It shall be unlawful for any person to permit any drainage system, canal, ditch, conduit or other watercourse of any kind or nature, natural or artificial, to become so obstructed as to cause the water to back up and overflow therefrom, or to become unsanitary.

Maintenance of any such watercourse in such condition shall constitute a nuisance and the same shall be subject to abatement. (1978 Code § 10-316)