The standards for resource conservation, as set forth in this article, shall apply to all land subdivision and developments in the Township. The standards for greenway delineation shall apply to all land subdivision and developments within the Flexible Rural Residential District of Chapter 240, Zoning.
A.
General standards to minimize adverse impacts. All subdivisions and
land developments shall avoid or minimize adverse impacts on the Township's
natural, cultural and historic resources, as defined below.
B.
Groundwater resources. 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 base flow of the Township's surface waters. These regulations
shall be applied in conjunction with those provided for in this chapter
dealing with groundwater conservation and replenishment. 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.
C.
Stream valleys, swales, springs, and other lowland areas. The Newlin
Township Open Space, Recreation and Environmental Resources Plan describes
and maps stream valleys (which include stream channels and floodplains),
swales, springs and other lowland areas as 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 generally poorly suited for on-site subsurface
sewage disposal systems. The following activities shall be minimized:
(1)
Disturbance to streams and drainage swales.
(2)
Disturbance to year-round wetlands, areas with seasonally high water
tables, and areas of surface water concentration.
(3)
Because of their extreme limitations, stream valleys, swales and
other lowland areas warrant designation as greenway lands. They may
also require adjoining buffer lands to be included in the greenway,
to be determined by an analysis of the protection requirements of
such areas on a case-by-case basis. In certain instances, seasonal
high water table soils may be excluded from the greenway where it
can be demonstrated that they are suitable for low-density residential
uses and conventional on-site sewage systems.
D.
Woodlands. Woodlands occur extensively throughout the Township, often
in association with stream valleys and wet areas, poor and erodible
agricultural soils, and moderate to steep slopes. Woodland conditions
within the Township vary with respect to species composition, age,
stocking, and health. They range from relatively recent post-agricultural
young stands to mature mixed-age forests. Most woodlands in the Township
represent one or more of the following resource values:
(1)
As soil stabilizers, particularly on moderate to steep slopes, thereby
controlling erosion into nearby streams, ponds, impoundments and roads.
A closely related function is their enhancement of groundwater recharge.
(2)
As a means of ameliorating harsh microclimatic conditions.
(3)
As a source of wood products, i.e., poles, saw-timber, veneer and
firewood.
(4)
As habitats for woodland birds, mammals and other wildlife.
(5)
As recreation resources for walkers, equestrians, picnickers and
other related outdoor activities.
(6)
As visual buffers between areas of development and adjacent roads
and properties.
(7)
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:
(a)
Configuration and size.
(b)
Present conditions, i.e., stocking, health and species composition.
(c)
Site potential, i.e., the site's capabilities to support woodlands,
based upon its topographic, soil and hydrologic characteristics.
(d)
Ecological functions, i.e., in protecting steep slopes, erodible
soils, maintaining stream quality and providing for wildlife habitats.
(e)
Relationship to woodlands on adjoining and nearby properties
and the potential for maintaining continuous woodland areas.
(8)
The evaluation of the tract's woodlands shall be undertaken by a qualified forester, landscape architect, horticulturist or another qualified professional acceptable to the Supervisors. 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(7) above.
(9)
In designing a subdivision and land development plan for any tract,
the applicant shall be guided by the following standards:
(a)
Healthy woodlands exceeding one acre shall be preserved and
designated as greenway areas, to the maximum extent possible. Proposed
site improvements shall be located, designed and constructed to minimize
the loss or degradation of woodland areas.
(b)
Subdivisions shall be designed to preserve woodlands 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. Preservation
shall include ground, shrub, understory and canopy vegetation.
(c)
Disturbance or removal of woodlands occupying environmentally
sensitive areas shall be undertaken only when approved by the Township
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.
(d)
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.
E.
Upland rural-agricultural areas. These areas comprise fields, pastures,
meadows, and former agricultural areas in early stages of woodland
succession, with fences, stone walls, tree copses 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 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.
(1)
Several elements of these working landscapes lend themselves to incorporation
into the Township's greenway network. These include prime agricultural
soils and natural features that visually punctuate the landscape,
such as hedgerows, tree copses, stone walls, and visually prominent
places such as knolls and hilltops.
