This chapter shall be known as and may be cited
to as the "Willistown Township Environmental Protection Ordinance
of 1995."
The provisions of this chapter shall be severable,
and if any of the provisions hereof shall be held to be unconstitutional,
invalid or illegal by a court of competent jurisdiction, such decision
shall not affect the validity of any of the remaining provisions of
this chapter. It is hereby declared to be the intent of the Board
of Supervisors that this chapter would have been adopted if such illegal,
invalid or unconstitutional section, sentence, clause, part or provision
had not been included herein. Nothing in this chapter shall be construed
to affect any suit or proceeding pending in any court or any rights
acquired or liability incurred or any permit issued or any cause or
causes of action existing under the Willistown Code prior to this
amendment.
As used in this chapter, the following terms
shall have the meanings indicated:
ACCELERATED EROSION
The removal of the surface of the land through the combined
action of man's activities and natural processes at a rate greater
than would occur from natural processes alone.
ACCESSORY USE OR STRUCTURE
A use or structure on the same lot with, and of a nature
customarily incidental and subordinate to, the principal use or structure.
[Added 11-13-2006 by Ord. No. 5-2006]
ADVERSE VISUAL IMPACTS
Impacts which result from development/construction activity
or actions which result in degraded settings (such as graffiti, defacing
of property or illegal dumping) which diminish or destroy the physical
attractiveness, scenic quality or seemliness of an area or view.
AGRICULTURAL ACTIVITY
Activities associated with agriculture such as agricultural
cultivation, agricultural operation, and animal heavy use areas. This
includes the work of producing crops, including tillage, plowing,
disking, harrowing, planting, or harvesting crops; or pasturing and
raising of livestock; and installation of conservation measures. Construction
of new buildings or impervious area is not considered an agricultural
activity.
[Added 12-12-2022 by Ord.
No. 3-2022]
AGRICULTURAL CONSERVATION PLAN
A plan written by a planner certified by NRCS that identifies
agricultural conservation practices and includes site specific BMPs
for agricultural plowing or tilling activities and animal heavy use
areas.
[Added 12-16-2013 by Ord. No. 5-2013]
AGRICULTURAL CONSERVATION PRACTICES
Practices installed on agricultural lands to improve farmland,
soil and/or water quality which have been identified in a current
agricultural conservation plan.
[Added 12-16-2013 by Ord. No. 5-2013]
AGRICULTURALLY SUITED SOILS
Those soils rated as Class I or Class II for productivity
for crops by the Soil Survey of Chester and Delaware Counties (USDA
1963).
AIR QUALITY
A measure of the levels of pollution in the air and the potential
for any adverse effects on public health in the environment.
ALLUVIAL SOIL
Consisting of or formed from material such as gravel, sand,
silt or clay deposited by flowing water and showing little or no modification
of the original material by soils-forming processes.
ANTECEDENT CONDITIONS
The specified characteristics of the land surface (e.g.,
meadow) prior to a proposed disturbance or prior to a rainfall event
(e.g., amount of moisture in the soil); the basis for calculating
increases in runoff attributable to the disturbance or storms which
must be controlled.
ALTERATION
As applied to land, a change in topography as a result of
the moving of soil and rock from one location or position to another;
also the changing of surface conditions by causing the surface to
be more or less impervious; land disturbance.
[Added 4-9-2007 by Ord. No. 6-2007]
AS-BUILT PLANS (DRAWINGS)
Engineering or site plans or drawings that document the actual
locations, dimensions and elevations of the improvements, and building
components, and changes made to the original design plans. The final
version of these documents, or a copy of same, are signed and sealed
by a qualified licensed professional and submitted to the Township
at the completion of the project, as per the requirements of this
chapter as "final as-built plans."
[Added 12-16-2013 by Ord. No. 5-2013]
BANKFULL
The channel at the top-of-bank or point from where water
begins to overflow onto a floodplain.
[Added 12-12-2022 by Ord.
No. 3-2022]
BASE FLOOD
A flood which has a one-percent chance of being equaled or
exceeded in any given year (also called the "one-hundred-year flood"
or "one-percent annual chance flood").
[Amended 8-14-2017 by Ord. No. 5-2017]
BASE FLOOD DISCHARGE
The volume of water resulting from a base flood as it passes
a given location within a given time, usually expressed in cubic feet
per second (cfs).
[Added 8-14-2017 by Ord.
No. 5-2017]
BASE FLOOD ELEVATION (BFE)
The elevation shown on the Flood Insurance Rate Map (FIRM)
for Zones AE, AH, A1-30 that indicates the water surface elevation
resulting from a flood that has a one-percent or greater chance of
being equaled or exceeded in any given year.
[Amended 8-14-2017 by Ord. No. 5-2017]
BASEFLOW
Portion of stream discharge derived from groundwater; the
sustained discharge that does not result from direct runoff or from
water diversions, reservoir releases, piped discharges, or other human
activities.
[Added 12-12-2022 by Ord.
No. 3-2022]
BASEMENT
A floor level completely below grade or floor level in which
more than 2/3 of the perimeter walls are below grade. A wall shall
be considered below grade where the dimension from the first floor
line to the finished grade is five feet or less, and the slope of
the finished grade extending 10 feet from the building walls does
not exceed 30°. For floodplain management purposes, "basement"
is defined as any area of the building having its floor below ground
level on all sides.
[Amended 8-14-2017 by Ord. No. 5-2017]
BASE SITE AREA
The amount of land remaining when existing and proposed road
and utility rights-of-way are subtracted from the gross tract area.
[Added 6-28-1999 by Ord. No. 2-1999]
BASIN
See "detention basin" or "retention basin."
BEDROCK
The solid rock underlying soils and the regolith in depths
ranging from zero to several hundred feet.
BENCHMARK
A fixed reference giving the measurement in elevation of
that point in relation to mean sea level or some other reference datum.
BERM
Well-compacted earthfill ridge.
BEST MANAGEMENT PRACTICE (BMP)
Activities, facilities, designs, measures, or procedures
used to manage stormwater impacts from regulated activities, to provide
water quality treatment, infiltration, volume reduction, and/or peak
rate control, to promote groundwater recharge, and to otherwise meet
the purposes of this chapter. Stormwater BMPs are commonly grouped
into one of two broad categories or measures: "structural" or "nonstructural."
In this chapter, nonstructural BMPs or measures include certain low-impact
development and conservation design practices used to minimize the
contact of pollutants with stormwater runoff. These practices aim
to limit the total volume of stormwater runoff and manage stormwater
at its source by techniques such as protecting natural systems and
incorporating existing landscape features. Nonstructural BMPs include,
but are not limited to, the protection of sensitive and special value
features such as wetlands and riparian areas, the preservation of
open space while clustering and concentrating development, the reduction
of impervious cover, and the disconnection of rooftops from storm
sewers. Structural BMPs are those that consist of a system that is
designed and engineered to capture and treat stormwater runoff. Structural
BMPs include, but are not limited to, a wide variety of practices
and devices from large-scale retention ponds and constructed wetlands
to small-scale underground treatment systems, infiltration facilities,
filter strips, bioretention, wet ponds, permeable paving, grassed
swales, riparian buffer, sand filters, detention basins, and manufactured
devices. Structural and nonstructural stormwater BMPs are permanent
appurtenances to the site.
[Added 4-9-2007 by Ord. No. 6-2007;
amended 12-12-2022 by Ord. No. 3-2022]
BUFFER
[Amended 4-9-2007 by Ord. No. 6-2007]
A.
A designated area between two uses deemed incompatible
with each other or along the perimeter of a natural feature to be
protected from an incompatible use or along the perimeter of that
use, which will absorb or otherwise preclude such incompatibility
and shall be permanently maintained.
B.
The area of land immediately adjacent to any
stream, measured perpendicular to and horizontally from the top-of-bank
on both sides of a stream (see “top-of-bank”).
