This chapter shall be known as the "Radnor Township Stormwater Management Ordinance."
The governing body of the municipality finds that:
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 infiltration, and threatens public health and safety.
B. 
Inadequate planning and management of stormwater runoff resulting from land development throughout a watershed can also harm surface water resources by changing the natural hydrologic patterns, accelerating stream flows (which increase scour and erosion of stream beds 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 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 municipality and all of the people of the commonwealth, their resources, and the environment.
D. 
Stormwater can be an important water resource by providing infiltration 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, infiltration, 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. 
Public education on the control of pollution from stormwater is an essential component in successfully addressing stormwater.
G. 
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).
H. 
Nonstormwater discharges to municipal separate storm sewer systems can contribute to pollution of waters of the commonwealth by the municipality.
I. 
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) infiltration and recharge, 2) evapotranspiration, and/or 3) harvest and use precipitation near where it falls to earth. Green infrastructure practices, LID, and CD contribute to the restoration or maintenance of pre-development hydrology.
The purpose of this chapter is to promote the public health, safety, and general welfare, property, and water quality implementing drainage and stormwater management practices, criteria, and provisions included herein for land development, construction, and earth disturbance activities, to achieve the following throughout the Township:
A. 
Promote alternative project designs and layouts that minimize the impacts on surface and groundwater.
B. 
Promote nonstructural best management practices (BMPs).
C. 
Minimize increases in runoff stormwater volume.
D. 
Minimize impervious surfaces.
E. 
Manage accelerated stormwater runoff and erosion and sedimentation problems and stormwater runoff impacts at their source by regulating activities that cause these problems.
F. 
Provide review procedures and performance standards for stormwater planning and management.
G. 
Utilize and preserve existing natural drainage systems as much as possible.
H. 
Manage stormwater impacts close to the runoff source, requiring a minimum of structures and relying on natural processes.
I. 
Focus on infiltration of stormwater to maintain base flow, to prevent degradation of surface and groundwater quality, and to otherwise protect water resources.
J. 
Protect base flows and quality of streams and watercourses, where possible.
K. 
Meet legal water quality requirements under state law, including regulations at 25 Pennsylvania Code Chapter 93 to protect, maintain, reclaim, and restore the existing and designated uses of the waters of the commonwealth.
L. 
Address the quality and quantity of stormwater discharges from the development site.
M. 
Provide standards to meet certain NPDES MS4 permit requirements.
N. 
Implement an illicit discharge detection and elimination program that addresses nonstormwater discharges into the Township's separate storm sewer system (MS4).
O. 
Preserve the flood-carrying capacity of streams.
P. 
Prevent accelerated scour, erosion and sedimentation of stream channels.
Q. 
Provide performance standards and design criteria based on watershed-wide stormwater management planning.
R. 
Provide proper operation and maintenance of all permanent stormwater management facilities and BMPs that are implemented within the municipality.
S. 
Implement the requirements of total maximum daily loads (TMDLs) where applicable to waters within or impacted by the Township.
The Township is empowered or required to regulate land use activities that affect runoff and surface and groundwater quality and quantity by the authority of:
A. 
Act of October 4, 1978, 32 P.S., P.L. 864 (Act 167) § 680.1 et seq., as amended, the "Storm Water Management Act" (hereinafter referred to as "the Act");
B. 
Act of July 31, 1968, P.L. 805, No. 247, Pennsylvania Municipalities Planning Code, Act 247, as amended;[1] and
[1]
Editor's Note: See 53 P.S. § 10101 et seq.
C. 
Radnor Township Home Rule Charter.
A. 
All regulated activities and all activities that may affect stormwater runoff, including but not limited to land development, redevelopment, and earth disturbance activity located within the municipality, are subject to regulation by this chapter.
B. 
This chapter contains the stormwater management performance standards and design criteria that are necessary from a watershed-wide perspective. Local stormwater management design criteria (e.g., inlet spacing, inlet type, collection system design and details, outlet structure design, etc.) shall continue to be regulated by the applicable municipal ordinances and applicable state regulations.