(2)
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).
F.
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.
(1)
Areas of steep slope shall be preserved in accordance with Chapter 240. Zoning, and as required below.
(2)
All grading and earthmoving on slopes exceeding 15% shall be minimized.
(3)
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.
(4)
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 following
the land contours).
(5)
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 Township no
reasonable alternatives exist for the 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.
G.
Significant natural areas and features. 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
by the Township's Map of Potential Conservation Areas or by the applicant's
existing resources and site analysis plan by incorporating them into
proposed greenway areas or avoiding their disturbance in areas proposed
for development.
H.
Historic structures and sites. Historic structures and sites shall
be protected as follows:
(1)
All subdivisions and land developments shall comply with all applicable
provisions of the Pennsylvania Historical and Museum Commission.
(2)
Plans requiring subdivision and land development approval shall be
designed to protect existing historic resources as listed in the Chester
County Newlin Township Historic Resource Atlas of 2010, the Unionville
Area Regional Comprehensive Plan Chapter 4 of 2011, or the Newlin
Township Open Space, Recreation and Environmental Resources Plan of
1994. 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 Township a plan will have an impact upon a historic
resource, the developer shall mitigate that impact to the satisfaction
of the Township by modifying the design, relocating proposed lot lines,
providing landscape buffers, or other approved means.
(3)
Township participation, review and approval of the applicant's interaction with the Pennsylvania Historical and Museum Commission with regard to the preservation of historic resources, as required for PADEP approval of proposed sewage disposal systems, shall be in accordance with § 185-79, Sewage disposal facilities.
I.
Historic rural road corridors and scenic viewsheds. The Newlin Township
Open Space, Recreation and Environmental Resources Plan identifies
a number of historic rural roads in various parts of 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.
J.
Trails.
(1)
When a subdivision or land development proposal is traversed by or
abuts an existing trail customarily used by pedestrians and/or equestrians,
the Township may require the applicant to make provisions for continued
recreational use of the trail.
(2)
The applicant may alter the course of the trail within the tract
for which development is proposed under the following conditions:
(a)
The points at which the trail enters and exits the tract remain
unchanged.
(b)
The proposed alteration exhibits quality trail design according
to generally accepted principles of landscape architecture (for example:
PADEP, Bureau of State Parks' publication "Non-Motorized Trails").
(c)
The proposed alteration does not coincide with a paved road
intended for use by motorized vehicles.
(3)
When trails are intended for public or private use, they shall be
protected by a permanent conservation easement on the properties on
which they are located. The width of the protected area in which the
trail is located should be a minimum of 10 feet. The language of the
conservation easement shall be to the satisfaction of the Township
upon recommendation of the Township Solicitor.
(5)
An applicant may propose and develop a new trail. If said trail is available for use by the general public and connects with an existing trail, the land area protected for said trail may be credited toward the open space requirement described in Article III, Flexible Rural Development Regulations, of Chapter 240, Zoning.
(6)
Trail improvements shall demonstrate adherence to principles of quality
trail design.
(7)
Trails shall have grades not exceeding 30%.
(8)
Width of the trail surface may vary depending upon type of use to
be accommodated, but in no case shall be less than three feet or greater
than six feet.
(9)
No trail shall be designed with the intent to accommodate motorized
vehicles.
A.
Resource inventory and analysis. The tract's resources shall be delineated
on an existing resources and site analysis plan (ER/SA Plan).
B.
Four-step design process. All residential subdivisions with greenway
lands shall follow the four-step design process described below.
(1)
Step 1: Delineation of greenway lands, including stormwater and wastewater
management areas. General locations for greenway land, including stormwater
and wastewater management areas, shall be delineated according to
the following procedure:
(a)
Using the ER/SA plan as a base map, primary and secondary conservation
areas shall be delineated.
(b)
Greenway land shall include all primary conservation areas plus enough secondary conservation area to meet or exceed the minimum acreage requirement for greenway land set forth in Chapter 240, Zoning.
