A.
Statement of findings. The Borough Council finds that:
(1)
Inadequate management of accelerated stormwater runoff resulting
from development throughout a watershed increases flood flows and
velocities, contributes to erosion and sedimentation, overtaxes the
carrying capacity of existing streams and storm sewers, greatly increases
the cost of public facilities to convey and manage stormwater, undermines
floodplain management and flood reduction efforts in upstream and
downstream communities, reduces groundwater recharge, and threatens
public health and safety.
(2)
A comprehensive program of stormwater management, including
reasonable regulation of development and activities causing accelerated
erosion, is fundamental to the public health, safety, welfare, and
the protection of the people of the Borough and all the people of
the commonwealth, their resources, and the environment.
(3)
Through project design, impacts from stormwater runoff can be
minimized to maintain the natural hydrologic regime, and sustain high
water quality, groundwater recharge, stream baseflow, and aquatic
ecosystems. The most cost effective and environmentally advantageous
way to manage stormwater runoff is through nonstructural project design,
minimizing impervious surfaces and sprawl, avoiding sensitive areas
(i.e., stream buffers, floodplains, steep slopes), and designing to
topography and soils to maintain the natural hydrologic regime.
B.
Purpose. The purpose of this article is to promote health, safety, and welfare within the Delaware River South watershed by minimizing the damages described in § 153-700A(1) of this chapter through provisions designed to:
(1)
Promote alternative project designs and layout that minimizes
impacts to surface and groundwater.
(2)
Promote nonstructural best management practices.
(3)
Minimize increases in stormwater volume.
(4)
Minimize impervious surfaces.
(5)
Manage accelerated runoff and erosion and sedimentation problems
at their source by regulating activities that cause these problems.
(6)
Utilize and preserve the existing natural drainage systems.
(7)
Encourage recharge of groundwater where appropriate and prevent
degradation of groundwater quality.
(8)
Address the quality and quantity of stormwater discharges from
the development site.
(9)
Maintain existing flows and quality of streams and watercourses
in the Borough and the commonwealth.
(10)
Preserve and restore the flood-carrying capacity of streams.
(11)
Provide proper maintenance of all permanent stormwater management
facilities that are constructed in the Borough.
(12)
Provide performance standards and design criteria for watershed-wide
stormwater management and planning.
C.
Statutory authority. The Borough is empowered to regulate land use
activities that affect runoff by the authority of the Act of October
4, 1978, P.L. 864 (Act 167), 32 P.S. § 680.1 et seq., as
amended, the Storm Water Management Act, and the Tullytown Borough
Zoning Ordinance.
D.
Applicability. This chapter shall apply to all areas of the Borough,
in that the Borough in its entirety is located within the Delaware
River South watershed, as delineated in Appendix D,[1] which is hereby adopted as part of this chapter. This
article shall only apply to permanent best management practices (BMPs)
and/or stormwater management facilities constructed as part of any
of the regulated activities listed in this article. The following
activities are defined as "regulated activities" and shall be regulated
by this chapter:
(1)
Land development.
(2)
Subdivision.
(3)
Construction of new or additional impervious or semipervious
surfaces (driveways, parking lots, patios, tennis courts, etc.).
(4)
Construction of new buildings or additions to existing buildings.
(5)
Diversion or piping of any natural or man-made stream channel.
(6)
Installation of BMPs and/or stormwater management facilities
or appurtenances thereto.
[1]
Editor's Note: Appendix D is included at the end of this chapter.
E.
Repealer. Any ordinance or ordinance provision of the Borough inconsistent
with any of the provisions of this article is hereby repealed to the
extent of the inconsistency only.
F.
Separability. Should any section or provision of this article be
declared invalid by a court of competent jurisdiction, such decision
shall not affect the validity of any of the remaining provisions of
this article.
G.
Compatibility with other ordinance requirements. Approvals issued
pursuant to this article do not relieve the applicant of the responsibility
to secure required permits or approvals for activities regulated by
any other applicable code, rule, act, or ordinance.
A.
General. For the purposes of this article, certain terms and words
used herein shall be interpreted as follows:
(1)
Words used in the present tense include the future tense; the
singular number includes the plural, and the plural number includes
the singular; words of masculine gender include feminine gender; and
words of feminine gender include masculine gender.
