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

LOCATION AND CLIMATE

The Bear River Basin in Wyoming is located in the southwest corner of the State and has an area of about 1,500 square miles (see Figure A-8). The Basin extends northward approximately 110 miles from the Utah-Wyoming State line and eastward between 6 and 22 miles from the Utah-Wyoming and Idaho-Wyoming State lines. Besides the Bear River, the major streams in the Basin are its tributaries, Sulphur Creek, Yellow Creek, Twin Creek, Smiths Fork, and Thomas Fork. The average annual precipitation varies from about 9 inches along portions of the Bear River main stem to over 25 Inches In the Uinta Mountains.

STREAMFLOW

Most of the dependable streamflow is derived from melting snow in the mountainous regions of the drainage basin. Because of the relatively low elevation of the mountains in the Basin, most of the runoff usually occurs early in the spring. Reservoir storage is required to store the spring runoff in May and June for irrigation releases during July and August when the crop demands are greatest. However, only about 15,3000 acre-feet of storage capacity has been constructed for Wyoming uses.

The estimated annual water yield of the Bear River Basin in Wyoming is 273,400 acre-feet. Another 139,600 acre-feet of water per year flow into Wyoming from Utah and Idaho resulting in 413,000 acre-feet of water per year which would leave the State under natural conditions. In Wyoming, man's depletions of the Bear River total 68,400 acre-feet per year of which 60,600 acre-feet are consumed by irrigation, 800 acre-feet are consumed by stockwater, municipal, and industrial uses, and 7,000 acre-feet are consumed by reservoir and stock pond evaporation. The depleted outflow from the Bear River Basin is 344,600 acre-feet per year. The recorded streamflow of the Bear River at the Utah-Wyoming State line, south of Evanston, varied from 58 percent to 151 percent of average in the 1948-1968 period.

Most flooding results from high spring runoff. Flood damage has occurred to agricultural property on the floodplains. Urban property in the towns of Evanston and Cokeville has received flood damage. Currently a clearing and channeling program is being undertaken by the SCS to protect Evanston from flooding by the Bear River.

SURFACE WATER QUALITY

The water quality of the interstate waters of the Basin is generally within the established standards. The only major M & I water, quality problem is below the town of Evanston when the city's sewage treatment facilities are occasionally overloaded, and the raw sewage is dumped directly into the Bear River through a bypass system. The town is currently attempting to resolve the problem. Irrigation return flows may in some areas carry significant amounts of dissolved solids into receiving streams, but no particular problems are being caused by these return flows. Other agricultural enterprises presently have only minor effects on water quality.

Interstate streams for which water quality standards have been established include the Bear River, Raymond Creek, and Thomas Fork.

WATER RIGHTS

Provisions of the Wyoming Constitution 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. The procedures for obtaining a valid water right are outlined by the State Statutes. Wyoming's water law is based on priority of appropriation . . . "first in time is first in right."

About 80,240 acres in the Bear River Basin of Wyoming have adjudicated water rights, with the earliest water right having a priority of May 1, 1862. Currently, about 58,690 acres are being irrigated in the Wyoming portion of the Basin. In most years only the water rights with the early priorities have a dependable water supply.

INTERSTATE COMPACTS

The Bear River Compact, negotiated in 1955, allocates the waters of the Bear River among the states of Utah, Wyoming, and Idaho. This Compact divides the Bear River Basin into three divisions: the Upper Division, the Central Division, and the Lower Division. The Upper Division is the portion of the Bear River from its headwaters in the Uinta Mountains to and including Pixley Dam located south of Cokeville. The Central Division is the portion of the Bear River from Pixley Dam to Stewart Dam located south of Montpelier, Idaho. The Lower Division is the portion of the Bear River including its tributaries from Stewart Dam to the Great Salt Lake.

Article IV of the Compact states that the direct flow of the Bear River will be administered in accordance with the water law of the state in which the appropriation was made except when a water emergency exists and then the water will be apportioned to each state within each division.

A water emergency is said to exist in the Upper Division when the divertible flow from the mainstem of the Bear River and its tributaries, north of the Utah-Wyoming State line above Evanston, is less than 1,250 cfs. During a water emergency situation, the flow is then allocated among the four sections of the Upper Division as follows: 

1.  Upper Utah Section                0.6 percent

2.  Upper Wyoming Section            49.3 percent

3.  Lower Utah Section               40.5 percent

4.  Lower Wyoming Section             9.6 percent

If a state section in the Upper Division does not use its allocated apportionment of water, the other section in that state has first priority for the water and second priority is given to the other state in the Upper Division.

