Match: Format:
 
  News   Pilot Products   Basin Plans   Contact Us   Home       

WATER AND RELATED LAND RESOURCES OF THE GREEN RIVER BASIN, WYOMING:
SUMMARY, CONCLUSIONS, AND RECOMMENDATIONS

LOCATION AND CLIMATE

Wyoming's Green River Basin covers an area of 17,104 square miles in southwestern Wyoming which is drained by the Colorado River system. The Great Divide Basin, a closed topographic basin some 3,916 square miles in area, situated east of and adjacent to the Green River Basin, is included in the study area for convenience. The total area, some 21,020 square miles, extends northward approximately 168 miles from the Wyoming-Utah and Wyoming-Colorado state lines, and east-west approximately 213 miles along the state lines (see Figure A-7). Annual precipitation varies from as little as 6 inches over the interior plateau to over 40 inches in the Wind River Mountains. Annual snowfall varies from 40 to 50 inches in the southern half, with some mountain areas receiving much more.

STREAMFLOW

Many of the perennial headwater streams contribute over 80 percent of their annual flows during the heavy snowmelt period in May, June, and July. Since runoff is greatest In May and June and requirements for crops reach a maximum in late summer, reservoirs are required to store spring runoff to provide irrigation water for the latter part of the growing season.

Using 1948-1968 averages, the streamflow entering Wyoming from other states averages 391,400 acre-feet per year. The water yield within Wyoming is 1,926,600 acre-feet per year, and the water flowing downstream from Wyoming would be 2,318,000 acre-feet per year under natural conditions. In the Basin, 241,600 acre-feet of surface water are consumed annually for irrigation, 4,700 acre-feet by municipal, domestic, and livestock uses, 16,200 acre-feet by industrial uses, 300 acre-feet by recreation, fish and wildlife uses, and 7,000 acre-feet are diverted out of the Basin for the city of Cheyenne's municipal supply. Another 26,300 acre-feet per year evaporate from reservoirs in the Basin. These uses total 296,100 acre-feet per year. The depleted streamflow leaving the State averages 2,021,900 acre-feet per year. The flow of the Green River has varied from 41 percent to 165 percent of average in the 1948-1968 period.

Flood damage is not a major problem. The small amount of annual flood damage that does occur is generally restricted to agricultural developments, roads and railroad crossings, and farm structures on floodplains.

WATER QUALITY

The quality of interstate waters in the Basin generally is within the limits of established standards. Salinity increases as the Colorado River flows downstream, and salinity is a problem in the lower Colorado River Basin. There is no salinity standard on the Colorado River at this time, primarily because the proportional contributions to salinity from man-made and natural sources are not now accurately known. The Federal Government is now seeking ways to stabilize salinity in the Colorado River system.

In Wyoming, industrial water uses are largely 100 percent consumptive and have little effect on salinity. Low population density and adequate waste water treatment limit municipal salinity contributions to minor amounts. Irrigation may contribute significant amounts of salinity, but since few irrigation return flows are monitored in the Basin this contribution is difficult to quantify. A major portion of salinity is from natural or geologic sources. The Green River in Wyoming averages 320 ppm total dissolved solids at Green River, Wyoming.

WATER RIGHTS

Provisions of the Wyoming Constitution declare water to be State property, allow the appropriation of water for beneficial uses, and establish the Office of the State Engineer and the Board of Control to supervise such appropriations. Priority of appropriation- "first in time is first in right"-is the basis for Wyoming water law.

There are about 537,000 acres in the Basin with valid irrigation rights, but the acreage actually irrigated is about 332,300 acres. The discrepancy between water right acreage and actually irrigated acreage is common throughout the State.

INTERSTATE COMPACTS

The Colorado River Compact of 1922 divided the beneficial uses of water in the Colorado River between the Upper Basin (those parts of the states of Wyoming, Colorado, New Mexico, Utah, and Arizona which drain into the Colorado River system above Lee Ferry, Arizona) and the Lower Basin (those parts of the states of Arizona, California, Nevada, New Mexico, and Utah which drain into the Colorado River system below Lee Ferry). Each of the Basins was allocated the beneficial consumptive use of 7.5 million acre-feet of water annually.

A provision of the Compact requires the Upper Basin to deliver an aggregate of 75 million acre-feet for any period of 10 consecutive years. The Colorado River Storage Project was authorized by Congress in 1956 to provide Upper Basin reservoirs to regulate the river and make the required water deliveries at Lee Ferry. Thirty-two million acre-feet of storage space have been constructed in four units of the Project-Flaming Gorge, Curecanti, Navajo, and Glen Canyon.