An exemption shall not relieve the applicant from implementing the requirements of the municipal ordinance or from implementing such measures as are necessary to protect public health, safety, and property. An exemption shall not relieve the applicant from complying with the special requirements for watersheds draining to identified high quality (HQ) or exceptional value (EV) waters or any other current or future state or municipal water quality protection requirements. If a drainage problem is documented or known to exist downstream of, or is expected from the proposed activity, then the municipality may withdraw exemptions listed in Table 245-6.1 and require the applicant to comply with all requirements of this chapter. Even though the applicant is exempt, he is not relieved from complying with other municipal ordinances or regulations.
A. 
General exemptions.
(1) 
Table 245-6.1 summarizes the exemptions from certain provisions of this chapter. Exemptions are for the items noted in Table 245-6.1 only and shall not relieve the applicant from other applicable sections of this chapter.
(2) 
Any regulated activity that is exempt from some provisions of the chapter is exempt only from those provisions. If development is to take place in phases, the developer is responsible for implementing the requirements of the chapter as the impervious cover/earth disturbance threshold is met. The date of the municipal chapter adoption shall be the starting point from which to consider tracts as "parent tracts" in which future subdivisions and respective impervious area and earth disturbance computations shall be cumulatively considered. Exemption shall not relieve the applicant from implementing such measures as are necessary to protect health, safety, and property. For example:
If a property owner proposes a 150-square-foot shed after adoption of the municipal stormwater management chapter, that property owner would be exempted from water quality and quantity requirements of the chapter as noted in Table 245-6.1 of the chapter. If, within three years the property owner proposes to construct a 499-square-foot room addition, the applicant would be required to comply with the requirements for the simplified method for the full 649 square feet of impervious cover created since adoption of the municipal chapter. If an additional 700-square-foot swimming pool/patio is proposed later, the property owner would be required to implement the full stormwater quantity and quality control submission requirements of this chapter for the total 1,349 square feet of additional impervious surface added to the original property since adoption of the Municipal Chapter.
Table 245-6.1
Ordinance Exemptions
Ordinance Article or Section
Type of Project
Regulated Impervious Surface
Earth Disturbance
0 to 499 Square Feet
500 to 999 Square Feet
1,000 plus Square Feet
0 to 4,999 Square Feet Disturbance
5,000 Square Feet to Less Than 1 Acre
Greater Than or Equal to 1 Acre
Article IV
SWM site plan requirements
Development
Redevelopment
Exempt
Not exempt
Simplified approach
Not exempt
Exempt
Modified1
Not exempt
§ 245-17
Nonstructural project design
Development
Redevelopment
Exempt
Not exempt
Simplified approach
Not exempt
Exempt
Not exempt
Not exempt
§ 245-18
Infiltration volume requirements
Development
Redevelopment
Exempt
Not exempt
Simplified approach
Not exempt
Exempt
Exempt
Not exempt
§ 245-19
Water quality requirements
Development
Redevelopment
Exempt
Not exempt
Simplified approach
Not exempt
Modified2
Modified2
Not exempt
§ 245-20
Stream bank erosion requirements
Development
Redevelopment
Exempt
Not exempt
Simplified approach
Not exempt
Exempt
Exempt
Not exempt
§ 245-21
Stormwater peak rate control and management districts
Development
Redevelopment
Exempt
Exempt
Not exempt
Exempt
Not exempt
Not exempt
Erosion and sediment pollution control requirements
Must comply with Title 25, Chapter 102 of the PA Code and other applicable state and municipal codes, including the Clean Streams Law.[1]
Not exempt
NOTES:
"Regulated impervious surface" in Table 245-6.1 includes new, additional, impervious surface/cover as part of development or redevelopment.
Exempt - exempt from required section provision only - SWM site plan submission may still be required if other section provisions are applicable.
Modified1 - Modified SWM site plan need only consist of items in §§ 245-26A(2) and (4); 245-26B(7), (8), (11), and (22); and 245-26D(1) and (3) and related supportive material needed to determine compliance with §§ 245-17 and 245-21. Modified SWM site plan is required that includes all elements of § 245-17, as applicable.
