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.
(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.
(2) All floodplain areas shall be preserved from any destruction or damage from clearing, grading, filling or dumping of, waste material, stumps, or other material of any kind, except as permitted under the terms Article
XX of Chapter
275, Zoning, of the Code of the Township of Marlborough.
(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:
(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) Steep slopes. Areas of steep slope shall be preserved in accordance with Article
XXI of Chapter
275, Zoning, of the Code of the Township of Marlborough and as required below:
(a)
In conservation development, steep slopes greater than 25% shall
be included within greenway lands.
(b)
In conservation development, slopes between 15 and 25% should
be considered for inclusion within greenway lands.
(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.
(c)
The applicant may alter the course of an existing trail within
the development tract under the following conditions:
[1]
The points at which the trail enters and exits the tract remain
unchanged.
[2]
The proposed alteration does not coincide with a paved road
intended for use by motorized vehicles.
(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.
(i)
The land area permanently designated for trails, or trail spurs or connections, shall be credited toward the greenway land requirement described in §
275-195 of Chapter
275, Zoning.
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.
(a)
The applicant shall prioritize natural and cultural resources in terms of their highest to least suitability for inclusion in the proposed greenway land in accordance with §
215-81A, List of resources to be conserved, and §
215-81B, Additional design standards.
(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.
(d)
Wastewater facilities shall comply with the requirements of §
215-48 and the Township Sewage Facilities Plan Update.
(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.
D. Step 4: Design of lot lines.
(1) Lot lines shall follow the configuration of dwelling locations and
streets in a logical manner.
(2) Lot lines are not required (as in a condominium form of home ownership).
The tot lot and playfield standards of §
215-50C through
E shall apply to conservation subdivisions and developments. If the applicant chooses to provide other facilities for which standards are provided in §
215-50, such standards shall apply.