A treaty committing the United States to deliver not less than 1.5 million acre-feet of water annually to Mexico was made effective in 1945. According to the Colorado River Compact, such delivery is to be made from water surplus to Upper and Lower Basin consumptive uses. If such surpluses are insufficient, the deficiency shall be borne equally by the Upper and Lower Basins, and whenever necessary the Upper Basin shall deliver at Lee Ferry water to supply one-half the deficiency in addition to the 1O-year 75-million acre-foot delivery.

The Upper Colorado River Basin Compact was ratified in 1948 by all the Upper Basin states, and Federal approval followed in 1949. This compact apportions consumptive use of water in the Upper Basin as follows: 50,000 acre-feet per year to Arizona; of the remainder, 51 3/4 percent to Colorado, 11 1/4 percent to New Mexico, 23 percent to Utah, and 14 percent to Wyoming. The compact also divided the waters of Henrys Fork between Wyoming and Utah on a priority of appropriation basis. The waters of the Little Snake River below its confluence with Savory Creek were divided between Wyoming and Colorado on a priority of appropriation basis for existing development; the unused waters were divided equally.

AVAILABLE SURFACE WATER RESOURCES

The water available for allocation under the Colorado River Compact was estimated in 1921. Since that time it has become apparent that water supplies are insufficient to meet the compact allocations. Recently, it has been estimated that approximately 6.3 million acre-feet would be available annually after the 75-million acre-foot, 10-year delivery to the Lower Basin. If the Upper Basin must deliver one-half of the 1.5-million acre-foot per year Mexican delivery, the consumptive uses available to the Upper Basin would average about 5.8 million acre-feet per year. Augmentation of water supplies will be required if full compacted uses of Colorado River water are to be made.

Assuming 7.5 million acre-feet are available each year to the Upper Basin, Wyoming's 14-percent share would be 1,043,000 acre-feet annually. If only 6.3 million acre-feet per year are available, Wyoming's share is reduced to about 875,000 acre-feet per year. If the Lower Basin's contention that the Upper Basin Mexican Treaty obligation amounts to one-half of the total required is valid, Wyoming's share could be reduced to as low as 805,000 acre-feet per year. The Upper Basin Mexican water delivery requirements have not been determined, however. Present uses are chargeable to the compact amount.

GROUNDWATER

There are numerous aquifers in the Basin. Wells in shallow aquifers (depths to 300 feet below the surface) generally yield less than 20 gallons per minute (gpm) of poor to good quality water. The concentration of total dissolved solids (TDS) ranges from 250 to 2,800 ppm. Exceptional yields as high as 2,000 gpm are reported from alluvial sands and gravels. Terrace gravels reportedly may yield 2,000 gpm. Yields from shallow consolidated sandstones and conglomerates vary from less than 10 gpm to more than 200 ppm.

Deeper wells into consolidated aquifers produce moderate to large yields; however, the potential yield at any specific well site is unpredictable with the information presently available. The main body of the Wasatch formation may yield 700 gpm to a well which penetrates a great thickness of the formation. Likewise, the Battle Spring formation in the Great Divide Basin may produce a maximum yield of 1,000 gpm to a well which penetrates the entire formation thickness. Generally, the deeper aquifers yield water of inferior quality.

The principal uses of groundwater in the Basin are for livestock and domestic water supplies. Residents of many communities in the Basin use groundwater as a source of municipal supply. Municipal, domestic, and stock water uses consume an estimated 400 acre-feet annually. Industrial uses, including oil well drilling, secondary oil recovery, coal mining operations and others, use about 4,400 acre-feet of groundwater annually. About 1,300 acres in the Basin use groundwater as the principal source of water supply. Irrigation consumptive uses are estimated to be 1,200 acre-feet annually.

AGRICULTURE

Rangeland for grazing and irrigated lands to provide a winter feed base are interdependent components of the Basin's agricultural enterprise. Projected national needs for lamb and mutton indicate that no expansion in sheep and lamb production will be needed by 1980, but that moderate expansion will be needed for the years 2000 and 2020. Projections of national needs for beef show a sharp increase through the projection period. The Green River Basin should help Wyoming to maintain its share of national meat production by increased efficiencies and expanded Irrigation.