BUFFER PLANTING STRIP, BUFFER STRIP OR SCREEN
A strip of required yard space adjacent to a use or facility within a property or to the boundary of a property or district, as designated in Chapters
73,
123, and
139, which is landscaped for the full width (or as otherwise specified in Chapter
73) and on which is located a visual barrier of sufficient density not to be seen through and of sufficient height to constitute an effective screen and give immediate visual screening to an abutting property or district. The required screen shall be permanently maintained and shall constitute a planting of dense trees and shrubs consistent with the requirements of Chapter
73, Article
X.
[Added 3-14-2016 by Ord.
No. 4-2016]
BUILDING
A combination of materials to form a permanent structure having walls and a roof. Included shall be all manufactured homes and trailers to be used for human habitation. See also Chapter
139, §
139-6. Definitions.
[Amended 11-13-2006 by Ord. No. 5-2006; 8-14-2017 by Ord. No. 5-2017]
CALIPER
The diameter of a tree (in inches) measured at the trunk
six inches above the ground surface.
[Amended 7-18-2016 by Ord. No. 7-2016]
CARTWAY
The portion of a street or alley right-of-way, paved or unpaved,
customarily used by vehicles in the regular course of travel over
the street.
CHECK DAM
Small dam constructed in a gully or other small watercourse
to decrease flow velocity, to minimize channel scour and to promote
deposition of sediment.
CFS
Cubic feet per second.
CHANNEL
An open drainage feature through which stormwater flows.
Channels include, but shall not be limited to, natural and man-made
drainageways, swales, streams, ditches, canals, and pipes flowing
partly full.
[Added 4-9-2007 by Ord. No. 6-2007]
CHANNEL EROSION
The widening, deepening, or headward cutting of channels
and waterways caused by stormwater runoff or bankfull flows.
[Added 4-9-2007 by Ord. No. 6-2007]
CISTERN
Reservoir or tank for storing water.
COMPLETELY DRY SPACE
A space which will remain totally dry during flooding; the
structure is designed and constructed to prevent the passage of water
and water vapor.
[Added 11-13-2006 by Ord. No. 5-2006]
CONCRETE LATTICE BLOCKS
Concrete blocks manufactured with an open waffle-like pattern
usually used to control erosion when placed in a mat in swale inverts
or other areas subject to higher water velocities.
CONSERVATION
The planned management of a natural feature to prevent its
exploitation, destruction or neglect.
CONSERVATION DESIGN
A series of holistic land development design goals that maximize
protection of key land and environmental resources, preserve significant
concentrations of open space and greenways, evaluate and maintain
site hydrology, and ensure flexibility in development design to meet
community needs for complementary and aesthetically pleasing development.
Conservation design encompasses the following objectives: conservation/enhancement
of natural resources, wildlife habitat, biodiversity corridors, and
greenways (interconnected open space); minimization of environmental
impact resulting from a change in land use (minimum disturbance, minimum
maintenance); maintenance of a balanced water budget by making use
of site characteristics and infiltration; incorporation of unique
natural, scenic and historic site features into the configuration
of the development; preservation of the integral characteristics of
the site as viewed from adjoining roads; and reduction in maintenance
required for stormwater management practices. Such objectives can
be met on a site through an integrated development process that respects
natural site conditions and attempts, to the maximum extent possible,
to replicate or improve the natural hydrology of a site.
[Added 12-12-2022 by Ord.
No. 3-2022]
CONSERVATION PLAN
A plan written by a planner certified by NRCS that identifies
conservation practices and includes site-specific BMPs for agricultural
plowing or tilling activities and animal heavy use areas.
[Added 12-12-2022 by Ord.
No. 3-2022]
CONSERVATION PRACTICES
Practices installed on agricultural lands to improve farmland,
soil and/or water quality which have been identified in a current
conservation plan.
[Added 12-12-2022 by Ord.
No. 3-2022]
CONTROL WEIR
Device for measuring or regulating the flow of water.
CONVEYANCE
A natural or man-made, existing, or proposed stormwater management
facility, feature or channel used for the transportation or transmission
of stormwater from one place to another. For the purposes of this
chapter, "conveyance" shall include pipes, drainage ditches, channels,
and swales (vegetated and other), gutters, stream channels, and like
facilities or features.
[Added 12-16-2013 by Ord. No. 5-2013; amended 12-12-2022 by Ord. No.
3-2022]
CULTURAL LANDSCAPE
A natural setting, the appearance of which represents the
historic settlement pattern and development of a community. Such settings,
which may or may not contain an historic structure, often reflect
certain time periods of local significance. When applied to historic
structures, a cultural landscape also includes the setting of the
structure and its contribution to the integrity of the structure.
Examples include, but are not limited to, historic structures surrounded
by large specimen trees, scenic vistas encompassing historic farmsteads
and hedgerows, stone walls or ruins against a backdrop of equestrian
activity and rural roads framing historic villages.
[Added 6-28-1999 by Ord. No. 2-1999]
CUMULATIVE SUBSTANTIAL DAMAGE
Flood-related damages sustained by a structure on two or
more separate occasions during a ten-year period for which the cost
of repairs at the time of each such flood event, on average, equals
or exceeds 25% of the market value of the structure before the damages
occurred.
[Added 8-14-2017 by Ord.
No. 5-2017]
CUT
Portion of land surface or area from which earth has been
removed or will be removed by excavation; depth below original ground
surface to excavated surface.
DBH
The diameter of a tree at breast height, measured 4.5 feet
from the ground surface.
DECLARATION OF LAND RESTRICTION (NONCONVERSION AGREEMENT)
A form signed by the property owner to agree not to convert
or modify, in any manner that is inconsistent with the terms of the
permit and these regulations, certain enclosures below the lowest
floor of elevated buildings and certain accessory structures. The
form requires the owner to record it on the property deed to inform
future owners of the restrictions.
[Added 8-14-2017 by Ord.
No. 5-2017]
DETENTION BASIN
A structure designed to retard surface runoff for a period
of time sufficient to cause the deposition of sediment and to reduce
the velocity and volume of surface flows leaving a site, thus preventing
further erosion. Detention basins are designed to drain completely
soon after a rainfall event and become dry until the next rainfall
event.
[Amended 4-9-2007 by Ord. No. 6-2007]
DEVELOPABLE LAND
The amount of land available for development as determined
by subtracting the total protected land from the base site area.
[Added 6-28-1999 by Ord. No. 2-1999]
DEVELOPMENT
Any man-made change to improved or unimproved real estate,
including but not limited to the construction, reconstruction, renovation,
repair, expansion or alteration of buildings or other structures;
the placement of manufactured homes; streets and other paving; utilities;
filling, grading and excavation; mining; dredging; drilling operations;
storage of equipment or materials; and the subdivision of land.
[Amended 11-12-1996 by Ord. No. 3-1996]
DISCHARGE
[Added 10-22-2012 by Ord. No. 3-2012]
A.
(verb) To release water from a project, site, aquifer, drainage
basin, or other point of interest;
B.
(noun) The rate and volume of flow of water such as in a stream,
generally expressed in cubic feet per second (see "peak discharge").
DISCHARGE VOLUME
The volume of fluid passing a point per unit time, commonly
expressed as cubic feet per second.
DISTURBED AREA
Land area disturbed by or where an earth disturbance activity
is occurring or has occurred.
[Amended 4-9-2007 by Ord. No. 6-2007; 12-12-2022 by Ord. No.
3-2022]
DIVERSION TERRACE
Channel or ditch, together with a ridge, constructed across
a sloping land surface on the contour or with predetermined grades
to intercept and divert surface runoff before it gains sufficient
volume and velocity to create harmful erosion.
DRAINAGE EASEMENT
A right-of-way granted to use private land to facilitate
the flow of water, within which the owner shall erect no permanent
structures but may use the land in any other way not inconsistent
with the grantee's rights or other applicable regulations.
DRIPLINE
A generally circular line, the circumference of which is
determined by the outer reaches of a tree's widest branching points;
the outer edge of foliage line creating the canopy ring of the top
of a tree.
