[Added 9-16-2009 by Ord. No. 09-9-1]
A.
The standards for resource conservation shall apply to all subdivision
and land development applications in the Township.
Natural, cultural and historic resources shall be conserved
in accordance with the following:
A.
Surface and 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.
(1)
Disturbance to the following areas shall be prohibited, unless specifically
authorized by the Board as necessary, and with the minimum practicable
disturbance needed:
(a)
Streams, springs, swales.
(b)
Buffer zones.
(c)
Wetland areas, areas with seasonally high water tables, vernal
pools and other areas of surface water concentration. Seasonal high
water table soils may be disturbed where it can be demonstrated that
they are suitable for low-density residential uses and conventional
on-site sewage systems.
(3)
In conservation development, floodplain areas shall be located within
greenway lands.
(4)
Streets, buildings and other impervious surfaces shall be located
to have the least practicable disturbance to areas identified as having
the greatest permeability where precipitation is most likely to infiltrate
and recharge the groundwater.
B.
Woodlands. In addition to the standards in § 215-42A, the following standards shall apply:
(1)
Woodlands on any tract proposed for subdivision or land development
shall be evaluated to determine the extent to which such woodlands
should be partly or entirely located within greenway land. Evaluation
criteria shall include:
(a)
Configuration and size.
(b)
Stocking, health and species composition.
(c)
The site's capabilities to support woodlands, based upon
its topographic, soil and hydrologic characteristics.
(d)
Ecological functions, including, but not limited to protecting
steep slopes, stabilizing erodible soils, maintaining stream quality
and providing habitat for birds, mammals and other wildlife and plant
communities.
(e)
Relationship to woodlands on adjoining and nearby properties
and the potential for maintaining continuous woodland areas.
(f)
Potential recreational use for pedestrian and equestrian trails,
picnicking and other outdoor activities.
(g)
Potential for visual buffers between areas of development and
adjacent roads and properties.
(2)
The evaluation of the tract's woodlands shall be undertaken by a forester, arborist, landscape architect, horticulturalist or another 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. The report shall include, at a minimum, one or more maps indicating boundaries and conditions of woodland areas accompanied by a report addressing the criteria in Subsection B(1) above.
(3)
In designing a subdivision or land development plan for any tract,
the applicant shall be guided by the following standards:
(a)
Healthy woodlands exceeding one acre shall be preserved to the
greatest extent possible. Proposed site improvements shall be located,
designed and constructed to minimize the loss or degradation of woodland
areas. In instances where disturbance or tree cutting is unavoidable
or considered desirable in accordance with sound forest management
practices, an effort shall be made, with consultation from a forester
or other qualified professional, to retain as much of the woodland
as possible, of a size and configuration which would promote its growth
and natural regeneration.
(b)
Disturbance of groves of trees, single specimen trees, hedgerows,
and other vegetation, providing wildlife food and cover or visual
amenity, shall be minimized.
(c)
Woodlands along roadways, property lines, stone fences and hedgerows
shall be preserved as buffers against adjacent properties and between
areas being subdivided or developed within a property. Preservation
shall include ground, shrub, understory and canopy vegetation.
(d)
Disturbance or removal of woodlands and vegetation performing
important soil-stabilizing functions on wet soils, stream banks and
steep slopes may be undertaken on a limited, selective basis to minimize
the adverse impacts of such actions, only when approved by the Board.
(e)
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.
(f)
Removal of invasive species shall be permitted.
(4)
Upland rural-agricultural areas. Upland rural-agricultural areas
consist of fields, pastures, meadows, and former agricultural areas
in early stages of woodlands succession, with fences, stone walls,
tree groves and hedgerows, typically bordered by stream valleys and
upland woodlands. These comprise the Township's historic working
landscape, including historic houses, barns and other structures,
as well as 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. It is recognized that these
areas frequently offer the fewest constraints for development.
(a)
Elements that lend themselves to incorporation into the greenway
land include prime agricultural soils and natural features such as
hedgerows, tree groves, stone walls and visually prominent places
such as knolls and hilltops.
(b)
Preferred locations for development are non-prime agricultural
soils and lower topographic settings where development will be visually
less obtrusive.
(5)
(6)
Rare and endangered species. Disturbance of natural areas containing
rare or endangered plants and animals, documented by the Pennsylvania
Natural Diversity Inventory and the Montgomery County Natural Areas
Inventory, shall be avoided. In conservation development, they shall
be protected by incorporating them into greenway land.
(7)
Historic structures and sites.
