Wildlife Service produces information on the characteristics, extent, and status of the nation's wetlands and deepwater habitats. Wetlands are lands transitional between terrestrial and aquatic systems where the water table is usually at or near the surface or the land is covered by shallow water. For purposes of this classification wetlands must have one or more of the following three attributes:

The wetland classification system is hierarchical, with wetlands and deepwater habitats divided among five major systems at the broadest level. The five systems include Marine (open ocean and associated coastline), Estuarine (salt marshes and brackish tidal water), Riverine (rivers, creeks, and streams), Lacustrine (lakes and deep ponds), and Palustrine (shallow ponds, marshes, swamps, sloughs). Systems are further subdivided into subsystems which reflect hydrologic conditions. Below the subsystem is the class which describes the appearance of the wetland in terms of vegetation or substrate. Each class is further subdivided into subclasses; vegetated subclasses are described in terms of life form and substrate subclasses in terms of composition. The classification system also includes modifiers to describe hydrology (water regime), soils, water chemistry (pH, salinity), and special modifiers relating to man's activities (e.g., impounded, partly drained). The three major wetland systems mapped within the Snake/Salt River basin are Riverine, Lacustrine, and Palustrine.

The wetlands mapping produced by the National Wetland Inventory and converted into Arc/Infor coverages by the Spatial Data and Visualization Center is included in the GIS mapping for the Snake/Salt River basin plan. The mapping is at a scale of 1:24,000.

Wetlands in the basin provide food, shelter, and breeding habitat for waterfowl and other wildlife. Wetlands may also improve water quality by contributing to the removal of nutrients, sediment, and other impurities in water, in turn protecting rivers and lakes. Also, wetlands can help control erosion and flooding during high water events.

Wetlands Projects:

Many wetland creation and enhancement projects were constructed throughout the Snake/Salt River basin by the Soil Conservation Service and the Natural Resource Conservation Service (NRCS) in the 1990's. Various projects near Jackson were constructed as part of the mitigation plan for Jackson Lake rehabilitation due to loss of wetlands, and are located in the Gros Ventre, Buffalo Fork, and South Park areas.

At the upper end of the Palisades Reservoir, the Wyoming Game and Fish Department had created a wildlife viewing area adjacent to Highway 89. However, much of the wildlife and waterfowl would leave when the reservoir level would drop and leave the area dry. The NRCS, with funding help from U.S. Bureau of Reclamation, Wyoming Game and Fish Depart-ment, U.S. Forest Service, and the Town of Alpine, designed a wetland area that would keep water in the area to provide wildlife habitat year round. A system of seven dikes was constructed, up to seven feet in height, with clay cores and gravel shells. The design called for the lower dikes to be under water when the reservoir was full, and 35 islands were placed in the created pond areas. The water for the wetland area is diverted from Salt River, and as much as 30 cfs of water can be diverted. By creating a flow-through system, problems with mosquitoes and moss were avoided. Nearly all of the water that flows through the system returns to Palisades Reservoir. Currently, the facility is operated by the Wyoming Game and Fish Department, who is also the holder of the associated water rights.

Snake River Restoration Project:

The Upper Snake River Restoration Project is located in the Jackson valley, and is intended to rehabilitate and restore fishery and wildlife habitat along the Snake River. In the 1950's, approximately 22 miles of dikes and levees were constructed along the Snake River in an effort to reduce flooding. For example, the elevation of the community of Wilson is actually lower than that of the nearby river bed, and extensive flooding would occur during a 100 year event. The levees now protect residents in the area from flood events, and the 100 year flood plain is now within the levee system in this area. These structures reduced the flood plain from approximately 25,000 acres to 2,500 acres throughout the Jackson valley. As a result of the reduced area available to the river during flood events, river velocities can increase to the point that the river bed is unstable. Over the years this has greatly reduced fish and wildlife habitat along the river, as well as vegetation. In an effort to restore some of what was lost, Teton County and the Teton Conservation District have sponsored this project, along with the U.S. Corps of Engineers. According to the USCOE, this will be a $54 million project spanning 14 years.