EARTH DISTURBANCE or EARTH DISTURBANCE ACTIVITY
A construction or other human activity which disturbs the
surface of the land, including, but not limited to, clearing and grubbing;
grading; excavations; embankments; road maintenance; land development;
building construction; and the moving, depositing, stockpiling, or
storing of soil, rock, or earth materials.
[Amended 4-9-2007 by Ord. No. 6-2007; 12-16-2013 by Ord. No.
5-2013; 12-12-2022 by Ord. No. 3-2022]
EARTHMOVING
See "earth disturbance activity."
[Amended 4-9-2007 by Ord. No. 6-2007]
ENCROACHMENT
[Amended 4-9-2007 by Ord. No. 6-2007]
A.
Any physical action which may jeopardize the
health and longevity of a natural feature.
B.
A structure or activity that changes, expands,
or diminishes the course, current, or cross section of a watercourse,
floodway, or body of water.
ENERGY DISSIPATER
A concrete or stone structure designed to reduce the velocity
and force of a concentrated flow of water.
ENVIRONMENTALLY SENSITIVE AREA
An area with one or more of the following characteristics:
C.
Soils classified as having a high water table.
D.
Soils classified as highly erodible, subject
to erosion or having a shallow depth to bedrock.
E.
Wetlands or other sensitive estuaries.
F.
Stream corridors, aquifer recharge areas, springs
or other surface water and groundwater resource areas.
H.
Significant geologic formations.
I.
Land incapable of meeting percolation requirements.
J.
Mature stands of native vegetation.
EROSION
The wearing away of soil by action of wind, water or other
geologic agents.
EROSION AND SEDIMENT CONTROL PLAN
A plan that is designed to minimize accelerated erosion and
sedimentation. Said plan must be submitted to the Township and possibly
to the Chester County Conservation District for approval before construction
can begin.
[Added 4-9-2007 by Ord. No. 6-2007]
ESSENTIALLY DRY SPACE
A space which will remain dry during flooding, except for
the passage of some water vapor or minor seepage; the structure is
substantially impermeable to the passage of water.
[Added 11-13-2006 by Ord. No. 5-2006]
EVAPOTRANSPIRATION (ET)
The combined processes of evaporation from the water or soil
surface and transpiration of water by plants.
[Added 12-12-2022 by Ord.
No. 3-2022]
EXCEPTIONAL VALUE WATERS
Surface waters of high quality which satisfy Pennsylvania Code Title 25 Environmental Protection, Chapter
93, Water Quality Standards, § 93.4b(b) (relating to antidegradation).
[Added 4-9-2007 by Ord. No. 6-2007]
EXISTING MANUFACTURED HOME PARK OR SUBDIVISION
A manufactured home park or subdivision for which the construction
of facilities for servicing the lots on which the manufactured homes
are to be affixed (including, at a minimum, the installation of utilities,
the construction of streets, and either final site grading or the
pouring of concrete pads) is completed before the effective date of
the floodplain management regulations adopted by a community.
[Added 8-14-2017 by Ord.
No. 5-2017]
EXPANSION TO AN EXISTING MANUFACTURED HOME PARK OR SUBDIVISION
The preparation of additional sites by the construction of
facilities for servicing the lots on which the manufactured homes
are to be affixed (including the installation of utilities, the construction
of streets, and either final site grading or the pouring of concrete
pads).
[Added 8-14-2017 by Ord.
No. 5-2017]
EXPOSURE
Direction of slope with respect to points of a compass.
EXTERIOR SLOPE
The slope of soil located and making up the wall of the outside
edge of a basin.
FILL
Material, exclusive of structures, placed or deposited so
as to form an embankment or raise the surface elevation of the land;
any sediment deposited by any agent so as to fill or partly fill a
depression or other area.
FINAL GRADE
The last line of cut, fill or paving placement made to meet
specific contour elevations for the finished surface.
FLOOD
A temporary inundation of normally dry land areas.
[Amended 8-14-2017 by Ord. No. 5-2017]
FLOOD INSURANCE RATE MAP (FIRM)
The official map on which the Federal Emergency Management
Agency has delineated both the areas of special flood hazards and
the risk premium zones applicable to the community.
[Added 8-14-2017 by Ord.
No. 5-2017]
FLOOD INSURANCE STUDY (FIS)
The official report provided by the Federal Emergency Management
Agency that includes flood profiles, the Flood Insurance Rate Map,
the Flood Boundary and Floodway Map, and the water surface elevation
of the base flood.
[Added 8-14-2017 by Ord.
No. 5-2017]
FLOOD-FRINGE
That portion of the floodplain outside the floodway.
FLOODPLAIN
A relatively flat or low-lying land area adjoining a river,
stream or watercourse which is subject to periodic partial or complete
inundation.
[Added 4-9-2007 by Ord. No. 6-2007]
FLOODPLAIN AREA
A relatively flat or low land area which is subject to partial
or complete inundation from an adjoining or nearby stream, river or
watercourse; and/or any area subject to the unusual and rapid accumulation
of surface waters from any source.
[Added 11-13-2006 by Ord. No. 5-2006]
FLOODPROOFING
Any combination of structural and nonstructural additions,
changes, or adjustments to structures which reduce or eliminate flood
damage to real estate or improved real property, water and sanitary
facilities, structures and their contents.
[Amended 8-14-2017 by Ord. No. 5-2017]
FLOODWAY
The channel of the watercourse and those portions of the
adjoining floodplains that are reasonably required to carry and discharge
the 100-year flood (also called the base flood or 1% annual chance
flood). Unless otherwise specified, the boundary of the floodway is
as indicated on maps and flood insurance studies provided by FEMA.
In an area where no FEMA maps or studies have defined the boundary
of the floodway, it is assumed, absent evidence to the contrary, that
the floodway extends from the centerline of the stream and to 50 feet
beyond the top of the bank of the stream on both sides.
[Amended 4-9-2007 by Ord.
No. 6-2007; 8-14-2017 by Ord. No. 5-2017; 12-12-2022 by Ord. No. 3-2022]
FORB
A herbaceous plant other than a grass that is commonly found
growing in meadows.
[Added 3-13-2000 by Ord. No. 1-2000]
FORESTER
A professional trained in the care and management of trees
and forests and certified by the Commonwealth of Pennsylvania, including
a graduate forester certified by the Society of American Foresters
or an arborist trained through the International Society of Arboriculture
or an equivalent program.
[Added 11-11-2002 by Ord. No. 3-2002]
FOREST MANAGEMENT PRACTICES
That combination of generally accepted methods for preserving,
promoting and protecting silviculture, which may include selective
cutting, burning and removal of trees.
FOREST MANAGEMENT/TIMBER OPERATIONS
Planning and activities necessary for the management of forest
lands. These include timber inventory, preparation of forest management
plans, silvicultural treatment, cutting budgets, logging road design
and construction, timber harvesting, site preparation, and reforestation.
[Added 12-12-2022 by Ord.
No. 3-2022]
FREEBOARD
A vertical distance between the elevation of the design high
water and the top of a dam, levee, tank, basin, swale, or diversion
berm. The space is required as a safety margin in a pond or basin.
[Added 4-9-2007 by Ord. No. 6-2007]
FRENCH DRAIN
The removal of excess surface water or groundwater through
rock channels in a closed ditch by internal flow/percolation; a hole
filled with stone or rock, which permits some vertical transmission
of water.
GABION
A rectangular wire mesh cage filled with rock and used as
a protecting apron, revetment, etc., against erosion.
GEOTEXTILE
A fabric manufactured from synthetic fiber that is used to
achieve specific objectives, including infiltration, separation between
different types of media (i.e., between soil and stone), or filtration.
[Amended 12-12-2022 by Ord. No. 3-2022]
GRADE/GRADING
A.
(noun) A slope, usually of a road, channel, or natural ground,
specified in percent and shown on plans as specified herein.
B.
(verb) To finish the surface of a roadbed, the top of an embankment,
or the bottom of an excavation.
[Added 12-12-2022 by Ord.
No. 3-2022]
GRADIENT
Change of elevation per unit length; slope.
