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of hardy grasses. Mesas and lower mountain slopes between 5,000 and 8,000 feet support oak, big sagebrush, Douglas fir, pinon pine, and juniper. 2.3 Principal Flood Problems Most of the annual precipitation in the higher regions of the Colorado River Basin occurs as snow, and a deep snowpack usually accumulates. General rainstorms covering large areas for extended periods can occur in the region during spring, sunmer, and fall. Convective-type cloudburst storms of small areal extent, which account for approximately one-half of the normal annual precipitation, can be expected during sunmer and fall in the Palisade area. However, flooding along the Colorado River is normally the result of rapid melting of the mountain snowpack in spring and early summer (late May through early July), with floodflows occasionally augmented by rain. General rainstorms and convective-type thunderstorms generally have little effect on a stream as large as the Colorado River. In the study area, 100-year floods on the Colorado River would result from snowmelt runoff, and 500-year floods would result from snowmelt augmented by rain. Damage resulting from a 100-year or 500-year flood would principally be associated with agricultural and rural residential areas, and public facilities. Residential losses would include damage to foundations, lower floors, walls, furnishings, appliances, and lawns and gardens. Agricultural damage would involve erosion and deposition of silt and debris on crop and pasture lands. Public facility losses would comprise damage to streets, highways, bridges, and irrigation and sewage treatment systems. Other costs attributable to flooding might be temporary evacuation of some areas, eroded streambanks, and flood fighting and post flood cleanup and restoration. The Colorado River has a long history of snowmelt flooding, but due to the rural nature of the region, detailed information on flood events in the study area is not available. The first flood of record on the Colorado River in the study area occurred in June and July 1884. Other floods on the river were recorded in 1917, 1920, 1921, 1935, 1952, 1957, 1983, and 1984. The 1884 flood is generally considered the most severe known in the Palisade area. It resulted from rapid melting of a deep snowpack and concurrent heavy rains. 2.4 Flood Protection Measures There are no flood-protection measures in existence at Palisade. Reservoirs in the Colorado River Basin above the study area are operated for water conservation purposes and consequently provide 4