The governing body of the municipality finds that:
A. 
Inadequate management of accelerated stormwater runoff resulting from development throughout a watershed increases runoff volume, flood flows, and velocities, contributes to erosion and sedimentation, degrades water quality, overtaxes the carrying capacity of 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, and increases nonpoint source pollution of water resources.
B. 
A comprehensive program of stormwater management, including reasonable regulation of development and activities causing accelerated erosion, is fundamental to the public health, safety, welfare, and the protection of the people of the municipality and all the people of the commonwealth, their resources, and the environment.
C. 
Through project design, impacts from stormwater runoff can be minimized to maintain the natural hydrologic regime and sustain high water quality, groundwater recharge, stream base flow, and aquatic ecosystems. The most cost-effective and environmentally advantageous way to manage stormwater runoff is through nonstructural project design, minimizing impervious surfaces and sprawl, avoiding sensitive areas (i.e., stream buffers, floodplains, steep slopes), and designing to topography and soils to maintain the natural hydrologic regime.
D. 
Stormwater is an important resource that provides groundwater recharge for water supplies and supports the base flow of streams.
E. 
The use of green infrastructure and low-impact development (LID) is 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.
F. 
Federal and state regulations require this municipality to obtain a permit for discharges from its MS4 under the NPDES program; and to implement a program of stormwater controls.
The purpose of this chapter is to promote health, safety, and welfare within West Rockhill Township and its watersheds by minimizing the harms and maximizing the benefits described in § 352-1A of this chapter through provisions designed to:
A. 
Promote alternative project designs and layouts that minimize impacts to surface water and groundwater.
B. 
Promote nonstructural best management practices.
C. 
Minimize increases in stormwater volume.
D. 
Minimize impervious surfaces.
E. 
Manage stormwater runoff close to the source, reduce runoff volumes, mimic predevelopment hydrology and manage accelerated runoff and erosion and sedimentation problems at their source by regulating activities that cause these problems.
F. 
Utilize and preserve the existing natural drainage systems.
G. 
Maintain groundwater recharge to prevent degradation of surface water and groundwater quality and to otherwise protect water resources.
H. 
Maintain the predevelopment peak and volume of stormwater runoff and prevent degradation of surface water quality.
I. 
Minimize nonpoint source pollutant loadings to the groundwaters and surface waters.
J. 
Minimize impacts on stream temperatures.
K. 
Maintain existing flows and quality of streams and watercourses in the municipality and the commonwealth.
L. 
Preserve natural drainage systems and restore the flood-carrying capacity of streams.
M. 
Provide proper operation and maintenance of all permanent stormwater management BMPs that are constructed in the municipality.
N. 
Provide procedures and performance standards and design criteria for stormwater management and planning.
O. 
Provide standards to meet NPDES MS4 permit requirements.
P. 
Meet legal state water quality requirements, including regulations a 25 Pa. Code Chapter 93 to protect, maintain, reclaim, and restore the existing and designated uses of the waters of this commonwealth.
Q. 
Prevent scour and erosion of stream banks and streambeds, and reduce accelerated erosion, scour, aggradation, and degradation.
The municipality is empowered to regulate land use activities that affect runoff by the authority of 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 by the authority of the Pennsylvania Municipalities Planning Code, Act 247 of 1968, as amended by Act 170 of 1988, as further amended by Act 209 of 1990 and Act 131 of 1992, 53 P.S. § 10101 et seq.
A. 
This chapter shall apply to all regulated activities and all activities that may affect stormwater runoff, including land development and earth disturbance activity within the municipality.
B. 
This chapter shall apply to temporary and permanent stormwater management BMPs constructed as part of any of the regulated activities listed in this section and all activities related to proper operation and maintenance of all stormwater management facilities and BMPs; and all activities that may contribute nonstormwater discharges to the municipality's regulated small MS4. Stormwater management and erosion and sedimentation control during construction activities which are specifically not regulated by this chapter shall continue to be regulated under existing laws and ordinances.
C. 
This chapter contains only the stormwater management performance standards and design criteria that are necessary or desirable from a watershed-wide perspective. 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 applicable ordinances.
D. 
The following activities are defined as "regulated activities" and shall be regulated by this chapter except as exempted by § 352-5 of this chapter:
(1) 
Land development.
(2) 
Subdivision.
(3) 
Construction of new or reconstruction of, or addition of new, impervious or semi-impervious surfaces (e.g., driveways, parking lots, roads, etc.), except for reconstruction of roads where there is no increase in impervious surface; and/or construction of new buildings or additions to existing buildings.
(4) 
Redevelopment.
(5) 
Diversion piping or encroachments in any natural or man-made stream channel.
