This study aims to determine the number of people willing to pay (WTP) for clean water using the Contingent Valuation Method (CVM). The sub-watersheds are located on the Pucang Sawit, Pepe, Premulung, and Kalianyar rivers. The data were random collected through interviews using questionnaires. The primary data consisted of four types, namely socioeconomic, perceptions of the environment and clean water, conservation of polluted water and simulations. The calculation of WTP with the CVM approach was carried out in 4 stages, including creating a hypothetical market, obtaining the WTP value, using an analytical model with dummy variables, and data analysis. The data analysis includes descriptive, regression, model significance, coefficient of determination (R2), and partial test. The results showed that 69.2% of respondents chose the 3rd simulation, with the willingness to plant 20 clumps of portulaca plants, to clean 50 litres of water for IDR 300,000. Based on the partial test, the variables that significantly affect WTP were the monthly expense, number of family members, gender, participation in environmental activities, and willingness to pay for water conservation. The contribution of this study is to be able to determine the WTP of a water conservation activity polluted in another area.