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1092 ~. . Meteorological studies indicated that storm-producing conditions in the Montana area and the South Platte River drainage above Narrows Dam are similar with respect to moisture sources, orographic conditions, and precipitation patterns. These study conditions concluded that rainfalls as great or greater than the 1964 Montana storm are possible in the South Platte Basin from a storm of this type. The storm studies were reviewed and concurred in by the National Weather Service, and the Corps of Engineers. The Corps of Engineers has ,also concurred in the techniques used in computing the resultant inflow design flood (IDF). The Colorado State Water Conservation Board contracted with the consulting firm of Dames and Moore, Inc. in February 1975 for an independent review of the above studies. The following tabulation shows a comparison of the IDF results for the original 1948 studies and the Montana storm studies, as computed in August 1975. Inflow design flood Flood volume acre-feet Peak discharge ft3/s 1948 USBR 1975 USBR 1,363,000 11 2,030,000 ~ 344,000 497,lOO 11 Based on 2D-day volume ~ Based on ID-day volume The latest inflow design flood with peak discharge of 497,lOO cubic feet per second and a ID-day volume of 2,030,000 acre-feet incorporates several changes in retention loss rates and noncontributing areas suggested by the Corp of Engineers and by Dames and Moore in their report of June 1975. Project Water Supply . ' A supplemental irrigation water supply from the reservoir will be provided to irrigab1e lands of the Lower South Platte Water Conservancy District (l66,370 acres) and the Central Colorado Water Conservancy District (l20,700 acres). 2