A. 
The identified floodplain area shall be any areas of Derry Borough classified as special flood hazard areas (SFHAs) in the Flood Insurance Study (FIS) and the accompanying Flood Insurance Rate Maps (FIRMs) dated March 17, 2011, 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 of Derry and declared to be a part of this chapter.
The identified floodplain area shall consist of the following specific areas:
A. 
Floodway area.
(1) 
Description: the area identified as floodway in the FIS that represents the channel of a watercourse and the adjacent land areas that must be reserved in order to discharge the base flood without cumulatively increasing the water surface elevation by more than one foot at any point. This term shall also include floodway areas that have been identified in other available studies or sources of information for those special floodplain areas where no floodway has been identified in the FIS.
(2) 
Special requirements:
(a) 
Any encroachment that would cause any increase in flood heights shall be prohibited.
(b) 
No new construction or development shall be allowed, unless a permit is obtained from the Department of Environmental Protection Regional Office.
B. 
Special floodplain area.
(1) 
Description: the areas identified as Zones AE and A1-30 in the FIS which are subject to inundation by the one-percent-annual chance flood event determined by detailed methods and have base flood elevations (BFEs) shown.
(2) 
Special requirements:
(a) 
No new construction or development shall be located within the area measured 50 feet landward from the top-of-bank of any watercourse, unless a permit is obtained from the Department of Environmental Protection Regional Office.
(b) 
In special floodplain areas without a designated floodway, no new development shall be permitted unless it can be demonstrated that the cumulative effect of all past and projected development will not increase the BFE by more than one foot.
C. 
Approximate floodplain area.
(1) 
Description: the areas identified as Zone A in the FIS that are subject to inundation by the one-percent-annual-chance flood event determined using approximate methodologies. Because detailed hydraulic analyses have not been performed, no BFEs or flood depths are shown.
(2) 
Special requirements:
(a) 
No new construction or development shall be located within the area measured 50 feet landward from the top-of-bank of any watercourse, unless a permit is obtained from the Department of Environmental Protection Regional Office.
(b) 
When available, information from other federal, state, and other acceptable sources shall be used to determine the BFE, as well as a floodway area, if possible. When no other information is available, the BFE shall be determined by using a point on the boundary of the identified floodplain area that is nearest the construction site in question.
(c) 
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 Borough of Derry Engineer.
The identified floodplain area may be revised or modified by the Derry Borough Council where studies or information provided by a qualified agency or person documents the need for such revision. However, prior to any such change, approval must be obtained from the FEMA. Additionally, as soon as practicable, but not later than six months after the date such information becomes available, a community shall notify the FEMA of the changes by submitting technical or scientific data.
Should a dispute concerning any identified floodplain boundary arise, an initial determination shall be made by the Derry Borough Planning Commission and any party aggrieved by this decision or determination may appeal to the Zoning Hearing Board. The burden of proof shall be on the appellant.