Glendo Unit

State: Wyoming and Nebraska
Region: Great Plains

Related Documents
Glendo Unit History (56 KB)

Related Facilities

Construction

Construction began December 1954 on the Glendo Dam, Reservoir, and Powerplant and was completed in 1958. Construction of the Fremont Canyon Powerplant and power conduit was begun in 1956 and completed in 1961. Construction of Gray Reef Dam and Reservoir was started in 1959 and completed in 1961. Water is released from Glendo Reservoir to supplement the irrigation water supplies of contracting users in Wyoming and Nebraska. The water users need dependable storage in addition to their natural flow water rights. This makes possible the improvement of crop production and an increased crop yield. Principal crops are beans, potatoes, alfalfa, corn, and small grains. The Unit provides opportunities for recreation, fishing, and hunting. Camping, picnicking, boating, and water sports opportunities are available at Glendo Reservoir. A boat ramp, accessible restroom, accessible fishing pier, picnic tables, and campground are located immediately below Gray Reef Dam. Glendo Reservoir is stocked with fish by the Wyoming Game and Fish Commission and, to a lesser extent, fishing is afforded at Gray Reef Reservoir. Hunting for waterfowl is available at both reservoirs. For specific information about any of these recreation sites, click on the name below. http://www.recreation.gov/detail.cfm?ID=978 http://www.recreation.gov/detail.cfm?ID=1233 http://www.recreation.gov/detail.cfm?ID=1238 Addition of Glendo Unit power generation facilities increases available power in the North Platte River Basin by about 500 million kilowatt-hours annually. This increase comes principally from the Glendo and Fremont Canyon Powerplants; however, some of the gain is due to the conversion of the Alcova Powerplant from seasonal to year-round operation made possible by the regulation afforded by Glendo Reservoir. Glendo Reservoir has an exclusive flood control capacity of 271,917 acre-feet and a surcharge capacity of 329,251 acre-feet for a total flood capacity of 601,168 acre feet and controls floods that menaced the local area and the valley downstream prior to construction of the dam. As of 1998, Glendo Reservoir has prevented $49.6 million in flood damages. The Glendo Unit The Glendo Unit is part of the Pick-Sloan Missouri River Basin Program. The unit consists of six major project features: Glendo Dam, Glendo Reservoir, Glendo Power Plant, Gray Reef Dam, Gray Reef Reservoir, and the Fremont Canyon Power Plant. The Glendo Unit was designed as a multi-purpose natural resource system which is adjacent to, and works in conjunction with, the North Platte and Kendrick Projects, which are not part of the Missouri River Basin Program. Glendo provides supplemental irrigation water to 37,251 acres in Nebraska and Wyoming, and the two powerplants which have a combined generating capacity of 104.8 megawatts, supply electrical power to Colorado, Nebraska, and Wyoming. In conformity with the 1953 stipulation and order modifying the 1945 North Platte River Decree, in addition to providing power generation and irrigation water, the unit provides flood control, sediment retention, water storage and recreation, and fish and wildlife enhancement, as well as pollution control to improve the quality of both the municipal and industrial water supply in the North Platte River Valley between Gray Reef Dam and Glendo Reservoir.(1) The Glendo Unit is in eastern and central Wyoming on the North Platte River. Although Glendo Dam and most of Glendo Reservoir are located in northern Platte County, Wyoming, portions of the reservoir extend into southeastern Converse County, Wyoming. About four and one half miles north and west of the dam site sits Glendo, Wyoming, the town nearest the dam. The town lies 80 miles east and south of Casper, and 100 miles north of Cheyenne, Wyoming. The Fremont Canyon Powerplant is located approximately four miles below Pathfinder Dam at the backwaters of Alcova Reservoir. Gray Reef Dam is also on the North Platte River. It is 27 miles southwest of Casper, and about four miles downstream from Alcova Dam.