For any of the activities regulated by this Ordinance, the final approval of subdivision and/or land development plans, the issuance of any building or occupancy permit, or the commencement of any land disturbance activity may not proceed until the property owner or developer or his/her agent has received written approval of a stormwater management plan from the Township.
The stormwater management plan shall consist of all applicable calculations, maps, and plans. A note on the maps shall refer to the associated computations and erosion and sedimentation control plan by title and date. The cover sheet of the computations and erosion and sedimentation control plan shall refer to the associated maps by title and date. All stormwater management plan materials shall be submitted to the Township in a format that is clear, concise, legible, neat, and well organized; otherwise, the stormwater management plan shall be disapproved and returned to the applicant.
The following items shall be included in the stormwater management plan:
A. A feasibility analysis that evaluates the potential application of infiltration, flow attenuation, bioretention, wetland, or wet pond BMPs must be submitted with the stormwater management plans required in Article IV for those developments not intending the use of such facilities. This analysis shall provide:
1. A general assessment of the anticipated additional runoff based on the design storm and post-development condition and utilizing the calculation procedures required in Section 305;
2. indication of drainage areas on the development site resulting in impervious, pervious, and rooftop runoff;
3. indication of type of land use (residential, non-residential) generating the impervious surface runoff;
4. delineation of soils on the site from the SCS, Soil Survey of Bucks and Philadelphia Counties and onsite soil study. Soil study shall be conducted by a soil scientist and shall include sufficient probes/deep holes to evaluate application of BMPs;
5. indication of soils generally suitable for infiltration and/or wet pond/artificial wetland BMPs as shown in "General Soil Suitability for Infiltration, Wet Pond and Artificial Wetland Best Management Practices With Consideration to Runoff Point of Origin and Land Use Type", including specification of those soils requiring modifications;
6. calculated acreage of suitable soils for infiltration BMPs and wet pond or artificial wetland BMPs and percentage of suitable soils based on total site acreage;
7. calculated acreage of suitable soils for infiltration BMPs and wet pond or artificial wetland BMPs made unavailable due to proposed development layout and justification that alternative development layout which would reduce impact on suitable soil availability is unfeasible;
8. analysis of potential infiltration or wet pond or artificial wetland BMPs which could be implemented to manage the projected post-development runoff with consideration of suitable soil availability runoff point of and type of land use (items 2. and 3. above) and the general design standards and maintenance issues included in this Ordinance including an indication of how most post-development runoff can be managed by these BMPs (e.g. the entire post-development runoff or partial amount of runoff expressed as a percentage); and
9. rationale for the decision to not proceed with implementation of wet pond or artificial wetland BMPs such as insufficient soil suitability.
10. rationale for not proceeding with infiltration oriented BMPs in accordance with Section 303.A.1.c of this Ordinance.
The feasibility analysis must allow the Township to review the general soil characteristics of a site and the proposed development for that site and determine if infiltration BMPs or wet pond or artificial wetland BMPs could have been more thoroughly pursued for use by the developer. The information required in the analysis is detailed enough to determine the potential applicability of these BMPs for a proposed development, but general enough not to force a developer into incurring excessive cost associated with conducting laborious field and/or laboratory soil testing for a site which ultimately may not be suitable for infiltration or wet pond or artificial wetland BMP implementation. However, with the requirements for conducting a feasibility analysis, developers will be aware that they are expected to use these BMPs wherever possible and are required to provide adequate justification if these BMPs are not to be implemented. Essentially, all developers will be conducting feasibility analysis since such analysis would become the preliminary step in evaluating the potential for implementation of these mandatory BMPs where possible. Taking into consideration the areal extent of suitable soils necessary to accommodate an infiltration facility, or wet pond, or wetland BMP for the type and size of development proposed, developers for those sites that are determined to be generally suitable are required to conduct the detailed soil testing and other feasibility testing required in other sections of this Ordinance which contain the description and additional design criteria of these BMPs.
B. A detailed geologic evaluation of the project site shall be performed to determine the suitability of recharge facilities. The evaluation shall be performed by a qualified geologist and/or soil scientist, and at a minimum, address soil permeability, depth to bedrock, susceptibility to sinkhole formation, and subgrade stability.
C. Whenever a stormwater management facility will be located in an within Carbonate Geology Overlay District (refer Section 1904 of the Solebury Township Zoning Ordinance) a geological evaluation of the proposed location shall be conducted to determine susceptibility to sinkhole formations. The design of all facilities over limestone formations shall include measures to prevent ground water contamination and, where necessary, sinkhole formation. Soils used for the construction of basins shall have low-erodibility factors ("K" factors). Installation of an impermeable liner shall be required in detention or retention basins.
D. It shall be the developer's responsibility to verify whether the site is underlain by limestone. The following note shall be attached to all stormwater management plans and signed and sealed by the developer's professional engineer "I,_______________________, certify that the proposed detention basin (circle pne) is/is not underlain by limestone."
