Collbran Project

State: Colorado
Region: Upper Colorado Basin Region

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Collbran Project History (80 KB)

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Construction

The contract for construction of Vega Dam was awarded in 1957 and the dam was completed in 1960. Other construction and rehabilitation contracts were awarded beginning in 1959. All work was completed in 1962. Construction and operation of the reservoirs have improved lake fisheries and wildlife values. Some minor damage to stream fisheries and wildlife values resulted from the reduction of flows downstream from storage or diversion structures and from inundation of stream habitat in the Vega Reservoir area. However, the net effect is an increase in fish and wildlife. The Vega State Recreation Area is administered by the Colorado Division of Parks and Outdoor Recreation. Fishing, camping, boating, picnicking, and sightseeing are the principal activities. In 1996, visitation totaled 91,235. The State of Colorado and Reclamation are upgrading the facilities at the Vega State Recreation Area to include accessible features for peole with disabilities. Completion of these upgrades is planned for the summer of 2000. For specific information about recreational opportunities at Vega Reservoir click on the name below. http://www.recreation.gov/detail.cfm?ID=64 Two hydroelectric powerplants are in operation, with a combined installed capacity of 13,500 kilowatts. Although there is no specific reservoir capacity assigned for flood control, the Collbran Project has provided an accumulated $63,000 in flood control benefits from 1950 to 1999. The Bureau of Reclamation has spent some time developing the Western Slope of Colorado. The Silt, Grand Valley, Collbran, Dallas Creek, Fruitgrowers, Paonia, Smith Fork, Uncompahgre, and Bostwick Park Projects, major parts of the Colorado-Big Thompson Project and the Wayne N. Aspinall Unit of the Colorado River Storage Project, all lie west of the continental divide. With the support of local residents, Reclamation helped develop the west-central portion of Colorado for irrigation and municipal purposes. The Collbran Project fulfills only one of these tasks, providing only irrigation water to local farmers and ranchers. Located in west-central Colorado, the Collbran project includes Vega Dam and Reservoir, Upper and Lower Molina powerplants, East Fork Diversion Dam, Bonham Dam and Reservoir, about thirty-seven miles of canal, and about eighteen miles of pipeline and penstock.(1) Grand Mesa, the principal landmark of the region, juts from the western slope of the Continental Divide. Rising to an elevation of about 11,000 feet, many small, natural lakes, drained by numerous streams, dot its northern slope. Several of these water sources contribute directly to the project water supply. Plateau Creek the largest of these streams draining the northern slopes of Grand Mesa, flows generally westward from its headwaters on the mesa to its confluence with the Colorado River near Cameo, Colorado. Though it is fed primarily by the Grand Mesa watershed, the creek also receives some water from Battlement Mesa. Along its course Plateau Creek formed the Plateau Valley, location of project lands. Approximately twenty miles long the Valley ranges in width from less than a mile to eight miles across, with an elevation from 5,500 feet to 7,000 feet above sea level. Project lands lie south of the creek, extending in a narrow discontinuous strip the full length of the Valley. The principal towns in the Valley are Collbran, Molina, and Mesa. The main line of the Denver and Rio Grande Railroad (D&RG) which operated between Denver and Pueblo, Colorado and Salt Lake City, Utah, one ran through the valley. General William Jackson Palmer began construction of the D&RG in 1871. The line, in one form or another, continues to operate. In addition, the portion of the Valley immediately south and west of Grand Junction, near the project area, contains one of the world's largest deposits of carnotite (uranium and vanadium rich ore).(2) The first known humans on the Western Slope date back 7,500 years ago. Occupation prior to then remains purely speculative. Charcoal samples from fire pits, some of the oldest evidence of human occupation, date back to between 6,100 and 5,100 B.C. These samples offer the first conclusive evidence of human settlement. Numerous other artifacts and physical evidence, including additional charcoal samples and tree ring analysis, suggest an almost constant human occupation dating from around 300 B.C. Archeologists speculate that the Ute Indians, arrived sometime between 1000 and 1400 A.D. Spanish documents dating from the seventheenth-century provide the earliest references to the Ute presence in western Colorado. Records from the Dominquez-Escalante Expedition in 1776, furnish additional documentary proof of the Ute inhabitation of the Western Slope. The Ute inhabited the region until 1881 when they were relocated to reservations in Utah.