Cutthroat Trout Management:

The Wyoming Game and Fish Department has created and implemented a cutthroat trout management program for various species of cutthroat across Wyoming. In the Snake/Salt River basin, this program is managed for the success of the Yellowstone cutthroat trout. At the current time, Snake River cutthroat are considered the same species as Yellowstone cutthroat, although there are visual differences between the two. Interestingly, it is possible for fish to travel from the Snake River basin into the Yellowstone River basin by way of Pacific Creek and Atlantic Creek on Two Ocean Pass. In this location, the stream splits into two, with one flowing into the Yellowstone drainage and the other into the Snake, providing a free waterway to cross the divide.

According to the management plan, there has been a decline in Yellowstone cutthroat due to habitat loss and genetic introgression. Specific threats to the species include stocking, angling pressure, habitat loss, whirling disease, and the New Zealand mud snail. Genetic purity has been a major concern of some groups, and has prompted them to petition to list the Yellowstone cutthroat as an endangered species.

Management in the Jackson Region

A fish management crew was established for the Snake/Salt River basin in 1955 in Jackson. Their management responsibilities primarily include enhancement of the wild trout fishery and preservation of the native Snake River cutthroat trout. According to the Yellowstone cutthroat management document, there are 987 streams and lakes in the region, of which 701 are suitable for trout. Of the waters suitable for fish, 653 contain native cutthroat populations. Nearly all of these water features contain Snake River cutthroat, with only three containing Yellowstone cutthroat. Interestingly, the Snake River cutthroat is the only subspecies of cutthroat trout that has increased in numbers over time. This is generally due to the widespread introduction of the fish outside of its historical range, as well as continued strength within the Snake/Salt River basin. Various management activities have been incorporated by the Jackson crew of the Wyoming Game & Fish Department to ensure success of the Snake River cutthroat trout. Major spawning habitat projects have been conducted over the last 30 years to improve the year to year increase of the fish population. Special regulations have been implemented to protect the wild trout fishery. The main example of this is the reduced limit of two trout per day in wilderness areas, which are most likely to hold pure strains of cutthroat. This regulation has been in effect for nearly 30 years. Likewise, additional brook trout can be kept by anglers in an effort to reduce the impact on the native fishery by this introduced species. Other management techniques such as spawning season closures, slot limits, and trophy regulations have also been implemented.

Present Cutthroat Management

The Wyoming Game and Fish Department has managed the fisheries in the Snake/Salt River basin primarily as a wild trout fishery. Stocking has been eliminated on all wild trout streams in the basin, with the exception of the Salt and Hoback Rivers. However, stocking is required in some areas where factors such as temperature, icing, reduced winter flows, and inadequate spawning habitat limit the success of the fishery. Cutthroat trout used for stocking in the basin have been obtained from the Auburn fish hatchery, which initially utilized fish taken from Flat Creek in 1953. The Jackson National Fish Hatchery also utilized fish from this source. In 1987, fish were taken from Lower Bar BC Spring Creek for creation of another cutthroat broodstock at the Wigwam state hatchery. Genetic testing has since revealed that the Wigwam fish population is much more genetically pure than the Auburn fish population. Additional DNA testing is to be conducted throughout the basin to determine the integrity of the native fish stocks in various streams and rivers. Additional work is being conducted to determine if genetic markers can be found to distinguish Snake River and Yellowstone cutthroats. Results from this testing will help with future management decisions regarding stocking and so forth. In other areas of Wyoming, upstream barriers and other management tools have been used to manage native fish stocks. This is not, however, anticipated in the Snake/Salt River basin.

