| OCR Text |
Show to 4,600 feet in the north. The limited amount of natural inflow into Juab Valley from the Wasatch Mountains is mostly consumed by irrigation in the valley. This land is located between elevations 4,880 and 5,400 feet. The lowest part of Utah Valley is occupied by Utah Lake. The lake averages about 7 feet deep and has a water surface elevation of approximately 4,489 feet. This shallow water body has a surface area of 150 square miles. Provo, American Fork, and Spanish Fork Rivers that enter Utah Lake from the east are its major contributors. Other small streams and return flows from irrigated lands east of the lake also contribute to the lake supply as do springs emerging in the lake bottom and around the lake shore. Jordan River flows northward 40 miles from the outlet of Utah Lake to Great Salt Lake. About 7 miles from its head, Jordan River passes through Jordan Narrows which separates Utah Valley from Salt Lake Valley and is locally referred to as " point- of- the- mountain." Practically all of the arable lands of the Unit were derived from alluvial material transported into the valleys by stream action. Characteristic features in Uinta Basin are the long, narrow strips of land on either side of and adjacent to Duchesne River. These lands occur on gently sloping benches or mesas, alluvial fans, and valley flood plains and are dissected by the entrenched river and its tributaries. The lands are relatively smooth and usually in plots of sufficient size to facilitate cultivation and irrigation. These Uinta Basin lands vary in elevation from ab out 4,900 to about 6,880 feet above sea levela Lands in Bonneville Basin are situated on recent alluvial fans, terraces, deltas, alluvial- deltaic fans, and lacustrine deposits on the valley floor. Ancient Lake Bonneville at one time inundated most of the basin and had considerable influence on the physiography of the area. Most of the valley fill was transported into the lake by entrant streams where it was hydraulically stored and reworked, then deposited as deltas, benches, or on the lake bottom. Since disappearance of the lake, recent alluvial fan material has been superimposed over much of the older lake deposits. These lands are normally smooth to gently sloping. The elevation range is from about 4,490 in Provo Bay area to about 6,000 feet above sea level in the Heber- Francis area. Geology a. General The Bonneville Unit area extends over parts of two major physiographic and structural divisions in northeast and 115 |