Modified2 - Modified SWM site plan need only consist of items and related material needed to determine compliance with § 245-24.
Simplified approach - Must comply with provisions of Appendix B of the ordinance.[2]
Redevelopment - See § 245-21I for alternate stormwater peak rate control criteria.
[1]
Editor's Note: See 35 P.S. § 691.1 et seq.
B. 
Exemptions for specific activities.
(1) 
Use of land for gardening or home consumption.
(2) 
Agriculture when operated in accordance with a conservation plan, nutrient management plan, or erosion and sedimentation control plan approved by the County Conservation District, including activities such as growing crops, rotating crops, tilling soil, and grazing animals. For agriculture with an approved conservation plan, installation of new or expansion of existing farmsteads, animal housing, waste storage, and production areas having impervious surfaces that result in a net increase in impervious surface of between 500 to 999 square feet shall apply the simplified approach, and net increases in impervious surface of greater than or equal to 1,000 square feet shall be subject to the provisions of this chapter.
(3) 
High tunnel if:
(a) 
The high tunnel or its flooring does not result in an impervious surface exceeding 25% of all structures located on the landowner's total contiguous land area; and
(b) 
The high tunnel meets one of the following:
[1] 
The high tunnel is located at least 100 feet from any perennial stream or watercourse, public road, or neighboring property line.
[2] 
The high tunnel is located at least 35 feet from any perennial stream or watercourse, public road or neighboring property line and located on land with a slope not greater than 7%.
[3] 
The high tunnel is supported with a buffer or diversion system that does not directly drain into a stream or other watercourse by managing stormwater runoff in a manner consistent with the requirements of Pennsylvania Act 167.
(4) 
Forest management operations which are following the Department of Environmental Protection's (PADEP) management practices contained in its publication "Soil Erosion and Sedimentation Control Guidelines for Forestry," are operating under an approved erosion and sedimentation plan and must comply with the stream buffer requirements in § 245-24.
(5) 
Repaving without reconstruction.
(6) 
Emergency exemption. Emergency maintenance work performed for the protection of public health, safety, and welfare. A written description of the scope and extent of any emergency work performed shall be submitted to Radnor Township within two calendar days of the commencement of the activity. If Radnor Township finds that the work is not an emergency, then the work shall cease immediately, until a stormwater site-plan in accordance with this chapter is submitted and approved by the municipality.
(7) 
Maintenance exemption. Any maintenance to an existing stormwater management system made in accordance with plans and specifications approved by the Township Engineer or Radnor Township.
Any ordinance or ordinance provision of the Township inconsistent with any of the provisions of this and other federal and state regulations are hereby repealed to the extent of the inconsistency only. Existing Chapter 245 of the Radnor Township Code of Ordinances is specifically repealed and replaced by this chapter.
Should any section or provision of this chapter be declared invalid by a court of competent jurisdiction, such decision shall not affect the validity of any of the remaining provisions of this chapter.
A. 
Approvals issued pursuant to this chapter do not relieve the applicant of the responsibility to secure required permits or approvals for activities regulated by any other applicable code, rule, act, or ordinance.
B. 
To the extent that this chapter imposes more rigorous or stringent requirements for stormwater management, the specific requirements contained in this chapter shall be followed.
C. 
Nothing in this chapter shall be construed to affect any of the Township's requirements regarding stormwater matters that do not conflict with the provisions of this chapter, such as local stormwater management design criteria (e.g., inlet spacing, inlet type, collection system design and details, outlet structure design, etc.). Conflicting provisions in other municipal ordinances or regulations shall be construed to retain. The requirements of this chapter shall supersede any conflicting requirements in other municipal ordinance or regulations.
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, or employee of the Township purporting to validate such a violation.
A. 
If the Township determines that any requirement under this chapter cannot be achieved for a particular regulated activity, the Township Engineer may, after an evaluation of alternatives, approve measures other than those in this chapter, subject to Subsections B and C.
B. 
Waivers or modifications of the requirements of this chapter may be approved by the Township Engineer if 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 the ordinance 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 the ordinance. 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 the ordinance 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 municipality unless that action is approved in advance by PADEP or the Delaware County Conservation District.