Water Resources of the Big Wood River and Silver Creek Area  by Paul M. Castelin and Sherl L. Chapman 1972

The relationship between the surface and ground water systems of the Big wood river-Silver Creek area is such that any stress on one system will result in an effect on the other. . . The aquifers in the basin are bounded on all sides by rocks of low permeability except at the inlet near Hailey and at the outlets at the southeast and southwest corners of the study area. The primary aquifer in the basin is a series of fluvioglacial sediments from which water is obtained under both confined and unconfined conditions. Wells drilled into the consolidated rocks surrounding the basin yield very little water. . . recharge to the aquifers in the study area is from precipitation, loss from the Big Wood River and irrigation canals, percolation of water applied in excess of consumptive use of crops and underflow from the Big Wood River Basin above Hailey. The total annual amount of inflow to the basin which includes recharge and surface water is estimated at 650,000 acre-feet. . . The amount of decline in water well levels would be dependent upon the auntity of water withdrawn and the consumptive use of the crops grown.