The Colorado River Storage Project (CRSP) provides for the comprehensive development of the Upper Colorado River Basin. The project furnishes the long-time regulatory storage needed to permit States in the upper basin to meet their flow obligation at Lees Ferry, Arizona, as defined in the Colorado River Compact, and still utilize their apportioned water.
Water stored by the project provides a portion for direct use in the upper basin. Sediment and flooding are better controlled and recreation development and fish and wildlife conservation have benefited. Because of project development, a significant amount of electrical energy is produced to meet the needs of the upper basin and adjacent areas.
The project includes four storage units: Glen Canyon on the Colorado River in Arizona near the Utah border; Flaming Gorge on the Green River in Utah near the Wyoming border; Navajo on the San Juan River in New Mexico near the Colorado border; and the Wayne N. Aspinall Storage Unit on the Gunnison River in west-central Colorado. Authorized with, but not part of, are a number of participating projects which will share in the power revenues of the larger project to help pay for irrigation construction costs. These participating projects are listed in the authorization paragraphs.
Unit descriptions and facilities
The reservoirs formed by four units of the CRSP have a total capacity of nearly 34 million acre-feet. During periods of low streamflow, the stored water in the upper basin is released to meet the Lees Ferry obligation. Powerplants and other facilities are provided at each dam except Navajo, and a complex transmission system also has been provided. This transmission system carries CRSP power to key load points in the marketing area. The system is integrated with preference-user and private-company transmission lines to form the CRSP Interconnected Transmission System. CRSP hydropower is delivered to preference-user organizations for distribution to their consumers as required by Federal Reclamation Law.
Glen Canyon Unit
Glen Canyon Dam, 15 miles upstream from Lees Ferry, is the key feature of the CRSP. This 710-foot-high structure provides more storage capacity than all other storage features of the project combined. The concrete arch dam has a crest length of 1,560 feet and contains 4,901,000 cubic yards of concrete. Thickness of the dam at the crest is 25 feet, and the maximum base thickness is 300 feet.
A separate spillway is constructed in each abutment. Each spillway consists of an intake structure with two 40- by 52.5-foot radial gates and a lined spillway tunnel. The downstream portions of the spillway tunnel were used during construction as diversion tunnels. Each spillway tunnel reduces in size from 48 to 41 feet in diameter. The combined spillway discharge capacity is 208,000 cubic feet per second at an elevation of 3,700.0 ft.
The outlet works near the left abutment of the dam consist of four 96-inch-diameter pipes. Each outlet is controlled by one 96-inch-ring follower gate and one 96-inch hollow-jet valve. The combined river outlet works capacity is 15,000 cubic feet per second.
Total capacity for Lake Powell is 27 million acre-feet, and the active capacity is 20,876,000 acre-feet. At normal water surface elevation, the reservoir has a length of 186 miles and a surface area of 161,390 acres.
The powerplant at the toe of the dam consists of four 118,750-kilowatt and four 136,562-kilowatt generators driven by eight turbines. Total nameplate generating capacity for the powerplant is 1,021,248 kilowatts. Eight penstocks through the dam convey water to the turbines. Each penstock reduces in size from 15 to 14 feet in diameter.
Glen Canyon Bridge
The absence of rail facilities near the construction site of Glen Canyon Dam necessitated construction of Glen Canyon Bridge for the transportation of construction materials and equipment from railheads to the site. A single-span, steel-arch structure, the bridge has an overall length of 1,271 feet. At its completion in 1959, it was the highest arch bridge in the world and the second longest of its type in the United States. The bridge spans the Colorado River 865 feet downstream from the dam. The deck of the bridge is 700 feet above river level.
Flaming Gorge Unit
Flaming Gorge Dam is on the Green River in northeastern Utah about 32 miles downstream from the Utah-Wyoming border. The concrete thin-arch structure has a maximum height of 502 feet and a crest length of 1,285 feet, and contains 987,000 cubic yards of concrete. The top thickness is 27 feet, and the maximum base thickness is 131 feet.
Floodwaters are spilled through a 675-foot-long tunnel spillway extending through the left abutment. The concrete-lined tunnel has a maximum capacity of 28,800 cubic feet per second and reduces in size from 26.5 feet in diameter at the upstream portal to 18 feet in diameter at the downstream portal. The spillway intake structure is controlled by two 16.75- by 34-foot hydraulically operated fixed-wheel gates.
The outlet works consist of two 72-inch steel pipes through the dam, reducing to 66 inches at the toe of the dam and continuing downstream to a valve structure on the left riverbank where discharge is directed into the river channel. Each outlet is controlled by a 66-inch hydraulically operated ring-follower gate at the downstream toe of the dam and a 66-inch hydraulically operated hollow-jet valve at the valve structure. Discharge capacity at elevation 6,045.0 feet is 4,000 cubic feet per second.