Future Cutthroat Management

Future management of the cutthroat fishery will include protocols to deal with whirling disease. This disease has devastated fish populations of particular rivers in other states such as Montana, although rainbow trout populations have seen the most severe impact. Regulations now require all imported fish to be certified free of the pathogen. Also, disinfection procedures using chlorine are used within the Game and Fish Department to prevent further spread of the disease. Fish facilities are inspected annually for this and other problems, as are areas downstream of fish hatcheries. In waters where the parasite has been found, such as the Salt River, sampling is conducted on a two year cycle. Other waters that are currently free of whirling disease are sampled on a four year cycle. At this time, there have been no recorded losses of trout to the disease. Education of the public is also a major focus to prevent further spread of the disease. The Game and Fish Department has created and distributed signs and brochures regarding procedures to avoid spreading the problem to adjacent tributaries and waters.

In addition to whirling disease, a threat to the fishery could come from the New Zealand mud snail. While the snail itself is not harmful to fish, they can reproduce in dramatic numbers and compete with other food sources for trout. In certain areas in the Madison River in Montana, as many as 300,000 snails have been found in one square meter. The snails themselves do not provide an adequate food source for trout. The snails have been detected in Yellowstone Park, as well as in the Snake River above Jackson Lake in the Polecat Creek area. However, they have not been a problem in the Snake/Salt River basin at this point. Future management objectives are aimed to prevent spread of the snails to new streams and rivers by education of the public, as well as continued monitoring.

As stated by the management plan, most objectives have been in place for over 25 years, although additional recommendations may come from DNA testing and other recent issues. The following are possible management scenarios presented by the plan.

  1. Continue sampling and analysis of genetic integrity throughout the basin to determine classification.
  2. Maintain current wild fishery, with investigations into the genetics of hatchery fish.
  3. Work to protect and improve fishery habitat with input from agencies, landowners, and other organizations.
  4. Monitor fish stocks by inventory of distribution, abundance, habitat condition, and so forth.
  5. Restore Yellowstone cutthroat stocks to historic waters when possible.
  6. Continue and enhance educational programs regarding native fish.
  7. Utilize passage barriers to protect highly rated wild fish. Also, remove passage barriers to allow increase in native range.
  8. Maintain and expand Yellowstone cutthroat broodstock to preserve distinct population.
  9. Use restrictive regulations as necessary to protect specific fish populations.
  10. Continue to monitor native fish for health problems such as whirling disease and for the presence of exotic species such as New Zealand mud snails.

Big Game Habitat:

A significant portion of the Snake/Salt River basin serves as habitat for various big game animals. Much of this habitat is considered crucial in that a particular species cannot maintain its population in a specific herd over the long term without utilizing that habitat. There are many other areas that are not classified as crucial to wildlife, yet are utilized by them in different parts of the year. While big game habitat is not necessarily a use of water, water features in these areas are necessary for survival. The Snake/Salt River basin serves as habitat for elk, moose, mule deer, big horn sheep, and antelope. GIS files outlining big game habitat for various species have been created by the Wyoming Game and Fish Department, and are included in the GIS mapping for the Snake/Salt River basin plan.

The National Elk Refuge is located just north of Jackson, and covers approximately 25,000 acres. In the winter, the refuge is home to more than 7,500 elk. The area includes nearly 1,600 acres of wetlands and marshlands, and is home to 47 different species of mammals and nearly 175 species of birds. The National Elk Refuge is managed by the U.S. Fish and Wildlife Service.

In addition to the National Elk Refuge, there are five other elk management and feeding areas across the basin. These areas are managed by the Wyoming Game and Fish Department, and are located at Alpine, Forest Park, Dog Creek, Camp Creek/Horse Creek, and South Park. These feedgrounds were established to substitute for natural winter range lost to human development and to prevent elk from competing with domestic livestock for winter hay.


Introduction and Background:

Wyoming is a headwaters state. As such, the beneficial use of water within Wyoming can often be influenced or affected by the issues and decisions made by others located downstream of Wyoming. While interstate compacts provide certainty for the long-term development and use of Wyoming's apportioned water resources, new issues important to a larger public beyond Wyoming and often derived from enactments of federal law periodically bring pressures upon and affect the use and management of water in Wyoming. In this regard, the State of Wyoming, through the State Engineer's Office, is routinely engaged in a variety of "downstream issues" to represent and protect the State's water interests.