(3) After the Dominquez-Escalante Expedition in 1776, the next major explorer to traverse the Western Slope was Major John Wesley Powell from 1868-1869. Ten years later, in 1879, Powell published his famous Report on the Lands of the Arid Region of the United States. The Report detailed Powell`s observations about the lands west of the 100th Meridian, including the Western Slope. Powell`s book also included his belief that without the development of irrigation works farming in the region remained an impossibility. After publication of Powell`s Reports, except for the Ute, the region remained scarcely populated. After the government removed the Ute inhabitants of the area to the Uintah Reservation in August of 1881, the land opened to homesteaders. Before long settlers founded the city of Grand Junction and claimed all of the lands north of the river. The new inhabitants claimed the lands most easily irrigated first.(4) Settlers who ended up with the less desirable lands soon discovered that they required irrigation works to survive. Residents of Plateau Valley and Grand Mesa soon began constructing irrigation works to ensure successful farms. To regulate the flows of the larger creeks landowners constructed seventeen small private reservoirs on Grand Mesa between 1893 and 1911. These reservoirs were: Cottonwood Lakes Reservoirs Nos. 1, 2, 4 and 5; Neversweat Reservoir; Little Meadows Reservoir: Big Meadows Reservoir; Lambert Reservoir; Bonham Reservoir; Big Creek Reservoir No. 1; Atkinson Reservoir; Forty Acre Reservoir; Silver Lake Reservoir; De Camp Reservoir; Kitson Reservoir; Currier Reservoir; and Blackman Reservoir. These reservoirs fill with water during the spring runoff allowing irrigators to use the stored water to supplement the low natural streamflows of late summer. Most of the reservoirs, built by individuals, water users, or small cooperative associations, lie in basins formed by glacial action.(5) These reservoirs would fill with water during the spring runoff allowing irrigators in the Plateau Valley to supplement on demand the low natural stream flows of later summer. In addition, privately constructed canals and ditches were also operated intermittently throughout the winter months to supply the communities of Collbran, and Mesa, as well as the rural areas with domestic and stock water. Initial Investigations Investigations into the feasibility of a project in Plateau Valley began in 1936. On September 15, 1936, a Plateau Valley attorney and landowner, S. D. Lieurance wrote to Reclamation`s Denver office requesting an investigation into possible irrigation expansion into the Valley, including the Sunnyside lands north of Plateau Creek; an area on which an irrigation canal financed and constructed by private interests previously failed. In a letter of September 21, 1936, Acting Chief Engineer, Sinclair Harper responded to Lieurance stating that F. C. Merriell had already begun investigations of irrigation developments in western Colorado. Subsequently, the landowners of Plateau Valley formally petitioned Reclamation to study new potential irrigation development. Merriell promised, in a letter dated March 12, 1937, that Reclamation would study the area. Reclamation conducted investigations between 1937 and 1943. In December 1944, the scope of the Collbran investigations changed when the city of Grand Junction requested that the project be extended to include consideration of a municipal water supply for the city. In March 1945, the Grand Valley Domestic Water Committee also requested consideration of a domestic water supply for Grand Valley. After discovering that the Grand Valley municipal aspects of the project would be too costly, Reclamation abandoned plans to include municipal water supplies for the city in the project plan. Though the plans to include a municipal water supply for Grand Junction remained in the project plan, the city later requested their removal on the basis that they opted to divert municipal water from another source. After almost twenty years of investigations, Congress authorized the Collbran Project on July 3, 1952. The subsequent Definite Plan Report of November 1952, outlined the project features which included construction of the Vega Dam and Reservoir, Upper and Lower Molina powerplants, and canals, as well as development of supplemental irrigation water for arable lands and additional power generation for industrial and domestic use.