1. Any stormwater facility located on State highway rights-of-way shall be subject to approval by PennDOT.
2. Pretreatment in accordance with §§221(12) and 221(13) shall be provided prior to infiltration.
3. All wet basin designs shall incorporate biologic controls consistent with the West Nile guidance found in Appendix E.
4. Any stormwater management facility (i.e., BMP, detention basin) designed to store runoff and requiring a berm or earthen embankment required or regulated by this Part shall be designed to provide an emergency spillway to handle flow up to and including the one hundred (100) year proposed conditions. The height of embankment must provide a minimum one (1.0) foot of freeboard above the maximum pool elevation computed when the facility functions for the one hundred (100) year proposed conditions inflow. Should any stormwater management facility require a dam safety permit under Chapter 105, the facility shall be designed in accordance with Chapter 105 and meet the regulations of Chapter 105 concerning dam safety which may be required to pass storms larger than the one hundred (100) year event.
5. Any facilities that constitute water obstructions (e.g., culverts, bridges, outfalls, or stream enclosures), and any work involving wetlands governed by Chapter 105 shall be designed in accordance with Chapter 105 and will require a permit from DEP.
6. Any other drainage conveyance facility that does not fall under Chapter 105 must be able to convey at a minimum, without damage to the drainage structure or roadway, runoff from the fifty (50) year design storm with a minimum one (1.0) foot of freeboard measured below the lowest point along the top of the roadway. Any facility that constitutes a dam as defined in Chapter 105 may require a permit under dam safety regulations. Any facility located within a PennDOT right-of-way must meet PennDOT minimum design standards and permit submission requirements.
7. Any drainage conveyance facility and/or channel not governed by Chapter 105 must be able to convey at a minimum, without damage to the drainage structure or roadway, runoff from the fifty (50) year design storm. Conveyance facilities to or exiting from stormwater management facilities (i.e., detention basins) shall be designed to convey the design flow to or from that structure. Roadway crossings located within designated floodplain areas must be able to convey runoff from a one hundred (100) year design storm. Any facility located within a PennDOT right-of-way must meet PennDOT minimum design standards and permit submission requirements.
8. Storm sewers must be able to convey at a minimum proposed conditions runoff from a fifty (50) year design storm without surcharging inlets, where appropriate. Storm sewers and other drainage conveyance systems may be required to convey larger design storms based on individual drainage/sub-drainage area characteristics.
9. Adequate erosion protection shall be provided along all open channels, and at all points of discharge.
10. The design of all stormwater management facilities shall incorporate sound engineering principles and practices. The Township reserves the right to disapprove any design that would result in the construction of or continuation of a stormwater problem area. (Ord. 181, 10/11/2006, §307)