The Flaming Gorge Reservoir has a total capacity of 3,788,900 acre-feet and an active capacity of 3,515,700 acre-feet. At normal water surface elevation, the reservoir has a surface area of 42,020 acres. Three 10-foot-diameter penstock pipes near the center of the dam convey water to the powerplant. The powerplant is at the downstream toe of the dam and houses three 51,000-kilowatt generators driven by three 50,000-horsepower Francis-type turbines.
Navajo Dam and Reservoir
Navajo Dam is on the San Juan River in northeastern New Mexico about 34 miles east of Farmington. The dam is a rolled earthfill embankment with a structural height of 402 feet and a crest length of 3,648 feet. The dam contains 26,840,863 cubic yards of materials. The top width of the dam is 30 feet, and the maximum base width is 2,566 feet.
The spillway, on the right abutment, consists of an approach channel, concrete crest structure without gates, spillway bridge, concrete chute and stilling basin, and outlet channel. The width of the spillway ranges from 138 feet in the chute section to 195 feet in the stilling basin. The design capacity at maximum water surface elevation is 34,000 cubic feet per second.
Releases of water for downstream requirements are made through the outlet works, consisting of a concrete tower intake structure, an 18.75-foot-diameter concrete-lined tunnel, and valve house. Control is by one 6- by 13-foot fixed-wheel gate, two 72-inch ring-follower gates, and two 72-inch hollow-jet valves. The outlet works tunnel, located in the right abutment, is 1,603 feet long. Discharge capacity is 4,200 cubic feet per second at an elevation of 6,101.5 ft.
An auxiliary outlet works consisting of a concrete intake structure and a concrete-lined tunnel with gate chamber for two 4-foot-square gates also is located in the right abutment. Discharge is into the spillway stilling basin.
Navajo Reservoir extends 35 miles up the San Juan River, 13 miles up the Pine River, and 4 miles up the Piedra River in southern Colorado. When filled, the reservoir occupies 15,610 acres, with a total capacity of 1, 708,600 acre-feet and an active capacity of 1,036,100 acre-feet.
The Aspinall Unit developed the water storage and hydroelectric power generating potential along a 40-mile section of the Gunnison River in Colorado by the construction of three dams and powerplants: Blue Mesa, Morrow Point, and Crystal.
Blue Mesa Dam is on the Gunnison river about 30 miles below Gunnison, and 1.5 miles below Sapinero, Colorado. The zoned earthfill embankment has a structural height of 390 feet, a crest length of 785 feet, and a volume of 3,080,000 cubic yards of materials.
The spillway consists of a concrete intake structure with two 25- by 33.5-foot radial gates, concrete-lined tunnel, concrete flip bucket structure, and stilling basin. Maximum discharge of the spillway is 34,000 cubic feet per second.
The outlet works consists of an intake structure, tunnel, and manifold anchor block. The outlet works is controlled by one 16- by 18-foot fixed-wheel gate in the intake structure and by two 84-inch ring-follower gates and two 84-inch hollow-jet valves in a gate house at the terminus of the outlet conduits. Maximum discharge from the outlet works is 5,000 cubic feet per second at maximum water surface elevation, with two 84-inch hollow-jet valves 62 percent open.
Blue Mesa Reservoir has a total capacity of 940,700 acre-feet and an active capacity of 748,430 acre-feet. At maximum water surface elevation, the reservoir occupies 9,180 acres.
The Blue Mesa Powerplant consists of two 30,000-kilowatt generators, driven by two 41.55-horsepower turbines. Each Turbine is designed to operate at a maximum head of about 360 feet.
One 16-foot-diameter penstock conveys water to the two turbines and also carries water for the outlet works. After branching from the main penstock, each of the penstock laterals is controlled by 156-inch butterfly valves. The main penstock is reduced by a wye branch to the outlet works control valves.
Morrow Point Dam, 12 miles downstream from Blue Mesa Dam, is Reclamation's first thin-arch, double-curvature dam. It is 468 feet high, 52 feet thick at the base, and 12 feet thick at the crest. The dam has a crest length of 720 feet and a volume of 360,000 cubic yards of concrete.
The spillway consists of four orifice-type openings in the top central part of the dam, providing a free-fall discharge higher than 350 feet to the concrete stilling basin at the toe of the dam. Each of the four spillway openings is controlled by a 15- by 16.83-foot fixed-wheel gate. Maximum capacity of the spillway is 41,000 cubic feet per second.
The outlet works consists of one stainless-steel lined 4-foot-square conduit through the dam. Control is by two 3.5-square-foot slide gates. Discharge capacity of the outlet works is 1,500 cubic feet per second.