Irrigated land is projected to increase from 332,300 acres at present to 413,300 acres by the year 2020. Potential new land developments include the Seedskadee, Savery-Pot Hook, and Eden Reclamation Projects, and private developments.

The present (1968) annual depletion of water in the Basin for agricultural purposes totals 267,900 acre-feet, including 241,600 acre-feet from irrigation and 26,300 from reservoir evaporation. This is over 90 percent of the water now depleted by man for all purposes in the Basin. This annual depletion for agriculture is projected to increase to 415,000 acre-feet by the year 2020,

COAL

A 1968 report by the Cameron Engineers gives projections of Green River Basin mineral industries. The coal industry is projected to experience enormous growth in the Basin, with production increasing from 864,000 tons in 1967 to 82,610,000 tons in 2020. The primary uses of coal will be for steam-electric power plants, synthetic liquid fuels and gas plants, and coal coking or carbonizing plants. Employment is projected to increase to 12 times present employment by the year 2020. Capital investment would increase to 38 times its present value by 2020. The present consumptive use of about 7,000 acre-feet of water is projected to increase to 186,000 acre-feet per year by the year 2020.

OIL AND GAS

The oil and gas industry provides a significant payroll and a major tax base for the State. The industry apparently has a finite limit of resources and is projected to decline. In 1967 the industry consumed 4,500 acre-feet of water in the Basin. Water uses will decline accordingly as production decreases.

OIL SHALE

National projections indicate an increasing inability for the United States to supply its own liquid fuel requirements from natural crude oil. Thus, development of the extensive oil shale formations in Wyoming's Green River Basin is projected to help meet the Nation's requirements. Production of synthetic crude oil from oil shale is projected to increase from nothing at present to 200,000 barrels per day by the year 2020. By 2020 this new industry will require a capital investment of $441 million and an employment force of 2,320 persons. Water use is projected to reach 18,800 acre-feet per year by 2020.

URANIUM

A number of companies have been involved in uranium exploration in the Basin, and production is projected in the Basin by the year 1980. A peak production of 1.3 million tons a year is projected by year 2000, after which production will probably decline due to the advent of the breeder reactor. Groundwater will probably be the source of water supply for the uranium mining operations.

TRONA

The only known commercial deposits of trona (a deposit of hydrous carbonate of sodium) occur in Wyoming's Green River Basin, which is the center of the world's soda ash industry. The tonnage of ore mined annually is projected to increase from 2.3 million tons in 1967 to 10 million tons by the year 2020. Employment in this industry is projected to increase from 700 in 1967 to 3,400 in 2020, capital investment to increase from $126 million to $300 million, and annual water requirements from 4,428 acre-feet in 1967 to 18,500 acre-feet in 2020.

TIMBER

At present, the timber industry is not of major economic importance in the Basin. The Cameron Report forecasts include the establishment of a kraft pulp and paper mill in the Basin sometime after 1980. Such a mill would have an accompanying consumptive use of water of 4,800 acre-feet per year.

MUNICIPAL, DOMESTIC, AND STOCK WATER

The population served by municipal water systems in the Basin is 22,880 people. Municipal and domestic water diversions together total about 6,400 acre-feet per year, about one-half of which is consumptively used. Stock water depletions total about 2,000 acre-feet per year. Projections indicate that the annual water consumption for these purposes by year 2020 will be 9,000 acre-feet per year.

RECREATION AND FISH AND WILDLIFE

Outdoor recreation is a large and growing industry in the Green River Basin.

There are over 2,500 miles of streams in the Basin classified for sport fishing, and these presently support nearly 323,000 annual fisherman-days of use. This use could be increased to 702,000 fisherman-days before significant management changes would be required. In addition to the Basin's stream fishery, there are about 69,800 surface acres of still water classified for sport fishing. These support over 427,000 annual fisherman-days of use, and under present management conditions are capable of supporting a total of 555,500 fisherman-days. Much of the still water fishing is done on Flaming Gorge and Fontenelle Reservoirs.

An economic study done in 1966 indicated that fishing generated a total annual income of $1,307,348 to Sweetwater County and $1,800,964 to Sublette County. Hunting expenditures in 1965 in the Basin totaled some $5,934,768.

The Wyoming position regarding scenic rivers is given in An Outdoor Recreation Plan for Wyoming. October 1970: "The State of Wyoming has taken the position that it is the State's responsibility to administer the rivers within its boundaries, and that the development of scenic rivers programs and other similar programs affecting the water of Wyoming should be under the jurisdiction of the State." The Upper Green River has been suggested in the State Recreation Plan for possible designation as a State scenic river.