GRASS, PERMANENT
Grass cover that is used for final, long-living, lasting
lawn cover; seed mixture containing perennial grass seed.
GRASS, TEMPORARY
Grass that is used for fast cover and short-living lawn cover;
seed mixture containing no perennial grass seed, only annual.
GREEN INFRASTRUCTURE
Systems and practices that use or mimic natural processes
to infiltrate, evapotranspire, or reuse stormwater on the site where
it is generated.
[Added 12-12-2022 by Ord.
No. 3-2022]
GROUND STABILIZATION FABRIC
A woven or nonwoven material designed to prevent upward or
downward movement of soil or other solids while permitting water movement.
(Trade names include Mirafi 500, Bidim, Typar and Supac.)
GROUNDWATER
Water that occurs in the subsurface and fills or saturates
the porous openings, fractures and fissures of underground soils and
rock units.
[Added 12-12-2022 by Ord.
No. 3-2022]
GROUNDWATER RECHARGE
Replenishment of geologic structures and rock or soil interstices
which have the capacity to store water.
HEC-1
The U.S. Army Corps of Engineers, Hydrologic Engineering
Center (HEC) hydrologic runoff model.
[Added 12-12-2022 by Ord.
No. 3-2022]
HEC-HMS
The U.S. Army Corps OF Engineers, Hydrologic Engineering
Center (HEC) — Hydrologic Modeling System (HMS).
[Added 12-12-2022 by Ord.
No. 3-2022]
HEDGEROW
A line of plants that may occur naturally where seeds collect
and are left undisturbed, such as along fence lines, property lines
or between fields, or that is specially planted, e.g., to act as a
windbreak.
HIGH QUALITY WATERS
Surface waters having quality which exceeds levels necessary to support propagation of fish, shellfish, and wildlife and recreation in and on the water by satisfying Pennsylvania Code Title 25 Environmental Protection, Chapter
93, Water Quality Standards, § 93.4b(a).
[Added 4-9-2007 by Ord. No. 6-2007]
HIGH TUNNEL
A structure which meets the following:
[Added 1-27-2020 by Ord. No. 1-2020;
amended 12-12-2022 by Ord. No. 3-2022]
A.
Is used for the production, processing, keeping, storing, sale
or shelter of an agricultural commodity as defined in Section 2 of
the Act of December 19, 1974 (P.L. 973, No. 319), known as the "Pennsylvania
Farmland and Forest Land Assessment Act of 1974," or for the storage of agricultural equipment or supplies;
and
B.
Is constructed with all the following:
(1)
Has a metal, wood or plastic frame;
(2)
When covered, has a plastic, woven textile or other flexible
covering; and
(3)
Has a floor made of soil, crushed stone, matting, pavers or
a floating concrete slab.
HIGHEST ADJACENT GRADE
The highest natural elevation of the ground surface prior
to construction next to the proposed walls of a structure.
[Added 8-14-2017 by Ord.
No. 5-2017]
HISTORIC RESOURCE(S)
All buildings, sites, structures, objects and districts inventoried
by the Willistown Township Historical Commission as having potential
historical or architectural significance.
HISTORIC STRUCTURE
Any structure that meets one or more of the following characteristics:
[Added 11-12-1996 by Ord. No. 3-1996]
A.
Listed individually in the National Register
of Historic Places (a listing maintained by the Department of Interior)
or preliminarily determined by the Secretary of the Interior as meeting
requirements for individual listing on the National Register.
B.
Certified or preliminarily determined by the
Secretary of the Interior as contributing to the historical significance
of a registered historic district or a district preliminarily determined
by the Secretary to qualify as a registered historic district.
C.
Individually listed on a state inventory of
historic places in states with historic preservation programs which
have been approved by the Secretary of the Interior.
D.
Individually listed on a local inventory of
historic places in communities with historic preservation programs
that have been certified either:
(1)
By an approved state program as determined by
the Secretary of the Interior; or
(2)
Directly by the Secretary of the Interior in
states without approved programs.
HYDRIC SOILS
Soils which in their natural, undrained state are wet frequently
enough at or near the surface to periodically produce anaerobic conditions,
thereby influencing plant species' composition and/or growth on such
soils.
HYDROLOGY
Properties, distribution and effects of water on the earth's
surface, in the soil and underlying rocks and in the atmosphere.
HYDROSEEDING
Dissemination of seed, hydraulically, in a water medium that
may also include mulch, lime and fertilizer.
IDENTIFIED FLOODPLAIN AREA
This term is an umbrella term that includes all of the areas within which the community has selected to enforce floodplain regulations. It will always include the area identified as the Special Flood Hazard Area on the Flood Insurance Rate Maps and Flood Insurance Study, but may include additional areas identified by the community. See §
73-19A and
B for the specifics on what areas the community has included in the Identified Floodplain Area.
[Added 11-13-2006 by Ord. No. 5-2006; amended 8-14-2017 by Ord. No.
5-2017]
IMPERVIOUS SURFACE
A surface that has been compacted or covered with a layer of material so that it prevents or is resistant to infiltration of water, including but not limited to: structures such as roofs, buildings, storage sheds; other solid, paved or concrete areas such as streets, driveways, sidewalks, parking lots, patios, terraces, decks, swimming pools, tennis or other paved courts; or athletic playfields comprised of synthetic turf materials. For the purposes of determining compliance with this chapter, compacted soils or stone surfaces used for vehicle parking and movement shall be considered impervious. Uncompacted gravel areas with no vehicular traffic, such as gardens, walkways, or patios areas, shall be considered pervious per review by the Municipal Engineer. Surfaces that were designed to allow infiltration (i.e., pavers and areas of porous pavement) are not to be considered impervious surface if designed to function as a BMP per review by the Municipal Engineer. Additionally, for the purposes of determining compliance with Article
VIII, Stormwater Management, the total horizontal projection area of all ground-mounted and freestanding solar collectors, including solar photovoltaic cells, panels, and arrays, shall be considered pervious so long as the designs note that natural vegetative cover will be preserved and/or restored underneath the solar photovoltaic cells, panels, and arrays, and the area disturbed is planned as a vegetated pervious surface.
[Amended 12-16-2013 by Ord. No. 5-2013; 12-12-2022 by Ord. No. 3-2022]
IMPOUNDED WATER
An artificial collection or storage of water, as in a reservoir,
pit, dugout or sump.
INFILTRATION
Movement of surface water into the soil, where it is absorbed
by plant roots, evaporated into the atmosphere, or percolated downward
to recharge groundwater.
[Added 4-9-2007 by Ord. No. 6-2007]
INFILTRATION FACILITY
A stormwater BMP designed to collect and discharge runoff
into the subsurface in a manner that allows infiltration into underlying
soils and groundwater (e.g., French drains, seepage pits, or seepage
trenches, etc.).
[Added 12-12-2022 by Ord.
No. 3-2022]
INTERIOR SLOPE
The slope of soil located and making up the wall of the inside
edge of a basin.
INTERMITTENT STREAM
A channel with banks and a bed within which concentrated
water flows some of the time.
[Added 3-13-2000 by Ord. No. 1-2000]
LAND DEVELOPMENT
Any of the following activities:
[Added 11-13-2006 by Ord. No. 5-2006]
A.
The improvement of one lot or two or more contiguous
lots, tracts or parcels of land for any purpose involving:
(1)
A group of two or more residential or nonresidential
buildings, whether proposed initially or cumulatively, or a single
nonresidential building on a lot or lots regardless of the number
of occupants or tenure; or
(2)
The division or allocation of land or space,
whether initially or cumulatively, between or among two or more existing
or prospective occupants by means of, or for the purpose of, streets,
common areas, leaseholds, condominiums, building groups or other features.
B.
A subdivision of land. Regarding the activities
described in Section 503(1.1) of the Municipalities Planning Code,
those addressed in Subsections (ii) and (iii), concerning accessory
buildings and amusement parks, respectively, shall not be considered
land developments for purposes of this chapter; any conversion of
an existing single-family detached dwelling or single-family semidetached
dwelling into two or more dwelling units shall be considered a land
development. In addition, any nonfee lease for purposes of easement
or right-of-way shall not be considered a land development.
