Township of Weisenberg, PA Drainage Plan Requirements

General description of project.

General description of proposed permanent stormwater controls.

The name and address of the project site, the name and address of the owner of the property and the name of the individual or firm preparing the drainage plan.

Map(s) of the project area showing:

The location of the project relative to highways, municipalities or other identifiable landmarks.

Existing contours at intervals of two feet. In areas of steep slopes (greater than 15%), five-foot contour intervals may be used. Off-site drainage areas impacting the project including topographic detail.

Streams, lakes, ponds or other bodies of water within the project area.

Other features including flood hazard boundaries, existing drainage swales, wetlands, closed depressions, sinkholes and areas of natural vegetation to be preserved.

(5)

Locations of proposed underground utilities, sewers and water lines. The locations of all existing and proposed utilities, sanitary sewers and water lines within 50 feet of property lines of the project site.

(6)

An overlay showing soil types and boundaries based on the Lehigh County Soil Survey, as applicable, latest edition. Any hydric soils present on the site should be identified as such.

(7)

An overlay showing geologic types, boundaries and any special geologic features present on the site.

(8)

Proposed changes to land surface and vegetative cover.

(9)

Proposed structures, roads, paved areas and buildings.

(10)

Final contours at intervals of two feet. In areas of steep slopes (greater than 15%), five-foot contour intervals may be used.

(11)

Stormwater management district boundaries applicable to the site.

(12)

Clear identification of the location and nature of permanent stormwater BMPs.

(13)

An adequate access easement around all stormwater BMPs that would provide municipal ingress to and egress from a public right-of-way.

(14)

A schematic showing all tributaries contributing flow to the site and all existing man-made features beyond the property boundary that would be affected by the project.

(15)

The location of all public water supply wells within 400 feet of the project and all private water supply wells within 100 feet of the project.

Stormwater management controls and BMPs.

All stormwater management controls and BMPs shall be shown on a map and described, including:

Groundwater recharge methods such as seepage pits, beds or trenches. When these structures are used, the locations of septic tank infiltration areas and wells shall be shown.

Other control devices or methods such as rooftop storage, semipervious paving materials, grass swales, parking lot ponding, vegetated strips, detention or retention ponds, storm sewers, etc.

All calculations, assumptions and criteria used in the design of the BMPs shall be shown.

All site testing data used to determine the feasibility of infiltration on a site.

All details and specifications for the construction of the stormwater management controls and BMPs.

The BMP operations and management plan, as required in Article XI, describing how each permanent stormwater BMP will be operated and maintained and the identity of the person(s) responsible for operations and maintenance. A statement must be included, signed by the landowner, acknowledging that the stormwater BMPs are fixtures that cannot be altered or removed without approval by the municipality.

Environmental resources.

An environmental resources site design assessment that describes the following:

The extent to which the proposed grading and impervious cover avoid disturbance of significant environmental resources and preserve existing site hydrology.

An assessment of whether alternative grading and impervious cover site design could lessen the disturbance of significant environmental resources and/or make better use of the site hydrologic resources.

(c)

A description of how the proposed stormwater management controls and BMPs serve to mitigate any adverse impacts on environmental resources on the site.

Significant environmental resources considered in the site design assessment include, but are not limited to, steep slopes, ponds, lakes, streams, wetlands, hydric soils, floodplains, riparian vegetation, native vegetation and special geologic features.

The SWM site plan shall provide the following information:

The overall stormwater management concept for the project.

A determination of site conditions in accordance with the BMP Manual 4. A detailed site evaluation shall be completed for projects proposed in areas of carbonate geology or karst topography, and other environmentally sensitive areas, such as brownfields.

Stormwater runoff design computations and documentation as specified in this Part 3, or as otherwise necessary to demonstrate that the maximum practicable measures have been taken to meet the requirements of this Part 3, including the recommendations and general requirements in § 405-47.

Expected project time schedule.

(5)

A soil erosion and sediment control plan, where applicable, as prepared for and submitted to the approval authority.

(6)

The effect of the project (in terms of runoff volumes, water quality, and peak flows) on surrounding properties and aquatic features and on any existing stormwater conveyance system that may be affected by the project.

(7)

Plan and profile drawings of all SWM BMPs, including drainage structures, pipes, open channels, and swales.

(8)

SWM site plan shall show the locations of existing and proposed on-lot wastewater facilities and water supply wells.

(9)

The SWM site plan shall include an O&M plan for all existing and proposed physical stormwater management facilities. This plan shall address long-term ownership and responsibilities for O&M as well as schedules and costs for O&M activities.

(10)

A justification must be included in the SWM site plan if BMPs other than green infrastructure methods and LID practices are proposed to achieve the volume, rate and water quality controls under this Part 3.

§ 405-58 Plan submission.

For regulated activities specified in § 405-38B(1) and (2):

The drainage plan shall be submitted by the developer to the Township Secretary (or other appropriate person) as part of the preliminary plan submission for the subdivision or land development.

Four copies of the drainage plan shall be submitted.

Distribution of the drainage plan will be as follows:

One copy to the municipal governing body.

One copy to the municipal engineer.

(c)

Two copies to the Lehigh Valley Planning Commission, except for drainage plans involving less than 10,000 square feet of additional impervious cover.

Drainage plans involving more than 10,000 square feet of additional impervious cover shall be submitted by the developer (or, at the option of the municipality, through the municipality) to the Lehigh Valley Planning Commission as part of the preliminary plan submission. The Lehigh Valley Planning Commission will conduct an advisory review of the drainage plan for consistency with the Jordan Creek, Little Lehigh Creek, Maiden Creek, and the Sacony Creek Watershed Stormwater Management Plans, as applicable. The LVPC will not review details of the erosion and sedimentation plan or the BMP operations and maintenance plan.

