The agricultural plain of the St. Lawrence Valley ends at Saint-Tite at the foot of Laurentians. Saint-Tite is located in the watershed of the Rivière des Envies, whose main tributary is the Little Mekinac River. The major lakes are: Trottier, Perchaude and Pierre-Paul. This lake is the head of the Pierre-Paul River flowing into Sainte-Thècle, Quebec and Saint-Adelphe, Quebec, to throw in the Batiscan River, at the height the village of Saint-Adelphe.