Township of Millcreek, PA SWM Site Plan and Report Requirements

The following activities are specifically exempt from the SWM site plan and report preparation provisions of this chapter, unless the Township determines that the activity is likely to, has, or will negatively impact the purposes and objectives set forth in Article I. For example, where an activity occurs on very steep terrain or where an activity is the latest in a series of incremental developments expected to cause pronounced stormwater impacts, it may be that these activities will be required to comply with the plan preparation requirements contained herein even though their activities qualify under the listing in this section. Upon making such determination, the Township shall give notice in writing to the applicant and direct the applicant to immediately cease and desist all activity and affirmatively comply with the formal plan, submission, and approval procedures of this chapter. Exemption shall not relieve the applicant from providing adequate stormwater management to meet the purpose of this chapter.

Any regulated activity that would create 5,000 square feet or less of impervious area; provided, however, that the Township may require plan preparation for developments creating in excess of 1,500 square feet of impervious area if drainage or stormwater management problems exist upon the subject premises or upon properties adjacent to it. This criteria shall apply to the total site even if development is to take place in phases. Impervious cover shall include, but not be limited to, any roof, parking or driveway areas and any new streets and sidewalks. Any areas designed to initially be gravel or crushed stone shall be assumed to be impervious for the purposes of this exemption criteria.

(1)

An applicant proposing regulated activities, after demonstrating compliance with § 116-14 and this section, may be exempted from various requirements of this chapter according to the following table:

	New Impervious Area¹ (square footage)	Applicant Must Provide
	0 to 1,000	—
	1,000 to 1,500	Documentation of impervious area
	1,500 to 5,000	Volume controls and Simplified Method or small project SWM application
	> 5,000	Rate and volume controls, SWM site plan

	NOTE:
	¹	Gravel in existing condition shall be considered pervious. Gravel in proposed condition shall be considered impervious.

(2)

The exemption set forth above shall be cumulative, and all development activity within a five-year period shall be included within calculations.

(3)

A small project stormwater management application (on a form adopted by the Township) may be used for projects under 5,000 square feet of new impervious surface and single-family residential home construction, where soils on the site are entirely Type A, B and/or C. The small project SWM application allows documentation of new impervious surface, credits through disconnection of impervious surfaces and tree planting, and sizing of volume control BMPs that may be required.

(4)

Alternatively, or where Type D soils are present on the site, general standards for regulated activities creating 5,000 square feet or less of impervious area, in the aggregate under the Simplified Method, are as set forth on Appendix C to this chapter.[1] Except for circumstances in which the Township requires a SWM site plan and report, the Simplified Method will be available for use regardless of soil type.

[1]

Editor's Note: Appendix C is included as an attachment to this chapter.

Use of land for gardening for home consumption.

Agriculture when operated in accordance with a conservation plan or erosion and sedimentation control plan prepared by the County Conservation District. The agricultural activities such as growing crops, rotating crops, filling of soil and grazing animals and other such activities are specifically exempt from complying with the requirements of this chapter when such activities are conducted in accordance with a conservation plan prepared by the County Conservation District. The construction of buildings, parking lots or any activity that may result in impervious surface which increases the rate and volume of stormwater runoff shall comply with the requirements of this chapter.

Forest management and timber operations are exempt from the rate and volume control requirement and SWM site plan preparation requirement of this chapter, provided that such activities are performed according to the requirements of 25 Pa. Code Chapter 102. Temporary roadways are not exempt.

The Township may deny or revoke any exemption pursuant to this section at any time for any project which the Township believes may pose a threat to public health, public safety, property or the environment.

The SWM site plan and SWM site report shall consist of all applicable calculations, maps and plans. All SWM site plan materials shall be submitted to the Township in a format that is clear, concise, legible, neat and well-organized. Otherwise, the SWM site plan shall be rejected. Appropriate provisions from Chapter 125, Subdivision and Land Development, and Chapter 145, Zoning, PPIC and other applicable regulations shall be followed in preparing the SWM site plan.

The SWM site plan shall include, but not be limited to:

(1)

Plans, which shall be of one size and in a form that meets the requirements for recording in the office of the Erie County Recorder of Deeds.