Reservoir capacity behind Morrow Point Dam is 117,190 acre-feet at maximum water surface. The active capacity is 42,120 acre-feet. Surface area for Morrow Point Reservoir is 817 acres at an elevation of 7,160.0 ft.
The powerplant chamber is tunneled into the canyon wall in the left abutment about 400 feet below the ground surface. The powerplant chamber is 231 feet long and 57 feet wide with a height ranging from 65 to 134 feet. There are two 60,000-kilowatt generators driven by two 83,000-horsepower turbines. The power penstocks consist of 13.5-foot-diameter steel liners in 18-foot-diameter tunnels.
Crystal Dam is located 6 miles downstream from Morrow Point Dam and approximately 20 miles east of Montrose, Colorado. The dam is a double-curvature thin-arch type, 323 feet high, with a crest length of 620 feet, and a volume of 154,400 cubic yards of materials.
The spillway consists of an ungated ogee crest on the right side of the dam and a plunge pool at the toe of the dam. The crest is at an elevation of 6,756.0 feet, 1 foot above normal water surface. The plunge pool is unlined except for a downstream retaining wall to contain the river fill material.
Water is conveyed from the reservoir to the hydraulic turbine by an 11.5-foot-diameter concrete penstock, the lower portion of which is steel lined. The intake structure consists of a metal trashrack, a 10.58- by 17.27-foot bulkhead gate, an 8.33- by 13.58-foot fixed-wheel gate, and a transition. The fixed-wheel gate is provided for emergency closure and for inspection and maintenance of the penstock. Water from the turbine exits through the draft tube to the tailrace.
The river outlets consist of an intake structure on the upstream face of the dam and two 54-inch pipes through the dam and powerplant. The 54-inch ring-follower emergency gates and 48-inch jet-flow regulating gates in the powerplant control outlet flows. The intake structure includes a metal trashrack, a concrete arch conduit to convey water to the 54-inch pipes, and provisions for installing a bulkhead gate. The Morrow Point Dam river outlet bulkhead gate can be used to close off the outlet pipes for inspection or maintenance.
The reservoir has a total capacity of 25,236 acre-feet and an active capacity of 12,891 acre-feet at an elevation of 6,700 ft, with a surface area of 301 acres.
The powerplant, completed in 1978, has a generating capacity of 28,000 kilowatts from one unit driven by a 39,000-horsepower hydraulic turbine. It is connected to the main CRSP transmission system at the Curecanti substation by a 115-kilovolt line.
The Bureau of Reclamation operates and maintains the storage units of the CRSP.
Settlement of the upper drainage basin began in 1854 when the early pioneers established Fort Supply in Wyoming on the Emigrant Trail and diverted water from Blacks Fork to the adjacent lands. Breckenridge, Colorado, on the basin's eastern rim, was settled in 1859 by miners and prospectors pushing over the mountains from older mining districts on the eastern slope of the Continental Divide. Within the next decade, other mining camps were established nearby. Unsuccessful miners turned to farming and supplied agricultural products to the mining communities. Settlements grew downward from the mountains to the valleys, the advance being slowed somewhat by conflicts with the Indians who occupied the territory. Grand Junction, Colorado., now the largest community in the upper drainage basin, was not settled until 1882. The greater part of the Uinta Basin in northeastern Utah was established as an Indian reservation in 1861, and lands unoccupied by the Indians were not open to settlement until 1905. Numerous tributary streams in the upper drainage basin have been diverted to irrigate mountain meadows and valleys, farmlands, and broader valleys at the base of the mountains.
Investigations of means to develop the waters of the Upper Colorado River system were started by the Reclamation Service in 1902, the year of its organization. Since that year, many of the larger irrigation projects within the basin have been undertaken with Federal assistance, and the Bureau of Reclamation has constructed, or is now constructing, 25 projects to utilize water in the upper basin. The need for the Colorado River Storage Project was envisioned at the time of the Colorado River Compact of 1922. In dividing Colorado River water between the Upper and Lower Colorado River Basins, the compact set aside for consumption in the upper basin 7,500,000 acre-feet of water each year. However, this allocation is contingent upon the upper basin's delivering to the lower basin not less than 75 million acre-feet of water in any period of 10 consecutive years and delivering additional water for use in Mexico under certain circumstances. The dividing point between the two basins is at Lees Ferry, near the northern border of Arizona.
Water allocated to the upper basin was further apportioned to the individual States of Arizona, Colorado, New Mexico, Utah, and Wyoming by the Upper Colorado River Basin Compact of 1948. This compact also created the Upper Colorado River Commission, consisting of representatives of the Federal Government and each contracting State except Arizona.