(a)
Subdivision and land development applications shall be designed
to protect existing historic sites as documented in the Township's
Open Space Plan and Historic Resource Inventory. The protection of
an existing historic site shall include the conservation of the landscape
associated with and significant to that site to preserve its historic
context.
(b)
Where, in the opinion of the Board, a plan will have an impact
upon an historic site, 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.
(c)
Township review and approval of the applicant's interaction
with the State Historical and Museum Commission with regard to the
preservation of historic resources, as required by state and federal
law, shall be required prior to final plan approval.
(8)
Scenic road corridors. All subdivision and land development proposals shall preserve the scenic road corridors identified in the Township's Open Space Plan. These scenic corridors shall be protected by locating greenway land next to them or otherwise by providing building setbacks and architectural designs that minimize intrusion on the character being preserved. In instances where such designs fail to satisfactorily protect scenic corridors, applicants shall provide naturalistic, planted screening buffers to minimize the adverse visual impacts of the proposed development. The trees and shrubs specified for such buffers shall be selected from the list of approved species in § 215-43.
(9)
Trails.
(a)
When a subdivision or land development proposal is traversed
by, or abuts, an existing trail customarily used by pedestrians and/or
equestrians, the Board may request the applicant to make provisions
for continued recreational use of the trail. In conservation designs,
the trail should be included in greenway land accessible to the public.
(b)
An applicant may propose and develop a new trail. Trails shall
be designed to implement the Township and County Open Space Plan.
(d)
When trails are intended for public use, they shall be protected
by a trail easement. The width of the easement within which the trail
is located shall be a minimum of two feet on each side of the width
of the trail surface. The language of the easement shall be to the
satisfaction of the Board upon recommendation of the Township Solicitor.
(e)
The width of the trail surface may vary depending upon the type
of use to be accommodated, but shall, in no case, be less than three
feet or greater than 10 feet.
(f)
Trail improvements shall demonstrate adherence to principles
of quality trail design, guided by publications such as Pennsylvania
Bureau of State Parks publication "Non-Motorized Trails" or USDA Forest
Service "Trail Construction and Maintenance Handbook."
(g)
Trails shall have a vertical clearance of no less than 14 feet.
(h)
No trail shall be designed with the intent to accommodate motorized
vehicles, other than maintenance or emergency vehicles.
Residential development proposed under the Conservation Design Overlay District and containing greenway land shall follow the four-step design process described below. Applicants are required to document the design process in accordance with § 215-17F(1) and (2).
A.
Step 1: Delineation of greenway land, 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:
(1)
Using the ER/SA Plan as a base map, Primary and Secondary Conservation
Areas shall be delineated consistent with the Map of Potential Conservation
Areas.
(2)
Greenway land shall include all primary conservation areas and enough secondary conservation area to meet or exceed the minimum acreage requirement for greenway land set forth in Chapter 275, Zoning.
(b)
The locations and boundaries of primary conservation areas shall
follow the actual boundaries of floodplains, wetlands and steep slopes
over 25%.
(c)
Secondary resources with the highest resource significance shall
be included in the greenway land. The locations and boundaries of
secondary conservation areas shall be based on the priorities established
above and 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 resource significance shall be located within Secondary
Conservation Areas, which shall be included within greenway land.
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 and/or the pre-sketch conference.
(d)
Greenway land shall be delineated in a manner clearly indicating
greenway land boundaries as well as the types of resources included
within them.
(3)
Preferred locations for stormwater and wastewater management facilities
shall be identified using the ER/SA Plan as a base map.
(a)
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.
(b)
Opportunities to use these facilities as a buffer between the
proposed greenway land and development areas are encouraged.
(c)
Stormwater management facilities should be located in areas
identified as groundwater recharge areas.
(4)
Development areas consist of 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.
B.
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:
(1)
Fit the tract's natural topography;
(2)
Be served by adequate water and sewerage facilities;
(3)
Provide views of and access to adjoining greenway land;
(4)
Avoid encroaching upon greenway land in a manner visually intrusive
to users of such areas; and
(5)
Be located at least 100 feet from primary conservation areas and
50 feet from secondary conservation areas.
C.
Step 3: Alignment of streets and trails. 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.
(1)
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.
(2)
Streets and driveways crossing wetlands and traversing slopes over
15% shall be avoided to the greatest extent practicable.
(3)
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.
(4)
Green "terminal vistas" shall be provided whenever possible at the
terminus of streets or on the outside of curves.
