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of bank erosion, inundation, and resul tant channel changes constitute the present flood problem. No urban areas are affected by floods. The principal items damaged by the 1957 flood were the agricultural lands and roads and bridges adjacent to, or over the river. A few farm buildings were flooded. The total known damages in all categories in this reach amounted to slightly more than $45,000. A common type of damage from the 1957 flood was bank erosion. The slope of the stream ranges from 65 feet per mile above Basalt, to 40 feet per mile below Basalt. Velocities probably in excess of 10 feet per second occurred during the 1957 flood. The banks are composed largely of sand, gravel, and cobbles overlain by a comparatively thin mantle of soil, and are quite erosible. Spoil-type dikes, constructed by local interests with material bulldozed in the process of channel clearing, proved to be very erosible. A substantial percentage of the total damages was due to overtopping of the low banks and the inundation of pasture and croplands. The banks in most instances range from only 2 feet to 5 feet in height. In 2 locations, where old channel areas have been reclaimed, considerable volumes of overflow and widespread flooding resulted from bank overtopping at the upper ends of the areas. More than one-half of the known damages in the 1957 flood were caused to roads and bridges in the area, with nearly $24,000 of damages being caused to 3 bridges and their abutments. Two of these were public bridges and have since been restored. A third bridge, which was private, was completely destroyed and has not been replaced. The City of Aspen is known to have a long history of flooding, the earliest occurring in 1880 (Reference 6). The flood of June-July 1917 is considered the most severe in the Aspen area, with a peak discharge of 3, 170 cfs on the Roaring Fork Ri ver. The largest recorded flood on Castle Creek near the City of Aspen occurred in 1918, with a peak flow of 1,090 cfs; on Hunter Creek, the largest flood occurred in 1953 with a peak flow of 1,010 cfs. The highest peak flow on the Crystal River above its confluence with Avalanche Creek was 3,980 cfs, recorded in 1957. A peak of 836 cfs for Maroon Creek was recorded in 1980 (Reference 7). In 1983 and 1984, large snow depths in the area resulted in unusually high snowmelt floods. Flood losses can include damage to grazing lands, irrigation systems, and fences; residential and commercial buildings; parks and other recreational facilities; roads, bridges, and public utilities. Stream channels may be subject to severe erosion. 7