Article VII Resource Conservation and Greenway Delineation Standards

This section is intended to ensure that the Township's limited groundwater resources are protected for purposes of providing water supplies for its residents and businesses and to protect the baseflow of the Township's surface waters.

These regulations shall be applied in conjunction with those provided for in § 315-13I(2) of this chapter and Article XXIV of Chapter 390, Zoning, of the Township's Code, dealing with groundwater protection. In cases where a perceived conflict may arise, the stricter regulation shall prevail (as interpreted by the Board).

The proposed subdivision and land development of any tract shall be designed to cause the least practicable disturbance to natural infiltration and percolation of precipitation to the groundwater table, through careful planning of vegetation and land disturbance activities and the placement of streets, buildings and other impervious surfaces.

New development or expansion of existing development shall demonstrate a nonnegative water balance after the development proposal occurs, as compared to predisturbance conditions. If the groundwater is used for water supply, a water balance analysis must include uses in its calculations, regardless of where the withdrawal occurs.

All new development or expansion of existing development in the Township of West Vincent shall be undertaken in a manner so as to guarantee a nonnegative hydrologic balance, pre development and post development. Any reduction in groundwater recharge resulting from the construction of new impervious surfaces, alteration of grading and drainage, loss of vegetation, construction of sanitary and storm sewers, and/or modification from any other predevelopment condition, plus any groundwater consumed for water supply or other purposes, shall be compensated for by the increased infiltration of precipitation and wastewater effluent into the soil mantle. This recharge system shall utilize design and engineering standards and techniques to be approved by the Supervisors upon recommendations after review by the Township Engineer.

Predevelopment and post-development water balance calculations must be made to determine the resultant impact on groundwater resources. Typically, the impact of changed site conditions must be estimated by using average rainfall, total disturbance acreage, and appropriate soil cover factors as applied in the Cover-Complex Method developed by the United States Department of Agriculture Natural Resources Conservation Service or another method acceptable to the Township Engineer. This calculation will provide an estimate of increased stormwater runoff resulting from development and, therefore, the net reduction in groundwater recharge. The estimate shall be developed on an average annual basis, in inches and gallons. If groundwater withdrawals are being undertaken for water supply or other purposes, this quantity also must be considered as a debit for the groundwater system. The difference between the predevelopment and post-development conditions equals the total debit which must be balanced through modifications to stormwater management techniques or to wastewater effluent application which mitigate the total loss of groundwater recharge.

Stream valleys, swales, springs and other lowland areas. Stream valleys (which include stream channels and floodplains), swales, springs and other lowland areas are resources that warrant restrictive land use controls because of flooding hazards to human life and property, their groundwater recharge functions, their importance to water quality and the health of aquatic communities, and their wildlife habitats. They are poorly suited for on-site subsurface sewage disposal systems.

[Amended 10-17-2022 by Ord. No. 201]

Woodlands and forests. Woodlands and forests occur extensively throughout the Township, often in association with stream valleys and wet areas, poor and erodible soils, and moderate-to-steep slopes. Approximately 2/3 of the Township is within the Hopewell Big Woods, a globally significant landscape. Forested lands within the Township contain critical value forests and woodlands with exceptional habitat and ecological value. These areas are susceptible to degradation by disturbance that fragments or clears forested land. Greenways shall maximize preservation of an interconnected system of critical value forests and woodlands.

[Amended 10-17-2022 by Ord. No. 201]

Woodland conditions within the Township of West Vincent vary with respect to species composition, age, stocking and health. They range from young post-agricultural stands to mature mixed-age forests. Most woodlands in the Township represent one or more of the following resource values:

As soil stabilizers, particularly on moderate-to-steep slopes, thereby controlling erosion into nearby streams, ponds, impoundments and roads.

As areas with enhanced groundwater recharge.

As a means of maintaining stream base flows and protecting the water quality in Exceptional Value and High Quality watersheds.

As a means of ameliorating harsh microclimatic conditions, in both summer and winter.

As habitats for woodland birds, mammals and other wildlife, including endangered, threatened, rare, and vulnerable species, as well as species uniquely adapted to interior forest conditions.

As a source of wood products (i.e., poles, saw timber, veneer and firewood).

(g)

As recreation resources for walkers, equestrians, picnickers and to facilitate other outdoor activities.

(h)

As visual buffers between areas of development and adjacent roads and properties.

Because of their resource values, all woodlands on any tract proposed for subdivision or land development shall be evaluated by the applicant to determine the extent to which such woodlands should be designated partly or entirely as greenway or development lands. Evaluation criteria shall include:

Configuration and size.