(2) Winters are long and cold with little snow accumulation, and springs are cold with only moderate precipitation. Summers in the region often consist of frequent periods of extreme temperatures. Year-round temperatures range from -46 degrees to 107 degrees Fahrenheit, and rainfall averages just under twelve and one-half inches. These abrupt changes in temperatures and unpredictable levels of precipitation limit the growing season to approximately 133 days.(3) The project lands are within the Great Plains Region of the Bureau of Reclamation. This region consists mostly of dry land farming and cattle grazing. The most important crops grown in the area are dry edible beans, corn, sugar beets, and alfalfa hay.(4) The region`s first known inhabitants arrived in the area more than 11,000 years ago. Because of the region`s harsh climatic conditions, many of these Indians did not make permanent settlements, but rather extracted what they needed for survival and moved on. The site now referred to as the Spanish Diggings, extending from Manville, Wyoming in the north to Guernsey, Wyoming in the south, and from the North Platte River in the west, to present day Highway 85 in the east, was an important semi-permanent settlement used by the long succession of migrating Indian groups. The trend of temporary occupation continued with the coming of the white man. Explorers from Spain, Great Britain, and Mexico, passed through the area because of its location near the upper end of the North Platte and Sweetwater River systems and its proximity to the Continental Divide.(5) The United States came into possession of the land when the region was included within the Louisiana Purchase of 1803. American explorers, and then settlers, used the North Platte River Valley as a passage through the Rocky Mountains. The region also saw much activity as a route for the Overland Stage, Pony Express, and the first transcontinental telegraph. At this point more people began settling in the region on a permanent basis, rather than just passing through. In order to sustain agriculture in the arid region, settlers built the valley`s first irrigation systems, without large storage reservoirs, in the early 1880s. The region has been under cultivation ever since.(6) Original project authorization occurred as part of the Flood Control Act of December 22, 1944, Public Law 534. This approved the general plan stated in Senate Documents 191, and 475, revised and coordinated by Senate Document 247, 78th Congress, second session. However, controversy over project details prevented construction under its original authorization. Reauthorization occurred ten years later on July 16, 1954, under Public Law 503, 83rd Congress. On August 20, 1958, Public Law 85-695 authorized construction of Gray Reef Dam and Gray Reef Reservoir as part of the Glendo Unit.(7) Preliminary investigations for the Glendo Unit began in 1944. At that time studies showed that water originating in streams and drains above Glendo was being wasted when it could be captured and used for new irrigation. With that idea in mind, the Glendo Dam was conceived. As originally authorized, the Glendo Dam and Reservoir was to provide 150,000 acre-feet of storage space for retaining silt and conserving tributary run-off and return flow from the Kendrick project. The purpose of the dam and reservoir was to help reduce loss of capacity in Guernsey Reservoir due to silting, and to allow more power production at the North Platte River hydroelectric powerplants by storing additional water for power production and restoring water from releases made through upstream powerplants at Fremont Canyon and Alcova, thus allowing year round operation of these plants. No additional irrigation development was included in the original plan for the Glendo Unit.(8) Reclamation and the Corps of Engineers did detailed studies and surveys which determined that the original planned capacity for the reservoir was insufficient. In 1947, Reclamation discovered the overall Pick-Sloan Missouri River Basin Program plan could incorporate the Glendo Unit more effectively by increasing Glendo Reservoir`s capacity to provide storage space for hydroelectric power delivery and flood control. Thus, nine alternative project plans varying in their utilization of the Glendo Reservoir were developed. Plans five and nine received the most consideration.