(6) The project proposed to use the existing private dams located on Grand Mesa to regulate the flow and delivery of water to the Upper and Lower Molina Powerplants. The Leon-Park Feeder Canal channeled the surplus flows of Leon and Park Creeks into Vega Reservoir. The water would then be delivered to farmers for irrigation through the Southside Canal. The project was to provide supplemental irrigation water to project lands and additional hydroelectric generation. Congress authorized the Collbran Project in July of 1952, however, they did not appropriate funds for construction of the project features at that time. Consequently, in October of 1953, over a year later, Reclamation discontinued work on the Collbran Project awaiting indications that the project would actually proceed to the construction phase. Work already accomplished included water right studies and topographic mapping of the existing private reservoirs in the Big Creek and Cottonwood Creek drainages. In March of 1954, the town of Grand Junction informed Reclamation that it had initiated investigations into alternate sources for a domestic water supply. Reclamation then began analyzing the feasibility of modifying the Collbran project to exclude municipal and domestic water supply features. Reclamation completed preliminary studies in August and found that a very desirable project plan was possible if the municipal features were omitted. Reclamation spent the next eight months formulating the best plan for development of irrigation and power on the project. In May 1955, Reclamation presented the revised project plan to the Plateau Valley Water Committee. The Committee accepted the modifications and expressed their desire to move forward with project development. On August 26, 1955, Plateau Valley water users filed a petition with the District Court to form the Collbran Conservancy District (CCD). In late October of 1955, after holding a hearing in the Mesa County District Court, Judge Charles Blaine created the District with a court decree. Reclamation completed the field draft of the revised Definite Plan Report and forwarded it to the Upper Colorado Regional Office for final review, processing, and circulation. The CCD entered their Statement of Claim for project Water Rights December 12, 1955. Nearly two years passed before Reclamation made any more progress on the Collbran project. Finally, on January 2, 1957, Upper Colorado Region Director Ernest Larson received a letter from Commissioner Wilbur Dexheimer authorizing him to proceed with work on the project. From this point on, work on the project progressed fairly steadily. On January 12, the CCD Board approved the repayment contract. Reclamation approved the repayment contract, the water allotment petitions, and water exchange agreements in April. Officials of the District signed the repayment contract on May 27, 1957. Larson signed the contract on June 11, 1957, the same day that Reclamation opened bids for construction of Vega Dam and county road relocation.(7) On July 12, 1957, Reclamation awarded the contract for construction of Vega Dam and county road relocation to C. F. Lytle Company of Sioux City, Iowa, marking the start of actual construction work on the Collbran Project after twenty years of investigations and planning. The contractor initiated construction on July 16, 1957, with the clearing of brush for the county road relocation. Work accomplished in July consisted primarily of clearing, for both the dam foundation and the road relocation. The contractor completed and Reclamation accepted the county road relocation in August of 1958. The U. S. Forest Service and Reclamation signed a contract on July 30, 1957, for construction of an access road between the existing Bonham and Cottonwood Reservoirs. The lands surrounding the reservoirs belonged to the Forest Service, making their cooperation on the project necessary. Reclamation planned to incorporate the existing reservoirs into the project plan, making access for rehabilitation and maintenance a necessity. In September of 1957, Reclamation appointed H. F. Bahmeier Project Manager and E. H. Jefferies Resident Engineer. Both men were assigned to work out of the Grand Junction Projects Office. Excavation for the dam foundation and the outlet works began August 10, 1957, most of which ended in September; excavation for the dam foundation continued until December. Also in September, the contractor completed work on the initial phase of construction, including diversion and care of the stream during construction. Care of the stream was accomplished by constructing a coffer dam and doing a small amount of work in the unlined earth diversion ditch on the right abutment of the embankment foundation. On September 11, concrete construction began with the placement of concrete in the outlet works cutoff collars. The contractor completed the majority of the work on the outlet works in November. Muddy conditions caused by rain and snow forced the contractor to halt earth work in October, however concrete work continued on schedule. Reclamation began work on the government housing camp on November 4, 1957. Located on a small tract of land approximately one-half mile west of the town of Collbran, the initial camp consisted of fifteen Transa-homes, five trailers, a laboratory, warehouse and office. Adverse weather conditions plagued construction of the camp. During the winter months temperatures dropped as low as twenty-degrees below zero.