Present conditions (i.e., stocking, health and species composition).

Site potential (i.e., the site's capabilities to support woodlands, based upon its topographic, soil and hydrologic characteristics).

Ecological functions (i.e., in protecting steep slopes, erodible soils, maintaining stream quality and providing for wildlife habitats, including interior forests and Natural Heritage Areas).

Relationship to woodlands on adjoining and nearby properties and the potential for maintaining continuous woodland areas.

Presence of specimen trees.

The evaluation of the tract's woodlands shall be undertaken by a forester, landscape architect, ecologist or other qualified professional acceptable to the Township. This evaluation shall be submitted as a report and made a part of the application for a preliminary plan. At a minimum, that report shall include one or more maps indicating boundaries and conditions of woodland areas accompanied by a report addressing the criteria in Subsection D(2) above.

In designing a subdivision and land development plan for any tract, the applicant shall adhere to the following standards:

Critical value forests, critical value woodlands, and interior forests shall be preserved and designated as greenway areas to the maximum extent possible.

Where forested or woodland areas on the tract abut forest lands that are permanently protected through conservation easement, ownership by state or local government, or ownership by a conservation organization, the adjacent forest lands may be considered in determining location of interior forests.

Forests and woodlands may comprise up to 100% of required greenway lands.

Proposed site improvements shall be located, designed and constructed to minimize the fragmentation of forest and woodland areas and loss of heritage and specimen trees.

Subdivisions shall be designed to preserve woodlands and forests along roadways, property lines and lines occurring within a site such as streams, swales, stone fences and hedgerows. Such lines and the native vegetation associated with them shall be preserved as buffers between adjacent properties and between areas being subdivided within a property.

Disturbance or removal of woodlands and forests occupying environmentally sensitive areas shall be undertaken only when approved by the Board and on a limited, selective basis to minimize the adverse impacts of such actions. This shall include, but not necessarily be limited to, vegetation performing important soil-stabilizing functions on wet soils, stream banks and sloping lands.

(g)

No clearing or earth disturbance (except for soil analysis for proposed sewage disposal systems) shall be permitted on a site before the completion of subdivision and land development agreements. The determination of sight distance clearances along roadways shall be made graphically and not by clearing on site prior to final plan approval.

Upland rural-agricultural areas. These areas comprise fields, pastures, meadows, and former agricultural areas in early stages of woodlands succession, with fences, stone walls, tree coppice and hedgerows, typically bordered by stream valleys and upland woodlands. These comprise the Township's historic working landscape, dotted with historic houses, barns and other structures. They give the Township much of its rural character. They also contain the greatest concentration of prime agricultural soils. Because of their openness and high visibility, development in these areas is likely to be most readily seen and disruptive to the historic landscape. They sometimes provide habitat for wildlife in conjunction with nearby woodlands and stream valleys. However, it is recognized that these areas also frequently offer the fewest constraints for development.

Several elements of these working landscapes lend themselves to incorporation into the Township's greenway network. These include prime agricultural soils and natural features which visually punctuate the landscape, such as hedgerows, tree coppice, stone walls, and visually prominent places such as knolls and hilltops.

These areas can also accommodate development, with preferred locations being the non-prime agricultural soils and lower topographic settings where development will be visually less obtrusive. Compact clustered residential designs, with coordinated architectural and landscape architectural themes, are encouraged in highly visible locations where future development cannot be avoided (such as at the far edge of open fields).

Slopes. Moderately sloping lands (15 to 25%) and steeply sloping lands (over 25%) are prone to severe erosion if disturbed. Erosion and the resulting overland flow of soil sediments into streams, ponds and public roads are detrimental to water quality and aquatic life and a potential hazard to public safety.

Areas of steep slope shall be preserved in accordance with Article XVII of Chapter 390, Zoning, and as required below.

All grading and earthmoving on slopes exceeding 15% shall be minimized.

No site disturbance shall be allowed on slopes exceeding 25%, except grading for a portion of a driveway accessing a single-family dwelling when it can be demonstrated that no other routing which avoids slopes exceeding 25% is feasible.

On slopes of 15% to 25%, the only permitted grading beyond the terms described above shall be in conjunction with the siting of a single-family dwelling, its access driveway and the septic system (which should typically be designed with a long, narrow drainage field or trenches following the land contours).

