average annual rainfall on the watershed is 25 inches, and the estimated annual run-off on watershed 543,000 acre-feet. The engineering features consist of a storage reservoir controlled by the East Park Dam on Stony Creek, at a point about 40 miles above Orland (pl. 4, fig. 2), and a diversion dam situated at Miller Buttes for turning water into two canals, one on each side of the creek, covering lands in the vicinity of Orland. The storage dam is of concrete masonry, gravity section, 139 feet high from bedrock, 60 feet long on the bottom and 250 feet long on top. The canal system includes 25 miles of main canal and 80 miles of laterals. The farmers are pledged to dispose of their holdings in excess of 160 acres to bona fide settlers under the terms of the reclamation act. Colorado, Grand Valley Project.-This is planned to irrigate about 53,000 acres of land in Mesa County, Colo. The work involves the construction of a diversion dam in Grand River, about 60 miles of main canal, with a series of short tunnels on the first few miles of tanal having an aggregate length of about 20,000 feet. It is probable that considerable power will be developed at drops in the canal, and used to pump water to elevations above the main canal. The average elevation of the irrigable area is 4,700 feet above sea level; the temperature ranges from 15° below to 100° above zero, and the rainfall on the irrigable area is from 6 to 11 inches annually. The watershed area is 8,550 square miles. The soil is largely red mesa sand, black bottom sandy loam, and adobe. The apple and peach orchards of the Grand Valley bottom lands are famous, the crops sometimes selling for more than $1,000 per acre per annum. Strawberries and cantaloupes are usually grown between the rows while the orchards are growing, also potatoes and other vegetables; alfalfa and sugar beets are also grown. Colorado, Uncompahgre Valley Project. Here the waters of Gunnison River are diverted by means of a tunnel 30,645 feet in length, cross section 10 by 11 feet, cement lined, with a capacity of 1,300 second-feet. The tunnel passes through the mountains to Uncompahgre Valley, where its water is used to supplement the local supply and extend the irrigable area to about 140,000 acres of land. The tunnel was commenced in 1904 and carried water in 1910. There are 330 miles of canals in the distributing system. The lands to be irrigated in Montrose and Delta Counties have a general elevation of 5,000 to 6,400 feet above sea level and the temperature ranges from 20° below to 98° above zero. The watershed area is 4,350 square miles, and the estimated run-off of watershed is 1,610,000 acre-feet. The rainfall on the irrigable area is from 6 to 12 inches, and the rainfall on the watershed ranges from 7 to 20 inches. The lands for which water is now available are mainly in private ownership. The farm unit varies from 40 to 80 acres, and the duty of water is 4 acre-feet per annum at the farm. About 60,000 a cres are suitable for raising apples and peaches. Orchard lands produce as high as $500 per acre in the valley. The bottom lands, comprising from 80,000 to 90,000 acres, are adapted to the growing of alfalfa and sugar beets. Idaho, Boise project.-When fully developed the Boise project will reclaim approximately 243,000 acres and will supplement the supply for about 79,000 acres of land in the fertile valleys of the Boise and Snake Rivers in southwestern Idaho. The general elevation is 2,500 feet above sea level, and the temperature ranges from 28° below to 107° above zero. The thermometer rarely reaches zero, however, and freedom from wind marks the winter months. The summers are long, sunshiny, and warm, and with irrigation promote the most rapid vegetable growth. The soil is largely of volcanic origin, free from rocks, easily worked, and rich in the necessary mineral constituents. With rotation of crops and the addition of vegetable mold it becomes very productive. Farms in a good state of cultivation produce 3 to 8 tons of alfalfa per acre in three cuttings, 2 to 5 tons of clover, 50 bushels of wheat, and 75 bushels of oats. After the last cutting the fields furnish pasturage. Both clover and alfalfa seed yield good crops. Apples, prunes, and small fruits produce well and are shipped in quantities to eastern markets. Sugar-beet culture is also profitable. Storage reservoirs on the headwaters of the Boise River are necessary and are being built. A diversion dam (pl. 5, fig. 1) has been completed on Boise River, 8 miles above Boise, diverting water into a canal irrigating lands under it and supplying Deer Flat reservoir in the vicinity of Nampa, which has a capacity of 186,000 acrefeet. The watershed area of the Boise River is 2,610 square miles; the average annual rainfall on watershed is 25 inches, and the estimated annual run-off of watershed is 2,190,000 acre-feet. The average rainfall on the irrigable area is 12.7 inches. Idaho, Minidoka project. The irrigable area under the Minidoka project consists of about 76,700 acres under a gravity system and 48,000 acres under a pumping system. The lands lie on both sides of Snake River, in the southern part of Idaho, in Lincoln and Cassia Counties. The works include a diversion, power, and storage dam on Snake River at a point about 6 miles south of Minidoka, Idaho, and two canal systems (pl. 5, fig. 2), one on each side of the river, heading at the diversion dam and covering lands in the vicinity of Acequia, Rupert, Heyburn, and Burley. Power is developed at the diversion dam for generating electrical energy for pumping water to lands on the south side of the river too high to be reached by a gravity system. |