[R.O. 1996 § 415.010; Ord. No. 2393 § 1, 11-28-2016]
A. Statutory Authorization. The legislature
of the State of Missouri has in Section 79.110, RSMo., as amended,
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 Grain
Valley, Missouri, ordains as follows.
B. Findings Of Fact.
1.
Flood Losses Resulting From Periodic
Inundation. The special flood hazard areas of Grain Valley, 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.
2.
General Causes Of The Flood Losses.
These flood losses are caused by:
a.
The cumulative effect of development
in any delineated floodplain causing increases in flood heights and
velocities; and
b.
The occupancy of flood hazard areas
by uses vulnerable to floods, hazardous to others, inadequately elevated
or otherwise unprotected from flood damages.
3.
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.
a.
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. The base flood is the flood that is estimated to
have a one percent (1%) chance of being equaled or exceeded in any
given year as delineated on the Federal Insurance Administrator’s
FIS and illustrative materials for Jackson County, dated December
7, 2023, as amended, and any future revisions thereto.
[Ord. No. 2431, 8-28-2023]
b.
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.
c.
Computation of a floodway required
to convey this flood without increasing flood heights more than one
(1) foot at any point.
d.
Delineation of floodway encroachment
lines within which no development is permitted that would cause any
increase in flood height.
e.
Delineation of flood fringe, i.e.,
that area outside the floodway encroachment lines but still subject
to inundation by the base flood.
C. Statement Of Purpose. It is the purpose of this Chapter to promote the public health, safety and general welfare; to minimize those losses described in Subsection
(B)(1) above; 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:
1.
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.
2.
Require uses vulnerable to floods,
including public facilities that serve such uses, be provided with
flood protection at the time of initial construction.
3.
Protect individuals from buying lands
that are unsuited for the intended development purposes due to the
flood hazard.