Grading or earthmoving on all sloping lands of 15% or greater shall not result in earth cuts or fills whose highest vertical dimension exceeds six feet, except where, in the judgment of the Board, no reasonable alternatives exist for construction of roads, drainage structures and other public improvements; in which case such vertical dimensions shall not exceed 12 feet. Roads and driveways shall follow the line of existing topography to minimize the required cut and fill. Finished slopes of all cuts and fills shall be as required to minimize disturbance of natural grades.

Critical habitat areas. Natural areas containing rare or endangered plants and animals as well as other features of natural significance exist throughout the Township. Some of these have been carefully documented (e.g., by the Pennsylvania Natural Diversity Inventory), whereas, for others, only their general locations are known. Subdivision applicants shall take all reasonable measures to protect significant natural areas and features either identified in Appendix L of the Township Zoning Ordinance, or by the applicant's existing resources and site analysis plan (as required in § 315-13D) by incorporating them into proposed greenway areas or avoiding their disturbance in areas proposed for development.

[Amended 10-17-2022 by Ord. No. 201]

Historic resources. Historic resources in the Township are listed in the Township Open Space and Recreation Plan and the Historic Site Inventory.

All subdivisions and land developments shall comply with § 315-49 of this chapter and Article XXV, Historic Preservation, of Chapter 390, Zoning, of the Township's Code.

Plans requiring subdivision and land development approval shall be designed to protect existing historic resources of all classes. The protection of an existing historic resource shall include the conservation of the landscape immediately associated with and significant to that resource to preserve its historic context. Where, in the opinion of the Board, a plan will have an impact upon a historic resource, the developer shall mitigate that impact to the satisfaction of the Board by modifying the design, relocating proposed lot lines, providing landscape buffers, or other approved means.

§ 315-52 Design process for residential subdivisions with greenway lands.

Township participation, review and approval of the applicant's submission to the Pennsylvania Historical and Museum Commission with regard to the preservation of historic resources, as required by the Pennsylvania Department of Environmental Protection prior to approval of proposed sewage disposal systems, shall be in accordance with § 315-39 of this chapter.

Scenic road corridors and viewsheds. The Township Open Space and Recreation Plan identifies scenic roads and visual resources in the Township. All applications for subdivision and land development shall attempt to preserve the scenic visual corridors along such roads by incorporating them into greenway areas or otherwise providing for building setbacks and architectural designs to minimize their intrusion. In instances where such designs fail to satisfactorily protect corridors, applicants will be required to provide naturalistic landscape buffers to minimize their adverse visual impacts. The species specified for such buffers shall be selected on the basis of an inventory of tree and shrub species found in existing hedgerows and along wooded roadside edges in the vicinity of the development proposal.

Trails. When a subdivision or land development proposal is traversed by or abuts an existing or proposed trail as shown on the Township Trail Plan, the applicant shall make provisions for continued recreational use of the trail in accordance with the standards contained in § 315-48 of this chapter.

[Amended 10-17-2022 by Ord. No. 201]

Resource inventory and analysis. The tract's resources shall be delineated on an existing resources and site analysis plan, as required in § 315-13D of this chapter.

Five-step design process. Following the resource inventory and analysis, all residential subdivisions with greenway lands shall follow a five-step design process as described below. Applicants will be required to document the design process as described in § 315-13F of this chapter.

[Amended 10-17-2022 by Ord. No. 201]

Step 1: Delineation of greenway lands and development areas. Greenway lands and development areas shall be delineated according to the following procedure, as illustrated below, using as an example a hypothetical fifty-acre subdivision parcel, of which 40 acres are considered to be net usable land ("adjusted tract area").

Total tract area:	50 acres
Adjusted tract area (ATA):	40 acres
Minimum greenway requirements:
Primary conservation areas (land unsuitable for development):	10 acres
Secondary conservation areas (50% of ATA):	20 acres
Total:	30 acres
Development area (50% of ATA):	20 acres

"Primary conservation areas" (i.e., floodplains, submerged lands, wetlands, riparian and wetland buffers, critical value forests, critical value woodlands, and slopes over 25%) shall be deducted from the gross tract area per the Township Zoning Ordinance to determine adjusted tract area, and comprise 10 acres in the example. Primary conservation areas shall be delineated in their entirety on the plan.

Additional minimum acreage requirements for greenway areas consist of "secondary conservation areas," to be calculated on the basis of the standards in § 390-123 of of the Township's Code. In the example, a minimum of 50% of the adjusted tract (or 20 acres) must be secondary conservation areas.

Total greenway area requirements are the sum of primary conservation and secondary conservation areas, which, in the example, comprise 30 acres.

The locations and boundaries of primary conservation areas shall follow the actual boundaries of the environmental resources.

