Township of Tredyffrin, PA Article I General Provisions

§ 174-1 Title.

This chapter shall be known and may be cited as the "Tredyffrin Township Stormwater Management Ordinance."

§ 174-2 Statement of findings.

A. Inadequate management of accelerated stormwater runoff resulting from development throughout a watershed increases flood flows and velocities, contributes to erosion and sedimentation, overtaxes the carrying capacity of existing streams and storm sewers, greatly increases the cost of public facilities to convey and manage stormwater, undermines floodplain management and flood reduction efforts in upstream and downstream communities, reduces groundwater recharge, and threatens public health and safety.

B. Inadequate planning and management of stormwater runoff resulting from land development throughout a watershed can harm surface water resources by changing the natural hydrologic patterns, accelerating stream flows (which increase scour and erosion of streambeds and stream banks, thereby elevating sedimentation), destroying aquatic habitat, and elevating aquatic pollutant concentrations and loadings such as sediments, nutrients, heavy metals, and pathogens. Groundwater resources are also impacted through loss of recharge.

C. A comprehensive program of stormwater management, including regulation of development and activities causing accelerated erosion, as well as minimization of impacts of development, redevelopment, and activities causing accelerated erosion and loss of natural infiltration, is fundamental to the public health, safety, welfare, and the protection of the people of the commonwealth and the residents of Tredyffrin Township, their resources, and the environment.

D. Stormwater is an important water resource which provides groundwater recharge for water supplies and baseflow of streams, which also protects and maintains surface water quality.

E. Impacts from stormwater runoff can be minimized by using project designs that maintain the natural hydrologic regime and sustain high water quality, groundwater recharge, stream baseflow, and aquatic ecosystems. The most cost-effective and environmentally advantageous way to manage stormwater runoff is through nonstructural project design that minimizes impervious surfaces and sprawl, avoids sensitive areas (i.e., stream buffers, floodplains, steep slopes), and considers topography and soils to maintain the natural hydrologic regime.

F. Federal and state regulations require Tredyffrin Township to implement a program of stormwater controls. Tredyffrin Township is required to obtain a permit for stormwater discharges from their separate storm sewer system under the National Pollutant Discharge Elimination System (NPDES).

G. Nonstormwater discharges to the Township's separate storm sewer system can contribute to pollution of waters of the commonwealth by the Township.

§ 174-3 Purpose.

The purpose of this chapter is to promote the public health, safety, and welfare within Tredyffrin Township by maintaining the natural hydrologic regime and minimizing the impacts described in § 174-2 through provisions designed to:

A. Accommodate site development and redevelopment in a manner that protects public safety and is consistent with, or reestablishes, the natural hydrologic characteristics of each watershed and sustains groundwater recharge, stream baseflows, stable stream channel (geomorphology) conditions, the carrying capacity of streams and their floodplains, groundwater and surface water quality, and aquatic living resources and their habitats.

B. Meet legal water quality requirements under state law, including regulations at 25 Pennsylvania Code Chapter 93.4, to protect, maintain, reclaim, and restore the existing and designated uses of the waters of this commonwealth.

C. Promote alternative project designs and layouts that minimize the impacts on surface and groundwater.

D. Conserve the natural drainage systems as much as possible.

E. Manage stormwater runoff close to the source, requiring a minimum of structures and relying on natural processes.

F. Provide procedures and performance standards for stormwater planning and management.

G. Maintain groundwater recharge, to prevent degradation of surface and groundwater quality, and to otherwise protect water resources.

H. Prevent scour and erosion of stream banks and streambeds.

I. Provide proper operation and maintenance of all permanent stormwater management best management practices that are implemented in Tredyffrin Township.

J. Provide standards to meet the NPDES permit requirements.

K. Promote nonstructural best management practices.

L. Minimize increases in runoff stormwater volume.

M. Minimize impervious surfaces.

N. Manage accelerated stormwater runoff and erosion and sedimentation problems and stormwater runoff impacts at their source by regulating activities that cause these problems.

O. Utilize and preserve existing natural drainage systems as much as possible.

P. Maintain existing baseflows and quality of streams and watercourses, where possible.

Q. Address the quality and quantity of stormwater discharges from the development site.

R. Implement an illegal discharge detection and elimination program that addresses nonstormwater discharges into the Township's separate storm sewer system. (See Chapter 172, Storm Sewers.)

S. Preserve the flood-carrying capacity of streams.

T. Protect water quality by removing and/or treating pollutants prior to discharge to ground- and surface waters throughout Tredyffrin Township, and to protect, restore, and maintain the chemical, physical, and biological quality of ground- and surface waters.

U. Reduce flooding impacts and prevent a significant increase in surface runoff rates and volumes, predevelopment to postdevelopment, which could worsen flooding downstream in the watershed, enlarge floodplains, erode stream banks, and create other flood-related health, welfare or property losses; in general, to preserve and restore the natural flood-carrying capacity of streams and their floodplains.

V. Protect adjacent lands from adverse impacts of direct stormwater discharges.

W. Maintain the existing water balance in all watersheds, subwatersheds, and streams in Tredyffrin Township, and protect and/or restore natural characteristics and habitats wherever possible throughout the watershed systems.

§ 174-4 Statutory authority.

Tredyffrin Township is empowered to regulate land use activities that affect runoff and surface and groundwater quality and quantity by the authority of:

A. Pennsylvania Stormwater Management Act (Act 167 of 1978, as amended);[1]

[1] Editor's Note: See 32 P.S. § 680.1 et seq.

B. Federal Clean Water Act, 33 U.S.C. § 1251;

C. Clean Streams Law, 35 P.S. § 691.1 et seq., since Tredyffrin Township is a municipal separate storm sewer system (MS4) under Phase II of the National Pollution Discharge Elimination System (NPDES) Stormwater Program of the Environmental Protection Agency (EPA);

D. Home Rule Charter and Optional Plans Law (Act 62 of 1972, as amended)[2] and the Tredyffrin Township Home Rule Charter;

[2] Editor's Note: See 53 Pa.C.S.A. § 2901 et seq.

E. Pennsylvania Municipalities Planning Code, Act 247, as amended.[3]

[3] Editor's Note: See 53 P.S. § 10101 et seq.