What strategies can help communities to overcome the public goods problem in the maintenance of communal spaces and infrastructure in urban environments This paper investigates whether an intervention targeted at Community-Based Organizations can motivate them to make increased contributions to the public good, thereby improving outcomes for the community. Using a randomized controlled trial conducted in Dakar, Senegal, the analysis tests the effectiveness of a program that provides incentives to community groups to encourage them to keep their neighborhoods clean, with the ultimate goal of reducing flooding. After one year, the intervention proved to be effective in engaging communities, improving cleanliness, and reducing flooding.