In the Snake River basin, the primary downstream issue relates to the on-going efforts at recovering a variety of salmon and steelhead fish species that are listed as either threatened or endangered by the National Marine Fishery Service (NMFS) pursuant to the Endangered Species Act (ESA). These anadromous fish species are located along the Columbia River and Lower Snake River in eastern Idaho. Interestingly, there are additional listed species of trout, snails and plants located along the Snake River upstream of the river reaches directly affected by the salmon and steelhead yet downstream of the Wyoming/Idaho border. These ESA listings are under the management of the Fish and Wildlife Service (FWS) and the flow and habitat needs of these species often conflict with the desired flow regimes for the listed anadromous fish. For a number of years federal agencies, primarily through the Corps of Engineers (COE) and NMFS, have committed extensive financial resources to a large variety of scientific studies and structural changes to existing COE dams and hydropower plants. River and reservoir operational changes within the Columbia River system were also addressed. One of the many options and potential solutions targeted for species recovery that was identified in the 1995 Biological Opinion of the NMFS on the Federal Columbia River Power System, focused on a COE juvenile migration study responding to concerns about the declining propagation of the listed salmon and steelhead. This study evaluated methods of moving the juveniles more rapidly to the ocean.

Of the contentious alternatives evaluated, one option proposed to augment the natural flow of the river system by increasing the downstream river flow velocity to convey the juvenile fish to and through the Columbia River and the existing set of mainstem reservoirs, to the ocean. Another controversial alternative to achieve this same migration result was an evaluation of the removal of some of the mainstem COE dams and reservoirs, thereby eliminating flow impediments and slack water regimes. With regard to river flow augmentation, the COE and NMFS requested that the Bureau evaluate their Upper Snake River reservoir operations and identify additional water resources that could be committed to the recovery of the listed fish species. Separate from facilities owned by Idaho Power Company, all of the larger reservoirs in the Snake River system upstream of Lower Granite Dam are owned and operated by the Bureau. This system of reservoirs has a combined capacity of about 7 million AF of active storage space. While most of this space is contracted for irrigation purposes, some quantities are also assigned to environmental quality, other water supplies, and flood control purposes.

In 1995, the Bureau agreed to annually provide 427,000 AF of water to these efforts, derived primarily from the Upper Snake River Rental Pool, the purchase of a small amount of natural flow water rights, and un-contracted storage space in the Bureau's extensive Snake River reservoir system. This initial commitment of water did not significantly impact the operations of Palisades or Jackson Lake Reservoirs, or the Snake River flow regime through Wyoming. However, the Bureau has reported that there have been some problems and concerns expressed by residents, irrigators, the states, tribes and elements of the federal government.

Million Acre Feet Study:

In 1997, the COE requested that the Bureau analyze the effects of providing flow augmentation for the listed species at a level of an additional one million (1,000,000) acre-feet of water from the entire Snake River basin upstream of Lower Granite Dam. This is a commitment of water beyond the 427,000 AF already being provided for the recovery efforts. This study evaluated the possible affects of acquiring both natural flow water rights and reservoir storage space in Bureau facilities located in the Boise, Payette and Owyhee River basins, as well as the upper Snake River. The Bureau study developed new water demand schedules up to a total of 1,427,000 AF under several reservoir operation scenarios and then evaluated the environmental, economic, social, cultural and recreational effects of meeting these new demands. Admittedly, due to limited time and study scope, the Bureau's analysis was theoretical and presented general results on a broad basin-wide basis. Indeed, the actual selection of any particular water right or source would have a direct bearing on the specific and degree of potential impacts.

The Bureau study identified a block of water coming from natural flow water rights in Wyoming (approx. 30,000 AF) as well as from other areas of the basin. The Bureau simply assumed for their study that they would be able to acquire certain quantities of water rights from existing appropriators in Wyoming, and from Nevada, Idaho, and Oregon, that would be a portion of the additional one million acre-feet.

