The delineation of any of the floodplain district may be revised
by the Board of Supervisors where natural or man-made changes have
occurred and/or where more detailed studies have been conducted or
undertaken by the United States Army Corps of Engineers or other qualified
agency or an individual documents the need for a change. However,
prior to any such change, approval must be obtained from FEMA. An
approved letter of map revision (LOMR) serves as record of this change.
Initial interpretations of the boundaries of the floodplain
districts shall be made by the Floodplain Administrator or designee.
Should a dispute arise concerning the boundaries of any of the districts,
the Board of Zoning Appeals shall make the necessary determination.
The person questioning or contesting the location of the district
boundary shall be given a reasonable opportunity to present his case
to the Board of Zoning Appeals and to submit his own technical evidence
if he so desires.
A community's base flood elevations may increase or decrease
resulting from physical changes affecting flooding conditions. As
soon as practicable, but not later than six months after the date
such information becomes available, a community shall notify FEMA
of the changes by submitting technical or scientific data. The data
may be submitted via an LOMR. Such a submission is necessary so that
upon confirmation of those physical changes affecting flooding conditions,
risk premium rates and floodplain management requirements will be
based upon current data.
The Floodplain Administrator and the applicant shall not use
changed flood hazard area boundaries or base flood elevations for
proposed buildings or developments unless the Floodplain Administrator
or applicant has applied for a conditional FIRM revision and has received
the approval of FEMA.
If design flood elevations are not specified, the Floodplain
Administrator is authorized to require the applicant to:
A. Obtain, review and reasonably utilize data from a federal, state,
or other source; or
B. Determine the design flood elevation in accordance with accepted
hydrologic and hydraulic engineering techniques. Such analyses shall
be performed and sealed by a registered design professional. Studies,
analyses, and computations shall be submitted in sufficient detail
to allow review and approval by the Floodplain Administrator. The
accuracy of data submitted for such determination shall be the responsibility
of the applicant.
In riverine flood hazard areas where design flood elevations
are specified (Zone AE) but floodways have not been designated, the
Floodplain Administrator shall not permit any new construction, substantial
improvement or other development, including fill, unless the applicant
submits an engineering analysis prepared by a registered design professional
that demonstrates that the cumulative effect of the proposed development,
when combined with all other existing and anticipated flood hazard
area encroachment, will not increase the design flood elevation more
than one foot at any point within the community.
Prior to issuing a permit for any floodway encroachment, including
fill, new construction, substantial improvements and other development
or land-disturbing activity, the Floodplain Administrator shall require
submission of a certification prepared by a registered design professional,
along with supporting technical data, which demonstrates that such
development will not cause any increase in the base flood level.
A. Floodway revisions. A floodway encroachment that increases the level
of the base flood is authorized if the applicant has applied for a
conditional Flood Insurance Rate Map (FIRM) revision and has received
the approval of FEMA.
Prior to issuing a permit for any alteration or relocation of
any watercourse, the Floodplain Administrator shall require the applicant
to provide notification of the proposal to the appropriate authorities
of all adjacent government jurisdictions, as well as the appropriate
state agencies. A copy of the notification shall be maintained in
the permit records and submitted to FEMA.
A. Engineering analysis. The Floodplain Administrator shall require
submission of an engineering analysis prepared by a registered design
professional, demonstrating that the flood-carrying capacity of the
altered or relocated portion of the watercourse will not be decreased.
Such watercourses shall be maintained in a manner that preserves the
channel's flood-carrying capacity.
For applications for building permits to improve buildings and
structures, including alterations, movement, repair, additions, rehabilitations,
renovations, substantial improvements, repairs of substantial damage,
and any other improvement of or work on such buildings and structures,
the Floodplain Administrator, in coordination with the Building Official,
shall:
A. Estimate the market value, or require the applicant to obtain a professional
appraisal prepared by a qualified independent appraiser, of the market
value of the building or structure before the start of construction
of the proposed work; in the case of repair, the market value of the
building or structure shall be the market value before the damage
occurred and before any repairs are made.
B. Compare the cost to perform the improvement, the cost to repair the
damaged building to its pre-damaged condition, or the combined costs
of improvements or repairs, where applicable, to the market value
of the building or structure.
C. Determine and document whether the proposed work constitutes substantial
improvement or repair of substantial damage.
D. Notify the applicant when it is determined that the work constitutes
substantial improvement or repair of substantial damage and that compliance
with the flood-resistant construction requirements of the Building
Code is required and notify the applicant when it is determined that
work does not constitute substantial improvement or repair of substantial
damage.
It shall be the responsibility of the Floodplain Administrator
to assure that approval of proposed development shall not be given
until proof that necessary permits have been granted by federal or
state agencies having jurisdiction over such development, including
Section 404 of the Clean Water Act.