Before exploitation, the river was rich with life. Urban, industrial, and intensive agricultural use have made it one of the most polluted rivers in Quebec, especially from agricultural waste and pesticides; nevertheless, many municipalities use it as their source for drinking water. Although the number of species of living organisms has greatly decreased, a tenacious ecosystem still thrives along many parts of the Yamaska, some efforts are made by the citizens of various municipalities to alter human impact on the environments that connect to the stream. The Yamaska is used for recreational activities such as fishing and many navigate its waters, though it is not used for swimming.