This study is an application of CVM to a specific area in Brazil, the Corumbatai river basin, in the state of Sao Paulo, aiming to estimate the value attached by affected people to a hypothetical riparian forest restoration project. The method used was the double bounded dichotomous choice under a logit model. Data were obtained by street-intercept interviews with a net sample of 930 individuals, 20 years or older, living in seven municipalities (cities and respective rural areas) that contain the basin. Protest bid responses were not excluded in a first approximation, resulting in a R$ 2.06 mean willingness to pay (WTP) for the riparian forest restoration, equivalent to approximately R$ 274,000 per month (R$ 1.00 equivalent to US$ 0.52 at the survey period) when accounting for about 133,000 residences in the area. It was observed an expressive number of "no-no" responses from people ascribing the problem to government and farmers and suspecting on misuse of funds by the official agencies involved.