(a)

Plans for tracts of less than 20 acres shall be drawn to a scale of one inch equals no more than 50 feet;

(b)

Plans for tracts of 20 acres or more shall be drawn to a scale of one inch equals no more than 100 feet;

(c)

All lettering shall be drawn to a size to be legible if the plans are reduced to half size.

(2)

General format. All shall contain a title block setting forth: name and location address of the property site, name, address and telephone number of the applicant/owner of the property, name, address, telephone number, e-mail address and engineering seal of the professional engineer responsible for the SWM site plan.

(3)

The date of submission and dates of all revisions.

(4)

A graphical and written scale on all drawings and maps.

(5)

A North arrow on all drawings and maps.

(6)

A location map at a minimum scale.

(7)

Existing and proposed features. The plan shall show on separate drawings (one of existing conditions and the other of proposed conditions) the following under both predevelopment and postdevelopment conditions:

(a)

A key map showing the location of the development site within the watershed(s) and watershed subarea(s). On all site drawings, show the boundaries of the watershed(s) and subarea(s) as they are located on the development site and identify watershed names(s) and subarea number(s).

(b)

A location map at a minimum scale of one inch equals 1,000 feet and which illustrates the project relative to streets and highways, municipalities or other identifiable landmarks.

(c)

Metes and bounds description of the entire tract perimeter.

(8)

Contours. Show existing and final contours at intervals of one foot; in areas with slopes greater than 15%, five-foot contour intervals may be used.

(9)

Perimeters of all existing bodies of water (natural or artificial), watercourses (permanent and intermittent), swales, wetlands and other natural drainage courses on the development site or which will be affected by runoff from the development, areas of natural vegetation to be preserved, the total extent of the upstream area draining through the site and overland drainage paths. In addition, any areas necessary to determine downstream impacts, where required for proposed stormwater management facilities, must be shown.

(10)

Proposed impervious surfaces (structures, roads, paved areas and buildings), including plans and profiles of roads and paved areas and floor elevation of buildings.

(11)

Soils. Provide an overlay showing soil types and boundaries within the development site (consult county, NRCS and U.S. Geological Survey for information).

(12)

A key map showing all existing man-made features beyond the property boundary that may be affected by the project.

(13)

The location and clear identification of the nature of permanent stormwater BMPs.

(14)

The location of all existing and proposed utilities, on-lot wastewater facilities, water supply wells, sanitary sewers and water lines, on and within 50 feet of property lines, including inlets, manholes, valves, meters, poles, chambers, junction boxes and other utility system components.

(15)

Land cover. Show existing and final land cover classifications as necessary to support and illustrate the runoff calculations performed; include proposed structures, roads, paved areas and buildings and areas of intended future expansion.

(16)

Drainage area delineations. Show the boundaries of the drainage areas employed in the runoff calculations performed.

(17)

Stormwater management controls. Show any existing stormwater management or drainage controls and/or structures, such as storm sewers, swales, culverts, etc. which are located on the development site, or which are located off-site but will be affected by runoff from the development.

(18)

Existing and proposed land uses.

(19)

Horizontal alignment, vertical profiles and cross-sections of all open channels, pipes, swales and other BMPs.

(20)

Floodplain boundaries. Identify one-hundred-year floodplains on the development site (as appropriate) based on the Township's Flood Insurance Study maps.

(21)

The location of all erosion and sedimentation control facilities, shown separately from the SWM site plan (typically, an E & S control plan).

(22)

Stormwater controls. All proposed stormwater runoff control measures must be shown on the plan, including methods for collecting, conveying and storing stormwater runoff on-site, which are to be used both during and after construction. Erosion and sedimentation controls shall be shown in accordance with Article IV, Erosion and Sedimentation Controls, of this chapter. The site plan or the report shall provide information on the exact type, location, sizing, design and construction of all proposed facilities and their relationship to the existing watershed drainage system. The report shall include technical specifications for materials and methods to be used in the construction of the stormwater management facilities.

(a)

If the development is to be constructed in stages, the applicant must demonstrate that stormwater facilities will be installed to manage stormwater runoff safely during each stage of development.

(b)

A schedule for the installation of all temporary and permanent stormwater control measures and devices shall be submitted.