A water emergency is said to exist in the Central Division when the divertible flow within this division is less than 870 cfs or the flow of the Bear River at the Border gaging station is less than 350 cfs. When an emergency exists in the Central Division, the divertible flow of the Bear River main stem and designated tributaries including Smiths Fork is allocated as follows: 

Wyoming .............43 percent
Idaho ..............57 percent

A water emergency exists in the Lower Division whenever the flow past the Idaho-Utah State line is insufficient to satisfy the water rights in Utah. When this situation occurs, the water rights are administered according to priority without regard to State lines.

Article V lists the storage rights in each state dated prior to the Compact and grants 35,500 acre-feet of additional storage of Bear River water above Stewart Dam for use in Wyoming and Utah and an additional 1,000 acre- feet of storage on Thomas Fork for use in Idaho. The 35,500 acre-feet of additional storage rights above Stewart Dam are divided one-half to Wyoming and one-half to Utah. Reservoirs constructed in Wyoming before the Compact have a combined capacity of 2,150 acre-feet.

AVAILABLE WATER RESOURCES

Early priority water rights have appropriated the dependable direct-flow water supply, and reservoir storage is required to store the spring runoff and release it during the periods of low flow to supplement the Junior priority water rights. Approximately 70 percent of the annual runoff occurs in May, June, and July. Under the terms of Article V of the Bear River Compact, Wyoming was given the right to store 17,750 acre-feet of water per year. Since the date of the Compact, dams have been constructed that provide 13,131 acre-feet of storage space. Additional storage space could be constructed that would enable Wyoming to store its entire compact storage allocation every year. Although the compact storage allocation helps alleviate water shortage, an additional storage allocation is required to meet present and future water needs.

GROUNDWATER

Groundwater for domestic, stock, municipal, irrigation, and other uses is available in the unconsolidated sediments in the Bear River Valley. Groundwater in quantities adequate for domestic and stock uses is locally obtained from consolidated bedrock formations.

Wells drilled in the valley fill yield from less than 100 to about 1,300 gpm. The consolidated rock of the basin is only a minor water producer.

Rock deformation due to folding and faulting has caused rock beds in many places to be discontinuous, to have steep dips, and to have small recharge areas. The availability of groundwater in bedrock aquifers thus is dependent upon local geology. Small to moderate well yields (to several hundred gallons per minute) might be available from wells strategically located in these formations.

The City of Evanston has several municipal water supply wells that produce water from unconsolidated alluvium to supplement the supply obtained from the Bear River. Several wells in the northern Bear River Valley obtain water for irrigation from the valley fill alluvium. Well yields range from 400 to 1,100 gpm.

A large amount of groundwater is in storage in the alluvium. The maximum thickness of the alluvial aquifer is unknown, but is greater than 185 feet. Assuming an average saturated aquifer thickness of 100 feet, there may be at least half a million acre-feet of recoverable groundwater in storage.

Most of the water wells drilled into the valley fill are shallow and do not penetrate much of the saturated aquifer, and therefore, do not yield as much water as they might if drilled deeper.

Groundwater in the alluvium in the southern Bear River Valley is not a single distinct chemical type, but can be either a magnesium sulfate or a calcium bicarbonate water. Samples from the alluvium in the northern Bear River Valley indicate a calcium bicarbonate water. The mineral content ranges from 285 to 510 ppm TDS in the northern valley and 300 to 1,700 ppm in the southern valley. Generally, wells tapping the alluvium upgradient and away from return flow into the Bear River yield water of lower TDS. Almost all the waters obtained from alluvial aquifers are considered good to excellent for irrigation under normal drainage conditions and irrigation practices.

As of 1970, from records in the State Engineers Office, groundwater was used as the original supply to irrigate 1,874 permit acres and as a supplemental supply for 2,156 acres. The total groundwater depletion in 1970 is estimated to be 4,100 acre-feet for irrigation, 400 acre-feet for municipal, domestic, and stock water uses, and about 400 acre-feet in the phosphate industry.

