RECLAMATION OF ARID LANDS NEAVELL. 185 



average annual rainfall on the watershed is 25 inches, and the esti- 

 mated 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 (pi. 4, fig. 2), and a diversion dam situated at Miller 

 Buttes for turning water into two canal-s, 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 sys- 

 tem 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 

 canal 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 3.00° 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 gi'own 

 between the rows while the orchards are growing, also potatoes and 

 other vegetables ; alfalfa and sugar beets are also grown. 



Colorado^ V ncomfaligre Y alley Project. — Here the waters of Gun- 

 nison 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 Uncom- 

 pahgre Valley, where its water is used to sujoplement the local sup- 

 ply 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 temper- 

 ature 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 