Because of the abbreviated and broad basin-wide nature of this study, specific and definitive impacts on the resources within Wyoming are not provided. A summary of the general findings related to Jackson Lake and Palisades Reservoir are:

1) In the areas where natural flow water rights are acquired, the report indicated there would be job losses related to irrigated agriculture and the quality and character of rural communities would be irreversibly changed.
2) The recreation impacts, measured in terms of visitations, had predictable losses ranging between 6 and 14 percent for river recreation and between 1 and 11 percent for the reservoirs.
3) Negligible changes were identified between the current or base conditions and the additional one million acre-feet conditions for the cultural, wild and scenic rivers and Indian trust asset resources.
4) Slightly adverse affects were identified for the quality and amount of habitat for aquatic snails, bald eagles, plants and other general fish species. Slight decreases in water quality were also noted in the Wyoming river reaches.
5) Some improvements in streamside wildlife and riparian areas were anticipated.

The Bureau properly noted that the costs and degree of local opposition to an acquisition program such as this would be substantial. Even though the Bureau recommended willing buyer/willing seller types of water right transactions, it noted even those arrangements would require a lot of time, resources and state approval to provide proper protection of the water acquired and conveyed to the location of the new use. The Bureau also mentioned the high social and political price that could be paid if an aggressive and heavy-handed approach to water acquisitions was pursued, whether from federal storage space contractors or natural flow water rights. These less desired options included those legally based on federal takings and prior and superior claims legal arguments. The Bureau noted that those approaches would be resisted strenuously by many water and power users and other constituents by all legal means. The Bureau's "million acre-feet study" was submitted to the COE and since that time no further actions evaluating or implementing the options and alternatives presented have been pursued. Officials representing the State of Wyoming's interests were and continue to be involved in monitoring this study and other related ESA efforts downstream of the Wyoming/Idaho border.


Wyoming water law originated during territorial days and is based on the doctrine of prior appropriation. Under this scenario the first person to put water to beneficial use has the first right, which is also referred to as "first in time is first in right." As a result, water rights in Wyoming are regulated by priority, as they are in most of the western states. This means that the earliest rights are entitled to water during periods of limited supply, while those with later rights are denied water during these times.

The Wyoming Constitution states that water of all natural streams, springs, lakes, or other collections of still water is the property of the State, and is administered through the State Engineer. Water division superintendents administer the water within each of the four water divisions in the State, with assistance from local water commissioners and hydrographer-commissioners. Prior to 1986, Wyoming water law stated that water must be diverted and conveyed in order to be beneficially used. However, the passing of the Instream Flow Law in 1986 changed this to allow water to be left in the stream for a beneficial use, such as for fisheries. This instream right can only be held by the State of Wyoming, and the priority system still applies to these rights.

Instream Flow Law:

After much debate, the instream flow law was passed by the wyoming Legislature in 1986. The concept had not been recognized by the State Engineer prior to this, as it was generally accepted that water must be diverted to be beneficially used. Also, there were questions regarding the abandonability of the rights since it was not diverted. The Wyoming Legislature declared in 1986 that instream flow for maintenance or improvement of existing stream fisheries is a beneficial use of water that can be provided from natural streamflows or from storage water. The instream flow process includes three State agencies, which are: the Game and Fish Department, the Water Development Commission, and the State Engineer's Office. The Game and Fish Department first selects the stream segment on which to file for a right. This is done using biological reports, knowledge of the fisheries, and stream flow models, along with determination of how much flow will be required. The Wyoming Water Development Commission then applies for the appropriation. The WWDC must also conduct a hydrologic study to determine whether the instream flow can be provided from the unappropriated natural flow of the stream or whether storage water from an existing or new reservoir will be needed for part or all of the instream use. The WWDC study is then supplied to the State Engineer for his consideration.

After receiving reports from the Game and Fish Department and WWDC, the State Engineer may conduct his own evaluation of the proposed appropriations for instream use. Before granting or denying a permit for instream flow in the specified stream segment, the State Engineer must conduct a public hearing and consider all available reports and information. In the past, public involvement has ranged from very little to quite significant. Following the public input period, the State Engineer decides whether or not to approve, approve with modifications, or reject the application. If granted, an instream flow permit can contain a condition for review of continuation of the permit at a future time. Also, the Wyoming Water Development Commission is named as holder of the permit.

