Through the implementation of the contingent valuation method (CVM), the authors seek to reveal individuals’ willingness to pay for a reduction of the risk of erosive runoff in the Commerce Valley (Upper Normandy). A survey was conducted among 221 individuals. One of the goals of this study is to propose a new method to improve the estimation of willingness to pay in the framework of the CVM. This alternative estimator appears to reveal a WTP lower than the actual WTP, but more accurate in individual WTP forecasts than the use of a tobit model. The results also suggest that while the tobit’s forecasts overstate the WTP, their alternative estimator undervalues it.