(9) Plan five called for the reservoir to store surplus water for the Whalen-Tri-State Dam area. Stored water under this plan could be used under Warren Act contracts for canals that did not receive adequate water supplies from their natural flow rights. Plan nine called for maximum power production with only slight alteration of the existing program on the North Platte River below Guernsey Reservoir. However, neither plan could be put into action because of controversy among the technicians of several states as to the method of operation for Glendo Reservoir. Colorado`s interest in Glendo dealt with the idea that if any additional water supply became available downstream from the reservoir, then they might have grounds for requesting an increased use of water in the North Park area. Central Nebraska`s interest in the project stemmed from a fear that construction of Glendo Reservoir would reduce the flow of water into Lake McConaughy, thereby adversely affecting their water rights. As a result, Congress passed Public Law 841 which stated that no appropriation money could be used for any construction on the Glendo Unit until a definite plan report was agreed upon by Colorado, Nebraska and Wyoming, and then approved by Congress.(10) In 1954, Reclamation developed a plan, based on plan nine, which designed Glendo Reservoir with a capacity of 800,000 acre-feet. They divided the capacity into: 100,000 acre-feet for irrigation, 115,000 acre-feet for sediment control, 275,000 acre-feet for flood control, and 310,000 acre-feet for power production. The irrigation segment of the plan provided that 40,000 acre-feet of any one year`s runoff could be stored in the reservoir in addition to evaporation losses, with irrigation accumulation totaling 100,000 acre-feet. It declared that from this storage, up to 40,000 acre-feet could be used annually for irrigation, providing lands in Wyoming with 15,000 acre-feet, and lands in Nebraska with 25,000 acre-feet. The plan also stated that the Fremont Canyon and Glendo Powerplants would supply the existing and expanding commercial, industrial, and domestic need for power in Colorado, Nebraska, and Wyoming. Additionally, the plan specified that repayment for the project would be made from the sale of irrigation water and electrical energy in accordance with Reclamation law and provisions as authorized by Congress. Once the three states examined the plan and determined that it benefitted all, they agreed to it, and Congress approved the plan and reauthorized the building of the Glendo Unit in 1954.(11) Glendo Dam is an earthfill structure with a structural height of 190 feet, and an embankment height of 167 feet. It has a crest length of 2,096 feet, and a spillway capacity of 10,335 cubic feet per second. The outlet works consists of an intake structure with trashracks, an upstream tunnel and twenty-one foot wide conduit, a twenty-one foot surge tank, and a sixteen and one-half by twenty-one foot fixed-wheel gate. The penstock has a branch for the outlet works and a branch for the powerplant. Control for the outlet works consists of three regulating gates and three emergency gates. The outlet works was designed to pass 5,500 cfs with water surface elevation at 4570, and 10,000 cfs with water surface between elevations 4635 and 4653. Its maximum discharge is 11,200 cfs.(12) Approximately 2,440 feet of dikes are needed on the south side of the reservoir across a low area one and one-half mile west of the dam. Glendo Dam impounds the fourteen mile long Glendo Reservoir. At elevation 4653, the top of the reservoir`s flood control capacity, the reservoir`s total capacity equals 789,402 acre-feet. This provides space for storing an estimated 100-year sediment accumulation of 115,000 acre-feet. It also provides an allotted 271,917 acre-feet for flood control, 454,337 acre-feet for irrigation and power generation, and 329,251 acre-foot surcharge capacity.(13) A surcharge capacity is `the reservoir capacity provided through the reservoir. It is the reservoir capacity between the maximum water surface elevation and the highest of the following elevations (1) top of exclusive flood control capacity, (2) top of joint use capacity, or (3) top of active conservation capacity.