The locations and boundaries of secondary conservation areas shall be based upon the applicant's analysis of the tract's resource features, using the design standards in § 315-13D. The applicant shall also be guided by any written recommendations provided by the Township regarding the delineation of secondary conservation areas, following the site inspection or the pre-sketch conference.

Development areas constitute the remaining lands of the tract outside of the designated greenway areas, which, in the above example, consist of 20 acres, where house sites, streets and lots are to be delineated in accordance with steps 2, 3 and 4 below.

Step 2: Location of house sites. Applicants shall identify house site locations in the tract's designated development areas, designed to: fit the tract's natural topography, served by adequate water and sewerage facilities, and provide views of and access to adjoining greenway areas (without encroaching upon them in a manner visually intrusive to users of such areas). House sites should be located no closer than 100 feet and 50 feet from primary conservation areas and secondary conservation areas, respectively.

Step 3: Alignment of streets and trails.

With house site locations identified, applicants shall delineate a street system to provide vehicular access to each house in a manner conforming to the tract's natural topography and providing for a safe pattern of circulation and ingress and egress to and from the tract.

Streets shall avoid or at least minimize adverse impacts on the greenway areas. To the greatest extent practicable, wetland crossings and new streets or driveways traversing slopes over 15% shall be avoided.

Street connections shall minimize the number of new culs-de-sac to be maintained by the Township and to facilitate easy access to and from homes in different parts of the tract (and on adjoining parcels).

A network of trails shall also be shown, connecting streets with various natural and cultural features in the conserved greenway lands. Potential trail connections to adjacent parcels shall also be shown in areas where a Township trail network is envisioned in the Township Trail Plan.

Step 4: Location of land-based water management facilities. Preferred locations for the stormwater and wastewater management facilities will be identified using the site analysis plan and proposed greenway lands as the base maps. Opportunities to use these facilities as an additional buffer between the proposed greenways and development areas are encouraged. These facilities should generally be designed to improve the quality of stormwater runoff and wastewater effluent with emphasis placed on achieving maximum groundwater recharge. The facilities should be located in areas identified as groundwater recharge areas as indicated on the site analysis plan. The design of the facilities should strive to use the natural capacity and features of the site to facilitate the management of stormwater and wastewater generated by the proposal.

§ 315-53 Greenway design review standards.

Step 5: Design of lot lines. Lot lines for the subdivision should be drawn as the last step in the design procedure. They should follow the configuration of house sites and streets in a logical and flexible manner.

In designating greenway lands within the subdivision or land development plan, such areas shall be consistent with the following:

[Amended 10-17-2022 by Ord. No. 201]

Phoenixville Regional Comprehensive Plan, adopted as the Township Comprehensive Plan, and Zoning Ordinance.

Article XX of Chapter 390, Zoning, of the Township's Code.

Resources to be conserved. The design of greenway lands in any subdivision or land development plan shall reflect the standards set forth in §§ 315-51 and 315-52 above and, to the fullest extent possible, incorporate any of the following resources if they occur on the tract:

[Amended 10-17-2022 by Ord. No. 201]

Stream channels, floodplains, wetlands, swales, springs and other lowland areas, including adjacent buffer areas which may be required to insure their protection.

Areas where precipitation is most likely to recharge local groundwater resources because of topographic conditions and soils affording high rates of infiltration and percolation.

Class I, II and III agricultural soils as defined by the United States Department of Agriculture Natural Resources Conservation Service.

Moderate-to-steep slopes, particularly those adjoining watercourses and ponds, where disturbance and resulting soil erosion and sedimentation could be detrimental to water quality.

Woodlands and forests, particularly critical value forests, critical value woodlands, and those performing important ecological functions, such as protecting steep slopes, erodible soils, interior forest, and maintaining stream and/or wetland quality.

(6)

Hedgerows, groups of trees, specimen and heritage trees, and other vegetative features representing the tract's rural past.

(7)

Significant natural areas of species listed as endangered, threatened, rare, or vulnerable, such as those listed in Appendix L of the Township Zoning Ordinance.

(8)

Historic resources.

(9)

Visually prominent topographic features, such as knolls, hilltops and ridges, and scenic viewsheds, as seen from public roads (particularly those with historic features).

(10)

Existing trails connecting the tract to other locations in the Township.

Other design considerations. The configuration of proposed greenway lands set aside for common use in residential subdivisions shall comply with the following standards:

[Amended 2-22-2022 by Ord. No. 197; 10-17-2022 by Ord. No. 201]

They shall be free of all structures except historic buildings, stone walls, and structures related to permitted greenway uses.

