(a) Floodway (F1).
(1) Within any floodway area (F1), 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 will not result in any increase in the Base Flood Elevation.
(2) Because floodways present increased risk to human life and property due to their relatively faster and deeper flowing waters the Floodway shall be preserved to the greatest extent possible.
A. New development shall not be permitted in the floodway where reasonable alternatives exist elsewhere. In addition to the requirements below the applicant shall demonstrate that there are no reasonable alternatives other than the floodway encroachment before a permit is issued.
B. When the floodway is the only reasonable alternative the applicant shall demonstrate that the floodway encroachment is the minimum necessary to accomplish the project.
C. All permitted uses, activities, and development shall be undertaken in strict compliance with the flood proofing and related provisions contained herein, and in all other applicable codes, ordinances, and regulations.
(b) Floodway Fringe (F2) and Approximated Floodplain (F4).
(1) A. In the Floodway Fringe (F2) and Approximated Floodplain (F4), any development and/or use of land shall be permitted provided that all such uses, activities and/or development shall be undertaken in strict compliance with the flood-proofing and related provisions contained herein and in all other applicable codes, ordinances, and regulations.
B. In the Approximated Floodplain (F4) the Floodplain Administrator shall review, or shall cause to be reviewed, all proposed development not covered by subsection (b)(1)B.2. below to determine the amount being invested and the specific flood risk at the building site and assign a "minimal, moderate or significant" risk level.
1. Development determined to represent a minimal risk and costing less than ten thousand dollars ($10,000) shall be required to provide "Point on Boundary" elevation data and when available historic flood heights. The Floodplain Administrator shall attempt to determine a height that will be reasonably safe from flooding using this elevation data. If after review, the data is found satisfactory, the Floodplain Administrator shall enter the flood height in Section "G" of the Elevation Certificate. Any new or substantially improved structures permitted using this method (other than appurtenant structures) shall be required to have the lowest floor elevated at least three (3) feet above the highest adjacent grade even if the "point on boundary" or historic flood data would indicate a lower flood elevation. If this method is not adequate to allow the Floodplain Administrator to confidently determine the flood height or if the applicant is not satisfied with the height determined by the Floodplain Administrator the applicant shall be required to utilize one of the alternate methods set forth herein.
2. Development determined to represent a low to moderate risk and/or costing less than fifty thousand dollars ($50,000) shall either:
a. Provide the results of a Quick-2 engineering analysis; or
b. Attempt to obtain a Base Flood Elevation by submitting a Letter of Map Amendment request to FEMA; or
c. Obtain flood height data by using the USGS methodology set forth in the USGS Water Resources Investigation Report 87-4111.
The semidetailed method used will be reviewed by the Floodplain Administrator to determine a "Community Flood Elevation" in Section "G" of the Elevation Certificate. If the applicant is not satisfied with the height determined using these methods the applicant shall be required to utilize the method set forth below.
3. Development determined to represent a high risk and/or costing more than fifty thousand dollars ($50,000) shall develop a Base Flood Elevation using a detailed engineering study method such as HEC-ras. This data shall be prepared and certified by a registered professional engineer, who shall certify that the methods used correctly reflect currently accepted technical concepts. The resultant study shall include a cover letter, signed by the responsible professional, providing a statement of findings in basic terms and a completed Elevation Certificate including Base Flood Elevation. In addition, studies, analyses, computations, etc. shall be submitted in sufficient detail to allow a thorough technical review by the Floodplain Administrator. Base Flood Elevations determined using this method can be used to rate flood insurance, typically resulting in a reduced premium.
(2) All subdivision proposals and other proposed new developments which are proposed to take place either fully or partially within the Approximated Floodplain Area (F4) and which are greater than ten (10) lots or two (2) acres, whichever is the lesser, shall include base flood elevation data.
A. This data may be available from an authoritative source such as the U.S. Army Corps of Engineers, U.S. Geological Survey, Natural Resource Conservation Service or state and local water resource department.
B. If the required data is not available from other sources, the applicant shall develop the technical data using detailed methodologies comparable to those contained in a Flood Insurance Study. This data shall be prepared and certified by a registered professional engineer, who shall certify that the methods used correctly reflect currently accepted technical concepts.
