The identified floodplain area shall be:
A. Any areas of the Borough, classified as special flood hazard areas
(SFHAs) in the Flood Insurance Study (FIS) and the accompanying Flood
Insurance Rate Maps (FIRMs) dated September 29, 2017, and issued by
the Federal Emergency Management Agency (FEMA), or the most recent
revision thereof, including all digital data developed as part of
the Flood Insurance Study.
B. The above-referenced FIS and FIRMs, and any subsequent revisions
and amendments, are hereby adopted by the Borough and declared to
be a part of this chapter.
The identified floodplain area shall consist of the following
specific areas:
A. The floodway area shall be those areas identified in the FIS and
the FIRM as floodway and which represent the channel of a watercourse
and the adjacent land areas that shall be reserved in order to discharge
the base flood without increasing the water surface elevation by more
than one foot at any point. This term shall also include floodway
areas which have been identified in other available studies or sources
of information for those special flood hazard areas where no floodway
has been identified in the FIS and FIRM.
(1) Within any floodway area, no encroachments, including fill, new construction,
substantial improvements, or other development shall be permitted
unless it has been demonstrated through hydrologic and hydraulic analysis
performed in accordance with standard engineering practice that the
proposed encroachment would not result in any increase in flood levels
within the Borough during the occurrence of the base flood discharge.
(2) Within any floodway area, no new construction or development shall
be allowed, unless the appropriate permit is obtained from the Pennsylvania
Department of Environmental Protection Regional Office.
B. The AE Area/District shall be those areas identified as an AE Zone
on the FIRM included in the FIS prepared by FEMA for which base flood
elevations have been provided.
(1) The AE Area adjacent to the floodway shall be those areas identified
as an AE Zone on the FIRM included in the FIS prepared by FEMA for
which base flood elevations have been provided and a floodway has
been delineated.
(2) AE Area without floodway shall be those areas identified as an AE
Zone on the FIRM included in the FIS prepared by FEMA for which base
flood elevations have been provided but no floodway has been determined.
(a)
No permit shall be granted within any AE Zone without floodway;
no encroachments, including fill, new construction, substantial improvements,
or other development shall be permitted unless it has been demonstrated
through hydrologic and hydraulic analysis performed in accordance
with standard engineering practice that the proposed development,
together with all other existing and anticipated development, would
not result in an increase in flood levels of more than one foot within
the Borough during the occurrence of the base flood discharge.
(b)
No new construction or development shall be located within the
area measured 50 feet landward from the top-of-bank of any watercourse,
unless the appropriate permit is obtained from the Pennsylvania Department
of Environmental Protection Regional Office.
C. The A Area/District shall be those areas identified as an A Zone
on the FIRM included in the FIS prepared by FEMA and for which no
base flood elevations have been provided. For these areas, elevation
and floodway information from other federal, state, or other acceptable
sources shall be used when available. Where other acceptable information
is not available, the base flood elevation shall be determined by
using the elevation of a point on the boundary of the identified floodplain
area which is nearest the construction and/or site. In lieu of the
above, the municipality may require the applicant to determine the
elevation with hydrologic and hydraulic engineering techniques. Hydrologic
and hydraulic analyses shall be undertaken only by professional engineers
or others of demonstrated qualifications, who shall certify that the
technical methods used correctly reflect currently accepted technical
concepts. Studies, analyses, computations, etc., shall be submitted
in sufficient detail to allow a thorough technical review by the municipality.
In the absence of any of the above data or documentation, the Borough
may require elevation of the lowest floor to be at least three feet
above the highest adjacent grade. In helping to make this necessary
elevation determination, other sources of data, where available, shall
be used, such as:
(1) Areas identified as having alluvial soil types which are subject
to flooding as indicated in the Soil Survey for Delaware and Chester
Counties, Natural Resources Conservation Service, United States Department
of Agriculture.
(2) Corps of Engineers - Floodplain Information Reports.
(3) U.S. Geological Survey - Flood-Prone Quadrangles.
(4) Pennsylvania Department of Environmental Protection - Flood Control
Investigations.
(5) Known high-water marks from past floods.
(6) On-site field survey, to fix the precise boundaries on the floodplain
district survey maps of such, shall be sealed and certified by a professional
engineer, registered and licensed by the Commonwealth of Pennsylvania
to perform such surveys, and filed with the Zoning Officer. Any property
owner shall pay all costs of these surveys except for work done under
retainer to or on behalf of the Borough.
D. The AO and AH Area/District shall be those areas identified as Zones
AO and AH on the FIRM and in the FIS. These areas are subject to inundation
by one-percent annual chance shallow flooding where average depths
are between one and three feet. In Zones AO and AH, drainagepaths
shall be established to guide floodwaters around and away from structures
on slopes.
The identified floodplain area may be revised or modified by the Council where studies or information provided by a qualified agency or person documents the need for such revision. However, prior to any such change to the special flood hazard area, approval shall be obtained from FEMA. Additionally, as soon as practicable, but not later than six months after the date such information becomes available, the Borough shall notify FEMA of the changes to the special flood hazard area by submitting technical or scientific data. See §
140-22B for situations where FEMA notification is required.
Should a dispute concerning any identified floodplain boundary
arise, an initial determination shall be made by the Borough, and
any party aggrieved by this decision or determination may appeal to
the Council. The burden of proof shall be on the appellant.
Prior to development occurring in areas where annexation or
other corporate boundary changes are proposed or have occurred, the
Borough shall review flood hazard data affecting the lands subject
to boundary changes. The Borough shall adopt and enforce floodplain
regulations in areas subject to annexation or corporate boundary changes
which meet or exceed those in 44 CFR 60.3.