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and 1904. All of these floods peaked near 21,000 cfs. The 1904 flood was probably the worst flpod in terms of dollar damage (Refer- ence 6). The snowmelt runoff ftom 1983 produced a peak near 7,000 cfs. This was the highest peak: in 53 years. Extensive channel damage occurred because of the prolonged duration of the runoff. Buckhorn Creek has flooded on several occasions. were in 1923, 1938, 1948, and 1951 with discharges 5,750 and 14,000 cfs, respectively (Reference 7). The largest floods of 10,500, 10,200, Documentation of floods on ~ed~tone Creek is relatively sparse. However, an intense rainstorm ~n September 10, 1938, caused flooding in some of the lower areas of the floodplain (Reference 7). Floods have been recorded in the Boxelder Creek watershed on 13 occasions since 1900. On August 1, 1961, a storm with a frequency of 50 to 100 years caused an eatimated $76,150 in damage in the wellington vicinity. 'In May and June 1976, two overlapping 25- year storms caused an estimated $46,100 in damage and took four lives in the, Wellington vicinity (Reference 8). , NO record exists of a major flqad on Dry Creek in the study area. The absence of even minor flooding is generally attributed to the network of irrigation canals that have some capacity for inter- cepting Dry Creek flows (Reference 1). ' Fish Creek and the Fall River have not often been subject to major flooding, although the Fall River did overflow its banks in 1965 and cause some damage. In July 1982, extensive damage occurred throughout the TOwn of Estes Park because of the failure of Lawn Lake Dam located in the headwaters of the Fall River. 2.4 Flood Protection Measures There are no structures along the Big Thompson River or its tribu- taries that provide a major ,~eduction in floodflows. Numerous levees along the river will contain a high frequency flood (10 and 25 years) but provide little p~otection against the 100-year flood. In 1970 the U.S. Soil Conservation Service (SCS) proposed to con- struct five floodwater detention structures in the Boxelder Creek basin. Two of these structures were completed when discharges were computed for the detailed,analysis for Boxelder Creek. There are no flood-control structures located in the Cooper Slough basin (Reference 9). '. .. Although they are not actual flood-control structures, Dry Creek has several lakes and storage reservoirs that reduce the contributing drainage area by approximatelyi13 percent. The network of irrigation canals in the Dry Creek basin has some capacity for intercepting Dry Creek flows (Reference 1). Douglas Lake, also an irrigation reservoir, significantly reduces peak discharges. 10