The governing body of the City finds that a substantial area in the City limits consists of lands inundated, or from time to time inundated, and that indiscriminate filling of such lands, excavating or placing piling or other structures therein or thereon can create a hazard to persons and property riot only in the immediate area thereof, but furthermore, by changing the action of currents, tides and movements of water by various means, can create a hazard to other lands in the City and to the occupants thereof and, therefore, that the public health, safety, welfare and convenience require that the filling or excavating of such lands or placing of piling or other structures in such places should be so regulated as to eliminate such hazards if possible and, otherwise, should be prohibited. (Ord. 143 NS § 1, 1966.)