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244 . Collbran Project ., Collbran Project farmlands water is then carried by the stream channel for approx- imately 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. Bonham-Cottonwood Pipeline 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 cohic feet per second to the Upper Molina penstock. The Bonham section, about 5.4 miles long, extends from Bonham Reservoir to the Upper Molina penstock. It con- sists of a 33-inch pretensioned concrete pipe with a max- immn capacity of 50 cubic feet per second. A feeder line delivers water into this section from an unnamed stream inlet west of Bonham Reservoir. Extending about 3.7 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. I, DeCamp, and Big Meadows Reser- voirs, 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 in- side diameter to a 36-inch maximum. Upper Molina Penstock and Powerplant The Upper Molina penstock extends from the jnnction of the Bonham and Cottonwood pipelines, then continues approximately 2.4 miles down the north slope of Graud . Mesa, and terminates at the Upper Molina Powerplant. The penstock consists of welded steel pipe with a capa- city of 50 cubic feet per second, ranging in diameter from 36 inches at the junction with the Bonham-Cottonwood collection system to 33 inches at the lower section. Bonham Reservoir acts as a forebay for the Upper Molina Powerplant, which controls releases up to a max- imum capacity of 50 cubic feet per second from the reser- voir. 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. Lower Molina Penstock and Powerplant 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, Colo. 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 con- junction with Colorado River Storage Project power operations. Substations and Transmission Lines Power generated at the powerplants is transformed to a transmission voltage of 115 kilovolts at two sohstations constructed adjacent to the plants. A 5.5-mile transmis- sion 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 con- nects to the Colorado-Ute Electrical Association system for distribution. ! 't; ;y "t" -1 ,} f f DEVELOPMENT i ~ _iI"" Early History N umerons small private reservoirs were constructed on Grand Mesa to regulate the runoff of Big, Cottonwood. Mesa. and Bull Creeks. These reservoirs are filled with water during the spring runoff, and the stored water is released on demand of the irrigators in Plateau Valley to supplement the low natural streamflows of late summer. Individual water users or small cooperative associations built most of the reservoirs in basins formed by glacial action. ~