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

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

Some organizations are devoted to protecting the water and are working in concert with the municipality, the RCM 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.).