(c)

If appropriate, a justification should be submitted as to why any preferred stormwater management techniques, as listed in Article V, Design Criteria for Stormwater Management Controls, of this chapter, are not proposed for use.

(23)

Easements, rights-of-way, deed restrictions. All existing and proposed easements and rights-of-way for drainage and/or access to stormwater control facilities shall be shown, along with any areas subject to special deed restrictions relative to or affecting stormwater management on the development site.

(24)

A minimum twenty-foot-wide access easement around all stormwater management facilities that would provide ingress to and egress from a public right-of-way. In lieu of providing an easement to the public right-of-way, a note may be added to the plan, granting to the Township and to such person(s) or entity(ies) as will be responsible for future maintenance access to all easements via the nearest public right-of-way.

(25)

Construction details for all drainage and stormwater BMPs.

(26)

Construction sequence.

(27)

Identification of short-term and long-term ownership, operations and maintenance responsibilities.

(28)

Notes and statements.

(a)

A statement, signed by the landowner, acknowledging that the stormwater BMPs are fixtures that cannot be altered or removed without prior approval by the Township.

(b)

A statement referencing the Operation and Maintenance (O&M) Agreement and stating that the O&M Agreement is part of the SWM site plan.

(c)

A note indicating that record drawings will be provided for all stormwater facilities prior to occupancy or the release of financial security.

(29)

Required signature blocks.

(a)

The following signature block for the professional engineer in charge of preparing the stormwater management plan:

"I, __________, P.E., hereby certify that the Stormwater Management Plan meets all design standards and criteria of the Millcreek Township Stormwater Management Ordinance."

(b)

The following signature block for the Township reviewing the stormwater management plan, this to be signed by a professional engineer in the firm retained by the Township to review such plans:

"I, __________, P.E., have reviewed this Stormwater Management Plan in accordance with the Design Standards and Criteria of the Millcreek Township Stormwater Management Ordinance."

The SWM site report shall include, but not be limited to:

(1)

General data, including:

(a)

Project name;

(b)

Project location address and Township and Erie County tax index numbers;

(c)

Name, address and telephone number of the applicant/owner of the property;

(d)

Name, address, telephone number, e-mail address and engineering seal of the individual responsible for preparation of the SWM site report;

(e)

Date of submission and revisions.

(2)

Project description narrative which clearly discusses the project and provides the following information, where applicable:

(a)

Narrative.

[1]

Statement of the regulated activity, describing what is being proposed, overall stormwater management concept with a description of permanent stormwater management techniques, including construction specifications and materials to be used for stormwater management facilities.

[2]

Expected project schedule.

[3]

Location map showing the project site and its location relative to release rate districts.

[4]

Detailed description of existing site conditions including a site evaluation completed for projects proposed in areas of carbonate geology or karst topography, and other environmentally sensitive areas such as brownfields.

[5]

Total site area, pre- and post-, which must be equal or have an explanation as to why it is not.

[6]

Total site impervious area.

[7]

Total off-site areas.

[8]

Number and description of stormwater management facilities.

[9]

Type of development.

[10]

Predevelopment land use.

[11]

Whether the site is a water-quality-sensitive (WQS) development.

[12]

Whether the site is in a defined sensitive area.

[13]

Types of water quality and recharge systems used, if applicable.

[14]

Complete hydrologic, hydraulic and structural components for all stormwater management facilities.

(b)

Ownership and maintenance detail.

[1]

A written maintenance plan for all stormwater management features, including detention facilities and other stormwater management elements.

[2]

Identification of ownership and maintenance responsibility for all permanent stormwater management facilities (including name, address and telephone number of all persons or entities identified).

(c)

Summary tables.

[1]

Predevelopment hydrologic soil group (HSG) assumptions, curve numbers (CN), computation of average slope, hydraulic length, computed time concentration.

[2]

Existing conditions runoff volume and peak rate of runoff.

[3]

Postdevelopment runoff volume and peak rate of runoff.

[4]

Undetained areas, areas to ponds.

[5]

Land use for each subarea.

[6]

Hydrologic soil group (HSG) assumptions, curve numbers (CN).

[7]

Time of concentration computed for each subarea.

[8]

Postdevelopment peak rate of runoff routed to ponds and out.

