WSP00401 - Laserfiche WebLink

Home Browse Search

eGGS Water Requirements Service Area Lands considered to be served by the ground-water recharge program were the areas within the Lower South Platte Water Conservancy District (LSPWCD) overlying the alluvial aquifer. Lands within the North Sterling Irrigation District do not overlie the alluvial aquifer, These lands, amounting 'to 46,100 acres, cannot be served directly from ground water. Therefore, lands considered for recharge amount to 120,300 acres, Farm Delivery Requirements Water service from the Narrows Reservoir is contracted to the Central Colorado Water Conservancy District (CCWCD) and the Lower South Platte Water Conservancy District (LSPWCD). Detailed water requirement studies were conducted for 23 ditch systems within the LSPWCD as a part of the Narrows Unit feasibility studies (USBR, 1966). These studies resulted in an estimated average annual river diversion requirement for supple- mental surface water of 178,000 acre-feet during the period 1947-1961. The recharge service area, which excludes lands served by the North Sterling Irrigation District, was estimated to have an average annual river diversion requirement for supplemental surface water of 84,000 acre-feet. Annual conveyance losses for the existing distribution system have been estimated to be approximately 38 percent of the river diversions. The estimated annual farm-headgate demand for supplemental water on the 120,300 acres overlying the alluvial aquifer is estimated to average 52,100 acre-feet. It ranged from 20,300 acre-feet in 1951, to 109,100 acre-feet in 1972 (see exhibit 6). River Diversion Requirements The bulk of the water will be recharged early in the irrigation season, but will be pumped at a varying rate throughout the irrigation season with maximum pumpage anticipated to occur in July and August, Due to this lag time, drain-out of a portion of the recharged water will occur. Assuming homogeneous and isotropic aquifer characteristics between the recharge area and the stream, the amount of drain-out occurring in a given time frame depends largely upon the distance between the stream and the recharge ponds. 40