The flow of the Colorado River is extremely erratic, varying from 4 to 22 million acre-feet annually at Lees Ferry. There is a tendency for the high years or the low years to be grouped, thus accentuating problems of river regulation and use. In prolonged dry periods, there is not enough water to permit the upper basin to increase its use of water under the 1922 compact and, at the same time, make the required deliveries to the lower basin. In wetter periods, however, flows are more than sufficient for these purposes. Large storage reservoirs, that can be filled when flows are high and can provide additional water when needed for compact fulfillment, are required. Favorable sites for such reservoirs are found in the deep canyons of the Colorado River and its principal tributaries in the upper basin. A plan for the CRSP, including a series of dams and reservoirs to provide storage capacity in combination with power development and other services, was presented in a Bureau of Reclamation report in 1950, which was subsequently printed as House Document 364, 83d Congress, 2d session. The report was formulated in cooperation with other Federal agencies and with the Upper Colorado River Commission. An initial group of participating projects that would develop water for irrigation and other purposes in the upper basin and would be linked financially with the storage project also was described in the 1950 report.
Construction of four storage units of the Colorado River Storage Project and 11 participating projects was authorized by the act of April 11, 1956 (Public Law 485, 84th Cong., 70 Stat. 105). Additional projects have been added since the original legislation was adopted.
Authorized developments are:
Glen Canyon Unit on the Colorado River in Arizona and Utah,
Flaming Gorge Unit on the Green River in Utah and Wyoming,
Navajo Unit on the San Juan River in New Mexico and Colorado, and
Curecanti Unit, consisting of three dams on the Gunnison River in Colorado. In November 1980, this unit was renamed the Wayne N. Aspinall Storage Unit in honor of former Congressman Aspinall, a strong advocate of water resource development in the west.
Participating projects originally authorized are:
Central Utah (initial phase), Utah,
The Eden Project in Wyoming, by terms of its authorizing act of June 28, 1949, became financially related to the Colorado River Storage Project as a participating project. In 1962, authorizing legislation named the following two as participating projects:
In 1964, the following three projects also were named:
Bostwick Park, Colorado,
The Colorado River Basin Project Act of September 30, 1968, authorized five additional projects as participating projects:
2 Later found to be infeasible.
Construction of the Glen Canyon and Flaming Gorge Units began in October 1956. Glen Canyon Dam was topped out in 1963, and hydroelectric power from the powerplant started on line in 1964. Flaming Gorge Dam was topped out in late 1962, and the powerplant began commercial operation in 1963. Navajo Dam was commenced in 1957 and completed in 1963. Construction of the Aspinall Unit began with the start of Blue Mesa Dam in 1962. Blue Mesa was completed in 1966. Morrow Point Dam was started in 1963 and was completed in 1968. Power generation was initiated in September 1967 at the Blue Mesa Powerplant, and in December 1970 at Morrow Point. Construction on Crystal Dam commenced in June 1973 and was completed in 1976. The powerplant, completed in 1978, started power generation in July 1978.
The Upper Colorado River Basin has a scarcely tapped potential of agricultural, industrial, and recreational assets. It contains tremendous quantities of uranium, coal, and other minerals. Realization of the potential in economic growth and contribution to the national welfare are dependent on maximum utilization of limited water supplies. The Colorado River Storage Project and participating projects conserve the very limited precipitation which falls principally in the form of snow in the high mountains and use it for municipal, industrial, and agricultural growth. Project development provides municipal and industrial water supplies, flood control, extensive recreation, and fish and wildlife preservation.
Recreation and Fish and Wildlife
Construction and completion of these major units of the CRSP with subsequent filling of the reservoirs have created scenic and recreational attractions of unique national significance. Visitors come from every State in the union as well as from many foreign countries. The Congress has officially designated Glen Canyon, Flaming Gorge, and the Aspinall Unit as National Recreation Areas. Glen Canyon National Recreation Area is administered by the National Park Service, where visitation during 1982 totaled 2,322,162. Flaming Gorge, administered by the Forest Service, has a visitation during 1982 of 891,708. Blue Mesa, Morrow Point, and Crystal recreation areas are administered y the National Park Service. Attendance there during 1982 totaled 538,560. Navajo Unit recreation areas are administered by Colorado Division of Parks and Outdoor Recreation, and the New Mexico State Parks and Recreation Commission; visitation during 1982 totaled 290,924.
For specific information about any of these recreation sites, click on the names below.
Wayne N. Aspinall Unit
The Colorado River Basin Storage Control Project can generate 1,813 megawatts of hydropower. For further information, see the Western Area Power Administration´s descriptions of hydropower.
Although there is no specific reservoir capacity assigned for flood control, the Colorado River Storage Project has provided an accumulated $10,814,000 in flood control benefits from 1950 to 1999.