[Ord. No. 1812 §1, 1-20-2015[1]]
The Legislature of the State of Missouri has, in RSMo. 79.110, delegated the responsibility to local governmental units to adopt floodplain management regulations designed to protect the health, safety, and general welfare. Therefore, the Board of Aldermen of the City of Rock Hill, Missouri, ordains as follows.
[1]
Editor's Note: This ordinance also provided for the repeal of former Ch. 415, Flood Damage Prevention, adopted 3-17-1987 by Ord. No. 1118, as amended.
[Ord. No. 1812 §1, 1-20-2015]
A. 
Flood Losses Resulting From Periodic Inundation. The special flood hazard areas of the City of Rock Hill, Missouri, 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.
B. 
General Causes Of The Flood Losses. These flood losses are caused by:
1. 
The cumulative effect of development in any delineated floodplain causing increases in flood heights and velocities; and
2. 
The occupancy of flood hazard areas by uses vulnerable to floods, hazardous to others, inadequately elevated, or otherwise unprotected from flood damages.
C. 
Methods Used To Analyze Flood Hazards. The Flood Insurance Study (FIS) that is the basis of this Chapter uses a standard engineering method of analyzing flood hazards which consists of a series of interrelated steps.
1. 
Selection of a base flood that 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 base flood selected for this Chapter is representative of large floods which are characteristic of what can be expected to occur on the particular streams subject to this Chapter. It is in the general order of a flood which could be expected to have a one-percent chance of occurrence in any one (1) year as delineated on the Federal Insurance Administrator's FIS, and illustrative materials for St. Louis County dated February 4, 2015, as amended, and any future revisions thereto.
2. 
Calculation of water surface profiles are based on a standard hydraulic engineering analysis of the capacity of the stream channel and overbank areas to convey the regulatory flood.
3. 
Computation of a floodway required to convey this flood without increasing flood heights more than one (1) foot at any point.
4. 
Delineation of floodway encroachment lines within which no development is permitted that would cause any increase in flood height.
5. 
Delineation of flood fringe, i.e., that area outside the floodway encroachment lines but still subject to inundation by the base flood.
[Ord. No. 1812 §1, 1-20-2015]
It is the purpose of this Chapter to promote the public health, safety, and general welfare; to minimize those losses described in Section 415.020(A); to establish or maintain the community's eligibility for participation in the National Flood Insurance Program (NFIP) as defined in 44 Code of Federal Regulations (CFR) 59.22(a)(3); and to meet the requirements of 44 CFR 60.3(d) by applying the provisions of this Chapter to:
A. 
Restrict or prohibit uses that are dangerous to health, safety, or property in times of flooding or cause undue increases in flood heights or velocities;
B. 
Require that uses vulnerable to floods, including public facilities that serve such uses, be provided with flood protection at the time of initial construction; and
C. 
Protect individuals from buying lands that are unsuited for the intended development purposes due to the flood hazard.