1. For all regulated activities, unless specifically exempted in § 23-302:
A. Preparation and implementation of an approved SWM site plan is required;
B. No regulated activities shall commence until the township issues written approval of a SWM site plan, which demonstrates compliance with the requirements of this Chapter;
D. The SWM site plan approved by the township shall be on-site throughout the duration of the regulated activities.
2. For all regulated earth disturbance activities, erosion and sediment control BMPs shall be designed, implemented, operated, and maintained during the regulated earth disturbance activities (e.g., during construction) to meet the purposes and requirements of this Chapter and to meet all requirements under Title 25 Pa. Code (including, but not limited to Chapter 102, “Erosion and Sediment Control”) and the Clean Streams Law, 35 P.S. §§ 691.1 et seq. Various BMPs and their design standards are listed in the Erosion and Sediment Pollution Control Program Manual (E&S Manual), No. 363-2134-008 (April 15, 2000), as amended and updated.
3. For all regulated activities, stormwater BMPs shall be designed, installed, implemented, operated and maintained to meet the purposes and requirements of this Chapter and to meet all requirements under Title 25, Pa. Code and the Clean Streams Law, 35 P.S. §§ 691.1 et seq., conform to the state water quality requirements, meet all requirements under the Storm Water Management Act, 32 P.S. §§ 680.1 et seq., and any more stringent requirements as determined by the township.
4. The township may, after consultation with PADEP, approve measures for meeting the state water quality requirements other than those in this Chapter, provided that they meet the minimum requirements of, and do not conflict with state law including, but not limited to, the Clean Streams Law, 35 P.S. §§ 691.1 et seq.
5. All regulated activities shall include, to the maximum extent practicable, measures to:
A. Protect health, safety and property;
B. Meet the water quality goals of this Chapter by implementing measures to:
(1) Minimize disturbance to floodplains, wetlands, natural slopes, existing native vegetation and woodlands;
(2) Create, maintain or extend riparian buffers and protect existing forested buffers;
(3) Provide trees and woodlands adjacent to impervious areas whenever feasible;
(4) Minimize the creation of impervious surfaces and the degradation of waters of the commonwealth and promote groundwater recharge;
(5) Protect natural systems and processes (drainageways, vegetation, soils and sensitive areas) and maintain, as much as possible, the natural hydrologic regime;
(6) Incorporate natural site elements (wetlands, stream corridors and mature forests) as design elements;
(7) Avoid erosive flow conditions in natural flow pathways;
(8) Minimize soil disturbance and soil compaction;
(9) Minimize thermal impacts to waters of the commonwealth; and
(10) Disconnect impervious surfaces by directing runoff to pervious areas, wherever possible and decentralize and manage stormwater at its source.
6. Impervious areas.
A. The measurement of impervious areas shall include all of the impervious areas in the total proposed development, even if development is to take place in stages.
B. For developments taking place in stages, the entire development plan must be used in determining conformance with this Chapter.
7. If diffused flow is proposed to be concentrated and discharged onto adjacent property, the applicant must document that adequate downstream conveyance facilities exist to safely transport the concentrated discharge, or otherwise prove that no erosion, sedimentation, flooding, or other harm will result from the concentrated discharge.
A. Applicant must provide an easement for proposed concentrated flow across adjacent properties.
8. Stormwater drainage systems shall be provided in order to permit unimpeded flow along natural watercourses, except as modified by stormwater management facilities or open channels consistent with this Chapter.
9. Where watercourses traverse a development site, drainage easements (with a minimum width of 20 feet) shall be provided conforming to the line of such watercourses. The terms of the easement shall prohibit excavation, the placing of fill or structures, and any alterations that may adversely affect the flow of stormwater within any portion of the easement. Also, maintenance, including mowing of vegetation, within the easement may be required, except as approved by the appropriate governing authority.
10. When it can be shown that, due to topographic conditions, natural drainageways on the site cannot adequately provide for drainage, open channels may be constructed conforming substantially to the line and grade of such natural drainageways. Work within natural drainage ways shall be subject to approval by PADEP under regulations at 25 Pa.Code, Chapter 105, through the joint permit application process, or, where deemed appropriate by PADEP, through the general permit process.
11. Any stormwater management facilities or any facilities that constitute water obstructions (e.g., culverts, bridges, outfalls, or stream enclosures and the like) that are regulated by this Chapter, that will be located in or adjacent to waters of the commonwealth (including wetlands), shall be subject to approval by PADEP under regulations at 25 Pa. Code Chapter 105, through the joint permit application process, or, where deemed appropriate by PADEP, the general permit process. When there is a question whether wetlands may be involved, it is the responsibility of the applicant or his or her agent to show that the land in question cannot be classified as wetlands, otherwise, approval to work in the area must be obtained from PADEP.
12. Should any stormwater management facility require a dam safety permit under PADEP 25 Pa. Code Chapter 105, the facility shall be designed in accordance with Chapter 105 and meet the regulations of Chapter 105 concerning dam safety.
13. Any stormwater management facilities regulated by this Chapter that will be located on or discharged onto state highway rights-of-way shall be subject to approval by the Pennsylvania Department of Transportation (PennDOT).
14. Minimization of impervious surfaces and infiltration of runoff through seepage beds, infiltration trenches and the like are encouraged, where soil conditions and geology permit, to reduce the size or eliminate the need for detention facilities.
15. Infiltration BMPs should be dispersed throughout the site, made as shallow as practicable, and located to maximize use of natural on-site infiltration features while still meeting the other requirements of this Chapter. Soil compaction must be avoided or minimized in those areas.
16. The design of facilities over karst shall include an evaluation and implementation of measures to minimize adverse effects.
17. Roof drains shall not be connected to streets, sanitary or storm sewers, or roadside ditches in order to promote overland flow and infiltration/percolation of stormwater where it is advantageous to do so. When it is more advantageous to connect directly to streets or storm sewers, then the township shall permit it on a case-by-case basis.
18. Applicants are encouraged to use low impact development practices to reduce the costs of complying with the requirements of this Chapter and the state water quality requirements.
19. When stormwater management facilities are proposed within 1,000 feet of a downstream municipality, the developer shall notify the downstream municipality (and provide a copy of the SWM plan if requested).
(Ord. 2011-04-11, passed 4-11-2011)