E. General
1. General description of project.
2. General description of permanent stormwater BMPs and management techniques, including construction specifications of the materials to be used for stormwater management facilities.
3.Complete hydrologic, hydraulic, and structural computations for all stormwater management facilities.
F. Map(s) of the project area shall be submitted on 24-inch x 36-inch sheets and shall be prepared in a form that meets the requirements for recording at the offices of the Recorder of Deeds of Bucks County. The contents of the maps(s) shall include, but not be limited to:
1. The location of the project relative to highways, municipalities, or other identifiable landmarks.
2. Existing contours at intervals of 2 feet. In areas of steep slopes (greater than 25 percent), 5 feet contours may be used.
3. Existing streams, lakes, ponds, or other bodies of water within the project area.
4. Other physical features including flood hazard boundaries, sinkholes, streams, existing drainage courses, wetlands, areas of natural vegetation to be preserved, and the total extent of the upstream area draining through the site.
5. The locations of all existing and proposed utilities, sanitary sewers, and water lines located on the site and/or within 50 feet of property lines.
6. An overlay showing soil names and boundaries. The overlay shall include a table on the map showing the recharge capabilities of each soil represented onsite in inches per hour and describe their recharge or infiltration capabilities.
7. Proposed changes to the land surface and vegetative cover, including the type and amount of impervious area that would be added.
8. Proposed structures, roads, paved areas, and buildings. Where pervious pavement is proposed for parking lots, recreational facilities, non-dedicated streets, or other areas, pavement construction specifications shall be noted on the plan.
9. Final contours at intervals at 2 feet. In areas of steep slopes (greater than 25 percent), 5-feet contour intervals may be used.
10. The name of the development, the name and address of the owner of the property, and the name of the individual or firm preparing the plan.
11. The date of submission.
12. A graphic and written scale of one (1) inch equals no more than fifty (50) feet. For tracts of twenty (20) acres or more, the scale may be one (1) inch equals no more than one hundred (100) feet.
13. A North arrow.
14. The total tract boundary and size with distances marked to the nearest foot and bearings to the nearest degree.
15. Existing and proposed land use(s).
16. A key map showing all existing man-made features beyond the property boundary that may be affected by the project.
17. Horizontal and vertical profiles of all open channels, including hydraulic capacity.
18. Overland drainage paths.
19. A twenty (20) feet wide access easement around all stormwater BMPS and management facilities that would provide ingress to and egress from a public right-of-way.
20. A note on the plan indicating the location and responsibility for maintenance of stormwater management facilities that would be located off-site. All off-site facilities shall meet the performance standards and design criteria specified in this Ordinance.
21. A construction detail of any improvements made to sinkholes and the location of all notes to be posted, as specified in this Ordinance.
22. A statement on the plan, signed by the landowner, acknowledging the stormwater BMPS and management facilities to be a permanent fixture that can be altered or removed only after approval of a revised plan by the Township, which shall be recorded with the record plan and which shall be applicable to all future landowners.
23. The location of all erosion and sedimentation control facilities.
"(Design engineer), on this date (date of signature), has reviewed and hereby certifies that the stormwater management plan meets all design standards and criteria of the Solebury Township Stormwater Management Ordinance.'
G. Supplemental Information
1. A written description of the following information shall be submitted.
a) The overall stormwater management concept for the project.
b) Stormwater runoff computations as specified in this Ordinance.
c) Stormwater management BMPs to be applied both during and after development.
d) Expected project time schedule.
2. A soil erosion and sedimentation control plan, where applicable, including all reviews and approvals, as required by PADEP and/or Bucks County Conservation District.
3. A geologic assessment of the effects of runoff on sinkholes as specified in this Ordinance.
4. The effect of the project (in terms of runoff volume and peak flow) on adjacent properties and on any existing Township stormwater collection system that may receive runoff from the project site.
5. A Declaration of Adequacy and Highway Occupancy Permit from the PADOT District Office when utilization of a PADOT storm drainage system is proposed.
H. Stormwater Management BMPs
1. All stormwater management BMPs must be located on a plan and described in detail.
2. When infiltration methods such as seepage pits, beds, or trenches are proposed, the locations of existing and proposed septic tank, infiltration areas, and wells must be shown. A separation distance of no less than 20 feet shall be provided between any septic system and any facility used for stormwater management.
3. All calculations, assumptions, and criteria used in the design of the stormwater management BMPs must he shnwn If multiple facilities are proposed in conjunction with each other, such as infiltration Best Management Practices with vegetation based management practices , a summary narrative, shall be included describing any sequence and how the facilities are meant to function with each other to manage stormwater runoff.
I. All Stormwater Management Plans shall note the following: stormwater management facilities are a permanent part of the development and shall not be removed, altered, or modified.