[9]

Pond maximum return period design data, including maximum water surface elevation, berm elevation and emergency spillway elevation.

[10]

Water quality depth and volume requirements.

(d)

Calculations.

[1]

Complete hydrologic, hydraulic and structural computations, calculations, assumptions and criteria for the design of all stormwater BMPs.

[2]

Details of the berm embankment and outlet structure, indicating the embankment's top elevation, side slopes and top width, emergency spillway elevation, perforated riser dimensions, pipe barrel dimensions and dimensions and spacing of antiseep collars.

[3]

Design computations for the control structures (pipe barrel and riser, etc.).

[4]

A plot or table of the stage-storage (volume versus elevation) and all supporting computations.

[5]

Routing computations.

(e)

Drawings.

[1]

Drainage area maps for all watersheds and inlets depicting the time of concentration path for both existing conditions and postdeveloped condition.

[2]

All stormwater management facilities must be located on a plan and described in detail, including easements and buffers boundaries.

(3)

Description of, justification and actual field results for infiltration testing with respect to the type of test and test location for the design of infiltration BMPs.

(4)

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 municipal stormwater collection system that may receive runoff from the project site.

(5)

Description of the proposed changes to the land surface and vegetative cover, including the type and amount of impervious area to be added.

(6)

Identification of short-term and long-term operation and maintenance responsibilities as well as schedules and costs for inspection and maintenance activities for each permanent stormwater or drainage BMP, including provisions for permanent access or maintenance easements.

(7)

Runoff calculations. Calculations for determining pre- and postdevelopment discharge rates and for designing proposed stormwater control facilities must be submitted with the stormwater management plan. All calculations shall be prepared using the methods and data prescribed by Article III, Stormwater Management Standards, of this chapter.

(8)

Maintenance program. The proposed maintenance plan for all stormwater control facilities shall:

(a)

Identify the proposed ownership entity (e.g., property owner, private corporation, homeowners' or unit owners' association, other entity).

(b)

Identify the type of maintenance, probable frequencies, personnel and equipment requirements and estimated annual maintenance costs (with substantiation of the estimate's basis).

(c)

Identify the method for financing the continuing operation and maintenance of the facility if the facility is to be owned by other than a governmental agency.

(d)

Include copies of any legal agreements required to implement the maintenance program and, if applicable, copies of the maintenance agreement as required under Article IX, Maintenance of Stormwater Management Controls, of this chapter.

(9)

Financial guarantees. Submit financial guarantees in accordance with the provisions of Article XI, Financial Guarantees and Dedication of Public Improvements, of this chapter.

(10)

Supplemental information to be provided prior to recording of the SWM site plan, as applicable:

(a)

Other permits/approvals. A list of any approvals/permits relative to stormwater management that will be required from other governmental agencies (e.g., PaDEP Chapter 105 and 106 permits and/or NPDES permit) and anticipated dates of submission/receipt should be included with the stormwater plan submission. Copies of permit applications may be requested by the Township where they may be helpful for the plan review.

(b)

Signed and acknowledged Operations and Maintenance Agreement.

(c)

Signed and executed easements, as required for all on-site and off-site work.

(d)

Geologic assessment.

(e)

Soils investigation report, including boring logs, compaction requirements and recommendations for construction of detention basins.

(f)

A highway occupancy permit from PennDOT when utilization of a PennDOT drainage system is proposed or when proposed facilities would encroach onto a PennDOT right-of-way.

(g)

Notice to downstream municipality. To meet the § 116-12V requirement, the developer, by certified mail, shall notify the municipality immediately downstream of the proposed development that a stormwater control plan has been prepared and submitted. This letter shall identify the location of the proposed development site and the name of the affected stream. Copies of this letter and of the certified mail return receipt shall be included in the report.

Professional certification. The principal in charge of preparing the SWM site plan and report (including all calculations) shall be a registered professional engineer and the stormwater management plan shall be sealed by a registered professional engineer with training and expertise in hydrology and hydraulics. A professional engineer certifying a SWM site plan, report and/or as-built drawings shall maintain in force at all times professional liability or errors and omissions insurance coverage having limits of not less than $1,000,000. Documentation of qualifications and insurance coverage may be required by the Township.