This chapter shall be known and may be cited as the "Londonderry Township Stormwater Management Ordinance."
The Board of Supervisors of Londonderry Township, Chester County, Pennsylvania, finds that:
A. 
Inadequate management of accelerated runoff of stormwater resulting from development throughout a watershed increases runoff volumes, 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.
B. 
A comprehensive program of stormwater management (SWM), 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.
C. 
Stormwater is an important water resource that provides groundwater recharge for water supplies and supports the base flow of streams.
D. 
The use of green infrastructure and low impact development (LID) are intended to address the root cause of water quality impairment by using systems and practices which use or mimic natural processes to 1) infiltrate and recharge, 2) evapotranspire, and/or 3) harvest and use precipitation near where it falls to earth. Green infrastructure practices and LID contribute to the restoration or maintenance of predevelopment hydrology.
E. 
Federal and state regulations require certain municipalities to implement a program of stormwater controls. These municipalities are required to obtain a permit for stormwater discharges from their separate storm sewer systems under the National Pollutant Discharge Elimination System (NPDES) program.
The purpose of this chapter is to promote health, safety, and welfare within the Township and its watershed by minimizing the harms and maximizing the benefits described in § 125-102 of this chapter, through provisions designed to:
A. 
Meet legal water quality requirements under state law, including regulations at 25 Pa. Code Chapter 93, to protect, maintain, reclaim, and restore the existing and designated uses of the waters of this commonwealth.
B. 
Preserve natural drainage systems.
C. 
Manage stormwater runoff close to the source, reduce runoff volumes and mimic predevelopment hydrology.
D. 
Provide procedures and performance standards for stormwater planning and management.
E. 
Maintain groundwater recharge to prevent degradation of surface and groundwater quality and to otherwise protect water resources.
F. 
Prevent scour and erosion of stream banks and streambeds.
G. 
Provide proper operation and maintenance of all stormwater best management practices (BMPs) that are implemented within the municipality.
H. 
Provide standards to meet NPDES permit requirements.
The Township of Londonderry is empowered to regulate land use activities that affect runoff by the authority of the Act of July 31, 1968, P.L. 805, No. 247, the Pennsylvania Municipalities Planning Code, as amended;[1] and/or the Act of October 4, 1978, P.L. 864 (Act 167), 32 P.S. § 680.1 et seq., as amended, the Storm Water Management Act; and 53 P.S. § 65101 et seq., as amended, the Second Class Township Code.
[1]
Editor's Note: See 53 P.S. § 10101 et seq.
A. 
All regulated activities and all activities that may affect stormwater runoff, including land development and earth disturbance activity, are subject to regulation by this chapter.
B. 
Duty of persons engaged in a regulated activity. Notwithstanding any provision(s) of this chapter, including exemptions, any landowner or any person engaged in a regulated activity, including but not limited to the alteration or development of land, which may affect stormwater runoff characteristics shall implement such measures as are reasonably necessary to prevent injury to health, safety, or other property. Such measures also shall include actions as are required to manage the rate, volume, direction, and quality of resulting stormwater runoff in a manner which otherwise adequately protects health, property, and water quality of waters of the commonwealth.
C. 
Phased and incremental project requirements.
(1) 
Any regulated activity (including but not limited to new development, redevelopment, or earth disturbance) that is to take place incrementally or in phases, or occurs in sequential projects on the same parcel or property, shall be subject to regulation by this chapter if the cumulative proposed impervious surface or earth disturbance exceeds the corresponding threshold for exemption (as presented in Table 125-302.1).
(2) 
The date of adoption of this chapter shall be the starting point from which to consider tracts as parent tracts relative to future subdivisions and from which impervious surface and earth disturbance computations shall be cumulatively considered, unless such requirements have previously been adopted, then the earliest date of the applicable municipal ordinance adoption shall remain as the starting point.
(3) 
For example: If, after adoption of this chapter, an applicant proposes construction of a 200-square-foot shed, that project would be exempted from the requirements of this chapter as noted in Table 125-302.1. If, at a later date, an applicant proposes to construct a 900-square-foot room addition on the same property, the applicant would then be required to implement the stormwater management and plan submission requirements of this chapter for the cumulative total of 1,100 square feet of additional impervious surface added to the property since adoption of this chapter.
(4) 
This chapter shall operate in coordination with those parallel requirements of federal, state, and local regulations. The requirements of this chapter shall be no less restrictive in meeting the requirements for environmentally safe water quality and water patterns than the requirements of federal, state and other local regulations.
D. 
All regulated conditions and activities require a stormwater management permit as issued by the Township or a stormwater management exemption as issued by the Township.
Any other ordinance provision(s), regulation or portion thereof of the Township of Londonderry inconsistent with any of the provisions of this chapter is hereby repealed to the extent of the inconsistency only.
In the event that a court of competent jurisdiction declares any word, sentence, phrase, section or provision of this chapter invalid, such decision shall not affect the validity of any of the remaining provisions of this chapter.
Approvals issued and actions taken under this chapter do not relieve the applicant of the responsibility to secure required permits or approvals for activities regulated by any other code, law, regulation or ordinance.
Any permit or authorization issued or approved based on false, misleading or erroneous information provided by an applicant is void without the necessity of any proceedings for revocation. Any work undertaken or use established pursuant to such permit or other authorization is unlawful. No action may be taken by a board, agency or employee of the Township of Londonderry purporting to validate such a violation.
A. 
If the Township of Londonderry determines that any requirement under this chapter cannot be achieved for a particular regulated activity, it may, after an evaluation of alternatives, approve measures other than those in this chapter, subject to Subsections B and C below.
B. 
Waivers or modifications of the requirements of this chapter may be approved by the Township of Londonderry if strict enforcement will exact undue hardship because of peculiar conditions pertaining to the land in question, provided that the modifications will not be contrary to the public interest and that the purpose of this chapter is preserved. Cost or financial burden shall not be considered a hardship. Modification may be considered if an alternative standard or approach will provide equal or better achievement of the purpose of this chapter. A request for modifications shall be in writing and accompany the stormwater management site plan submission. The request shall provide the facts on which the request is based, the provision(s) of this chapter involved and the proposed modification.
C. 
No waiver or modification of any regulated stormwater activity involving earth disturbance greater than or equal to one acre may be granted by the Township of Londonderry unless that action is approved in advance by the Department of Environmental Protection (DEP) or the Chester County Conservation District.