UNCOMPAHGRE VALLEY PROJECT. The Uncompahgre Valley Project is one of the largest construction enterprises undertaken by the United States Reclamation Service under the Act of 17 June 1902. It effected the irri gation of 150,000 acres of arid lands lying on both sides of the Uncompahgre River in south western Colorado. It was accomplished by the diversion of the waters of the Gunnison River into the Uncompahgre Valley and the subsequent distribution of the water thus diverted, together wjth the waters of the Uncompahgre River, over the lands to be cultivated.
The engineering works connected with this project are as follows: (1) The Gunnison Tunnel, which pierces the divide which separates the Gunnison River from the Uncompahgre River. This tunnel is 30,582 feet long and passes under the sum mit of the divide at a depth of 2,220 feet. The eastern portal of the tunnel lies in the grand canyon of the Gunnison River. It is reached by a wagon road 10 miles in length, which is one of the picturesque drives of Colorado. The western portal is located in the Uncom pahgre Valley near Cedar Creek Station on the Denver and Rio Grande Railway.
(2) The South Canal, which carries the water from the Gunnison Tunnel to the Un compahgre River; 12 miles in length. This canal contains four short tunnels and many masonry drops.
(3) The West Canal, which distributes the waters from the Gunnison Tunnel and the Uncompahgre River over the lands west of the Uncompahgre River; 30 miles in length.
(4) The East Canal, which distributes the waters from the Gunnison Tunnel and the Uncompahgre River over the lands lying east of the Uncompahgre River; 35 miles in length.
(5) Numerous auxiliary canals and laterals.
(6) Impounding reservoirs on the head waters of the Gunnison River for the storage of flood water to supplement the regular flow of the stream during the dry months. Streams
of the arid region derive their summer flow in the main from melting snows in the high moun tain ranges. When the warm sun of the spring months begins to be felt the great body of snow on mountains and foothills disappears quickly in floods of more or less magnitude, depending upon prevailing seasonal conditions. During the summer months the flow depends upon the slowly-melting snow fields which lie in deep gulches and behind lofty precipices, where they are sheltered from sun and wind. This late flow is inadequate to the require ments, and to supplement it convenient basins are dammed and filled with flood waters to be released gradually when needed later in the year. To provide for this contingency sufficient reservoir sites have been segregated on the headwaters of the Gunnison River. These sites will be held and developed as future needs dictate. In addition to supplementing the irri gation waters these reservoirs will be useful as power producers.
The Uncompahgre Valley lies at about 5,000 feet above sea-level. It is sheltered by lofty mountain ranges and enjoys a mild and equable climate. The mountains surrounding the val ley form a portion of the continental divide, and contain many of the richest gold, silver, copper and rare metal mines in the world. The soil of the valley is of unusual fertility. The principal products are apples, peaches, apricots, primes, cherries, wheat, oats, potatoes, sugar beets and livestock.