The engineering characteristics of three foundation pit dewatering plans for the South-to-North Water Diversion Project are compared. The result manifests that the three plans, namely by well point dewatering, by seepage cut-off walls, and by grouting curtains are all feasible for large scale and deep excavation pits in deep permeable strata. During the project design, worksite dewatering test is recommended to obtain the accurate hydrogeology information. Moreover, the plans must be compared based on 3-D numerical calculation in terms of cost and technique to ensure the safety of the foundation pit slope and the environment. Safety monitoring is indispensible for making emergency measures in case of problems during the dewatering.