Audit agencies are often faced with the need to estimate the benefit of environmental improvements in the course of environmental performance audits. Currently, the contingent valuation method (CVM) is the only technique for assessing the non-use values of environmental goods. This study was designed to measure (indirectly through the CVM) the residential valuation of water quality improvements based on responses to a survey conducted in the Wuli Lake District near Wuxi City, Jiangsu Province, China. Respondents in a survey were asked to indicate their willingness to pay for the water environment provided by Wuli Lake as well as their willingness to pay for an integrated control program. Results from 452 questionnaires indicated that respondents were willing to pay 22.6 RMB per year per person (aggregate value of 56.5 million RMB per year) for the water quality aspects of the lake environment prior to implementation of the integrated control program and 891 RMB per year per person (222.75 million RMB per year) after the program’s implementation The results also indicated that respondents were willing to pay 140.2 RMB per year per person (620.63 million RMB annually) for the integrated control program. This indicates that the residents of Wuxi City value the water environment and would be willing to pay for the maintenance of and improvements to the water eco-environment.