It is unlawful for any person by himself, family, servants or agents to take or use water coming through the water mains without paying therefor as herein provided, or without authority, to open any stopcock, valve, water meter or other fixture attached to the system of water supply, or in any way to injure, deface or impair any part or any appurtenance of the waterworks, or to cast anything into any reservoir or tank of the waterworks. (1990 Code § 13.04.180)