If the department finds that the project will not injure the public trust or interest including fish and game habitat, that the project conforms to the requirements of law for sanitation, and that no material injury to the rights of any riparian owners on any body of water affected will result, the department shall issue a permit authorizing enlargement of the waterway affected. The permit shall provide that the artificial waterway shall be a public waterway, except intake or discharge canals or channels on property owned, controlled, and used by a public utility. The existing and future owners of land fronting on the artificial waterway are liable for maintenance of the waterway in accordance with the conditions of the permit.