LAND DISTURBANCE
Any activity which causes land to be exposed to the danger
of erosion, including clearing, grading, filling, plowing and transporting.
LANDSCAPE IMPROVEMENT
The addition of features to the land which enhance a particular
site from the standpoint of, e.g., noise abatement, recreational enjoyment,
wildlife preservation, visual amenity, etc. Such improvements might
include plantings, pathways, patios and fences. Landscape improvements
may include vegetative components but are not considered to be buffer
planting strips.
[Amended 3-14-2016 by Ord. No. 4-2016]
LEVEL SPREADER
A level embankment constructed across a slope to control
erosion by converting point discharge or surface runoff into a sheet
flow.
LIMITING ZONE
A soil horizon or condition in the soil profile or underlying
strata that includes one of the following:
[Added 12-12-2022 by Ord.
No. 3-2022]
A.
A seasonal high-water table, whether perched or regional, determined
by direct observation of the water table or indicated by other subsurface
or soil conditions.
B.
A rock with open joints, fracture or solution channels, or masses
of loose rock fragments, including gravel, with insufficient fine
soil to fill the voids between the fragments.
C.
A rock formation, other stratum, or soil condition that is so
slowly permeable that it effectively limits downward passage of water.
LOWEST FLOOR
The lowest floor of the lowest fully enclosed area (including
basement). An unfinished, flood-resistant partially enclosed area,
used solely for parking of vehicles, building access, and incidental
storage, in an area other than a basement area, is not considered
the lowest floor of a building, provided that such space is not designed
and built so that the structure is in violation of the applicable
nonelevation design requirements of this chapter.
[Amended 11-13-2006 by Ord. No. 5-2006]
LOW-IMPACT DEVELOPMENT (LID)
Site design approaches and small-scale stormwater management
practices that promote the use of natural systems for infiltration,
evapotranspiration, and reuse of rainwater. LID can be applied to
new development, urban retrofits, and revitalization projects. LID
utilizes design techniques that infiltrate, filter, provide evapotranspiration
and store runoff close to its source. Rather than rely on costly large-scale
conveyance and treatment systems, LID addresses stormwater through
a variety of small, cost-effective landscape features located on-site.
[Added 12-12-2022 by Ord.
No. 3-2022]
MAINTENANCE
The action taken to restore or preserve the as-built functional
design of any facility or system.
[Added 4-9-2007 by Ord. No. 6-2007]
MANUFACTURED HOME
A transportable, single-family dwelling intended for permanent
occupancy, office or place of assembly, contained in one or more sections,
built on a permanent chassis, which arrives at a site completed and
ready for occupancy except for minor and incidental unpacking and
assembly operations, and constructed so that it may be used with or
without a permanent foundation. The term includes park trailers, travel
trailers, recreational and other similar vehicles which are placed
on a site for more than 180 consecutive days.
[Added 11-12-1996 by Ord. No. 3-1996]
MANUFACTURED HOME PARK
A parcel of land under single ownership which has been planned
and improved for the placement thereon of manufactured homes for nontransient
use.
[Added 11-13-2006 by Ord. No. 5-2006]
MEAN WATER LEVEL
The observed limit of dry weather flow elevation in a watercourse
or water body.
[Added 3-13-2000 by Ord. No. 1-2000]
MINIMIZE
To reduce to the smallest amount possible using best management
practices. Minimize shall not mean complete elimination but shall
require that the most substantial efforts possible under the circumstances
have been taken to reduce the adverse effect of the action required
to be minimized. With respect to activities, the conduct of which
is adverse to the conservation of the natural features of land, the
requirement to minimize shall include but not be limited to the requirement
that the placement of dwellings and other structures and the location
of roads, sedimentation and erosion control devices and earthmoving
activities shall be planned, designed and carefully conducted so as
to permit the adverse effect of the activity in question to be reduced
to the smallest amount possible under the circumstances consistent
with the otherwise permitted development.
MINOR REPAIR
The replacement of existing work with equivalent materials
for the purpose of its routine maintenance and upkeep, but not including
the cutting away of any wall, partition or portion thereof, the removal
or cutting of any structural beam or bearing support, or the removal
or change of any required means of egress, or rearrangement of parts
of a structure affecting the exitway requirements; nor shall minor
repairs include addition to, alteration of, replacement or relocation
of any standpipe, water supply, sewer, drainage, drain leader, gas,
oil, waste, vent or similar piping, electric wiring or mechanical
or other work affecting public health or general safety.
[Added 11-13-2006 by Ord. No. 5-2006]
MITIGATION
Any action taken to lessen the specified undesirable impacts
of a proposed land use or land disturbance activity, including those
which would adversely affect the health or longevity of a natural
feature, pose a visual intrusion or conflict or otherwise be deemed
incompatible with surrounding properties.
NATIVE GROUND COVER PLANTS
Those plants indigenous to either the coastal plain or the Piedmont physiographic regions which promote erosion control and sediment filtration and are often found on stream banks. A partial list of such plants is contained in
Appendix B.
NATURAL INFILTRATION
The gradual downward flow of water from the surface through
soil to groundwater and water table reservoirs; percolation undisturbed
by man's activities.
NATURAL RESOURCE
A component of the environment and its landscape, such as
a water body or a woodland, identified by Willistown Township as important
for conservation.
NATURAL SUCCESSION
A natural, ecologic process of gradual change in vegetative
type, generally involving an increase in biomass and species diversity,
and followed by a concomitant change in wildlife species.
NEW CONSTRUCTION
Structures for which the start of construction commenced
on or after the effective start date of this floodplain management
ordinance and includes any subsequent improvements to such structures.
Any construction started after October 15, 1981, and before the effective
start date of this floodplain management ordinance is subject to the
ordinance in effect at the time the permit was issued, provided the
start of construction was within 180 days of permit issuance.
[Amended 11-13-2006 by Ord. No. 5-2006; 8-14-2017 by Ord. No. 5-2017]
NEW DEVELOPMENT
Any regulated activity involving placement or construction
of new impervious surface or grading over existing pervious land areas
not classified as redevelopment as defined in this chapter.
[Added 12-16-2013 by Ord. No. 5-2013]
NEW MANUFACTURED HOME PARK OR SUBDIVISION
A manufactured home park or subdivision for which the construction
of facilities for servicing the lots on which the manufactured homes
are to be affixed (including, at a minimum, the installation of utilities,
the construction of streets, and either final site grading or the
pouring of concrete pads) is completed on or after the effective date
of floodplain management regulations adopted by a community.
[Added 8-14-2017 by Ord.
No. 5-2017]
NONPOINT-SOURCE POLLUTION
Pollution that enters a water body from diffuse origins in
the watershed and does not result from discernible, confined, or discrete
conveyances.
[Added 4-9-2007 by Ord. No. 6-2007]
NONSTRUCTURAL BEST MANAGEMENT PRACTICE (BMP)
Methods of controlling stormwater runoff quantity and quality,
such as innovative site planning, impervious area and grading reduction,
protection of natural depression areas, temporary ponding on site,
and other techniques.
[Added 4-9-2007 by Ord. No. 6-2007]
NPDES
National Pollutant Discharge Elimination System, the federal
government’s system for issuance of permits under the Clean
Water Act, which is delegated to DEP in Pennsylvania.
[Added 4-9-2007 by Ord. No. 6-2007]
ONE-HUNDRED-YEAR FLOOD
A flood that, on the average, is likely to occur once every
100 years (i.e., that has 1% chance of occurring each year, although
the flood may occur in any year).
[Amended 11-13-2006 by Ord. No. 5-2006]
OVERLAY
A special use district, either graphically depicted on a map or described by metes and bounds, whose uses, conditional or by right, are permitted in the base zoning district as contained in Chapter
139, Zoning, of this Code.
OVERTOPPING
The spilling of water over the top of the berm of a basin
due to overfill of the basin's impounded water area.
