(1) Legislative Findings and Purpose. Council finds that development along the existing rivers and creeks within the City of Philadelphia has led to increased flooding, thereby endangering the loss of property and life, creating health and safety hazards, and causing the expenditure of public funds for protection and relief. To prevent such adverse conditions, it is necessary to impose restrictions and regulations on development along rivers and creeks that are subject to flooding.

(2) These special restrictions and regulations shall apply to the One-Hundred- Year Flood Plain along the Delaware and Schuylkill Rivers, the Poquessing Creek, the Byberry Creek, Walton Run, the Pennypack Creek, Wooden Bridge Run, the Tacony-Frankford Creek, the Wissahickon Creek, the Darby Creek, Cobbs Creek and Indian Creek, more fully defined in the Flood Insurance Study by the United States Department of Housing and Urban Development, Federal Insurance Administration dated December, 1978, or hereafter amended and approved by the Federal Insurance Administrator. The maps shall be filed with the Department of Licenses and Inspections, the Water Department and the Philadelphia City Planning Commission, and shall be available for public inspection upon request. All such controls shall supplement other provisions of this Title.

(3) Definitions:

(a) Development. See 10-1101(1) of The Philadelphia Code.

(b) FBFM. Flood Boundary and Floodway Map.^[284]

(c) Flood. A temporary inundation of normally dry land areas.

(d) Flood Plain or Flood Prone Area. Relatively flat or low land adjoining a stream, river, or watercourse, which is subject to partial or complete inundation; or, any area subject to the unusual and rapid accumulation or run-off of surface waters from any source.

(e) Floodway. The designated area of a flood plain required to carry and discharge floodwaters of a given magnitude.

(f) Floodway Fringe. That portion of the flood plain outside the floodway.

(g) One-Hundred-Year Flood. A flood that on the average, is likely to occur once every one hundred years (i.e., that has a one percent chance of occurring each year, although the flood may occur in any year); for purposes of this Section, the Regulatory Flood.

(h) Regulatory Flood. The flood which has been selected to serve as the basis upon which the flood plain management provisions of this [Section] and other ordinances have been prepared; for the purpose of this [Section], the One-Hundred-Year Flood.

(i) A Regulatory Flood Elevation. The One-Hundred-Year Flood Elevation, as defined by the Flood Insurance Study.

(j) Substantial Improvement. Any repair, reconstruction or addition to a structure which equals or exceeds fifty percent (50%) of the market value of the structure before improvement or repair commences.^[285]

(4) Applicability. These restrictions and controls shall not be applicable to construction, development or substantial improvement for which State or Federal approvals have been granted prior to the adoption of this Section.

(5) Special Controls. The following special controls are imposed to regulate setbacks in the flood plain, construction, and earth-moving activity along watercourses subject to flooding. These controls are in addition to the requirements of the Pennsylvania Department of Environmental Resources:

(a) Within the Floodway:

(.1) No encroachment (including fill, new construction, or any development) is permitted except that public utilities are permitted as long as they cause no increase in the One-Hundred (100) Year Flood level.

(.2) Public utilities shall be prohibited from placing mobile homes and/or offices within the floodway.

(.3) Construction or substantial improvement of any structure used for the production or storage of any of the following list of materials; or used for any activity requiring the maintenance of a supply in excess of five hundred fifty (550) gallons or other comparable volume; or used for any purpose involving the production, storage, or use of any amount of radioactive substance shall be prohibited; and no variances shall be granted by the Zoning Board of Adjustment:^[286]

(.a) Acetone;

(.b) Ammonia;

(.c) Benzene;

(.d) Calcium carbide;

(.e) Carbon disulfide;

(.f) Celluloid;

(.g) Chlorine;

(.h) Hydrochloric acid;

(.i) Hydrocyanic acid;

(.j) Magnesium;

(.k) Nitric acid and oxides of nitrogen;

(.l) Petroleum products--gasoline, fuel oil, and the like;

(.m) Phosphorus;

(.n) Potassium;

(.o) Sodium;

(.p) Sulphur and sulphur products;

(.q) Pesticides (including insecticides, fungicides, and rodenticides);

(.r) Radioactive substances insofar as such substances are not otherwise subject to regulation.

(b) Within the Floodway Fringe:

(.1) The development and/or use of land shall be permitted in accordance with the Zoning Code.

(.2) Construction of dwellings is permitted if the lowest floor elevation (including basements and cellars) is one foot (1∋) above the Regulatory Flood Elevation.

(.3) Construction of non-residential structures is permitted if the structure is floodproofed to one foot (1∋) above the Regulatory Flood Elevation.

(.4) If fill is used to raise the elevation of the site for residential construction, the fill area shall extend out laterally for the minimum required rear yard dimension but in no case less than fifteen feet (15∋) beyond the proposed structure. Of this rear yard, a maximum slope of one percent (1%) is permitted. The grade from the edge of the rear yard to the floodway line shall not exceed twenty percent (20%) unless a retaining wall is constructed.

(.5) Construction or substantial improvement of any structure used for the production or storage of any of the following list of materials; or used for any activity requiring the maintenance of a supply in excess of five hundred fifty (550) gallons or other comparable volume; or used for any purpose involving the production, storage, or use of any amount of radioactive substance shall be permitted if it is elevated or floodproofed to remain completely dry to one and one-half (1½) feet above the Regulatory Flood Elevation; and no variances shall be granted by the Zoning Board of Adjustment:^[287]

(.a) Acetone;

(.b) Ammonia;

(.c) Benzene;

(.d) Calcium carbide;

(.e) Carbon disulfide;

(.f) Celluloid;

(.g) Chlorine;

(.h) Hydrochloric acid;

(.i) Hydrocyanic acid;

(.j) Magnesium;

(.k) Nitric acid and oxides of nitrogen;

(.l) Petroleum products--gasoline, fuel oil, and the like;

(.m) Phosphorus;

(.n) Potassium;

(.o) Sodium;

(.p) Sulphur and sulphur products;

(.q) Pesticides (including insecticides, fungicides, and rodenticides;

(.r) Radioactive substances insofar as such substances are not otherwise subject to regulation.

(c) Within the approximate One-Hundred-Year Flood boundary as defined by the FBFM:^[288]

(.1) Development shall be permitted in accordance with Section 14-1606(5)(b).

(.2) The Water Department shall determine the regulatory flood elevation in accordance with standard hydrologic and hydraulic engineering methods.

(d) Prohibited Uses:^[289]

(.1) New structures or any additions to existing structures containing as the main use the following use classifications shall be prohibited within the One Hundred Year Flood Plain as defined on the FBFM Map:^[290]
(.a) Medical and surgical hospitals and medical centers, and sanitaria;

(.b) Rest, old age, nursing or convalescent homes, and nurseries;

(.c) Penal and correctional institutions;

(.d) Mobile homes.

(.2) A special permit for the uses set forth in (5)(d)(.1)(.a) through (.d) above may be obtained from the Department of Licenses and Inspections in accordance with the provisions of Act 166 of 1978, known as the "Pennsylvania Flood Plain Management Act," and the regulations promulgated thereunder, pertaining to the issuance of special permits. Special permits shall not be issued unless the criteria in the Act and regulations for the issuance of such permits have been met by the applicant and approved by the Department of Community Affairs.