(8) Reclamation completed work on the housing camp in July of 1958. In 1958, while work on the primary contract for construction of Vega Dam and county road relocation continued, Reclamation issued and awarded several small supporting contracts; including construction of an access road for the power features on Grand Mesa, clearing the reservoir area, and fencing Vega Reservoir. The contractors completed their contracts during the year. In 1958, while work on the primary contract for construction of Vega Dam and county road relocation continued, Reclamation issued and awarded several small supporting contracts; including construction of an access road for the power features on Grand Mesa, clearing the reservoir area, and fencing Vega Reservoir. The contractors completed their contracts during the year. Brasier Brothers Construction Company of Norwood, Colorado, received the bid for construction of the access roads on August 15. Carlson and Fast Construction Company, of Strausburg, Colorado, received the bid for clearing the Vega Reservoir site. They completed the job on October 1, 1958. A. F. Burkhard Company of Hotchkiss, Colorado, received the bid for construction of 4.1 miles of right-of-way fence. They began work on June 17 and completed the project September 12. Construction of the canal system began in November of 1958, when Reclamation awarded a contract to Theo Wood Construction Company for construction of the Southside tunnel. The contractor subsequently sublet the contract to three smaller contractors who commenced work on November 24, 1958.(9) Concrete work on the tunnel began July 8, 1959. The tunnel, a 2,300 feet long, concrete lined, horseshoe shaped, structure with a six-foot three-inch diameter, was holed through on August 22, 1959, and proved to be two feet shorter than originally computed.(10) Reclamation accepted all work on the Southside Tunnel as complete on May 5, 1960.(11) Work on the Vega Dam and road relocation contract progressed steadily during 1958. Just after the first of the year, the contractor began excavation for the spillway. Work on the spillway continued through to its completion in September. Placement of embankment materials began August 27. In September the contractor completed all first stage concrete work. They completed the remaining concrete work, except for a diversion plug in the outlet works intake structure, in October. Administrative occurrences in 1958, ranged from the simple expansion of the CCD to negotiations with the State of Colorado for administration of the Vega recreation area. The Collbran Conservancy District expanded in 1958, to include 776 more acres of privately owned lands. Reclamation withdrew an additional 9,188 acres of public lands for project purposes. Also in 1958, Reclamation began negotiations with the Colorado State Parks and Recreation Board. Reclamation requested that the State Board become the administering agency for the recreation area created at Vega Dam.(12) The two agencies signed an agreement the following year in August of 1959, transferring management of the recreation area to the State. On May 31, 1959, H. F. Bahmeier, Project Manager at the Grand Junctions Projects Office, retired. R. W. Jennings was appointed as his replacement. The change in Project Managers did not adversely affect progress on the project. Work on the first section of Southside Canal began in April of 1959, after Reclamation awarded the contract to Vitro Corporation of America (the Refinery Engineering Division). Vitro also received the bid for construction of the Upper and Lower Molina powerplants in June. The contractor began clearing right-of-way for 15.2 miles of Southside Canal on April 29, 1959. Earth moving operations began May 15. Construction of the powerplants began June 30, when the contractor began clearing the right-of-way. Excavation started in August on the Upper powerplant and ended in October. Excavation on the Lower powerplant began September 23. The contractor then placed the first concrete in the Upper plant October 6.(13) Two years later on October 10, 1961, the contractor completed the Upper and Lower Molina powerplants, penstocks and equalizing reservoir.