`(14)Current capacities in Glendo Reservoir differ some from the original designations due to the amount of sediment accumulation which has already occurred in the reservoir.(15) Bids for construction of Glendo Dam, powerplant foundation, and accompanying access roads opened on November 9, 1954. Out of fifteen bids, the contract went to C.F. Lytle Company and Greene Construction Company on November 27, 1954. They received notice to proceed November 29, 1954, and began excavation operations by mid December. Work on the fabrication of the penstock, surge tank, and outlet pipes began on-site in May of 1955, and concrete placement for the outlet works and powerplant occurred in June of the same year. The contractors finished fabrication of the penstock and outlet pipes in January of 1956, and installed them in March. By September of 1956, they completed construction of the contracted access roads and finished the powerplant foundation and switchyard grading. November and December of the same year saw completion of concrete placement for the spillway and erection of the 205 foot surge tank. The contractors finished Glendo Dam in the early fall of 1957, and completed all work for their contract March 13, 1958.(16) Construction of the reservoir required relocation of three miles of the Chicago, Burlington, and Quincy Railroad, and relocation of four miles of State Highway, U.S. 87. A contract to perform the earthwork and structures for the railroad relocation went to Morrison-Knudsen Construction Company in November 1955. They completed the contract exactly one year later. The process of removing the old track and laying the new, was performed by the railroad company, and was finished the end of December 1956. Bids for relocation of the highway opened in June of 1955. The contractor received notice to proceed in July, and began work in August. All work for the contract was completed in September of 1957.(17) The Glendo Powerplant is connected to Glendo Reservoir by a twenty-one foot wide, and 2,100 foot long diversion tunnel. The plant has two units with a maximum head of 130 feet, each capable of generating 19,000 kilowatts of power. From 1958 to 1993 the Glendo Powerplant has generated an average annual gross of just over 82 and one-half gigawatts of power.(18) Construction bids for the Glendo Powerplant and switchyard opened In October 1956, and the contractor received notice to proceed in November of the same year. Work began in 1957, and by August, the powerplant`s superstructure had been erected. By year`s end most of the second and third stage concrete in the powerplant had been placed, much of the piping, pumping equipment, and electrical equipment had been installed, a number of transformers and circuit breakers were placed, and the construction of a river gaging station 4,000 feet below the plant had been completed. In 1958 the contractor completely installed the plant`s two generators and initiated the plant`s power operations. All work under the contract specifications, except painting and clean-up, was finished December 19, 1958.(19) The Fremont Canyon Powerplant derives its names from General John C. Fremont, the explorer who, in 1842, explored the canyon in which the powerplant now sits. The canyon also bears the General`s name. The powerplant is located within the canyon on the left bank of the North Platte River. The Fremont Canyon Powerplant and power conduit are part of series of Reclamation developments in the North Platte drainage area. The power conduit is 35 miles southwest of Casper, Wyoming. The three mile long, eighteen foot wide power conduit`s inlet taps Pathfinder Reservoir. Its outlet works consists of two penstocks leading to the powerplant located in Fremont Canyon near the upper end of Alcova Reservoir. The powerplant contains two generators driven by two 33,500-horsepower Francis-type hydraulic turbines, which operate at a maximum head of 350 feet, and have a combined generating capability of 66,800 kilowatts. The conduit is controlled by a fourteen by eighteen foot fixed-wheel gate downstream from the inlet.