The instream flow appropriation goes into effect the date the State Engineer approves the permit. The water right cannot be adjudicated by the Board of Control for three years thereafter. An instream water right has a date of priority as of the date that the application was received and recorded by the State Engineer, and all senior priority water rights must be recognized in administration of the stream.

Only municipalities can condemn an instream flow right. However, within one mile of the State border, the water for an instream flow right is still open to appropriation. This allows for additional utilization of water prior to the flow leaving the State. Existing water rights cannot be condemned for instream flow, however, they can be gifted to the State for instream use. This has not happened as yet. As for regulation of water rights on a stream, this must be called for by the Game and Fish Department with the request proceeding through WWDC. Instream flow rights do not ensure ingress and egress rights to the stream for public use, however, the Game and Fish Department has tried to ensure that the segments with instream rights have public access as well. Also, these rights cannot be issued if they will limit Wyoming's use of water with respect to interstate compacts. This will be reviewed with all of the pending applications in the Snake/Salt River basin.

Instream Flow Right Applications:

The first filings in Wyoming for instream flow rights were for protection of various species of cutthroat trout. There are currently three applications pending in the Snake/Salt River basin, two of which are on Fish Creek below Wilson, with the other on the Salt River. There are currently 85 instream flow applications filed with the State, with 26 having been permitted as of December 2002. The right for the Greys River, Permit Number 11IF, is the ony permitted instream flow rights located within the Snake/Salt River basin. Instream flow filings for rivers and streams in the Snake/Salt River basin are shown in Table II-17. A map outlining the locations of these streams is shown in Figure II-8.

Table II-17. Snake/Salt River Basin Instream Flow Applications

PriorityStream SegmentStream
(S, T, R)
(S, T, R)

01/05/93Salt River2.60 mi.22121-36-11916-36-119

10/08/93Fish Creek No. 10.60 mi.15022-41-11727-41-117

10/08/93Fish Creek No. 21.50 mi.15034-41-11703-40.117
111F10/08/93Greys River10.10 mi.204-35007-36-11733-37-118

S, T, R = Section, Township, Range


For consistency with the other Wyoming basin plans, data has been collected on all of the major reservoirs that are of particular significance to the basin. Facilities with capacities of 1000 acre-feet or larger define this criteria. In depth data regarding these reservoirs such as capacity tables and water rights have been compiled on each of these larger facilities.

In addition to the information on key storage facilities in the basin, an inventory of reservoirs was compiled. As with the other basin plans, facilities with a dam height of 20 feet or greater or with capacities of 50 acre-feet or greater were included in the inventory. These facilities are within the limits of the Safety of Dams Law coverage.

Data on the various reservoirs were collected from a variety of sources, such as the Water Rights Database from the State Engineer's Office, the Active Dams Database, the Tabulation of Surface Water Rights and the U.S. Bureau of Reclamation. It was found during the data collection that there are a number of larger dams that were permitted at one time yet were never built, or were built and have since been removed. Generally, these facilities were to be in the vicinity of Grand Teton National Park, and some were to enlarge existing lakes. Dams that either were not built or have been removed were not considered for this study. Details on the major reservoirs in the basin are presented in Table II-18.

Table II-18. Major Reservoirs in the Snake/Salt River Basin

Normal Capacity
Dam Height
Area (acres)
Grassy Lake4631R193915,18270310
Jackson LakeVarious1911847,0006525,530

Compact & Court Decree Issues:

The Snake River Compact recognizes, without restriction, all existing water rights in Wyoming and Idaho established prior to July 1, 1949. It permits Wyoming unlimited use of water for domestic and stock watering purposes, providing stock water reservoirs shall not exceed 20 acre-feet in capacity. The compact allocates to Wyoming, for all future uses, the right to divert or store 4% of the Wyoming-Idaho state line flow of the Snake River. Idaho is entitled to the remaining 96% of the flow. The use of water is limited to diversions or storage within the Snake River drainage basin unless both states agree otherwise. The compact also provides preference for domestic, stock and irrigation use of the water over storage for the generation of power.