With the exception of the Seedskadee Wildlife Refuge below Fontenelle Reservoir, which will deplete 20,000 acre-feet of water annually, consumptive water uses for recreation, fish and wildlife purposes are small.

HYDROELECTRIC POWER

The 10,000 kilowatt powerplant at Fontenelle Dam Is the only hydroelectric powerplant currently operating in the Basin. A pumped storage peaking plant utilizing Boulder Reservoir and Burnt Lake has been suggested for future study by the USBR.

SUMMARY OF WATER RESOURCE REQUIREMENTS

A summary of present and projected water resource requirements in the Basin is as follows: 

					Consumptive Uses,
				  1,000 Acre-Feet Per Year

                 	    Present		      2020		
	        	Surface    Ground-	 Surface  Ground-
	        	Water	   Water	 Water    Water
Water Uses

Irrigation and	       	268         1              415      1+
Evaporation

Industry                 16         4              204      31

		 
Municipal, Domestic,      5         1                9      1+
and Stock

Recreation, Fish         --        --               20      --
and Wildlife

Cheyenne Diversion        7        --               31      --

Colo. River Storage      --        --               92      -- 
Project Evaporation

Total                   296         6              771      33+

Wyoming's compact allocation of consumptive uses from the Colorado River system is estimated to be from 875,000 to 1,043,000 acre-feet per year. Thus, between 104,000 and 272,000 acre-feet per year of surface water would be available for other uses in 2020, such as transbasin diversion or additional irrigation in the Basin.

POTENTIAL SOURCES OF WATER

A considerable amount of surface water is available for development in the Basin. Since the dependable direct flows of most streams are largely appropriated, however, the development of this surface water will probably require storage.

Groundwater supplies at shallow depths will, in most areas, be adequate for future domestic and livestock requirements. Municipal and industrial uses of groundwater will probably increase in the future. The Battle Spring formation in the Great Divide Basin might support a groundwater development for industrial use. Supporting a large new-land irrigation project solely with groundwater could be too expensive to be feasible. The quality of groundwater may not be adequate for some uses, and in areas of low recharge large withdrawals could result in mining of the resource.

Improved efficiency in existing water uses could enhance many present irrigation operations, and may provide water for additional uses. Improvements of water uses will probably occur when they appear justified for economic reasons.

POTENTIAL IRRIGATION PROJECTS

Irrigation developments projected for the Basin include:

  1. Eden Project Improvement- A diversion from East Fork and other New Fork River tributaries would provide a water supply to supplement 17,100 acres and to bring 3,100 acres into production. This irrigation would increase Wyoming's Colorado River depletions by 10,000 acre-feet per year. A transbasin diversion might also be included in the project.

  2. Lyman Project- This partially constructed USBR project will supplement the water supply for 36,000 acres in the Lyman, Wyoming area. The Colorado River depletion of the Lyman Project will be 10,000 acre-feet per year. Meeks Cabin Dam on Blacks Fork has already been constructed, and construction of China Meadows Dam on Smiths Fork will complete the project.

  3. Savery-Pot Hook Project- Located in Colorado and Wyoming on the Little Snake River, the Savery-Pot Hook Project will supplement about 10,700 acres and supply about 7,000 acres of new land in Wyoming. The Colorado River depletion of this authorized USBR project will be 12,000 acre-feet per year.

  4. Seedskadee Project- The USBR has constructed Fontenelle Dam to provide storage for irrigation, M & I water, recreation, fish and wildlife, and hydropower. Originally authorized for 57,000 acres of new land, more detailed studies have now sized the project at 34,000 acres, with water depletions of 51,000 acre-feet per year. The Seedskadee wildlife refuge will deplete the Colorado River system another 20,000 acre-feet per year. Fontenelle Reservoir has storage space allocated to irrigation, to the Seedskadee Wildlife Refuge, and 60,000 acre-feet allocated to the State of Wyoming for M & I purposes. The State is negotiating for additional storage space.

  5. Private Irrigation Projects- A projected 29,000 acres of private new irrigation developments has been projected. The corresponding streamflow depletion for this development would be about 29,000 acre-feet per year. Supplemental water supply projects are needed for tributaries entering the Upper Green River from the West. These may be supplied by reservoir projects, although groundwater supplies may be utilized as an alternative.

