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<br />Maximum observed peak flow data.--Extreme floods have been measured in <br />several areas of Colorado, being most prevalent along the eastern foothills and <br />plains and in the southwestern part of the State. Some of the largest observed <br />flood discharges for the South Platte River basin are listed in table 3 and are <br />plotted in figure 1. These observed peak discharges show both gaged and ungaged <br />sites. The discharges are plotted against contributing drainage area when the <br />areal extent of the storm was defined. As shown in figure 1, maximum observed <br />peak discharges for foothill streams plot much lower than discharges for other <br />streams when total drainage area is used. <br /> <br />Precipitation Data <br /> <br />National Weather Service precipitation-gage network.--The active National <br />Weather Service network within the general project area consists of 53 recording <br />and 71 nonrecording precipitation gages (pl. 1). Information about the <br />precipitation-gage network is contained in the monthly Climatological Data series <br />of the U.S. National Oceanic and Atmospheric Administration (1961-77). <br /> <br />In addition to the reguiar network, a network of volunteer observers has been <br />established by the National Weather Service to provide weather information on an <br />individual storm basis. This network will provide valuable supplemental <br />precipitation data for use in hydrologic studies. The number of observers in <br />foothill areas is listed by county in table 4. <br /> <br />Soil Conservation Service network.--The Soil Conservation Service operates a <br />snow survey that measures water equivalent of the snowpack during the winter and <br />spring. Another network, called SNOTEL, which is being established during 1975- <br />80, wili provide an automated-data system to report measurements of water <br />equivalent of the snowpack, precipitation, and temperature on a daily basis, or <br />more frequently if desired. Sites in the SNOTEL system of potential value to this <br />project are shown on plate 1. <br /> <br />RES EARCH <br /> <br />The foregoing discussion has identified .critical deficiencies in existing <br />hydrologic-analysis techniques when applied to the foothills flood environment. <br />This section of the report describes a research plan designed to study the <br />foothills-flood problem and develop improved flood-frequency computation and <br />information-transfer techniques. The research effort is concentrated on three <br />major study tasks: <br /> <br />1. Developing methods to identify and analyze flood records of foothill <br />streams. <br /> <br />2. Investigating flood-information-transfer techniques using physical and <br />climatic characteristics of foothill basins. <br /> <br />3. Testing and, if required, modifying hydrologic models for application in <br />foothill basins. <br /> <br />13 <br />