(20) Bids for construction of Fremont Canyon Powerplant opened in January 1957. Reclamation awarded the contract to Coker-Kiewet-Cunningham, who received notice to proceed in February and began work in March by excavating the unit`s tunnels. The contractor began work on installing Fremont Canyon area telephone and power lines in October of 1957. By year`s end they had cleared the right-of-way, completed the structures and strung the phone lines from Alcova to Red Hill, Wyoming, and erected the structures and strung the power lines from Fremont Canyon to Pathfinder. The contractor completed excavation of both tunnels in 1958. Concrete placement for the powerhouse began November 22, of the same year. During 1959, Coker-Kiewet-Cunningham completed installation of the trashracks and fixed-wheel gate in early January. They placed concrete in the powerplant from January through September, and placed the concrete section of the surge tank from May to July, finishing work on the steel section in September. Additionally, during this same time period the contractor completed the concrete work in both the tunnels. They finished all contractual work June 3, 1960.(21) Bids for completion work on Fremont Canyon Powerplant opened April 9, 1959. The contract went to the low bidder, Flora Construction Company and Argus Construction Company, on May 11, 1959. They received notice to proceed two days later. However, the original notice to proceed did not include provisions for work inside the powerhouse. They received the notice to proceed that specified the inside work on October 21, 1959. The contractors began work in November, but by the end of the year Reclamation declared that progress on the contract was generally unsatisfactory.(22) Throughout 1960, Reclamation felt the situation did not improve much, stating that the contractor was `plagued by lack of organization, inadequate supervision, inexperienced personnel and rapid labor `turnover`.`(23) The year ended with the contractor having completed less than 82 percent of the work in over 85 percent of the time allotted. However, all contractual requirements were completed by the contractor by March 5, 1961. Once the Flora and Argus Construction Companies progressed far enough with their work in 1960 for additional work to be done, General Electric Company received a contract to furnish and install the powerplant`s two generators. They completed work in mid-January 1961, and by January 27, 1961, both generators were released for commercial power and generation.(24) Gray Reef Dam and Gray Reef Reservoir, located on the North Platter River, two miles downstream from Alcova Dam, derived their names from the nearby geographical landmark known as Gray Reef. The dam is an earthfill structure with a structural height of 36 feet, an embankment height of 30 feet, and a crest length of 650 feet. Near the center of the dam there is a concrete chute spillway with a capacity of 20,000 cfs, that is controlled by two radial gates. The dam contains no outlet works. However, the dam does form the Gray Reef Reservoir, which was designed to reregulate releases from Alcova Dam. The reservoir has a maximum water surface elevation of 5,332, with a surface area of 182 acres. Its total capacity equals 1,800 acre-feet.(25) Bids opened for construction of Gray Reef Dam on August 13, 1959. The Government received eleven bids on the project, and granted the contract to Davis Construction Company, Incorporated, on September 18, 1959. The contractor began work at the site in December. Before the end of the year Davis Construction Company, Incorporated, hired an electrical subcontractor, C. S. P. Engineering Company, to install the transmission line to the dam site. By March 14, 1960, the subcontractor had installed and energized a 4160 volt transmission line to the dam site. In 1960, the prime contractor constructed the sump and drainage ditches, excavated the spillway, and placed the concrete for the spillway. That same year the prime contractor also hired Hammond Wyoming Company as a subcontractor to install the dam`s reinforcing bars, and the two radial gates with their corresponding gate hoists. All work progressed smoothly, and the prime contractor completed construction on May 12, 1961. Reclamation Commissioner Floyd E. Dominy officially dedicated the Gray Reef Dam and the Fremont Canyon Powerplant in a ceremony the morning of April 28, 1961.(26)

