21. Construction of a permanent undertaking in a watercourse must not widen the watercourse beyond the high-water mark, unless the undertaking is aimed at restoring the natural width of the watercourse. The same applies for the installation of a permanent facility.
A watercourse may not be permanently narrowed by encroaching on more than 20% of its width or, where an undertaking or facility is present that has already narrowed the watercourse by encroaching on more than 20% of its width, it may not be further narrowed beyond the extent of that existing encroachment.
871-2020O.C. 871-2020, s. 21.