One unique aspect of the Snake River Compact, compared to other compacts to which Wyoming is a party, is a requirement that calls for Wyoming to provide Idaho replacement storage for one-third of any usage after the first 2% is put to beneficial use. Early estimates of these replacement storage quantities, based upon the average state line flow, are 33,000 acre-feet. One result of this planning report is the update of Wyoming's estimated current use of water in the basin, which is presented in Chapter III. This will provide the state and water users with an important component of information for future development and project planning. In addition to the Snake River Compact, a court decision referred to as the Roxanna Decree is also in effect within the Snake/Salt River basin. Currently this decision does not have an impact on the operation of any major reservoir in the basin.

All of the major reservoir facilities in the Snake/Salt River basin are owned and managed by the U.S. Bureau of Reclamation for irrigation and hydropower production in Idaho. Jackson Lake Dam and Grassy Lake Dam are managed as part of the Minidoka Project, which provides irrigation water for over 1 million acres of farmland in Idaho. Palisades Dam, part of the Palisades Project, is also managed in conjunction with the Minidoka Project.


Water quality issues can affect the development and use of water in a river basin. Various properties are used to determine water quality such as physical, chemical, biological, bacteriological, and radiological characteristics. Quality of water can be affected by human activities as well as natural events.

The Environmental Quality Act was passed by the Wyoming Legislature in 1973. The purpose of the law was to address the concern that pollution "will imperil public health and welfare, create public and private nuisances, be harmful to wildlife, fish and aquatic life, and impair domestic, agricultural, industrial, recreational and other beneficial uses". The act authorized the state "to prevent, reduce and eliminate pollution; to preserve, and enhance the water and reclaim the land of Wyoming; to plan development, use, reclamation, preservation and enhancement of the air, land, and water resources of the state; to preserve and exercise the primary responsibilities and rights of the state of Wyoming; to secure cooperation between agencies of the state, agencies of other states, interstate agencies, and the federal government in carrying out these objectives" (Environmental Quality Act, 1973).

The State of Wyoming has designated the Water Quality Division (WQD) of the Wyoming Department of Environmental Quality (WDEQ) to oversee water quality and enforce the Environmental Quality Act. This is being done through various programs that have been set up to control various forms of potential pollution. Pollution can come from point and non-point sources, and can affect surface water and groundawater.

There have been numerous federal legislative efforts that authorize the remediation and protection of water quality and the environment. These include the Clean Water Act, Pollution Prevention Act, Safe Drinking Water Act, Clean Air Act, National Environmental Protection Act, Solid Waste Disposal Act, Toxic Substance Control Act, and the Federal Insecticide, Fungicide and Rodenticide Act. Most of the federal programs involved with water quality allow individual states to obtain primacy to administer the federal programs. The Environmental Protection Agency (EPA) can step in if a state is not conducting the program to their satisfaction, even if the state has primacy.

Basin Groundwater Quality:

Chapter 8 of the Wyoming Water Quality Rules and Regulations addresses groundwater quality standards and protection. These rules are enforced by the Wyoming Department of Environmental Quality Water Quality Division. Chapter 8 describes various classifications that have been created for groundwater and outlines the rules for discharges to these waters. Additional information regarding groundwater quality can be found in the groundwater availability portion of Section IV.

Basin Surface Water Quality:

According to the Wyoming Surface Water Classification List (WDEQ, 2001) there are many surface waters within the Snake/Salt River basin designated as Class 1 waters, including the following:

Many of the remaining rivers and streams in the basin are classified as 2AB in the primary classification from WDEQ, while a few are classified as 3B.

The Clean Water Act requires that a 305(b) report be created which covers statewide water quality, along with a 303(d) list, which is a list of impaired streams in the state. Impaired streams require the establishment of total maximum daily loads (TMDLs) for problem pollutants. A TMDL is the amount of a specific pollutant that a water body can receive and assimilate in a given time period and still meet water quality standards.