[2]
The locations and boundaries of primary conservation areas shall
follow the actual boundaries of floodplains, wetlands, and steep slopes
over 25%.
[3]
The locations and boundaries of secondary conservation areas
shall be based on the priorities established above, practical considerations
given to the tract's configuration, its context in relation to resources
on adjoining properties, and the applicant's subdivision objectives.
Secondary resources with the highest significance shall be included
in the greenway land. The applicant shall also be guided by any recommendations
provided by the Township regarding the delineation of secondary conservation
areas, following the site visit and/or the presubmission conference.
[4]
Greenway land shall be delineated in a manner clearly indicating
greenway land boundaries as well as the types of resources included
within them.
(c)
Preferred locations for stormwater and wastewater management
facilities shall be identified using the ER/SA plan as a base map.
These facilities should be designed to improve the quality of stormwater
runoff and wastewater effluent with emphasis placed on achieving maximum
groundwater recharge.
[1]
The design of these 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.
[2]
Opportunities to use these facilities as a buffer between the
proposed greenway land and development areas are encouraged.
[3]
Stormwater management facilities should be located in areas
identified as groundwater recharge areas.
[4]
Wastewater facilities shall comply with the requirements of
the Township Sewage Facilities Plan.
[5]
Such facilities located within the greenway land may be counted
toward the minimum greenway land requirement as follows. The following
stormwater management practices may be counted toward the minimum
greenway land requirement, provided they meet the guidelines in the
PA Stormwater Best Management Practices Manual: infiltration basin,
provided the berms do not exceed 36 inches in height; subsurface infiltration
bed; infiltration trench; rain garden; vegetated swale; infiltration
berm, provided the berms do not exceed 24 inches in height. The following
elements of sewage disposal systems may be counted toward the minimum
greenway land requirement: soil absorption areas suitable for active
or passive recreation; absorption fields serving individual dwelling
units; drainage easements for sewer lines.
(d)
Development areas constitute the remaining lands of the tract
outside the greenway land, where dwellings, streets and lots are to
be delineated in accordance with Steps 2, 3 and 4 below.
(2)
Step 2: Locations for dwelling units. Dwelling units shall be tentatively
located, using the proposed greenway land from Step 1 as reference
and orientation as well as other relevant data on the ER/SA Plan.
Dwelling units shall be sited to:
(a)
Fit the tract's natural topography;
(b)
Be served by adequate water and sewerage facilities;
(c)
Provide views of and access to adjoining greenway land;
(d)
Avoid encroaching upon greenway land in a manner visually intrusive
to users of such areas; and
(e)
Be located at least 100 feet from primary conservation areas
and 50 feet from secondary conservation areas.
(3)
Step 3: Alignment of streets and trails.
(a)
Once dwelling units have been located, applicants shall delineate
a street system that provides a safe pattern of vehicular and pedestrian
access to each dwelling unit. Streets and trails shall conform to
the tract's natural topography and provide for a safe pattern of circulation
to, from and within the tract.
(b)
Streets and driveways crossing wetlands and traversing slopes
over 15% shall be avoided to the greatest extent practicable.
(c)
Street connections are encouraged in order to minimize the number
of new culs-de-sac and to facilitate easy access to and from homes
in different parts of the tract and on adjoining parcels. Three-way
intersections shall be preferred over four-way intersections.
(d)
Lots shall generally be accessed from interior streets, rather
than from roads bordering the tract. Conservancy lots may be exempt
from this requirement, as determined by the governing body.
(e)
A tentative network of trails shall be shown, where appropriate,
providing access to natural and cultural features in the greenway
land. Potential trail connections to adjacent parcels shall also be
shown in areas where a county or municipal trail network is envisioned.
(f)
Common greens, shaped by the street system, shall meet the requirements of § 240-17B(5) and (6) of Chapter 240, Zoning.
(4)
Step 4: Design of lot lines. Lot lines for the subdivision should
be drawn as the last step in the design procedure. They shall follow
the configuration of dwelling sites and streets in a logical and flexible
manner.