They shall generally not include parcels smaller than three acres, have a length-to-width ratio of less than four to one, or be less than 75 feet in width, except for such lands specifically designed as neighborhood greens or when part of a trail system or pathway network.

They shall be directly accessible to the largest practicable number of lots within the subdivision. Non-adjoining lots shall be provided with safe and convenient pedestrian access to greenway land.

They shall be suitable for active recreational uses to the extent deemed necessary by the Board, without interfering with adjacent dwelling units, parking, driveways and roads.

§ 315-54 Resource conservation standards for site preparation and cleanup.

They shall be interconnected to greenway lands or open space areas on abutting parcels wherever possible, including provisions for pedestrian pathways for general public use, to provide a continuous network of greenway lands within and adjoining the subdivision.

(6)

They shall provide buffers to adjoining parks, preserves or other protected lands.

(7)

Except in those cases where part of the greenway is located within private house lots, they shall provide for pedestrian pathways for use by the residents of the subdivision. Consideration shall be given to providing for public access on such trails if they are linked to other publicly-accessible pathway systems within the Township. Provisions should be made for access to the greenway lands as required for land management and emergency purposes.

(8)

They shall be undivided by public or private streets, except where necessary for proper traffic circulation.

(9)

They shall be provided with sufficient perimeter parking where necessary and with safe and convenient access by adjoining street frontage or other rights-of-way or easements capable of accommodating pedestrian, bicycle, maintenance and vehicular traffic, and containing appropriate access improvements.

(10)

They shall be suitably landscaped either by retaining existing natural cover and wooded areas and/or according to a landscaping plan to protect greenway resources and which minimize maintenance costs.

(11)

They shall be preserved from the removal or clearing of underbrush within woodland areas unless required or necessary for approved recreational uses.

(12)

They shall be preserved from the removal or clearing of streamside buffers and provided with additional landscaping to create stream buffers in accordance with § 390-182 of Chapter 390, Zoning, except for occasional and necessary stream access.

(13)

They shall be made subject to such agreement with the Township and such conservation easements duly recorded with each lot deed in the office of the County Recorder of Deeds as may be required by the Board for the purposes of preserving and guaranteeing management and maintenance of the greenway lands.

(14)

Any areas proposed be utilized for sewage disposal systems or stormwater management structures proposed as part of a subdivision may not be included or designated as greenway land and shall be excluded from any calculation of greenway land requirements under this Article.

Ownership and maintenance. Applicants shall demonstrate compliance with greenway ownership and maintenance standards in § 390-125 of Chapter 390, Zoning, of the Township's Code.

Monitoring construction activities. The Township Historical Commission shall have the right to monitor on-site construction activities relative to the preservation and protection of historic resources and to the possible discovery of unrecorded archeological resources.

Conservation practices during site preparation and cleanup.

Protection of vegetation from damage. Where earthwork, grading or construction activities will take place within 50 feet of woodlands, forests, specimen trees, or other significant vegetation or site features, tree protection zones shall be delineated with fencing in accordance with § 390-174D of the Township's Code. Such fencing shall be installed prior to commencing of and shall be maintained throughout the period of construction activity.

[Amended 10-17-2022 by Ord. No. 201]

Protective fences and barriers placed around woody vegetation during construction shall be removed at the conclusion of post-construction cleanup activities.

[Amended 10-17-2022 by Ord. No. 201]

Protection of vegetation from grading change. Grade changes to occur at any location of the property shall not result in an alteration to soil or drainage conditions which would adversely affect existing vegetation to be retained following site disturbance, unless adequate provisions are made to protect such vegetation and its root systems.

Protection of vegetation from excavations.

When digging trenches for utility lines or similar uses, disturbances to the root zones of all woody vegetation shall be minimized.

If trenches must be excavated in the root zone, all disturbed roots shall be cut as cleanly as possible. The trench shall be backfilled as quickly as possible, avoiding soil compaction.

Protection of topsoil. Any activity resulting in the disturbance of topsoil shall comply with the soil erosion and sedimentation control regulations of the County Conservation District and the Pennsylvania Department of Environmental Protection, in addition to the following standards:

No topsoil shall be removed from the site.

Prior to grading operations or excavation, topsoil in the area to be disturbed shall be removed and stored on site.

Topsoil removed shall be redistributed and stabilized as quickly as possible following the establishment of required grades for a project or project phase. All exposed earth surfaces shall be stabilized by hydroseeding on slopes of less than 10% and by sodding, hydroseeding, or riprap on slopes exceeding 10%.