(14) Also in June of 1959, Reclamation awarded the contract for construction of the Bonham-Cottonwood Pipeline to Davis and Butler Construction Company. Construction of the 11.1 miles of pipeline began June 22, 1959, with clearing of right-of-way. Fashioned of pretensioned concrete pipe, plans called for the pipeline to be built in two separate sections--the Bonham line, 5.6 miles in length and the 5.5 mile Cottonwood line--and then joined together to furnish water to the powerplants.(15) Plans developed in 1959, to connect the Collbran project power transmission lines with the Public Service Company of Colorado`s system at its plant in Cameo, Colorado. The Cameo location would permit integration of the Molina and Grand Valley powerplants; it would also provide for easier coordination with pending Colorado River Storage Project (CRSP) units. In early September of 1959, C. F. Lytle Construction Company finished work on Vega Dam. Reclamation accepted the contract as complete on September 10. Though the dam had been completed in 1959, a few project features awaited construction. Reclamation awarded the contract for construction of the second section of the Southside Canal to A. S. Horner Construction Company on December 9, 1959. Work on this portion of the project did not commence until after the first of the year 1960.(16) On January 21, 1960, the contractor began construction operations. Reclamation accepted all work on both portions of the Canal as complete on November 23, 1960. On April 26, 1960, Reclamation awarded the contract for construction of the Leon-Park Feeder Canal to Cherf Brothers, Inc. and Sandkay Contractors, Inc.(17) The contractor completed all work on the contract January 25, 1961.(18) On June 24, 1960, Reclamation issued a notice to the Collbran Conservancy District informing them that the Collbran Project development period would begin on January 1, 1962. The District requested more time and after consultations with officials of the District, their attorney, and Congressman Wayne Aspinall, Reclamation decided to consider extending the start of the development period to January 1, 1963. Reclamation granted the Districts request later in the year. This was important because repayment obligations begin at the same time as the development period. Reclamation drafted a letter to the CCD on August 5, 1960, advising the water users that some project irrigation water would be available on a rental basis during the balance of the 1960 irrigation season.(19) On January 11, 1962, the Ute Water Conservancy District (UWCD), formed in April of 1956, contracted with Reclamation to provide water for municipal and industrial use. The contract allowed UWCD, comprised of the towns of Collbran, Plateau Valley, Molina, and Mesa, to divert water from the tailrace of the Lower Molina Powerplant. The UWCD has a priority right in Plateau Creek however the water quality of the tailrace was significantly higher than in the Creek; water from the tailrace flows into Plateau Creek a short distance below the Powerplant. By 1998, Reclamation had begun negotiations with the UWCD to extend the contract past its original expiration date of 2002.(20) Contractors completed all remaining construction in 1962, and on May 26, 1962, Vega Reservoir filled and then spilled for the first time. Initial commercial power production began December 16, 1962.(21) Additional construction activities on the power collection system were completed in 1963. Limited power production continued during 1963 on a testing basis. On January 1, 1963, the CCD assumed administration of the Collbran irrigation facilities for operation and maintenance. At the same time, Project Manager Everett Collins left Reclamation to become facilities manager for the CCD. Reclamation retained operation of the power features under the jurisdiction of the Grand Junction Projects Office.(22) Soon after construction began on the Collbran Project in 1957, Reclamation contracted with the private entities responsible for the individual reservoirs, to operate the seventeen small private reservoirs located on Grand Mesa in conjunction with the project. The owners pay Reclamation an O&M assessment based on an index of previous operating costs. Reclamation uses the storage water in the Grand Mesa reservoirs for power generation and then provides irrigation water from Vega Reservoir. The exchange of water between the various reservoirs allows Reclamation to optimize power generation at the Upper and Lower Molina Powerplants. Over the years, Reclamation has continuously maintained and rehabilitated the Grand Mesa dams.