In order to protect the health, safety, and general welfare of the residents of the municipality, as well as to protect, sustain, and enhance the surface and groundwater resources of the municipality, drainage and stormwater management practices shall be utilized as directed herein to achieve the following goals and objectives.
Accommodate site development and redevelopment in a manner that protects public safety and that is consistent with (or reestablishes) the natural hydrologic characteristics of each watershed and sustains groundwater recharge, stream base flows, 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.
Reduce and minimize the volume of stormwater generated.
Protect natural infiltration and groundwater recharge rates in order to sustain groundwater supplies and stream base flows.
Maintain runoff characteristics of the site after completion of development that are consistent with the carrying capacity and stable channel conditions of the receiving streams.
Protect water quality by removing and/or treating pollutants prior to discharge to ground- and surface waters throughout the municipality, and to protect, restore, and maintain the chemical, physical, and biological quality of ground- and surface waters.
Protect in-stream channels and geomorphology conditions of the receiving streams, protect their flood-carrying capacity and aquatic habitats and reduce in-stream erosion and sedimentation.
Reduce flooding impacts and prevent a significant increase in surface runoff rates and volumes, predevelopment to post-development, which could worsen flooding downstream in the watershed, enlarge floodplains, erode stream banks and create other flood-related health/welfare/property losses; in general, to preserve and restore the natural flood-carrying capacity of streams and their floodplains.
Protect adjacent lands from adverse impacts of direct stormwater discharges.
Ensure effective long-term operation and maintenance of all permanent stormwater management facilities.
Maintain natural drainage patterns and encourage the use of natural drainage systems.
Treat and release stormwater as close to the source of runoff as possible using a minimum of structures and maximizing reliance on natural processes.
Maintain the existing water balance in all watersheds, subwatersheds, and streams in the municipality, and protect and/or restore natural hydrologic characteristics and habitats wherever possible throughout the watershed systems.
Address certain requirements of the municipal separate storm sewer system (MS4) National Pollution Discharge Elimination System (NPDES) Phase II Stormwater Regulations.
Reduce the impacts of runoff from existing developed sites undergoing redevelopment while encouraging development and redevelopment in urban areas and areas designated for growth.
Meet legal water quality requirements under state law, including regulations at 25 Pa. Code Chapter 93.4a, to protect and maintain existing uses and maintain the level of water quality to support those uses in all streams, and to protect and maintain water quality in special protection streams.
Provide review procedures and performance standards for stormwater planning and management.
Prevent scour and erosion of stream banks and streambeds.
The governing body of the municipality finds that:
Stormwater runoff from lands modified by human activities threatens public health and safety by causing decreased infiltration of rainwater and increased runoff flows and velocities, which overtax the carrying capacity of existing streams and storm sewers, and greatly increases the cost to the public to manage stormwater.
Public education on the control of pollution from stormwater is an essential component in successfully addressing stormwater.
Nonstormwater discharges to municipal separate storm sewer systems can contribute to pollution of waters of the commonwealth.
Inadequate management of accelerated runoff of stormwater resulting from development throughout a watershed increases flows and velocities, contributes to erosion and sedimentation, overtaxes the carrying capacity of streams and storm sewers, greatly increases the cost of public facilities to carry and control stormwater, undermines floodplain management and flood control efforts in downstream communities, reduces groundwater recharge, threatens public health and safety, and increases nonpoint source pollution of water resources.
A comprehensive program of stormwater management, including reasonable regulation of development and activities causing accelerated runoff, is fundamental to the public health, safety, and welfare and the protection of people of the commonwealth, their resources, and the environment.
Stormwater is an important water resource, which provides groundwater recharge for water supplies and base flow of streams, which also protects and maintains surface water quality.
Federal and state regulations require certain municipalities to obtain a permit for stormwater discharges from their separate storm sewer systems under the National Pollutant Discharge Elimination System (NPDES). Permittees are required to enact, implement, and enforce a prohibition of nonstormwater discharges to the permittee's regulated small municipal separate storm sewer systems (MS4s).