It is anticipated that in the next 50 years groundwater depletions will increase about 2 percent for municipal, domestic and stock water uses. The depletion of groundwater by the phosphate industry may increase to about 870 acre-feet per year by 2020 if facilities necessary to produce elemental phosphorus are constructed.

AGRICULTURE

Agricultural activity is an important basic industry in the Basin. The combination of rangeland and irrigated crop and pasture land provides the feed and forage base for the cattle and sheep industry. Livestock contribute 95.6 percent and 89.9 percent, respectively, of the value of all agricultural products sold in Uinta and Lincoln Counties. Hay and pasture are the principal crops grown and are largely marketed through livestock.

Significant increases in feed and forage production are projected by the year 2020. Most of the increased production will result from improvements in production efficiencies, technology, and supplemental water supplies. Total irrigated lands are projected to increase from the present 58,690 acres to 68,700 acres by 2020. About 26,890 acres in the Basin have been classified as irrigable and are listed below:

  1. 11,530 acres along the Bear River

  2. 3,000 acres along Yellow Creek

  3. 360 acres along Twin Creek

  4. 6,000 acres along Smiths Fork

  5. 6,000 acres along Thomas Fork

Of the water presently consumed by man's activities in the Basin, about 97 percent is used in irrigation. Annual late-season irrigation shortages are common throughout the Basin, and an estimated 41,000 acre-feet per year of storage over and above the 17,750 acre-feet allocated to Wyoming by the Bear River Compact are required to supply supplemental water to presently irrigated lands.

Cameron Engineers project that the phosphate and timber industries will have expanded growth by the year 2020. Employment in the phosphate industry would increase by 8 times from the present 75 employees to 605 employees, groundwater consumption would little more than double from 400 acre-feet per year to 870 acre-feet per year, and capital investment would increase from $6.5 million to $81.7 million. Expansion in the timber industry is projected by Cameron Engineers after the year 2000. By the year 2020 the consumptive use of water would double in the timber industry from 50 acre-feet per year to 100 acre-feet per year. This would only have a minor impact in the Basin. Expansion of wood products industries could require additional water resources.

MUNICIPAL, DOMESTIC, AND STOCK

The municipal population served by municipal and private water systems is about 4,940 people, and about 580 people are supplied by rural domestic systems. The current municipal and rural domestic water diversions are about 1,100 acre-feet per year, about one-half of which is consumptively used. The diversion requirement is projected to increase to about 1,600 acre-feet per year by the year 2020. Stock water depletions are projected to increase from the present 640 acre-feet per year to 990 acre-feet per year by the year 2020. The total municipal, domestic, and stock depletions are projected to increase from the present 1,190 acre-feet per year to 1,790 acre-feet per year by the year 2020.

RECREATION AND FISH AND WILDLIFE

The Basin provides recognized opportunities for outdoor recreation, hunting, and fishing. Most of the fishing pressure is along the Bear River, Smiths Fork, and Thomas Fork. Big game hunting is mostly limited to the Tump Range except for deer hunting which is prevalent throughout the Basin. Hunting waterfowl is an important local activity. The potentials for water sports and boating are limited in the Basin. The consumptive use of water by recreation and fish and wildlife activities is small and will probably remain so.

HYDROELECTRIC POWER

There are presently no hydroelectric power facilities in the Basin, and the potential for such facilities is limited.

SUMMARY OF WATER RESOURCE REQUIREMENTS

A summary of present and projected consumptive uses in the Bear River Basin for surface water and groundwater is as follows: 

                          1,000 Acre-Feet Per Year

Water Use    		 Present     2000       2020

Irrigation        	   64.7      86.3      103.1
Industry              	     .4       0.9        1.0
Municipal, Domestic,        1.2       1.6        1.8
and Stock     		    
Total                      66.3      88.8      105.9

Reservoir and stock pond evaporation presently consumes an additional 7,000 acre-feet of water annually and will increase as more reservoir storage is constructed.

POTENTIAL SOURCES OF WATER

Surface water supplies could be developed on the Bear River, Smiths Fork, and Thomas Fork. However, a modification of the Bear River Compact to allow additional storage is required to provide dependable water supplies for future new uses. Existing water rights must also be considered in determining the available water supplies.

