Abstract: Zishancun Dam is a homogeneous earth dam.It has been operating in severe seepage because of poor foundation and dam body construction for a long time. The saturation line decreased 0.6~3.0m by means of using well and ditch diverting, improving drainage system downstream, so that the perils has been eliminated. It proved that well and ditch diverting is an effective treatment measures. It has characters of simple technology,easy construction and small cost. It effectively decreased saturation line of dam body, corrected seepage flow direction and improved the safety factor against sliding of dam slope downstream.?