Two copies of the drainage plan shall be submitted.

The LVPC will provide written comments to the developer and the municipality, within a time frame consistent with established procedures under the Municipalities Planning Code,[1] as to whether the drainage plan has been found to be consistent with the stormwater management plan.

[1]

Editor's Note: See 53 P.S. § 10101 et seq.

For regulated activities specified in § 405-38B(3) and (4), the drainage plan shall be submitted by the developer to the municipal building permit officer as part of the building permit application.

For regulated activities specified in § 405-38B(5), (6) and (7):

The drainage plan shall be submitted by the developer to the Lehigh Valley Planning Commission for coordination with the PADEP permit application process under 25 Pa. Code Chapter 105 (Dam Safety and Waterway Management), and Chapter 106 (Floodplain Management), of PADEP's rules and regulations, and the NPDES regulations.

One copy of the drainage plan shall be submitted.

Earthmoving for all regulated activities under § 405-38 shall be conducted in accordance with the current federal and state regulations relative to the NPDES and PADEP regulations, 25 Pa. Code Chapter 102.

§ 405-59 Drainage plan review.

The Township Engineer shall review the drainage plan, including the BMP operations and maintenance plan, for consistency with the adopted Jordan Creek, Little Lehigh Creek, Maiden Creek and Sacony Creek Watershed Stormwater Management Plans, as applicable, as embodied by this Part 3, and with any permits issued by PADEP. The municipality shall also review the drainage plan against any additional storm drainage provisions contained in Chapter 425, Subdivision and Land Development, or Chapter 500, Zoning, as applicable.

The Lehigh Valley Planning Commission shall provide an advisory review of the drainage plan for consistency with the Stormwater Management Plan.

For regulated activities specified in § 405-38B(1) and (2), the LVPC shall provide written comments to the Township, within a time frame consistent with established procedures under Act 247,[1] as to whether the drainage plan has been found to be consistent with the Stormwater Management Plan.

[1]

Editor's Note: See 53 P.S. § 10101 et seq.

For regulated activities specified in § 405-38B(5) and (6), the LVPC shall notify PADEP whether the drainage plan is consistent with the Stormwater Management Plan and forward a copy of the review letter to the Township and developer.

For any SWM Site Plan that proposes to use any BMPs other than green infrastructure and LID practices to achieve the volume and rate controls required under this Part 3, the municipality will not approve the SWM site plan unless it determines that green infrastructure and LID practices are not practicable.

The Township shall notify the applicant in writing whether the drainage plan, including the BMP operations and maintenance plan, is approved.

The Township shall not approve any subdivision or land development [regulated activities § 405-38B(1) and (2)] or building permit application [regulated activities § 405-38B(3) and (4)] if the drainage plan has been found to be inconsistent with the stormwater management plan.

The municipality may require an as-built survey of all stormwater BMPs and an explanation of any discrepancies with the drainage plan.

§ 405-60 Modification of plans.

A modification to a submitted drainage plan for a proposed development site which involves a change in control methods or techniques, or which involves the relocation or redesign of control measures, or which is necessary because soil or other conditions are not as stated on the drainage plan (as determined by the municipality) shall require a resubmission of the modified drainage plan consistent with § 405-48 subject to review per § 405-49 of this Part 3.

§ 405-61 Resubmission of disapproved plans.

A disapproved SWM site plan may be resubmitted, with the revisions addressing the Township's concerns, to the Township in accordance with this article. The applicable review fee must accompany a resubmission of a disapproved SWM site plan.

§ 405-62 Hardship waiver procedure.

The municipality may hear requests for waivers where it is alleged that the provisions of this Part 3 inflict unnecessary hardship upon the applicant. The waiver request shall be in writing and accompanied by the requisite fee based upon a fee schedule adopted by the municipality. A copy of the waiver request shall be provided to each of the following: municipality, municipal engineer, municipal solicitor and Lehigh Valley Planning Commission. The request shall fully document the nature of the alleged hardship.

The municipality may grant a waiver provided that all of the following findings are made in a given case:

That there are unique physical circumstances or conditions, including irregularity of lot size or shape, or exceptional topographical or other physical conditions peculiar to the particular property, and that the unnecessary hardship is due to such conditions, and not the circumstances or conditions generally created by the provisions of this Part 3 in the stormwater management district in which the property is located;

That, because of such physical circumstances or conditions, there is no possibility that the property can be developed in strict conformity with the provisions of this Part 3, including the no harm provisions, and that the authorization of a waiver is therefore necessary to enable the reasonable use of the property;

That such unnecessary hardship has not been created by the applicant;

That the waiver, if authorized, will represent the minimum waiver that will afford relief and will represent the least modification possible of the regulation in issue; and

(5)

That financial hardship is not the criteria for granting of a hardship waiver.

In granting any waiver, the municipality may attach such conditions and safeguards as it may deem necessary to implement the purposes of this Part 3. If a hardship waiver is granted, the applicant must still manage the quantity, velocity, direction and quality of resulting storm runoff as is necessary to prevent injury to health, safety or other property.

For regulated activities described in § 405-38B(1) and (2), the Board of Supervisors shall hear requests for and decide on hardship waiver requests on behalf of the municipality.

For regulated activities in § 405-38B(3), (4), (5), (6) and (7), the Zoning Hearing Board shall hear requests for and decide on hardship waiver requests on behalf of the municipality.