Abstract: The occurrence of confined water inrush and leakage is common in engineering projects such as foundation pits and tunnels. To economically, conveniently and accurately obtain the confined water level is of great significance for the guiding of engineering design and construction. By analyzing the piezocone penetration tests (CPTU) and geotechnical data from the projects of Jiangyin-Jingjiang Yangtze River Tunnel and Haitai Yangtze River Tunnel, a CPTU-based method for measuring the confined water level is proposed. This method allows for the calculation of the confined water level through measurement of pore pressure while obtaining the CPTU in-situ test parameters. The comparisons between the calculated and observed confined water levels show high consistency. The CPTU method offers advantages of convenience, speed and low construction cost, making it worth promoting and implementing in foundation pit and tunnel engineering.