(5)
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.
(6)
A tentative network of trails shall be shown, providing access to
various 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.
A.
List of resources to be conserved. The location of proposed greenway land in any subdivision or land development plan shall follow the standards set forth in § 215-79 and shall reflect the greenway land and trail corridor recommendations of the Township Open Space Plan, and protect the resources identified on the Map of Potential Conservation Lands. During the development review process, the Township shall be satisfied that the applicant has incorporated the following resources into the greenway land.
(1)
The following primary resources shall be included in the greenway
land. Lands containing primary resources are called primary conservation
areas (PCA). All PCAs shall be included in greenway land.
(2)
The following secondary resources shall be included in the greenway
land to the fullest extent practicable. Lands containing secondary
resources that are included in greenway land are called "secondary
conservation areas" (SCA).
(a)
Significant natural areas of species listed as endangered, threatened,
or of special concern, such as those listed in the Pennsylvania Natural
Diversity Inventory.
(b)
Precautionary steep slopes 15% to 25%, particularly those adjoining
watercourses and ponds.
(c)
Woodlands, particularly those performing important ecological
functions such as soil stabilization and protection of streams, wetlands
and wildlife habitat.
(d)
Hedgerows, groups of trees, and large individual trees over
twelve-inch dbh.
(e)
Existing trails, particularly those connecting the tract to
other trails and locations in the Township and adjoining municipalities.
(f)
Areas where precipitation is most likely to recharge local groundwater
resources because of topographic and soil conditions affording high
rates of infiltration and percolation.
(g)
Historic structures and sites.
(h)
Visually prominent topographic features such as knolls, hilltops
and ridges, and scenic views as seen from public roads. Significant
views from within the site outward shall also be considered.
(i)
Class I, II and III agricultural soils as defined by the USDA
Natural Resources Conservation Service.
B.
Additional design standards. Taking the above list into consideration,
the proposed greenway land shall be configured to:
(1)
Be free of all structures except historic buildings and structures
related to greenway land uses.
(a)
The Board may grant approval of structures and improvements
required for storm drainage, sewage treatment and water supply within
the greenway land, provided that such facilities are not detrimental
to the greenway land. The acreage of lands required for such uses
shall not be credited towards minimum greenway land acreage requirements
for the tract, unless the land they occupy is appropriate for passive
recreational use. Fields for land application of treated sewerage,
excluding buildings, may be counted toward the greenway land requirement.
In no case shall more than 50% of the greenway land be occupied by
sewage treatment or stormwater management facilities and related infrastructure.
(b)
At least 25% of the greenway land shall be free of structures
and infrastructure of any type.
(2)
Generally not include parcels smaller than three acres, have a length-to-width
ratio of less than 4:1, or be less than 75 feet in width, except for
such lands specifically designed as neighborhood greens, playing fields,
trail links, and boulevard or cul-de-sac islands.
(3)
Directly adjoin the largest practicable number of lots within the
subdivision or development.
(4)
Provide pedestrian and maintenance access to greenway land between
lots in accordance with the following requirements:
(a)
No more than 15 lots shall be contiguous to each other without
a centrally located access strip meeting the following standards:
(5)
Be suitable for active recreational uses to the extent deemed necessary
by the Board, without negatively affecting adjacent dwelling units,
parking, driveways, and roads.
(6)
Be interconnected wherever possible to provide a continuous network
of greenway land within and adjoining the subdivision.
(7)
Provide buffers to adjoining parks, preserves or other protected
lands.
(8)
Provide for pedestrian trails for use by the residents of the subdivision and/or the Township, except in those cases where part of the greenway land is located within private conservancy lots, as permitted in § 275-196G of Chapter 275, Zoning. Consideration shall be given to providing public access on such trails if they are linked to other publicly accessible pathway systems within the Township.
(9)
Provide access to the greenway land as required for land management
and emergency purposes.
(10)
Be undivided by public or private streets, except where necessary
for proper traffic circulation.
(11)
Be suitably landscaped by retaining existing natural cover and
wooded areas and/or new planting in accordance with a landscaping
plan.
(12)
Include common greens. An individual green shall be at least
5,000 square feet and no larger than 30,000 square feet.
(13)
Minimize views of new dwellings from exterior roads and abutting
properties by the use of changes in topography, existing vegetation,
or additional landscaping which meets the landscaping requirements
of this chapter.
(14)
Be consistent with the policies of the Upper Perkiomen Valley
Regional Comprehensive Plan and the Township Open Space Plan.