(23) Based on SEED inspections conducted in 1979, 1981, and 1982, Reclamation began considerable rehabilitation and maintenance operations on the Grand Mesa dams. In 1982 and 1983, Reclamation breached Blackman and Currier Dams, reducing to fifteen the total number of privately constructed dams operated by Reclamation. Rehabilitation of additional structures began in 1980; Reclamation scheduled the additional work through the year 2004. Much of the rehabilitation consisted of actually reconstructing the existing structure and making modification to the original designs when necessary, though the magnitude of the reconstruction depended on the current condition of the individual reservoir.(24) Vega Dam, a zoned, rolled earth, and rockfill structure, contains 981,825 cubic yards of material with a crest length of 2,100 feet and a maximum height above foundation of 162 feet. The dam lies near the Grand Mesa in western Colorado, about ten miles east of the town of Collbran. The outlet works, near the left abutment, consists of an intake structure, a five-foot-diameter concrete pressure conduit, a concrete gate chamber, a concrete horseshoe conduit, a control house, concrete stilling basin, and an outlet channel which discharges into the Southside Canal. The resulting Vega Reservoir, has a capacity of 33,800 acre-feet and with a shoreline of approximately seven miles and covers a surface area of about 900 acres. The Leon-Park Feeder Canal conveys water from Leon and Park Creeks to Vega Reservoir. Beginning at the Leon Creek Diversion Dam on Leon Creek the 450-cfs capacity canal extends about two miles to a siphon under Park Creek. The Park Creek Diversion Dam, about 1,000 feet above the siphon outlet, diverts water from Park Creek into the canal. The combined creek flows then travel the .7 mile to the reservoir. The Southside Canal conveys irrigation water westward from the reservoir to project lands. The 32.8 mile long canal heads at the outlet works of the reservoir and has an initial capacity of 240 cfs and a terminal capacity of fifty cfs at Mesa Creek. Thirteen siphons carry the canal across major streams of the area while seven concrete chutes drop the canal in elevation. A 2, 389 foot long, 6.25 diameter horseshoe tunnel carries the canal water through a ridge on the divide between Salt and Tea Creeks, eliminating canal construction through a badly eroded area. The Bonham-Cottonwood pipeline collects water from small streams and reservoirs in the watersheds of Big and Cottonwood Creeks on Grand Mesa and delivers it to the Upper Molina penstock. Consisting of two main branches, and several smaller feeder lines, the pipeline delivers a maximum of fifty cfs to the Upper Molina penstock. The Bonham section, about five and a half miles long, extends from Bonham Reservoir to the Upper Molina penstock. A thirty-three inch pretensioned concrete pipe this portion of the pipeline, with a maximum capacity of fifty cfs, delivers water from an unnamed stream inlet west of Bonham Reservoir. The Cottonwood section of the pipeline extends over three and a half miles from Cottonwood Reservoir No. 1 to the Molina Penstock. This portion of the pipeline receives water from Cottonwood No. 1, De Camp, and Big Meadows Reservoirs, as well as from three uncontrolled stream inlets which take releases from six other reservoirs. With a maximum capacity of just over twenty-eight cfs, the diameter of the pipe ranges from eighteen to thirty-six inches. Located on Grand Mesa twelve miles south of Collbran, Bonham Dam, an embankment structure, is 1,500 feet in length, with a twenty-five foot wide crest, and a maximum height of thirty-eight feet. The resulting Bonham Reservoir, with an active capacity of 1,222 acre-feet, acts as a forebay suppling the major portion of the water to operate the Molina powerplants. The East Fork Diversion Dam and Feeder Canal, along with the Bonham-Cottonwood Collection System, carry water from the East Fork of Big Creek and Atkinson and Lambert Reservoirs into the 1,000 acre-foot capacity reservoir. After being deposited in the reservoir, water travels through the outlet works to the powerplants. The Upper Molina Powerplant, located on the east bank of Cottonwood Creek, contains a single 8,640 KW generating unit. The Lower Molina Powerplant, located on the south bank of Plateau Creek near Molina, Colorado, contains a single unit with an installed capacity of 4,850 kW. Originally part of Reclamation`s Colorado River Storage Project (CRSP)(25) power operations, the Western Area Power Administration (Western) now manages the power produced by the powerplants.(26) Vega Dam and the Southside Canal provide water for the supplemental irrigation service to 22,210 acres of project lands. Principal crops are alfalfa, hay, small grains, and pasture. These crops are used primarily to support beef cattle and sheep production.