PEAK DISCHARGE
The maximum rate of flow of water at a given point and time
resulting from a predetermined storm.
PERENNIAL STREAM
A channel with banks and a bed within which concentrated
water flows all of the time.
[Added 3-13-2000 by Ord. No. 1-2000]
PERSON
An individual, partnership, public or private association,
corporation, firm, trust, estate, municipality, government unit, public
utility or any other legal entity whatsoever, which is recognized
by law as the subject of rights and duties.
[Amended 11-13-2006 by Ord. No. 5-2006]
POINT SOURCE
Any discernible, confined, and discrete conveyance, including,
but not limited to, any pipe, ditch, channel, tunnel, or conduit from
which stormwater is or may be discharged, as defined in state regulations
at 25 Pennsylvania Code § 92.1.
[Added 4-9-2007 by Ord. No. 6-2007]
POROUS PAVEMENT
Pavement which allows water to pass through to the base layers.
POST-CONSTRUCTION
Period after construction during which disturbed areas are
stabilized, stormwater controls are in place and functioning, and
all proposed improvements approved by the Township are completed.
[Added 12-16-2013 by Ord. No. 5-2013]
POST-FIRM STRUCTURE
A structure for which construction or substantial improvement
occurred after December 31, 1974, or on or after the community's initial
Flood Insurance Rate Map (FIRM) dated October 15, 1981, whichever
is later, and, as such, would be required to be compliant with the
regulations of the National Flood Insurance Program.
[Added 8-14-2017 by Ord.
No. 5-2017]
PREDEVELOPMENT
Ground cover conditions assumed to exist within the proposed
disturbed area prior to commencement of the regulated activity for
the purpose of calculating the predevelopment water quality volume,
infiltration volume, and peak flow rates as required in this chapter.
[Added 12-16-2013 by Ord. No. 5-2013; 12-12-2022 by Ord. No. 3-2022]
PRE-FIRM STRUCTURE
A structure for which construction or substantial improvement
occurred on or before December 31, 1974, or before the community's
initial Flood Insurance Rate Map (FIRM) dated October 15, 1981, whichever
is later, and, as such, would not be required to be compliant with
the regulations of the National Flood Insurance Program.
[Added 8-14-2017 by Ord.
No. 5-2017]
PRETREATMENT
Techniques employed in stormwater BMPs to provide storage
or filtering, or other methods to trap or remove coarse materials
and other pollutants before they enter the stormwater system but may
not necessarily be designed to meet the entire water quality volume
requirements of this chapter.
[Added 12-12-2022 by Ord.
No. 3-2022]
PROJECT PHASE
Designated job areas listed in order for completion, the
sum of which equals the total area of the project.
PROJECT SITE
The specific area of land where any regulated activities
in Willistown Township are planned, conducted, or maintained.
[Added 4-9-2007 by Ord. No. 6-2007]
PUPATION
The inactive stage in the metamorphosis of many insects,
following the larval stage and preceding the adult form.
[Added 3-13-2000 by Ord. No. 1-2000]
RAINFALL INTENSITY
The depth of accumulated rainfall per unit of time.
[Added 12-12-2022 by Ord.
No. 3-2022]
RATIONAL METHOD
A calculation used in hydrology to determine the peak runoff
rate from a small watershed not exceeding 20 acres in size.
RECHARGE
The replenishment of groundwater through the infiltration
of rainfall, other surface waters, or land application of water or
treated wastewater.
[Amended 12-12-2022 by Ord. No. 3-2022]
RECREATION, ACTIVE
Those recreational pursuits which require physical alteration
to the area in which they are performed. Such areas are intensively
used and include, but are not limited to, playgrounds, ball courts,
golf courses and swimming pools.
[Added 6-28-1999 by Ord. No. 2-1999]
RECREATION, PASSIVE
Those recreational pursuits which can be carried out with
little alteration or disruption to the area in which they are performed.
Such uses include, but are not limited to, hiking and picnicking.
[Added 6-28-1999 by Ord. No. 2-1999]
RECREATIONAL STRUCTURE
Anything constructed or erected on the ground or attached
to the ground, pursuant to the definition of "structure," as intended
for community recreational purposes. Such structures shall not include
facilities intended for the private use and benefit of individual
property owners (patios, decks, outdoor kitchens, etc.)
[Added 6-28-1999 by Ord. No. 2-1999;
amended 3-14-2016 by Ord. No. 4-2016]
RECREATIONAL VEHICLE
A vehicle which is built on a single chassis; not more than
400 square feet, measured at the largest horizontal projections; designed
to be self-propelled or permanently towable by a light-duty truck;
and not designed for use as a permanent dwelling but as temporary
living quarters for recreational, camping, travel or seasonal use.
[Added 11-12-1996 by Ord. No. 3-1996]
REDEVELOPMENT
Any regulated activity that involves demolition, removal,
reconstruction, or replacement of existing impervious surface(s).
[Added 7-18-2011 by Ord. No. 7-2011; amended 12-16-2013 by Ord. No.
5-2013]
REGULATED ACTIVITY
Any earth disturbance activity or activities, or any activity
that involves the alteration or development of land in a manner that
may affect stormwater runoff.
[Added 12-16-2013 by Ord. No. 5-2013]
REGULATED EARTH DISTURBANCE ACTIVITY
Any activity involving earth disturbance subject to regulation
under 25 Pa. Code Chapter 92, Chapter 102, or the Clean Streams Law.
[Added 4-9-2007 by Ord. No. 6-2007; amended 12-16-2013 by Ord. No.
5-2013]
REGULATED IMPERVIOUS SURFACE
Proposed impervious surface as part of a current proposed
activity and all existing impervious surfaces installed after December
16, 2013, (last ordinance update) as part of previous activity.
[Added 12-12-2022 by Ord.
No. 3-2022]
REGULATORY FLOOD ELEVA'T'ION
The base flood elevation (BFE) or estimated flood height
as determined using simplified methods plus a freeboard safety factor
of 1 1/2 feet. The freeboard safety factor also applies to utilities
and ductwork.
[Added 11-13-2006 by Ord. No. 5-2006; amended 8-14-2017 by Ord. No.
5-2017]
RELEASE RATE
The percentage of existing conditions peak rate of runoff
from a site or subarea to which the proposed conditions peak rate
of runoff must be reduced to protect downstream areas.
[Added 4-9-2007 by Ord. No. 6-2007]
RETENTION or TO RETAIN
The prevention of direct discharge of stormwater runoff into
surface waters or water bodies during or after a storm event by permanent
containment in a pond or depression; examples include systems which
discharge by percolation to groundwater, exfiltration, and/or evaporation
processes and which generally have residence times of less than three
days.
[Amended 12-12-2022 by Ord. No. 3-2022]
RETENTION BASIN
A reservoir, formed from soil or other material, which is
designed to temporarily detain a certain amount of stormwater from
a catchment area and which also may be designed to permanently retain
additional stormwater runoff from the catchment area. Retention basins
also may receive fresh water from year-round streams. Unlike detention
basins, retention basins always contain water, and thus may be considered
man-made lakes or ponds.
RETENTION VOLUME/REMOVED RUNOFF
The volume of runoff that is captured and not released directly
into the surface waters of the commonwealth during or after a storm
event.
[Added 12-12-2022 by Ord.
No. 3-2022]
RIPRAP
Broken rock, cobbles or boulders placed on earth surfaces
for the protection against the action of water.
ROAD MAINTENANCE
Earth disturbance activities within the existing road cross
section, such as grading and repairing existing unpaved road surfaces,
cutting road banks, cleaning or clearing drainage ditches, and other
similar activities.
[Added 4-9-2007 by Ord. No. 6-2007]
ROOT MAT
The surface and subsurface network of roots which support
a tree.
RUNOFF
Any part of precipitation that flows over the land surface.
[Added 12-12-2022 by Ord.
No. 3-2022]
RUNOFF COEFFICIENT
That portion of a total volume of water which can be expected
to flow off a particular surface.