Groundwater in the alluvial valley along the Bear River could be used to furnish some of the existing irrigation a supplemental supply, but it is doubtful if large irrigation projects will be developed using groundwater. Groundwater supplies at shallow depths should be adequate for future municipal, domestic, and stock water uses as well as for future growth in the phosphate industry.

Improving existing water use efficiencies will enhance the existing water supplies. Improvements in water efficiency usually occur when they are economically justified. Weather modification may provide additional water for development, but because of the difficulty in identifying the new water it will probably be used as a supplemental supply for the existing water rights and users.

POTENTIAL WATER DEVELOPMENT PROJECTS

Water supply studies have defined the needs for supplemental water for existing irrigation in the Bear River Basin in Wyoming. The studies indicate that an average annual supplemental supply of 45,700 acre-feet is required for presently irrigated lands. This is in addition to the yield from the 13,131 acre-feet of storage capacity that has been constructed for Wyoming uses under the terms of the Bear River Compact. Additional water supplies could be obtained from the yield of reservoirs or from groundwater. Since only 4,619 acre-feet of storage remain available to Wyoming under the Bear River Compact, the compact will have to be modified to provide for this water need. In addition, the irrigation of 10,000 acres of new land in the Bear River Basin would require an annual diversion requirement of about 43,000 acre-feet. Reservoir storage or development of groundwater supplies would be required to provide this water supply. Figure A-8 shows the location and capacities of potential reservoirs that have been identified in the Upper and Central Divisions of the Bear River Basin. Water supply studies indicate that the actual reservoir capacities required would greatly exceed the water supply yields because of the need for carry-over storage from years of large runoff into drought years.

The projected increase in M & I water use could be met from groundwater or from minor surface water developments. If a timber products processing industry having substantial water requirements were established in the Basin, additional water resource development would be required or some of the projected irrigation would have to be foregone In lieu of the new industry.

ALTERNATIVE WATER RESOURCE DEVELOPMENT

The following two alternatives define the range of approaches for water resource development in the Bear River Basin.

Alternative I - No water resource development. A "no water resource development" posture in the area would preclude improvements in supplemental water supplies for the existing irrigation along with water developments for other purposes. If this alternative were pursued, the present negotiations to modify the Bear River Compact could be terminated so far as Wyoming is concerned.

Alternative 2 - Improve Wyoming's Bear River water supplies. Additional reservoir storage for Wyoming water users would improve water supplies, enhance the economy of the area, enhance other conservation practices, and allow for a modest growth in the area's agricultural industry. Pursuit of this alternative requires continuation of the Bear River Compact negotiations.

ENVIRONMENTAL CONSIDERATIONS

Reservoir projects should provide for adequate minimum reservoir pools and sustained streamflows below the dams. The selection of reservoir sites should include consideration of the scenic qualities of the area and its importance in providing fish and wildlife habitat.

CONCLUSIONS

  1. Agriculture is a major industry in the Bear River Basin. Development of water supplies is required in order to maintain a healthy agricultural economy. The phosphate and timber industries are projected to grow providing increased employment in the area.

  2. A modification of the Bear River Compact is required to meet the needs of the area for supplemental water supplies and to provide for a modest expansion in irrigation. Several reservoir sites in the Basin have been identified that could supply the projected water requirements.

  3. Groundwater along the alluvial valley of the Bear River is available for development at shallow depths.

  4. The impacts of water projects on the environment need to be properly considered in the planning, design, and construction of projects.

RECOMMENDATIONS

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

  2. Public opinion should be ascertained regarding the desired levels of development in the Bear River Basin, the economic, environmental, social, and other impacts of the alternatives, and the best alternative(s) to follow.

  3. Detailed feasibility studies of the desired project-components of the alternatives should be undertaken to evaluate engineering and economic factors, and social and environmental impacts.

  4. Sources of financing, such as Federal funds, State loans and bonds, private sources, and others, should be reviewed. State laws should be analyzed to determine what legislation would be desirable and necessary for financing of water development projects under different types of financing arrangements.

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

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

  7. The type of organization required to implement and operate water development projects should be determined and established.

  8. Wyoming should continue to participate in negotiations regarding modification of the Bear River Compact.

  9. Soil and water conservation practices in the area should be encouraged and implemented through programs of the U. S. Department of Agriculture and others. There should be continuing investigations of potential watershed improvement projects to include flood, silt, and erosion control and water supply management purposes.

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