(2)
The word "includes" or "including" shall not limit the term
to the specific example but is intended to extend its meaning to all
other instances of like kind and character.
(3)
The word "person" includes an individual, firm, association,
organization, partnership, trust, company, corporation, or any other
similar entity.
(4)
The words "shall" and "must" refers to items which are mandatory;
the words "may" and "should" refer to items which are permissive.
(5)
The words "used or occupied" include the words "intended, designed,
maintained, or arranged to be used, occupied, or maintained."
B.
ACCELERATED EROSION
AGRICULTURAL ACTIVITIES
ALTERATION
APPLICANT
AS-BUILT DRAWINGS
BANKFULL
BASE FLOW
BIORETENTION
BMP (BEST MANAGEMENT PRACTICE)
CHANNEL EROSION
CISTERN
CONSERVATION DISTRICT
CULVERT
DAM
DEP
DEPARTMENT
DESIGN PROFESSIONAL (QUALIFIED)
DESIGN STORM
DESIGNEE
DETENTION BASIN
DETENTION DISTRICT
DEVELOPMENT SITE
DIFFUSED DRAINAGE DISCHARGE
DISTURBED AREAS
DOWNSLOPE PROPERTY LINE
DRAINAGE CONVEYANCE FACILITY
DRAINAGE EASEMENT
DRAINAGE PERMIT
DRAINAGE PLAN
EARTH DISTURBANCE ACTIVITY
EMERGENCY SPILLWAY
ENCROACHMENT
EROSION
EROSION AND SEDIMENT POLLUTION CONTROL PLAN
ERSAM
EXCEPTIONAL VALUE WATERS
EXISTING CONDITIONS
FLOOD
FLOODPLAIN
FLOODWAY
FOREST MANAGEMENT/TIMBER OPERATIONS
FREEBOARD
GRADE
GRASSED WATERWAY
GROUNDWATER RECHARGE
HEC-HMS, THE U.S. ARMY CORPS OF ENGINEERS, HYDROLOGIC ENGINEERING
CENTER (HEC)
HIGH QUALITY WATERS
HYDROLOGIC REGIME (NATURAL)
HYDROLOGIC SOIL GROUP
HYETOGRAPH
IMPERVIOUS SURFACE
IMPOUNDMENT
INFILL
INFILTRATION
INFILTRATION STRUCTURES
INLET
LAND DEVELOPMENT
(1)
(a)
(b)
(2)
(3)
LAND EARTH DISTURBANCE
LIMITING ZONE
(1)
(2)
(3)
MAIN STEM (MAIN CHANNEL)
MANNING EQUATION (MANNING FORMULA)
MUNICIPALITY
NATURAL HYDROLOGIC REGIME
NONPOINT SOURCE POLLUTION
NRCS
OPEN CHANNEL
OUTFALL
OUTLET
PARENT TRACT
PARKING LOT STORAGE
PEAK DISCHARGE
PENN STATE RUNOFF MODEL (CALIBRATED)
PIPE
PLANNING COMMISSION
PMF - PROBABLE MAXIMUM FLOOD
PRE-DEVELOPMENT
PRETREATMENT
RATIONAL METHOD
RECHARGE AREA
RECONSTRUCTION
RECORD DRAWINGS
REDEVELOPMENT
REGULATED ACTIVITIES
RELEASE RATE
RETENTION BASIN
RETURN PERIOD
RISER
ROOFTOP DETENTION
RUNOFF
SALDO
SEDIMENT BASIN
SEDIMENT POLLUTION
SEDIMENTATION
SEEPAGE PIT/SEEPAGE TRENCH
SHEET FLOW
SOIL-COVER COMPLEX METHOD
SOURCE WATER PROTECTION AREAS (SWPA)
SPECIAL PROTECTION SUBWATERSHEDS
SPILLWAY
STORAGE INDICATION METHOD
STORM FREQUENCY
STORM SEWER
STORMWATER
STORMWATER MANAGEMENT FACILITY
STORMWATER MANAGEMENT PLAN
STORMWATER MANAGEMENT SITE PLAN
STREAM
STREAM BUFFER
STREAM ENCLOSURE
SUBAREA
SUBDIVISION
SWALE
TIMBER OPERATIONS
TIME OF CONCENTRATION (Tc)
(TO) GRADE
WATERCOURSE
WATERS OF THE COMMONWEALTH
WELLHEAD
WELLHEAD PROTECTION AREA
WETLAND
Definitions of specific terms related to stormwater management provisions.
