Steady Flow Calculations for Cutoff Wall Depth Variation

Steady‐state flow through an earth dam with an impervious core and a cutoff extended various depths into an alluvial foundation was examined for dependance on the permeability ratio of the foundation and depth of the cutoff. The flow which can be calculated by hand by assuming water moving through the foundation alone, was compared to a more complete model including flow through the dam. The simplified assumptions for flow only through the foundation may be used for cases of horizontal permeability 10 to 100 times vertical permeability and cutoff depth ranging from 35%–100% of the foundation depth to give results within 10% of those of the more complete model.