The presence of an unsaturated region beneath a streambed during groundwater pumping near streams can reduce the pumping capacity, change flow paths, and alter the types of biological transformations in the streambed sediments. A three-dimensional, multiphase flow model of two horizontal collector wells along the Russian River near Forestville, California, was developed to investigate the impact of varying the ratio of the aquifer to streambed permeability on (1) the formation of an unsaturated region beneath the stream, (2) the pumping capacity, (3) stream water fluxes through the streambed, and (4) stream water traveltimes to the collector wells. The aquifer to streambed permeability ratio at which the unsaturated...