SCREENING
The creation of a visual barrier through some combination of plantings, fences and walls, pursuant to the requirements of this chapter, specifically Article
X; in no case shall combinations of plantings, fences and walls be used as a method to reduce or eliminate the requirements of Article
X, unless specifically permitted otherwise or by approval of the Board.
[Amended 3-14-2016 by Ord. No. 4-2016]
SCS
Soil Conservation Service, United States Department of Agriculture.
SEASONAL HIGH WATER TABLE SOILS
Those soils in which the groundwater surface is within one
foot of the ground surface at certain times of the year, according
to the Soil Survey of Chester County, United States Department of
Agriculture, Soil Conservation Service, and/or determined by on-site
investigation.
SEDIMENT
Solid material, both mineral and organic, that is in suspension,
is being transported or has been moved from its site of origin by
water.
SEDIMENT BASIN
A retention or detention basin located and designed to retain
rock, sand, gravel, silt and other stormwater-transported material
through trapping, screening, settling, etc.
SEDIMENT POLLUTION
The unwanted buildup of solid material, both mineral and
organic, that is transported in suspension from its site of origin
by water causing defile.
SEEPAGE BED
A broad area of excavated earth, filled with loose stone
or other particles, to which surface water is directed for infiltration
into geologic storage.
SEEPAGE PIT/SEEPAGE TRENCH
An area of excavated earth filled with loose stone or similar
coarse material into which surface water is directed for infiltration
into the underground water.
[Amended 4-9-2007 by Ord. No. 6-2007]
SELECTIVE LOGGING AND WOODCUTTING
The removal of single, scattered, mature trees or other trees
from unevenly aged tree stands to preserve and enhance healthy woodlands.
SEPARATE STORM SEWER SYSTEM
A conveyance or system of conveyances (including roads with
drainage systems, municipal streets, catch basins, curbs, gutters,
ditches, man-made channels, or storm drains) primarily used for collecting
and conveying stormwater runoff.
[Added 4-9-2007 by Ord. No. 6-2007]
SETTLING
The gradual subsidence of material in a liquid.
SHEET FLOW
A broad, flat continuous flow of water, as opposed to a concentrated,
channelized flow.
[Added 3-13-2000 by Ord. No. 1-2000]
SITE
Total area of land in the Township where any proposed regulated
activity, as defined herein, is planned, conducted, or maintained
or that is otherwise impacted by the regulated activity.
[Added 12-16-2013 by Ord. No. 5-2013]
SITE DISTURBANCE
Any activity which causes land on a given site to be exposed
to the danger of erosion, including removal of vegetation, clearing,
grading, filling, plowing and other types of earthmoving.
SODDING
The planting of stoloniferous or rhizomatous grasses to form
a turf/lawn.
SOIL-COVER COMPLEX METHOD
A mathematical method of runoff computation developed by
the Soil Conservation Service of the United States Department of Agriculture
which provides for accurate consideration of the effect of applied
conservation measures on runoff rates and volume.
SOIL STABILIZING FUNCTION
A plant or structure which encourages resistance of soil
to erosion, soil creep or other movement which results in net loss
of soil from an area.
SOIL TYPE
The subdivision of a soil series based on surface texture
as defined in the Soil Survey Manual of Chester and Delaware Counties,
Pennsylvania.
SPECIAL FLOOD HAZARD AREA (SFHA)
An area in the floodplain subject to a one-percent or greater
chance of flooding in any given year. It is shown on the FIRM as Zone
A, AO, A1-A30, AE, A99, or AH.
[Added 8-14-2017 by Ord.
No. 5-2017]
SPECIMEN PLANT
A specifically selected plant considered worthy of conservation
by the Township because of species, size, shape, form, historical
importance or any other significant characteristic, particularly as
applied to trees over 20 inches DBH or as otherwise noted in the Township's
Open Space, Recreation and Environmental Resources Plan.
SPILLWAY
An open or closed channel, or both, used to convey excess
water from a reservoir.
STABLE ROCK
Fixed rock which neither moves nor visibly erodes from the
action of water.
START OF CONSTRUCTION
Includes substantial improvement and other proposed new development
and means the date the permit was issued, provided the actual start
of construction, repair, reconstruction, rehabilitation, addition,
placement, or other improvement was within 180 days after the date
of the permit and shall be completed within 12 months after the date
of issuance of the permit unless a time extension is granted, in writing,
by the Floodplain Administrator. The "actual start" means either the
first placement of permanent construction of a structure on a site,
such as the pouring of slab or footings, the installation of piles,
the construction of columns, or any work beyond the stage of excavation;
or the placement of a manufactured home on a foundation. Permanent
construction does not include land preparation, such as clearing,
grading, and filling; nor does it include the installation of streets
and walkways; nor does it include excavation for a basement, footings,
piers, or foundations or the erection of temporary forms; nor does
it include the installation on the property of accessory buildings,
such as garages or sheds not occupied as dwelling units or not part
of the main structure. For a substantial improvement, the "actual
start of construction" means the first alteration of any wall, ceiling,
floor, or other structural part of a building, whether or not that
alteration affects the external dimensions of the building.
[Amended 8-14-2017 by Ord. No. 5-2017]
STATE WATER QUALITY REQUIREMENTS
As defined under state regulations, protection of designated and existing uses (see 25 Pennsylvania Code Chapters
93 and
96), including:
[Added 4-9-2007 by Ord. No. 6-2007]
A.
Each stream segment in Pennsylvania has a designated use, such as “cold water fishery” or “potable water supply,” which is listed in Chapter
93. These uses must be protected and maintained under state regulations.
B.
Existing uses are those attained as of November 1975, regardless of whether they have been designated in Chapter
93. Regulated earth disturbance activities must be designed to protect and maintain existing uses and maintain the level of water quality necessary to protect those uses in all streams and to protect and maintain water quality in special protection streams.
C.
Water quality involves the chemical, biological,
and physical characteristics of surface water bodies. After regulated
earth disturbance activities are complete, these characteristics can
be impacted by the addition of pollutants such as sediment and changes
in habitat through increased flow volumes and/or rates as a result
of changes in land surface area from those activities. Therefore,
permanent discharges to surface waters must be managed to protect
the stream bank, streambed, and structural integrity of the waterway
to prevent these impacts.
STORM SEWER
A pipe or conduit that carries intercepted surface runoff,
street wash and other wash waters or drainage, but excludes domestic
sewage and industrial wastes.
STORMWATER
Water which surfaces, flows or collects during and subsequent
to rain or snowfall.
STORMWATER MANAGEMENT (SWM) SITE PLAN
The plan prepared by the applicant or its representative, in accordance with the requirements of Article
VIII, Stormwater Management, indicating how stormwater runoff will be managed at a particular site in accordance with this article, and including all necessary design drawings, calculations, supporting text, and documentation to demonstrate that article requirements have been met, herein referred to as "SWM site plan." All references in this article to final or approved SWM site plans shall incorporate the approved SWM site plan and all subsequent approved revisions thereto.
[Added 12-12-2022 by Ord.
No. 3-2022]
STREAM
A natural watercourse.
[Added 12-12-2022 by Ord.
No. 3-2022]
STRUCTURE
A walled and roofed building, including a gas or liquid storage
tank, that is principally above ground; anything constructed or erected
on the ground or attached to the ground having an ascertainable stationary
location on or in land or water, whether or not affixed to the land.
SUBDIVISION
The division or redivision of a single lot, tract or parcel of land by any means into two or more lots, tracts, parcels or other divisions of land, including changes in existing lot lines, for the purpose, whether immediate or future, of lease, partition by the court for distribution to heirs or devisees, transfer of ownership or building or lot development. The subdivision by lease of land for agricultural purposes into parcels of more than 10 acres not involving any new street or easement of access or residential dwellings shall not be included within the definition of subdivision for the purpose of this chapter. Any subdivision of land for mortgage purposes only shall nevertheless comply with all of the requirements of this chapter, of Chapter
123, Subdivision and Land Development, and of Chapter
139, Zoning, of this Code.
