(2) that a regional watercourse under its exclusive jurisdiction is henceforth a local watercourse under the jurisdiction of the local municipality whose territory includes the watercourse or is bounded by it.A regional county municipality, after having declared that a local watercourse is henceforth a regional watercourse, may, when occasion requires, determine by by-law or procès-verbal, which municipality is responsible for the maintenance of such watercourse, and may declare in such by-law or procès-verbal what proportion each municipality shall contribute.