1. All subdivision and land developments shall comply with the Springfield Township Stormwater Management Ordinance, Ord. 152, adopted on July 28, 2009, as amended.
2. All subdivisions and land development applications shall comply with the Low Impact Development Practices as outlined in the Pennsylvania Stormwater Best Management Practices Manual, December 2006, as amended (“Manual”), where consistent with design requirements of this Ordinance. The Manual provides guidance on the development of site controls through the use of best management practices (BMPs). The most appropriate BMPs for stormwater management vary from site to site; however, the basic concepts are as follows:
A. Prevent stormwater impacts, especially pollutants.
B. Mitigate pollutants that cannot be prevented.
C. Manage stormwater as a resource.
D. Sustain the hydrologic balance (quantity and quality).
E. Integrate stormwater into the initial site design process.
F. Preserve and utilize natural systems (soil, vegetation, etc.).
G. Manage stormwater as close to the source as possible.
H. Disconnect/decentralize/distribute.
I. Slow down stormwater by increasing the time of concentration.
J. Inspect and maintain.
3. The stormwater management system shall be designed to meet the requirements of the Stormwater Management Ordinance and the Manual. Where the Delaware River (North) Watershed, Tohickon Creek Watershed, or Saucon Creek Watershed Act 167 (32 P.S. §§ 680.1 et seq., as amended, the “Stormwater Management Act”) requirements are more restrictive, the Act 167 requirements shall apply as determined by the Township Engineer.
4. The Township requires use of nonstructural BMPs (refer Chapter 5 of the Manual) to the maximum extent possible because of their ability to prevent stormwater generation and not just mitigate stormwater-related impacts. If nonstructural BMPs cannot be used, the reasons why must be demonstrated to the Township’s satisfaction. Stormwater generation can be reduced by designing the subdivision or land development in ways other than through use of standard or conventional development practices. Prevention and nonstructural BMPs are in contrast with structural BMPs (refer Chapter 6 of the Manual) that provide mitigation of stormwater impacts which cannot be prevented and/or avoided.
5. The following major “areas” of preventative nonstructural BMPs have been identified in the Manual:
A. Protect Sensitive and Special Value Features.
B. Cluster and Concentrate.
C. Minimize Disturbance and Minimize Maintenance.
D. Reduce Impervious Cover.
E. Disconnect/Distribute/Decentralize.
F. Source Control.
Specific nonstructural BMPs have been identified for each of these generalized areas, to better define and improve implementation. One of the most challenging technical issues considered in the Manual involves the selection of BMPs that have a high degree of non-point source (NPS) reduction or removal efficiency. In the ideal, a BMP should be selected that has a proven NPS pollutant removal efficiency for all pollutants of importance, especially those that are critical in a specific watershed.
6. Chapter 8 of the Manual provides a methodological approach to take credit for applying these nonstructural BMPs, provided that the “specifications” defined for each BMP in Chapter 5 of the Manual are properly followed.
7. Stormwater management requirements, including peak rate and volume not met with nonstructural best management practices, shall be controlled with structural best management practices such as infiltration basins, infiltration trenches, porous pavement, constructed wetlands, wet basins, retention basins, and dry extended detention basins in accordance with Chapter 6 of the Manual. Design, construction, and landscaping of structural Best Management Practices shall be in accordance with requirements of Chapter 6 of the manual and subject to approval by the Township.
8. The developer shall construct and/or install such drainage structures, onsite and offsite as necessary to provide a fully functioning stormwater collection and control system meeting the requirements of the Manual. The developer’s design shall utilize to the maximum extent possible and consistent with other requirements of this Ordinance, nonstructural BMPs.
9. On-lot drainage swales shall be designed to provide positive conveyance of surface water from the individual lot. Each swale lot shall convey stormwater from the lot to a storm sewer system, street, open space area, or stormwater management easement without crossing or combining with stormwater from more than one adjacent lot.
10. Drainage swales necessary to control surface drainage between lots shall be centered about the common property line.
11. Whenever an ephemeral, intermittent, or perennial stream is located within a development site, it shall remain open in its natural state and location, and shall not be piped, impeded, or altered (except for road crossings). It is the responsibility of the developer to restore existing eroded stream/channel banks within the development site and obtain all permits necessary from PADEP to do so. The developer must submit pictorial documentation of existing stream/channel banks to determine whether existing banks must be stabilized.
12. During review of the stormwater management plan, if the Township determines that offsite improvements are necessary to satisfactorily manage stormwater runoff from the proposed subdivision or land development, the developer shall be responsible for design, construction and permitting of those offsite improvements.
13. Existing points of concentrated drainage that discharge onto adjacent property shall not be altered without written agreement of the affected property owner(s) and Township, and shall be subject to any applicable discharge criteria specified in the Stormwater Management Ordinance. The agreement shall be recorded at the Bucks County Office of Recorder of Deeds and assignable to future owners.
14. Areas of sheet flow drainage shall be maintained wherever possible. If sheet flow is proposed to be concentrated and discharged onto adjacent property, the developer must document that adequate downstream conveyance facilities exist to safely transport the concentrated discharge, or otherwise prove that no erosion, sedimentation, flooding, or other harm will result from the concentrated discharge; and submit written approval from the affected adjacent property owner(s).
15. Whenever the location of concentrated runoff from a site is changed due to development, the developer must secure written approval from all adjacent downstream property owners. The developer shall indemnify and/or hold harmless the Township against any claim of damage from any downstream property owners that may result from the proposed development.
16. All proposed streets shall be designed so as to discharge surface water from their rights-of-way. Storm drainage improvements as deemed necessary by the Township shall be required along all existing streets on which a subdivision or land development abuts.
17. Setback to Boundaries. No piped storm sewer system outlet, detention basin, or energy dissipation structure shall discharge closer than 20 feet from the boundary of any drainage easement under the control of the developer or which may be utilized by the developer, so as to allow for adequate space for stormwater dissipation in vegetated land areas controlled by, or available to, the developer and/or to allow adequate space for equipment access for future maintenance.
(Ord. 163, passed 2-28-2012, § 517; Ord. 191, passed 1-8-2019)