Plan

Water used for the generation of power is collected from the Big and Cottonwood Creek drainage areas at elevations of more than 9800 feet above sea level. These waters are stored by the 17 previously existing reservoirs on Grand Mesa or collected by the Bonham-Cotonwood pipeline and piped down the mesa slopes through two hydroelectric powerplants and released into Plateau Creek. The two powerplants have a combined capacity of 13,500 kilowatts. Vega Dam is near the Grand Mesa in western Colorado, about 10 miles east of the town of Collbran. The dam is a zoned, rolled earth and rockfill structure with a maximum height above foundation of 162 feet, a crest length of 2,100 feet, and a volume of 981,825 cubic yards of material. The outlet works is near the left abutment and consists of an intake structure, 5-foot diameter concrete pressure conduit, concrete gate chamber for a 3.5-foot-square high-pressure emergency gate, 8-foot-diameter concrete horseshoe conduit containing a 51-inch-diameter steel pipe, control house containing two 2.25-foot-square high-pressure control gates, concrete stilling basin, and an outlet channel which discharges into the Southside Canal. Vega Reservoir has a surface area of about 900 acres, with a capacity of 33,800 acre-feet, and a shoreline of approximately 7 miles. The Leon-Park Feeder Canal conveys water from Leon and Park Creeks to Vega Reservoir. The canal begins at the Leon Creek Diversion Dam on Leon Creek and extends about 2 miles to a siphon under Park Creek. Water diverted from Park Creek by the Park Creek Diversion Dam, about 1,000 feet above the siphon outlet, then combines with the Leon Creek diversions, and flows about 0.7 mile to Vega Reservoir. The Southside Canal heads at the outlet works of Vega Reservoir and conveys irrigation water westward from the reservoir to project lands. The 32.8-mile-long canal has an initial capacity of 240 cubic feet per second and a terminal capacity of 50 cubic feet per second at Mesa Creek. Thirteen siphons carry the canal across major streams of the area, and seven concrete chutes are used to drop the canal in elevation. A 2,389-foot-long, 6.25-foot-diameter horseshoe tunnel carries the canal water through a ridge on the divide between Salt and Tea Creeks, eliminating canal construction through a badly eroded area. Bonham Dam is located on Grand Mesa, 12 miles south of Collbran. The dam consists of two embankments separated by a knoll. Reclamation rehabilitation in 1962 added earth and rockfill material to the crest and downhill face of the dam, raising the crest 2 feet. This allows a 4-foot freeboard above the normal reservoir water surface. The completed structure is 1,360 feet in length, has a 25-foot-wide crest, and is 38 feet high. The spillway was rehabilitated and now has a capacity of 1,830 cubic feet per second. Bonham Reservoir, in operation for more than 70 years, has a total capacity of 1,220 acre-feet. The Bonham power water outlet works consists of a 750-foot inlet channel, intake structure to a 36-inch-inside-diameter, steel-lined conduit, and a gate structure with a 36-inch cast-iron slide gate. The 36-inch steel-lined conduit is reduced to a 33-inch-inside-diameter, steel-lined pipe where it becomes the Bonham pipeline at a manhole structure about 100 feet downstream from the gate structure. The East Fork Diversion Dam and Feeder Canal divert the natural flow of the East Fork of Big Creek and releases from Atkinson and Lambert Reservoirs to Bonham Reservoir. The East Fork Diversion Dam is a concrete ogee, gravity-type structure with overflow section and wingwalls of concrete and embankments of compacted earth at each end of the dam. The concrete headworks are controlled by one 3-foot-square slide gate, feeding the canal. The sluiceway is controlled by a 6-foot-square radial gate. The East Fork Feeder Canal, with a capacity of 35 cubic feet per second, has a length of 1.3 miles. The first mile conveys water from East Fork to Atkinson Creek; the water is then carried by the stream channel for approximately 600 feet, where it is redirected into the feeder canal. The water is then carried by the feeder canal to its terminal drop structure, located at the east end of Bonham Dam, for storage in Bonham Reservoir. The Bonham-Cottonwood pipeline collects water from small streams and reservoirs in the