DWR_4151808 - Laserfiche WebLink

• SOUTH PLATTE Basinwide Conditions Assessment: The SWSI value of +0.3 indicates that June conditions were normal. Streamflow conditions are average to above average in the Cache la Poudre, St. Vrain, Big Thompson, and Boulder Creek drainages and considerably below average in the South Park and Tarryall drainages. Streamflow remains below normal in both the upper and lower reaches of the South Platte River in Colorado. Cumulative flow at the key index gaging station, South Platte River near Kersey, remains 30% below normal for the current water year, but still remains above the minimum flow period recorded in 1964. Reservoir storage remains near normal. Dillon and Eleven Mile Reservoirs are storing 107% and 111% of normal respectively. Soil moisture is classified as being normal. Outlook: Streamflow is expected to be normal for the St. Vrain, Big Thompson and Cache la Poudre drainages and below normal elsewhere in the basin. Administrative/Management Concerns: "River calls" have been in effect in most of the South Platte River basin. Recent rains have allowed some junior rights to be brought back into priority; however, as flows subside, additional junior rights have to be curtailed to satisfy senior rights. The South Platte Interstate Compact has been met only by curtailing junior rights in the lower reaches. Transmountain diversions from the Colorado basin to the South Platte basin via the Roberts and Moffat Tunnels have been increased to meet growing demands for irrigation and municipal uses. The Colorado-Big Thompson Project is working on a 50% quota to conserve diminishing water supplies. Public Use Impacts: Urban water use will be curtailed as supplies continue to decline. This primarily involves outdoor water use such as watering lawns and gardens. Water based recreation will be impacted slightly in the upper South Platte basin with reduced flows in the South Platte River above Spinney Mountain Reservoir. A call on the South Platte River above Denver has mandated that all natural flow into Cherry Creek Reservoir be released back into the river. The majority of water rights in the upper South Platte basin are controlled by the City of Denver, metro area suburbs, and downstream irrigation companies. In the lower reaches, the water is almost totally controlled by agricultural interests. The South Platte River, which historically went dry'in summer months, is maintaining minimal flows due to municipal and agricultural return flows. SURFACE WATER SUPPLY INDEX s sDUth Platt.River spin 4- 4111 -1- tv . a -2- - 11 0 -3- .IAI09 .IAgsi 4003 JA"N .MN JAM .0I07 JAMS JAM JM110 .6.I01 r ` 2