The territory of the Town of Dunham has two drainage basins: the Yamaska River for the northeast part of the territory and that of the Missisquoi Bay for the southwest part.

Several small rivers are accessible, as well as Selby Lake. The management of the rivers is under the jurisdiction of the Brome-Missisquoi Regional county municipality (MRC). On their website, you will find information about water management (management of surface water, rivers, buffer strip nurseries, etc.).

Various local organizations are devoted to protecting the water and are working in conjunction with the municipality, the MRC and the Ministry of Sustainable Development, Environment and Action against Climate Change (MDDELCC) for the protection of lakes and rivers. One has only to think of organizations such as bassins versants (OBV) de la Yamaska and Baie Missisquoi and, at the local level, the Association pour la Protection de l’Environnement du Lac Selby (A.P.E.L.S.).