It is unlawful for any person, organization, institution, corporation or the City of Berkeley to fill, or cause to be filled, to obliterate or cause to be obliterated, to obstruct or cause to be obstructed, to construct a building bridging a creek or cause such building to be constructed, or in any manner to interfere with or cause to be interfered with, any natural watercourse in Berkeley which carries off at any time of the year any storm water, or any surface waters, which have been precipitated by rains. This chapter does not apply to structures or conditions existing in creeks on or before January 4, 1990. (Ord. 6956-NS § 1 (part), 2006: Ord. 5961-NS § 2, 1989)