(c) AE Area without Floodway (F3). Within any AE area without floodway, no new construction or development shall be allowed unless it is demonstrated that the cumulative effect of the proposed development, when combined with all other existing and anticipated development, will not increase the elevation of the one hundred (100) year flood more than one (1) foot at any point. This requirement can be satisfied by utilization of the floodway area where determined.
(d) Approximated Floodplain (Zone A). Within any Approximated Floodplain Area:
(1) The Floodplain Administrator shall use elevation and floodway information from Federal, State, or other acceptable sources when available to determine the elevation above which development will be reasonably safe from flooding.
(2) When data from an acceptable source is not available, the Floodplain Administrator shall review, or shall cause to be reviewed, all proposed development to determine:
A. The amount being invested; and
B. The specific flood risk at the site.
The Floodplain Administrator shall then require the applicant to determine the elevation above which the development will be reasonably safe from flooding using the techniques set forth in the City of New Cumberland's Approximate A zone administrative procedures. When hydrologic and hydraulic analyses are required, they shall only be undertaken by a registered professional engineer who shall certify that the methods used correctly reflect currently accepted technical concepts. The resultant study shall include a cover letter, signed by the responsible professional, providing a statement of findings in basic terms. In addition, studies, analyses, computations, etc. shall be submitted in sufficient detail to allow a thorough technical review by the Floodplain Administrator.
Any development and/or use of land shall be permitted provided that all such uses,
activities and/or development shall be undertaken in strict compliance with the floodproofing and related provisions contained herein and in all other applicable codes, ordinances and regulations.
(e) Alteration or Relocation of a Stream.
(1) Whenever a developer intends to alter or relocate a stream within the Floodplain Area the developer shall notify in writing, by certified mail, the City of New Cumberland Floodplain Administrator, the State Coordinating Office, and any adjacent communities and property owners of all such intended activities prior to the alteration or relocation of the stream. Copies of all required notifications must be submitted to the Federal Insurance Administration. In addition, prior to issuing the local permit, the Floodplain Administrator shall require copies of all necessary permits from those governmental agencies from which Federal or State Law requires approval. Contact information for State and Federal permitting authorities as well as addresses for required notification of appropriate County, State, and Federal governmental agencies are contained in the City of New Cumberland Stream Alteration administrative procedures.
(2) The developer shall also assure the City of New Cumberland, in writing, that the carrying within the altered or relocated portion of the stream will be maintained. The Floodplain Administrator may require the applicant to demonstrate that the altered or relocated portion of stream will provide equal or greater conveyance than the original stream segment. If hydrologic and hydraulic analyses are required, they shall only be undertaken by professional engineers who shall certify that the methods used correctly reflect currently accepted technical concepts. The resultant study shall include a cover letter, signed by the responsible professional, providing a statement of findings in basic terms. In addition, studies, analyses, computations. etc. shall be submitted in sufficient detail to allow a thorough technical review by the Floodplain Administrator.
(3) The Floodplain Administrator may require the use of certain "best practice" techniques in the construction of bridges, culverts, or stream crossings to prevent damage, loss of stream crossings and localize flooding caused by blockage. These techniques may include, but are not limited to, wing walls, trash grates, or requiring openings to be of sufficient size to pass debris and/or anticipated future increases in flood heights.
(4) All new and replacement bridges, culverts, and other stream crossings shall adhere to the relevant anchoring requirements contained in this Ordinance.
(5) The developer is required to provide the City a legal agreement detailing all scheduled inspections and maintenance to be performed on altered or relocated watercourses including culverts, bridges and other stream crossings. It shall be the responsibility of the applicant to transfer this agreement to the new owner when the land associated with the watercourse alteration is transferred. A copy of all new agreements shall be provided to the Floodplain Administrator. Failure to transfer the agreement and provide a signed copy to the Floodplain Administrator shall subject the violator to the penalties set forth in Section 1721.08
(c).
(6) The applicant must submit any maps, computations or other material required by the Federal Emergency Management Agency (FEMA) to revise the Flood Insurance Study and/or Flood Insurance Rate Maps, when notified by the Floodplain Administrator, and must pay any fees or other costs assessed by FEMA for this purpose.
(Ord. 10-002. Passed 3-15-10.)