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area is underlain by gravel. There is evidence of sand, gravel, and cobble deposition in old streambeds near the confluence with the Gunnison River. The Manning's "n" for the Uncompahgre River channel is 0.035. The average slope of the channel is 0.00286 feet per foot. Mean velocities in the study area range from 2.6 to 6.1 feet !per second. The flood profiles for the Uncompahgre River as depicted in the 1983 FEMA Flood study is included as Plate 6-2. The lOa-year flood plain of the Unco~pahgre River is located mostly on the left overbank. The area on the right overbank of the Uncompahgre River from the old sewage lagoons to the confluence with the Gunnisdn River is influenced more by the flood plain of the Gunnison River than by that of the Uncompahgre River. 7, Fish Pond Cons.iderations. The existing 70-acre abandoned sewage lagoon is intended to be converted to a cold water fishery. About two-thirds of the pond depth would be shaljlow, about 4 feet deep. The remaining pond depth would be about 15 feet deep, depending on the amount of gravel removed 'and the depth to bedrock in the are"l of gravel extraction. , The water volume of the pond is estimated to be 550 acre-feet. o Seepage rate of the pond. The seepage rate of the fish pond (as!suming that no additional lining or other seepage control measures will be placed) was estima.ted to be about 1 cubic :foot per second. An analysis of the pond area for seepage is presented in Section 8, o Evaporation ra.te. The evaporation rate provided by the rity of Delta in a Well Permit Application Form to the Colorado Division of Resources indicated a maximum evaporation 'rate for the confluence area of 0.72 inches per day. ,~evaporation rate study was also made by the Bureau of Recla~ation for the Glenwood-Dotsero Springs salinity control :study for a proposed evaporation pond near the Coloradp-Utah border. Pan evaporation records were compiled from! several stations around Grand Junction, and one was compiled from Montrose. The records revealed significant variations due to local conditions at the site of the evaporation :Stations. Among the influencing factors are wind, vegetatipn, irrigation, the presence of nearby bodies of water, anp topography. Evaporation is primarily influenced by the; temperature of the water and the movement of wind over t.h", water. The City of DE:ll.ta' s evaporation rate of 0.72 inches per day as shown on the well permit is an expected rate of water loss during a limited period. For a surfa~e area of 70 acres, the maximum evaporation rate would be 951 gallons per 6