The classification of stream indicates what use is being or can be supported by that stream. In general, the quality of water in the Snake/Salt River basin is good based upon water bodies supporting their designated uses. This is evident in the lack of basin water features included in Wyoming's 2002 305(b) State Water Quality Assessment Report produced by WDEQ, which includes 303(d) listings. These listings are broken into four parts, the first being the 303(d) Waterbodies with Water Quality Impairments. There are no Snake/Salt River basin water features on this list. The second is the 303(d) Waterbodies with NPDES Discharge Permits Containing Waste loan Allocations Expiring. Flat Creek near Thayne and Snake River near Alpine are on this list, as NPDES discharge permits for the wastewater treatment plants in these areas have imminent expiration dates. The third is the 303(d) Waterbodies with Water Quality Threats, which includes Spread Creek-North Fork due to habitat degradation, Flat Creek between Snake River and Cache Creek due to habitat degradation, and Salt River near the Etna Gaging Station due to fecal coliform bacteria. There are no waters in the Snake/Salt River basin that were delisted from the 2000 303(d) list.

In summary, there are no water features in the basin requiring TMDLs, and there are current threats only in a few areas. Other water quality problems described in the 2002 Water Quality Assessment Report (though not on the 2002 303(d) list) include physical degradation of the Pacific Creek stream channel and general erosion in the Greys-Hoback watershed. Stream channel rehabilitation on the North Fork of Spread Creek has been done, however the stream will remain on the above mentioned 303(d) list until the riparian vegetation is better established.

According to "Water Resources Data Wyoming Water Year 2001" produced by U.S. Geological Survey (USGS), only three water quality sampling stations are currently being operated by USGS in the Snake/Salt River basin. These stations are shown in Table II-19.

Table II-19. Current USGS Water Quality Sampling Stations In The Snake/Salt River Basin

Station NameStation
Period of Record
Snake River above Jackson Lake, at Flagg Ranch130100651987 to Present
Snake River at Moose130136501995 to Present
Salt River above Reservoir, near Etna130275001994 to Present

Water quality data for the stations listed in Table II-19 can be found in the Water Quality technical memorandum. The data is for the 2001 water year, which covers results from October 2000 to September 2001. Review of the data indicates that there are no water quality problems apparent in the sample testing results, other than the fecal coliform test results at the Salt River station described above.

Additional water quality monitoring across Wyoming is conducted by WDEQ as part of their watershed monitoring program. During the late 1990's, water quality collection sites were selected in order to provide reference quality data. These sites generally did not have water quality problems, as the data were used as a reference for later testing. Due to the fact that these sites were intended to provide reference data, there are no evident impairments of the rivers and streams from the test results. Since 2000, data have been collected from sites that were targeted as being potentially impaired waters. This data will be available to the public later in 2003 following completion of WDEQ quality control procedures.

Aquifer Sensitivity and Vulnerability:

A program to assess the vulnerability of groundwater to contamination from surface pollutants was initiated in 1992 by WDEQ in cooperation with the University of Wyoming's Water Resources Center, the Wyoming State Geological Survey, and the US Environmental Protection Agency . This modified DRASTIC model takes into account depth to water, recharge, aquifer media, soil media, topography, impact to vadose zone, and hydraulic conductivity. Geographic Information System (GIS) software was used to combine various geologic, topographic, and soils characteristics into composite scores. These scores describe "aquifer sensitivity" - the intrinsic ability of the subsurface environment to transport surface contaminants into groundwater, and "groundwater vulnerability" - the integration of aquifer sensitivity with current land use practices likely to cause groundwater contamination. Final reports for this program were completed in 1998, and data was available digitally in 1999.

Figure II-1: Irrigated Lands

Figure II-2: Irrigated Lands

Figure II-3: Irrigated Lands

Figure II-4: Agricultural Wells

Figure II-5: Municipal Wells

Figure II-6: Domestic Wells

Figure II-8: Grand Teton National Park Snake River & Jackson Lake Private Use Estimates