OCR Text |
Show Stations located at Richfield and Delta record climatological data representative of the Sevier River area0 The mean annual precipitation recorded at these stations is 7.8 inches. The mean annual temperature is 49.7° F„ with extremes ranging from 25° below zero to a high of 106° F. The average frost- free period is 135 days and the growing season averages about 156 days. Topography and Physiography The Uinta Mountains, several peaks of which exceed 13,000 feet, extend eastward from the north- south trending Wasatch Range, forming the northern boundary of the Uinta Basin and the watershed which supplies much of the Unit water. The Uinta Mountain Range is one of the few east- west oriented ranges in the United States„ This range is about 150 miles long and 50 miles widec The southern slope of the Uinta Mountains in the Bonneville Unit area is drained by the Duchesne River, a tributary of the Green and Colorado Rivers. Duchesne River tributaries that would be intercepted by the Strawberry Aqueduct Collection System are Strawberry River, West Fork of the Duchesne River, and Rock Creeko Subtributaries include South Fork Rock Creek, Hades Creek, Twin Creek, Wolf Creek, Currant Creek, Layout Creek, and Water Hollow Creeko The Bonneville Basin portion of the Unit extends about 250 miles along the western base of the Wasatch mountains from Salt ' Lake City south to and including Sevier River drainage area. The Bonneville Basin portion also includes Heber Valley and part of Kamas Valley along the Provo River. In addition to Provo River, a number of other streams in the Unit area flow westward from the Wasatch Mountains to the floor of Bonneville Basin0 Listed in sequence from north to south, the major streams include City Creek, Red Butte Creek, Emigration Creek, Parleys Creek, Big and Little Cottonwood Creeks, American Fork River, Provo River, Hobble Creek, Spanish Fork River, Salt Creek, and Chicken Creek. In the Bonneville Basin the slope and the drainage are gently toward Great Salt Lake which occupies the lowest portion of the basin. The water surface elevation of the lake is approximately 4,200 feet. The area from Salt Lake City to Panguitch is separated by low hills into four valleys. Sevier River Valley is located to the south, Juab and Utah Valleys in the center, and Salt Lake Valley on the north. The Sevier River flows northward through Garfield, Piute, Sevier, Sanpete, and Juab Counties, then turns south into Millard County. The elevation of the Sevier Valley floor varies from about 7,000 feet in the south 114 |