(A)  Findings of Fact.

(1)   Flood Losses Resulting from Periodic Inundation. The flood hazard areas of the city are subject to inundation which results in loss of life and property, health and safety hazards, disruption of commerce and governmental services, extraordinary public expenditures for flood protection and relief, and impairment of the tax base all of which adversely affect the public health, safety and general welfare.

(2)   General Causes of these Flood Losses. These flood losses are caused by:

(a)   the cumulative effect of obstructions in floodways causing increases in flood heights and velocities;

(b)   the occupancy of flood hazard areas by uses vulnerable to floods or hazardous to others, which are inadequately elevated or otherwise unprotected from flood damages.

(3)   Methods Used to Analyze Flood Hazards. This article uses a reasonable method of analyzing flood hazards which consists of a series of interrelated steps.

(a)   Selection of a regulatory flood which is based upon engineering calculations which permit a consideration of such flood factors as its expected frequency of occurrence, the area inundated, and the depth of inundation. The reasonably characteristic of what can be expected to occur on the particular streams subject to this article. It is in the general order of a flood which could be expected to have a one percent chance of occurrence in any one year, as delineated on the Federal Insurance Administration’s Flood Insurance Study, and illustrative materials dated July 16, 1980 with accompanying Flood Insurance Rate Maps and flood boundary and floodway maps effective January 16, 1981 as amended, and any future revisions thereto.

(b)   Calculation of water surface profiles based on a hydraulic engineering analysis of the capacity of the stream channel and overbank areas to convey the regulatory flood.

(c)   Computation of the floodway required to convey this flood without increasing flood heights more than one foot at any point.

(d)   Delineation of the floodway encroachment lines within which no obstruction is permitted which would cause any increase in flood height.

(e)   Delineation of the floodway fringe, e.g., that area outside the floodway encroachment lines but which still is subject to inundation by the regulatory flood.

(B)  Statement of Purpose. It is the purpose of this article to promote the public health, safety, and general welfare and to minimize those losses previously described by applying the provisions of this article to:

(1)   Restrict or prohibit uses which are dangerous to health, safety, or property in times of flooding or cause undue increases in flood heights or velocities.

(2)   Require that uses vulnerable to floods, including public facilities which serve such uses, be provided with flood protection at the time of initial construction.

(3)   Protect individuals from buying lands which are unsuited for intended purposes because of flood hazard.

(4)   Assure that eligibility is maintained for property owners in the community to purchase flood insurance in the National Flood Insurance Program