Abstract: In this paper the hydrogeological and engineering geological condition are analyzed in detail.According to the design plan of Longzi Lake,the problem of large seepage volume might occur after the completion of the lake project.The groundwater level might rise because of the seepage of Longzi Lake and it might influence the entironment surrounding the lake.A three dimensional model of seepage simulation was established and the results of the computation proved the problem of large seepage volume to be true.Alternative plans are put forward which may help to solve the problem.Other new problems due to the change of the hydrogeological and engineering geological conditions are forecasted and analyzed.Finally,the methods to solve the problem are advised.