For all activities regulated by this Ordinance, the steps below shall be followed for submission. For any activities that require a PADEP joint permit application and regulated under Chapter 102 (Erosion and Sediment Control), Chapter 105 (Dam Safety and Waterway Management), or Chapter 106 (Floodplain Management) of PADEP's Rules and Regulations, require a PADOT highway occupancy permit, or require any other permit under applicable local, state, or federal regulations, the permit(s) shall be part of the plan submission.
A. The stormwater management plan shall be submitted by the developer as part of the Preliminary plan submission for the regulated activity.
B. The number of copies of the Stormwater Management Plan required to be submitted to the Township, shall be determined by resolution of the Board of Supervisors.
C. Distribution of the Stormwater Management plan shall be determined by resolution of the Board of Supervisors. The distribution list, as a minimum, shall include Solebury Township Engineer and the Bucks County Planning Commission, as well as any other agencies or entities designated by the resolution of the Board of Supervisors.
A. The Township Engineer shall review the stormwater management plan for consistency with the adopted Watershed Act 167 Stormwater Management Plan, this Ordinance, and applicable Township Ordinances. The Township shall require receipt of a complete plan, as specified in this Ordinance.
B. The Township Engineer shall review the Stormwater Management Plan for any subdivision or land development against the Municipal Subdivision and Land Development Ordinance provisions not superseded by this Ordinance.
C. For activities regulated by this Ordinance, the Township Engineer shall notify the Solebury Township Secretary in writing, whether the Stormwater Management Plan is consistent with Township Ordinances and other relevant regulations. Should the Stormwater Management Plan submitted by the applicant be determined to be consistent with Township Ordinances and other relevant regulations, the Township Engineer will forward a review letter to the applicant with a copy to the Solebury Township Secretary.
D. For regulated activities specified in Sections 104.E, F, and J of this Ordinance, the Township Engineer shall notify the Township Secretary in writing whether the stormwater management plan is consistent with this Ordinance and forward a copy of the review letter to the developer. Any disapproved stormwater management plan may be revised by the developer and resubmitted consistent with this Ordinance.
E. The Township shall not approve any subdivision or land development or regulated activities specified in Sections 104.A and 104.B of this Ordinance if the stormwater management plan has been found to be inconsistent with the adopted Watershed Act 167 Stormwater Management Plan. All required permits from PADEP must be obtained prior to, or as a requirement of, final approval.
F. The Township Building Permit Office shall not issue a building permit for any regulated activity specified in Section 104 of this Ordinance if the stormwater management plan has been found to be inconsistent with this Ordinance, as determined by the Township Engineer, or without considering the comments of the Township Engineer. All required permits from PADEP must be obtained prior to issuance of a building permit.
G. The developer shall be responsible for completing an "as-built survey" of all stormwater management BMPs included in the approved stormwater management plan. The as-built survey and an explanation of any discrepancies with the design plans shall be submitted to the Township Engineer for review. In no case shall the Township approve the as-built survey until the Township receives a copy of an approved Declaration of Adequacy, Highway Occupancy Permit from the PADOT District Office, and any applicable permits from PADEP.
H. The Township's approval of a stormwater management plan shall be valid for a period not to exceed two (2) years. If stormwater management facilities included in the approved stormwater management plan have not been constructed, or if an as-built survey of these facilities has not been approved within this 2-year time period, then the Township may consider the stormwater management plan disapproved and may revoke any and all permits. Stormwater management plans that are considered disapproved by the Township shall be resubmitted in accordance with Section 407 of this Ordinance.
A.set of design plans approved by the Township shall be on file at the site throughout the duration of the development activity. Periodic inspections may be made by the Township or designee during development activities.
It shall be unlawful for any person to undertake any development activity on any property except as provided for in the approved stormwater management plan and pursuant to the requirements of this Ordinance. It, shall be unlawful to alter or remove any BMP required by the stormwater management plan pursuant to this Ordinance or to allow the property to remain in a condition which does not conform to the approved stormwater management plan.
At the completion of the project, and as a prerequisite for the release of the performance guarantee under Section 701, the owner or his representatives shall:
A. Contact the Township Engineer to request inspection of the site for completion of stormwater management facilities and compliance with the approved plans and specifications.
B. Provide a set of as-built drawings as required pursuant to the Township Building Code and/or Subdivision and Land Development Ordinance.
A.modification to a submitted stormwater management plan for a development site that involves a change in stormwater management facilities or techniques, or that involves the relocation or redesign of stormwater management facilities, or that is necessary because soil or other conditions are not as stated on the stormwater management plan as determined by the Township Engineer, shall require a resubmission of the modified stormwater management plan consistent with Section 403 of this Ordinance and be subject to review as specified in Section 404 of this Ordinance.
A.modification to an already approved or disapproved stormwater management plan shall be submitted to the Township, accompanied by the applicable review. A modification to a stormwater management plan for which a formal action has not been taken by the Township shall be submitted to the Township, accompanied by the applicable Township review fee.
An occupancy permit shall not be issued unless the stormwater management facilities approved for the lot have been installed and found satisfactory to the Township Engineer.
