It shall be unlawful for any person to throw or otherwise dispose of trash, debris, tree laps, logs, or fell timber or make or cause to be made any obstruction which exists for more than a week (excepting a lawfully constructed dam) in, under, over or across any river, creek, stream, or swamp, so as to obstruct the free passage of boats, canoes, or other floating vessels, or fish in such waters. The provisions of this section shall be enforceable by duly authorized state and local law-enforcement officials and by conservation police officers whose general police power under § 29.1-205 and forest wardens whose general police powers under § 10.1-1135 shall be deemed to include enforcement of the provisions of this section. Violations of this section shall be punishable as a misdemeanor under § 18.2-12; and each day for which any violation continues without removal of such obstruction, on and after the tenth day following service of process on the violator in accordance with § 19.2-75, shall constitute a separate offense punishable as a misdemeanor under § 18.2-12.