M&I WATER SUPPLIES

Green River Basin M & I water demands associated with coal, oil shale, trona, uranium, and possibly the timber industry are located primarily in the central part of the Basin, between Kemmerer and Rawlins, Wyoming. Recent studies have lead to negotiation for the acquisition of additional storage capacity in Fontenelle Reservoir as a first step in meeting future demands. The present negotiations are for 60,000 acre-feet of capacity, and such acquisition would bring the State's allocation to 120,000 acre-feet. Additional alternatives for providing for the Green River Basin M & I water needs and for transbasin diversion to eastern Wyoming have been identified and include Kendall, New Fork, Boulder Lake Enlargement, Lower Green, or Plains Reservoirs (see Figure A-7). A 1972 State feasibility study investigated the Lower Green and Plains Reservoir sites. Both sites were found feasible, although the report favored the Plains Reservoir site.

ENVIRONMENTAL CONSIDERATIONS

The effects of alternatives of development on the quality of water in the Basin have been estimated. For the Green River at Green River, Wyoming, the present average total dissolved solids (TDS) concentration is 320 ppm. By 2020 the TDS concentration could range from 360 ppm to 480 ppm, depending upon the amounts and effects of new irrigation.

The Wyoming Game and Fish Commission has assessed the impacts of the proposed alternative storage sites. The kinds of Impacts noted were inundation of free-flowing streams. Inundation of big game and other wildlife habitat, creation of an occasionally fluctuating reservoir, and creation of additional flat-water recreation. In general, the adverse Impacts were judged to be less at the downstream sites than at the upstream ones. Positive impacts might include creation of waterfowl habitat and creation of a water body in a desertic area.

The Upper Green River from its headwaters to the confluence of Horse Creek has been suggested for designation as a wild, scenic, or recreation river, and such designation would conflict with the potential Kendall Reservoir.

CONCLUSIONS

  1. Further development of Green River Basin water resources is required to meet the projected water needs of the people of the Basin and the State.

  2. A key factor in determining the level of development within the Green River Basin is whether or not irrigation of new lands will develop. The choice of a development plan will depend on the amount of irrigation desired, along with factors relating to other uses.

  3. If none of the proposed dams and reservoirs is constructed, Wyoming will likely forfeit from 177,000 to 345,000 acre-feet per year of beneficial consumptive uses to which the State is entitled under interstate compacts.

  4. Water resource development will have an impact on water quality and the game and fish resources of the Basin. Good water quality can be maintained with proper project planning and water management. Provisions for minimum pools in reservoirs and for sustained streamflows can mitigate some of the adverse impact on fish resources and provide fisheries enhancement on the Big Sandy and Lower Green Rivers.

  5. Groundwater will continue to be utilized for stock and domestic purposes. The mineral industries will also continue to use groundwater, and in the future may significantly increase the amount used. Shallow groundwater and surface water are so interrelated that development of one can affect the distribution and availability of the other. Groundwater in natural underground storage in consolidated aquifers is abundant, but recharge is slight and may limit the sustained yield. The costs of deep large-yield wells may be prohibitive for other than municipal and industrial uses.

RECOMMENDATIONS

  1. In formulating a State Water Plan, water needs of the Green River Basin should be considered in conjunction with the water needs of the State of Wyoming.

  2. The water development plans presented in this report should be reviewed by the citizens of the Green River Basin and the State.

  3. Public meetings should be held to determine public opinion regarding the best plan of development considering:

    1. Desired levels of development in the Green River Basin.

    2. The economic impact of the alternatives.

    3. The economic impact of no development.

    4. The impact of development on environmental qualities of the area.

    5. Detailed feasibility studies of the individual project-components of the plans should be undertaken to evaluate engineering and economic factors such as direct and indirect project benefits, construction costs, and recreational and environmental values.

    6. Sources of financing, such as Federal funds, State loans and bonds, and others, should be reviewed. State laws should be reviewed to determine what legislation would be desirable and necessary for State financial considerations.

    7. The best plan should be determined from public opinion, feasibility studies, and financial considerations.

    8. Short-range and long-range goals should be established and implementation procedures outlined.

    9. The type of State or other organization required to administer the construction of water development projects should be determined and established.

    10. Soil and water conservation practices in the Basin should be promulgated and implemented through programs of the U. S. Department of Agriculture and others. The possibilities of improving water supplies by watershed management, water management, and flood control measures should be investigated.

    Green River Basin Reference Notebook Table of Contents
    Wyoming State Water Plan Homepage | Search the State Water Plan Website