(A) All regulated activities within the township which do not fall under the exemption criteria contained within § 151.006 of this chapter shall submit a SWM site plan consistent with this chapter to the township for review. These criteria shall apply to the total proposed development even if development is to take place in stages.
(B) Regulated activities shall be designed, implemented, operated and maintained to meet the purposes of this chapter through these two elements:
(1) Erosion and sediment control prevention during land development (earth disturbance during construction); and
(2) Water quality protection measures after completion of land development (post-construction).
(C) No approval of any subdivision or land development plan, or issuance of any building, erosion and sedimentation control permit, occupancy permit or the commencement of any earth disturbance at a project site within the township, shall proceed until the requirements of this chapter are met, including approval of a SWM site plan in accordance with § 151.050 and a permit has been issued under DEP regulations, where applicable.
(D) Erosion and sediment control during land development shall be addressed as required by § 151.034.
(F) All best management practices (BMPs) shall conform to the design criteria of this chapter and the BMP Manual.
(G) Stormwater drainage systems shall be provided in order to permit unimpeded flow along natural watercourses, except as modified by stormwater management facilities designed to encourage infiltration, groundwater recharge and improved water quality.
(H) Stormwater flows onto adjacent property shall not be created, increased, decreased, relocated or otherwise altered without written notification to the adjacent property owner(s). Such stormwater flows shall be subject to the requirements of this chapter.
(I) Existing points of concentrated drainage that discharge onto adjacent property shall not be altered without written approval of the affected property owner(s) and shall be subject to any applicable discharge criteria specified in this chapter.
(J) For all subdivision and land development applications, the tributary area discharging drainage to any location along the site property boundary shall not increase by more than 25% over the predevelopment condition without written approval from the adjacent affected property owner(s) and the township.
(K) Where a subdivision or land development site is traversed by watercourses, drainage easements shall be provided conforming to the line of such watercourses. The width of the easement shall be adequate to provide for the unimpeded flow of stormwater runoff from the 100-year storm event. However, in no case shall the easement be less than 30 feet in width. Terms of the easement shall be subject to approval by the township and 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. The easement shall also require periodic maintenance of the easement area by the landowner to ensure proper runoff conveyance.
(L) When it can be shown that, due to topographic conditions, drainageways on the project site cannot adequately provide for drainage, open channels may be constructed conforming substantially to the line and grade of such drainageway. Work within stream shall be subject to approval by the township and DEP through the joint permit application process, or, where deemed appropriate by DEP, through the general permit process.
(M) Any stormwater management facility regulated by this chapter that would be located in or adjacent to waters of the commonwealth or wetlands shall be subject to approval by DEP through the joint permit application process, or, where deemed appropriate by DEP, 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 DEP and the township.
(N) Any stormwater management facilities regulated by this chapter that would be located on state highway rights-of-way or would discharge stormwater to facilities located within a state highway right- of-way shall be subject to approval by PennDOT and the township.
(O) Site disturbance and impervious surface shall be minimized. Infiltrating stormwater runoff through seepage beds, infiltration trenches and the like shall be required, where soil conditions permit, to reduce the size or eliminate the need for retention/detention facilities.
(P) Infiltration BMPs shall be spread out, 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.
(Q) Normally dry, open top storage facilities shall completely drain both the volume control and rate control capacities over a period of time not less than 24 hours and not more than 72 hours from the end of the design storm.
(R) Design storm volumes to be used in the analysis of peak rates of discharge shall be obtained from the latest version of the Precipitation-Frequency Atlas of the United States, National Oceanic and Atmospheric Administration (NOAA), National Weather Service, Hydrometeorological Design Studies Center, Silver Spring, Maryland.
(S) If methods other than green infrastructure and LID methods are proposed to achieve the volume and rate controls required under this chapter, the SWM site plan must include a detailed justification demonstrating that the use of LID and green infrastructure is not practicable.
(T) All collected stormwater runoff shall be pretreated for water quality prior to discharge to surface or groundwater as required by § 151.027.
(U) Completed stormwater management facilities, including detention/retention basins, shall be surveyed by a surveyor or engineer to verify compliance with the character of stormwater management facilities as depicted on the approved final plan (or subsequently approved revision, thereof). As-constructed plans shall be submitted to the township for review and approval, upon completion of construction of all facilities and prior to the offer of dedication of any public facilities and/or submission of financial security for the required maintenance period. Public facilities will not be accepted by the township until such time the as-constructed plans have been reviewed and approved by the Township Engineer.
(V) The record plan and development agreement for an approved subdivision or land development shall define the ownership and maintenance responsibilities, as well as access rights for all drainage related easements. Specifically, the record plan shall contain a provision permitting access to such easement(s), at any reasonable time, for inspection and/or emergency repair/maintenance, by the township or its designee, of all facilities. In the event the property owner fails to honor the maintenance responsibilities set forth herein, in any manner, the township shall have the right of entry upon and within the area of the easement to undertake any required corrective or maintenance effort. The total cost of such, including administrative, engineering and legal costs for enforcement, may be imposed upon the responsible party as determined by the township.
(Ord. 239, passed 10-14-2020)