(6) 
Installation or modification of stormwater management facilities, nonstructural and structural stormwater management best management practices (BMPs) or appurtenances thereto.
(7) 
Temporary storage of impervious or pervious material (rock, soil, etc.) where ground contact exceeds 5% of the lot area or 5,000 square feet (whichever is less), and where the material is placed on slopes exceeding 8%.
(8) 
Earth disturbance which modifies existing grades and/or alters the existing/natural hydraulic regime.
A. 
Exemptions from any provision permitted by this section shall not relieve the applicant from all other requirements of this chapter.
(1) 
General exemptions. The following land use activities are exempt from stormwater management peak rate and plan requirements of this chapter. On all sites where a cumulative area of less than 1,000 square feet of impervious surface since the original adoption date of this chapter, September 24, 2002, is proposed, the applicant is exempt from stormwater management plan submission requirements of § 352-11A of this chapter and Stormwater Management Capital Fund contribution.
(a) 
Use of land for gardening for home consumption.
(b) 
Agricultural activity when operated in accordance with requirements of 25 Pa. Code Chapter 102, a conservation plan, nutrient management plan, or erosion and sedimentation control plan approved by the Bucks County Conservation District, including activities such as growing crops, rotating crops, tilling of soil, and grazing animals. Installation of new, or expansion of existing, farmsteads, animal housing, waste storage, production areas, or other areas having impervious surfaces shall be subject to the provisions of this chapter unless exempt pursuant to § 352-5C.
(c) 
Forest management operations following the Department of Environmental Protection's management practices contained in its publication "Soil Erosion and Sedimentation Control Guidelines for Forestry" and operating under requirements of 25 Pa. Code Chapter 102 and which have zoning permit approval from West Rockhill Township.
(d) 
Public road replacement, replacement paving, repaving and/or maintenance.
(e) 
Any aspect of BMP maintenance to an existing SWM facility made in accordance with plans and specifications approved by the Township.
(f) 
Lot line adjustment subdivisions when there is no proposed increase in the amount of impervious surface.
B. 
All regulated activities as described in § 352-4 of this chapter shall comply with the stormwater management requirements hereof except those activities meeting criteria listed in the Stormwater Management Exemption Criteria Table. Those activities listed in the Stormwater Management Exemption Criteria Table are, to the extent stated herein, exempt from peak rate control provisions of § 352-12; however, if located within a high-quality or exceptional-value watershed, are subject to compliance with water quality requirements of § 352-15 and groundwater recharge requirements of § 352-16. Groundwater recharge and water quality requirements may be addressed with nonstructural stormwater management BMPs as detailed in Appendix H.[1] These requirements shall apply to the total development even if development is to take place in phases. The starting point from which to consider tracts as "parent tracts" is September 24, 2002 (date of adoption of Ordinance No. 153). All impervious surface area constructed on or after the date of adoption of this chapter shall be considered cumulatively. Impervious surface existing on the parent tract prior to the date of adoption of this chapter shall not be considered in cumulative impervious area calculations for exemption purposes. An exemption shall not relieve the applicant from implementing such stormwater control measures and erosion control measures as are necessary to protect health, safety, and property.
(1) 
Regulated activities included within § 352-4 are exempt from peak rate control requirements of § 352-12 where the amount of impervious surface and proposed location on a parcel conforms to the following tables:
(a) 
Table 352-5B(1)(a).
Table 352-5B(1)(a)
Stormwater Management Peak Rate Exemption Criteria
Total Parcel Area
(acres)
Maximum Impervious Surface Area
(square feet)
<0.5
1,200
0.5 to 1.0
2,500
>1.0 to 2.0
4,000
>2.0 to 5.0
5,000
>5.0
7,500
(b) 
Table 352-5B(1)(b). Maximum amount of the impervious surface area permitted pursuant to Table 352-5B(1)(a) within a setback (excluding driveway access) measured from the downslope property boundary shall conform to the following table:
Table 352-5B(1)(b)
Setback*
(feet)
Maximum Impervious Surface Area Permitted Within the Setback
(square feet)
10
None permitted
20
1,000
50
2,500
100
4,000
200
5,000
500
7,500
NOTES:
*
The minimum setback distance is measured between the proposed impervious area (excluding driveway access) and/or stormwater control/structure discharge point to the downslope property boundary. The maximum allowable impervious surface area is the amount of impervious surface area permitted within the setback distance. For example, a total of 4,000 square feet of impervious surface is permitted within the 100-foot setback, of which none is permitted within the ten-foot setback, not more than 1,000 square feet is permitted within the twenty-foot setback, and not more than 2,500 square feet is permitted within the fifty-foot setback.
