Permit for alteration of watercourses.

Sec. 25. Hereafter, no person, firm, corporation, or municipality shall artificially alter the stage of water or widen or deepen the channel of any watercourse, except drains established by public authority, without first securing a written permit therefor from the commissioner or commissioners having jurisdiction over all the bridges and culverts on or over said watercourse, or the portion thereof affected by such proposed change.