[Added 11-13-2006 by Ord. No. 5-2006]
SUBSTANTIAL DAMAGE
Damage from any cause sustained by a structure whereby the
cost of restoring the structure to its before-damaged condition would
equal or exceed 50% or more of the market value of the structure before
the damage occurred.
[Added 11-12-1996 by Ord. No. 3-1996]
SUBSTANTIAL IMPROVEMENT
Any repair, reconstruction or improvement of a structure,
the cost of which equals or exceeds 50% of the market value of the
structure, either before the improvement or repair is started or,
if the structure has been damaged and is being restored, before the
damage occurred. For the purposes of this definition, substantial
improvement is considered to occur when the first alteration of any
wall, ceiling, floor or other structural part of the building commences,
whether or not that alteration affects the external dimensions of
the structure. The term does not, however, include either:
A.
Any project for improvement of a structure to
comply with existing state or local health, sanitary or safety code
specifications which are solely necessary to assure safe living conditions;
or
B.
Any alteration of a structure listed on the
National Register of Historic Places or a State Inventory of Historic
Places.
SURFACE WATER
All water whose surface is exposed to the atmosphere.
SURFACE WATERS OF THE COMMONWEALTH
Any and all rivers, streams, creeks, rivulets, ditches, watercourses,
storm sewers, lakes, dammed water, wetlands, ponds, springs, and all
other bodies or channels of conveyance of surface waters, or parts
thereof, whether natural or artificial, within or on the boundaries
of the commonwealth.
[Added 4-9-2007 by Ord. No. 6-2007]
SWALE
An artificial or natural waterway which may contain contiguous
areas of standing or flowing water only following a rainfall event,
or is planted with or has stabilized vegetation suitable for soil
stabilization, stormwater treatment, and nutrient uptake, or is designed
to take into account the soil erodibility, soil percolation, slope,
slope length, and contributing drainage area so as to prevent erosion
and reduce the pollutant concentration of any discharge.
[Amended 4-9-2007 by Ord. No. 6-2007]
TOEING
To tie the terminal edge or edges of a structure into an
anchor substance so as to hold in place.
TOP OF BANK
A point above the mean water level of a watercourse which
defines the maximum depth of channel flow in the watercourse. It is
either determined visually or computed as an elevation using the peak
rate of runoff from a two-year storm event.
[Added 3-13-2000 by Ord. No. 1-2000]
TOPOGRAPHY
The relative positions and elevations of the natural or man-made
features of an area that describe the configuration of its surface.
TOTAL PROTECTED LAND
The sum of the acreage of natural resource land requiring protection pursuant to Chapter
73, §
73-11.1.
[Added 6-28-1999 by Ord. No. 2-1999]
TOWNSHIP
The Township of Willistown, Chester County, Pennsylvania.
Where the provisions of this chapter require the approval or decision
of the Township, the reference shall be deemed to refer to the Township
governing body or its designee, on recommendation of the Township
Planning Commission, Zoning Officer and Engineer.
TRACT AREA, GROSS
The area of land contained within the title lines of the
tract.
[Added 6-28-1999 by Ord. No. 2-1999]
TRAVERSING
Using a series of straight lines, whose lengths and angled
measurements are known, to create a polygon for making field locations
by surveying.
UNIFORM CONSTRUCTION CODE (UCC)
The state-wide building code adopted by the Pennsylvania
General Assembly in 1999 applicable to new construction in all municipalities
whether administered by the municipality, a third party or the Department
of Labor and Industry. Applicable to residential and commercial buildings,
the UCC adopted the International Residential Code (IRC) and the International
Building Code (IBC), by reference, as the construction standard applicable
within the commonwealth for floodplain construction. For coordination
purposes, references to the above are made specifically to various
sections of the IRC and IBC.
[Added 11-13-2006 by Ord. No. 5-2006]
UNSTABILIZED EARTH
Soil subject to erosion due to lack of vegetation or inherent
nature of soil structure.
VARIANCE
A waiver from the strict terms of this chapter, by order
of the Zoning Hearing Board, after public hearing, when authorized
by law. A grant of relief by a community from the terms of a floodplain
management regulation.
[Added 8-14-2017 by Ord.
No. 5-2017]
VEGETATION
Plants in general or the sum total of plant life in an area.
VIEW
The relative ability to see a given object from a designated
location.
A.
UNOBSTRUCTEDThe ability to see most or all of the object; specifically, where more than 80% of the object is visible.
B.
FILTEREDThe ability to see some of the object; specifically, where 20% to 80% of the object is visible.
C.
HIDDENThe ability to see little or none of the object; specifically, where less than 20% of the object is visible.
VIOLATION
The failure of a structure or other development to be fully
compliant with the community's floodplain management regulations.
A structure or other development without the elevation certificate,
other certifications, or other evidence of compliance required in
44 CFR 60.3(b)(5), (c)(4), (c)(10), (d)(3), (e)(2), (e)(4), or (e)(5)
is presumed to be in violation until such time as that documentation
is provided.
[Added 8-14-2017 by Ord.
No. 5-2017]
VISUAL AMENITY
Any type of visible feature which the observer finds attractive
or pleasing to the eye.
WATER BODY
Any feature defined by a bank or shore in which water can
be found.
[Added 3-13-2000 by Ord. No. 1-2000]
WATERCOURSE
A channel with banks and a bed within which concentrated
water flows either continuously or intermittently, including, but
not limited to, intermittent streams, perennial streams, drainage
channels and swales.
[Amended 3-13-2000 by Ord. No. 1-2000]
WATER QUALITY INLET
A storm sewer inlet designed to separate suspended solids,
sediment, and other pollutants from stormwater runoff.
[Added 4-9-2007 by Ord. No. 6-2007]
WATERS OF THE COMMONWEALTH
Any and all rivers, streams, creeks, rivulets, ditches, watercourses,
storm sewers, lakes, dammed water, wetlands, ponds, springs, and all
other bodies or channels of conveyance of surface water and underground
water, or parts thereof, whether natural or artificial, within or
on the boundaries of the commonwealth.
[Added 4-9-2007 by Ord. No. 6-2007]
WATERSHED
Region or area drained by a river, watercourse, or other
body of water, whether natural or artificial.
[Added 4-9-2007 by Ord. No. 6-2007]
WATER TABLE
The uppermost level of saturation of pore space or fractures
by groundwater. Seasonal high-water table refers to a water table
that rises and falls with the seasons due either to natural or man-made
causes.
[Amended 12-12-2022 by Ord. No. 3-2022]
WATERWAY
A natural course or constructed channel for the flow of water.
WETLAND
Those areas inundated or saturated by surface or ground water
at a frequency and duration sufficient to support and that under normal
circumstances do support a prevalence of vegetation typically adapted
for life in saturated soil conditions; or areas that are defined and
delineated in accordance with the Federal Manual for Identifying and
Delineating Jurisdictional Wetlands, dated January 10, 1989, and as
may be amended from time to time; or as further defined and delineated
by the United States Army Corps of Engineers, the United States Environmental
Protection Agency or the Pennsylvania Department of Environmental
Resources.
WILDLIFE HABITAT
A community of plants that provide food, water, cover, nesting
and foraging or feeding conditions necessary to maintain populations
of animals.
WOODED LOT
Any lot having more than one viable tree of a caliper of
six inches or greater per 1,500 square feet of lot area. A wooded
lot is a lot that has woodland.
[Amended 6-25-2001 by Ord. No. 4-2001]
WOODLAND
An area characterized by a more or less dense and extensive
tree cover, including the dripline of trees; more particularly, a
plant community predominantly of healthy trees and other woody vegetation,
well stocked and growing more or less closely together. See also "wooded
lot." Land that conformed to this definition within 18 months of application
for subdivision, land development or stormwater management shall be
considered to be woodland.
[Amended 6-25-2001 by Ord. No. 4-2001]
ZONE OF AERATION
Subsurface zone above the water table in which the soil or
permeable rock is not saturated.