In lieu of meeting the minimum distance criteria, the applicant may provide documentation from a design professional that the increased flows from the site leave the site in the same manner as the predevelopment condition, and that there will be no adverse affects to properties along the path of flow(s). The Township may require the above-referenced documentation on any site, including a site meeting the minimum distance or parcel size criteria, when deemed necessary at the sole discretion of the Township.
(2) 
Construction or reconstruction of buildings or additions to existing buildings or other impervious surface (activities regulated pursuant to § 352-4) are exempt where the following conditions are met:
(a) 
An area of impervious surface is removed from the site equal to, or in excess of, the proposed impervious surface area.
(b) 
The area where existing impervious surface is removed pursuant to Subsection B(2)(a) above must be restored with a minimum of 12 inches of topsoil and stabilized pervious ground cover.
[1]
Editor's Note: Said appendix is included as an attachment to this chapter.
C. 
Simplified procedure for single residential lots (which do not meet peak rate exception criteria of § 352-5B). Construction projects on existing single residential dwelling lots which result in less than 2,500 square feet cumulative (from the date of this chapter) of new impervious area (including the building footprint, driveway, sidewalks, swimming pools, patios, and parking areas) and less than 5,000 square feet of earth disturbance that do not meet exemption criteria of § 352-5B may utilize the simplified procedure within Appendix G[2] to meet requirements of this chapter and are not required to submit formal stormwater management plans to the Township; however, a plot plan and design worksheets consistent with Appendix G must be submitted for Township review. This procedure may not be utilized for a proposed subdivision or land development.
[2]
Editor's Note: Said appendix is included as an attachment to this chapter.
D. 
Additional exemption criteria.
(1) 
Exemption responsibilities. An exemption shall not relieve the applicant from implementing such measures as are necessary to protect the public health, safety, and property.
(2) 
Drainage problems. Where drainage problems are documented or known to exist downstream of, or are expected from, the proposed activity, the Township may deny an exemption.
(3) 
HQ/EV streams. An exemption shall not relieve the applicant from meeting the special requirements for watersheds draining to high-quality (HQ) or exceptional-value (EV) waters contained in § 352-11M of this chapter. The Butter Creek and Ridge Valley Creek Watersheds (which are tributary to Unami Creek) are designated as high-quality watersheds.
E. 
The municipality, upon request by the applicant, may grant an exemption from the provisions of this chapter for a project qualifying under § 352-5B. If an exemption is granted, the municipality shall require the developer to pay a fee in an amount established by separate resolution of the Board of Supervisors to the Municipal Stormwater Management Capital Fund.
F. 
All applicants seeking an exemption of stormwater management peak rate requirements based upon criteria contained in § 352-5B shall, at a minimum, submit the following documentation for review:
(1) 
Three copies of the completed Township stormwater management application form.
(2) 
Stormwater management review fee and escrow, as established by separate resolution of the Board of Supervisors.
(3) 
Three copies of a plot plan for the parcel which is the subject of the exemption application containing, at a minimum, the following information:
(a) 
Property boundaries and area of the site, based on deed information, or field survey.
(b) 
Location map identifying the site relative to streets and other parcels in the vicinity of the site.
(c) 
Location of significant natural and existing man-made features, including wetlands, watercourses, woodlands, steep slopes, structures, parking areas, driveways, utilities, wells, and septic systems within 200 feet of proposed impervious surface, regardless of the location of the property boundary.
(d) 
Location and dimensions of existing and proposed impervious surface and other improvements, with setbacks drawn to relate the location of same to property lines, streets, and existing features.
(e) 
North arrow.
(f) 
Plan scale, as applicable.
(g) 
Information regarding existing/proposed topography and drainage patterns within 200 feet of proposed impervious surface, based on field survey, USGS mapping, and/or field observation.
(h) 
Other information deemed necessary by the Township Engineer to determine compliance with exemption criteria contained in § 352-5B. The municipality may deny or revoke any exemption pursuant to this section at any time for any project that the municipality believes may pose a threat to public health and safety or the environment.
A. 
It shall be unlawful for any person to undertake any regulated activity on any property except as provided for in the approved stormwater management plan and pursuant to the requirements of this chapter. It shall be unlawful to alter or remove any BMP required by the stormwater management plan pursuant to this chapter or to allow the property to remain in a condition which does not conform to the approved stormwater management plan.
B. 
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 municipality purporting to validate such a violation.
A. 
If the municipality determines that any requirement under this chapter cannot be achieved for a particular regulated activity, the municipality may, after an evaluation of alternatives, approve measures other than those in this chapter, subject to § 352-8B and C.
B. 
Waivers or modifications of the requirements of this chapter may be approved by the municipality 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 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 the 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 the 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 municipality unless that action is approved in advance by the Department of Environmental Protection (DEP) or the delegated county conservation district.
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 municipality purporting to validate such a violation.