A 175 Mi^2 watershed has a 4200 acre reservior within its boundary . The annual watershed runoff to the reservior is 13in. A flow of 120 mgd (368 ac-ft/day) is to be drafted from the reservior. The annual rainfall is 38in.
Estimate the reservior evaporation using the Penman Theory . The mean daily air temperature is 70 deg F, daily solar radiation is 550 ly/d , mean daily dew point temperature is 55 deg F, and the wind movement at 6in above the pan rim 40 mi/day
Determine the net gain or loss in reservior storage as a volume (ac-ft)