watersheds of Big and Cottonwood Creeks and delivers it to the Upper Molina penstock. The pipeline, consisting of two main branches and several smaller feeder lines, delivers a maximum of 50 cubic feet per second to the Upper Molina penstock. Extending about 4 miles from Cottonwood Reservoir No. 1 to the Upper Molina penstock is the Cottonwood section of the pipeline. It receives water directly from Cottonwood No. 1, DeCamp, and Big Meadows Reservoirs, as well as from three uncontrolled stream inlets which also take releases from six other reservoirs. This section has a maximum capacity of 28.3 cubic feet per second. The pipe ranges from a minimum of 18-inch inside diameter to a 36-inch maximum. The Upper Molina penstock extends from the junction of the Bonham and Cottonwood pipelines, then continues approximately 2.4 miles down the north slope of Grand Mesa, and terminates at the Upper Molina Powerplant. The penstock consists of welded steel pipe with a capacity of 50 cubic feet per second, ranging in diameter from 36 inches at the junction with the Bonham-Cottonwood collection system to 33 inches in the lower section. Bonham Reservoir acts as a forebay for the Upper Molina Powerplant, which controls releases up to a maximum capacity of 50 cubic feet per second from the reservoir. Upper Molina Powerplant consists of a single 8,640-kilowatt generating unit constructed on the east bank of Cottonwood Creek, operating at a design head of 2,490 feet with power tailwater discharges up to 50 cubic feet per second into the Molina Equalizing Reservoir. The Lower Molina penstock extends 4.7 miles from the Molina Equalizing Reservoir to the Lower Molina Powerplant. The penstock consists of steel pipe ranging in diameter from 36 inches at its upper end to 30 inches at the lower section. It has a maximum capacity of 50 cubic feet per second. The single-unit Lower Molina Powerplant is located on the south bank of Plateau Creek near Molina, Colorado. It has an installed capacity of 4,860 kilowatts at a design head of 1,400 feet and a maximum water discharge of 50 cubic feet per second. Both plants are operated in conjunction with Colorado River Storage Project power operations. Power generated at the powerplants is transformed to a transmission voltage of 115 kilovolts at two substations constructed adjacent to the plants. A 5.5-mile transmission line leads from the substation at the Upper Molina Powerplant, delivers energy produced at the plant to the substation at Lower Molina Powerplant, and then connects to the Tri-State Generation and Transmission system for distribution. The Bureau of Reclamation operates the 15 small Grand Mesa reservoirs, Bonham-Cottonwood pipeline, and the Molina Powerplants and penstocks. Since January 1, 1963, the Collbran Conservancy District has operated Vega Dam and Reservoir, the Leon-Park Diversion Dams and Feeder Canal, and the Southside Canal. Vega Dam was constructed across the channel of Plateau Creek, forming a reservoir with a total capacity of 33,800 acre-feet and an active capacity 32,980 acre-feet. The reservoir store surplus flows of Plateau, Leon, and Park Creeks. The Leon and Park Creek flows are brought to the reservoir through the 2.7-mile-long Leon-Park Feeder Canal. The Southside Canal extends west from Vega Reservoir 32.8 miles to a terminal drop structure on Mesa Creek about 3.25 miles south of the town of Mesa, Colorado. The canal crosses several north-flowing tributaries of Plateau Creek to which releases are made but does not intercept their flow. Most project water from Plateau, Leon, and Park Creeks, including both storage and direct flow, is released from Vega Reservoir and delivered by the Southside Canal. Some water is released at Vega Reservoir into Plateau Creek for diversion by downstream ditches.

Contact

Organization: Collbran Conservancy District
Address: PO Box 163
City: Collbran, CO 81624
Phone: 970-487-3306

Contact

Title: Area Office Manager
Organization: Western Colorado Area Office - Grand Junction
Address: 445 W. Gunnison Ave., Suite 221
City: Grand Junction, CO 81501
Phone: 970-248-0600

Owner

Title: Public Affairs Officer
Organization: Upper Colorado Regional Office
Address: 125 South State Street, Rm 7102
City: Salt Lake City, UT 84138-1102
Fax: 801-524-5499
Phone: 801-524-3774

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