The Qiantang River has high water level because of the tidewater. It is difficult question for foundation pit how to guarantee slope safety and construction convenience on the condition of high water level. The dewafering design and monitoring methods of building foundation pit nearby the Qiantang River are carried out according to the engineering case. The effects of foundation pit dewafering. The results show the foundation pit dewafering is effective by means of deep well for the soil layers of large permeability coefficient. When the water level of the Qiantang River is high

it is necessary to lower the high water lever by use of cut-off well.