Plan

The irrigation water from Glendo Reservoir is delivered to water users in the North Platte River Valley at and below Whalen Diversion Dam, a feature of the North Platte Project. These water users have early natural flow water rights but no storage rights and, therefore, need the dependable storage provided by Glendo Reservoir. An amendment to the North Platte River Decree was approved in 1953 by the States of Colorado, Wyoming, and Nebraska, and by the U.S. Supreme Court. It provides for retaining the existing regimen of the natural flow of the North Platte River below Pathfinder Dam, except that not more than 40,000 acre-feet of water plus space obtained by evaporation losses may be stored in Glendo Reservoir for irrigation during any water year, and the amount held in storage at any time for irrigation may not exceed 100,000 acre-feet. The amended decree permits the release from storage of 15,000 acre-feet of water annually to Wyoming and 25,000 acre-feet annually to Nebraska for irrigation. Glendo Dam is a zoned earthfill structure on the North Platte River about 4.5 miles southeast of Glendo. The embankment has a structural height of 190 feet and a length of 2,096 feet along the crest. About 2,800 feet of dikes are required across a low area on the south side of the reservoir 1.5 miles west of the dam. The dam forms a reservoir 14 miles in length, having a total capacity of 795,196 acre-feet at water surface elevation 4653, the top of the flood control capacity. Space is provided in the reservoir for storing 115,000 acre-feet of sediment, an estimated 100-year accumulation. There are 454,337 acre-feet allotted for irrigation and power and 271,917 acre-feet for flood control. In addition, a surcharge capacity of 329,251 acre-feet is available. These capacities differ slightly from the original storage allocations because of sediment accumulation. An uncontrolled concrete spillway 45 feet wide is located about 450 feet north of the right abutment of the dam. The Glendo Powerplant is joined to the Glendo Reservoir by a diversion tunnel 21 feet in diameter and 2,100 feet long. The plant contains two units having a maximum rated head of 130 feet. Each unit has an installed capacity of 19,000 kilowatts. The Fremont Canyon Powerplant, on the left bank of the North Platte River at the head of Alcova Reservoir, consists of two 33,400-kilowatt generators, driven by two 33,500-horsepower Francis-type hydraulic turbines. The turbines operate at a maximum head of 350 feet and an effective head of 300 feet. The powerplant generates power during releases of stored floodwater, irrigation water, and water to satisfy prior water rights from Pathfinder Reservoir of the North Platte Project. Water for power generation is conveyed to the powerplant by a 3-mile-long 18-foot-diameter, concrete-lined pressure tunnel. The tunnel branches to two 10.75-foot-diameter penstocks upstream of the powerplant. This conduit is controlled by a 14- by 18-foot fixed-wheel gate located 243 feet downstream from the inlet. Access to the powerplant is provided by a 1,692-foot-long unlined tunnel 16.5 feet high and containing a 16-foot-wide roadway. Gray Reef Dam is on the North Platte River about 27 miles southwest of Casper, and 2 miles downstream from Alcova Dam. The earthfill structure has a structural height of 36 feet, a crest length of 650 feet, and contains a volume of 40,000 cubic yards of material. The spillway consists of a concrete chute near the center of the dam controlled by two 35- by 20-foot radial gates. Capacity of the spillway is 20,000 cubic feet per second. There are no outlet works in the dam. The reservoir has a total capacity of 1,800 acre-feet, with a surface area of 182 acres. Gray Reef Reservoir is operated to reregulate widely fluctuating water releases from the Alcova Powerplant of the Kendrick Project. The Bureau of Reclamation operates and maintains all of the unit`s works. Within the limits of the amended decree, storage facilities of the North Platte River system provide considerable flexibility. Maximum capacity for regulation and storage is afforded through exchange of water between Glendo Reservoir and upstream reservoirs. Exchange water stored in Glendo is released by the close of the irrigation season. The proprietary and contractual interests in storage water are identifiable at all times regardless of location of the water in the system. Floodwater stored in Glendo Reservoir is released under regulations prescribed by the Secretary of the Army under authority of the Flood Control Act of 1944.

Contact

Title: Public Affairs Officer
Organization: Great Plains Region
Address: 2021 4th Avenue North
City: Billings, MT 59101
Fax: 406-247-7604
Phone: 406-247-7610

Contact

Organization: Bridgeport Irrigation Distict
Address: PO Box 1028
City: Bridgeport, NE 69336
Phone: 308-489-5658

Contact

Organization: Enterprise Irrigation District (Nebraska)
Address: PO Box 1558
City: Scottsbluff, NE 69363
Fax: 308-635-2777
Phone: 308-635-2777

Contact

Organization: Lucerne Canal and Power Company
Address: RR 1
City: Lingle, WY 82223
Phone: 307-837-2951

Contact

Organization: New Grattan Ditch Company
Address: PO Box
City: Torrington, WY 82240
Fax: 307-532-5555
Phone: 307-532-2821

Contact

Organization: Torrington Irrigation District
Address: PO Box 179
City: Torrington, WY 82240
Phone: 307-632-9213

Contact

Organization: Wright and Murphy Ditch
Address: 942 S Guernsey Rd
City: Wheatland, WY 82201
Phone: 307-837-2245

Contact

Title: Facility Manager
Organization: North Platte Projects Field Office
Address: 22122 Kortes Road
City: Alcova, WY 82620
Phone: 307-261-5960

Contact

Organization: Burbank Ditch
Address: 3060 Monte Vista
City: Torrington, WY 82240
Phone: 307-532-2053

Contact

Organization: Mitchell Irrigation District
Address: 120322 County Road F
City: Mitchell, NE 69357
Fax: 308-623-3114
Phone: 308-623-2526

PROJECTS & FACILITIES

Glendo Unit

General

History

Construction

Plan

Contact

Contact

Contact

Contact

Contact

Contact

Contact

Contact

Contact

Contact

Contact

More Information about the U.S. Bureau of Reclamation