Man-made structures shall be kept to a minimum and bridges, culverts or rip-rap shall be constructed to maintain the natural characteristics of the stream and shall meet the approval of the Township. (Ord. 644. Passed 8-17-88.)
1043.07 RETENTION/DETENTION BASINS TO UTILIZE NATURAL CONTOURS OF LAND.
Retention/detention basins shall be designed to utilize the natural contours of the land whenever possible. When such design is impracticable, the construction of basins shall utilize slopes as shallow as possible to blend the structure into the terrain. (Ord. 644. Passed 8-17-88.)
1043.08 SUBDIVISIONS AND LAND DEVELOPMENT IN FLOOD CONTROL DISTRICTS.
Any subdivision and/or land development within a Flood Control District shall comply with all the provisions of Chapter 1442 of the Building and Housing Code and the rules and regulations of Pennsylvania Department of Environmental Resources. (Ord. 644. Passed 8-17-88.)
1043.09 AREAS CONTAINING LAKES, WETLANDS, ETC.
All areas containing lakes, ponds, wetlands and watercourses shall be considered to be reserved for permanent open space. Any alteration, development, filling, piping or diverting of such water resources shall be in strict compliance with the provisions of the Zoning Code, especially those requirements pertaining to the flood zone set forth in Chapter 1286, and all prevailing rules and regulations of the State and Federal Governments. (Ord. 644. Passed 8-17-88.)
1043.10 CORRECTION OF OFF-SITE DRAINAGE PROBLEMS.
The Board of Commissioners may require that a landowner or developer provide reasonable corrective measures to alleviate an existing off-site drainage problem which may be affected by the proposed subdivision and/or land development. It shall be the responsibility of the landowner or developer to obtain all drainage easements on, over or through other properties, and the Township, its agents, workers, servants and employees shall be indemnified and held harmless from any liability. (Ord. 644. Passed 8-17-88.)
1043.11 WATER FROM NON-NATURAL SOURCES.
Any water originating from non-natural sources, such as swimming pools, air conditioning units, sump pumps, roof drains or other similar flow, shall be properly discharged into natural watercourses or storm drains. (Ord. 644. Passed 8-17-88.)
1043.12 STREAMS AND INTERMITTED STREAMS DEFINED.
For the purpose of this section, “streams” and ‘intermitted streams” are defined as those watercourses depicted on the Township Map, the U.S.G.S. maps of the area, and/or determined as such pursuant to an on-site survey by the Township or its representative. (Ord. 644. Passed 8-17-88.)
(a) The storm sewer system shall be designed to carry a ten-year peak flow rate, with a twenty-five year peak flow rate at all low points. The peak flow rate into each inlet shall be indicated on the stormwater drainage plan. The design flow rate shall be determined by the rationale formula, Q = CIA, where:
| Q | = | Peak runoff rate, cubic feet per second (CFS). | ||
| C | = | Runoff coefficient equal to the rate of the peak runoff rate to the average rate of rainfall over a time period equal to the time of concentration. | ||
| I | = | Average rainfall intensity in inches per hour for a time equal to the time of concentration. | ||
| A | = | Drainage area in acres. |
(b) Appropriate values for the runoff coefficient and rainfall intensity shall be taken from the following source:
Commonwealth of Pennsylvania
Design Manual, Part 2
Highway Design
August, 1981 (or the latest revision thereof)