The following specific definitions apply in this article:
The removal of the surface of the land through the combined
action of man's activity and the natural processes at a rate
greater than would occur because of the natural process alone.
The work of producing crops and raising livestock, including
tillage, plowing, disking, harrowing, pasturing and installation of
conservation measures. Construction of new buildings or impervious
area is not considered an agricultural activity.
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.
A landowner or applicant who has filed an application for approval to engage in any regulated activities as defined in § 153-700D of this chapter.
Those maintained by the contractor as he constructs the project
and upon which he documents the actual locations of the building components
and changes to the original contract documents. These, or a copy of
the same, are turned over to the engineer at the completion of the
project.
The channel at the top of the bank or point where water beings
to overflow onto a floodplain.
The portion of stream flow that is sustained by groundwater
discharge.
A stormwater management facility which utilizes woody and
herbaceous plants and soils to remove pollutants before infiltration
occurs.
Stormwater structures, facilities and techniques to control,
maintain or improve the quantity and quality of surface runoff. The
PA Handbook of BMPs for Developing Areas and the Maryland Stormwater
Design Manual may be referenced for specific BMP practices.
The widening, deepening, and headward cutting of small channels
and waterways caused by moderate to large floods.
An underground reservoir or tank for storing rainwater.
The Bucks County Conservation District.
A structure with appurtenant works which carries a stream
under or through an embankment or fill.
An artificial barrier, together with its appurtenant works,
constructed for the purpose of impounding or storing water or another
fluid or semifluid, or a refuse bank, fill or structure for highway,
railroad or other purposes that does or may impound water or another
fluid or semifluid.
The Pennsylvania Department of Environmental Protection.
Pennsylvania Department of Environmental Protection.
A Pennsylvania registered professional engineer, registered
landscape architect, or a registered professional land surveyor trained
to develop stormwater management plans.
The magnitude and temporal distribution of precipitation
from a storm event measured in probability of occurrence (e.g., a
five-year storm) and duration (e.g., 24 hours), used in the design
and evaluation of stormwater management systems.
The agent of the Tullytown Borough Planning Commission and/or
agent of the Borough Council involved with the administration, review,
or enforcement of any provisions of this chapter by contract or memorandum
of understanding.
An impoundment structure designed to manage stormwater runoff
by temporarily storing the runoff and releasing it at a predetermined
rate.
Those subareas in which some type of detention is required
to meet the plan requirements and the goals of Act 167.
The specific tract of land for which a regulated activity
is proposed.
Drainage discharge not confined to a single point location
or channel, such as sheet flow or shallow concentrated flow.
Unstabilized land area where an earth disturbance activity
is occurring or has occurred.
That portion of the property line of the lot, tract, or parcels
of land being developed, located such that all overland or pipe flow
from the site would be directed towards it.
A stormwater management facility designed to transmit stormwater
runoff and shall include streams, channels, swales, pipes, conduits,
culverts, storm sewers, etc.
A right granted by a landowner to a grantee, allowing the
use of private land for stormwater management purposes.
A permit issued by the Borough Council after the drainage
plan has been approved. Said permit is issued prior to or with the
final Borough approval.
The documentation of the stormwater management system, to be used for a given development site, the contents of which are established in § 153-703C.
A construction or other human activity which disturbs the
surface of land, including, but not limited to, clearing and grubbing,
grading, excavations, embankments, land development, agricultural
plowing or tilling, timber harvesting activities, road maintenance
activities, mineral extraction, and the moving, depositing, stockpiling,
or storing of soil, rock, or earth materials.
A conveyance area that is used to pass peak discharge greater
than the maximum design storm controlled by the stormwater facility.
A structure or activity that changes, expands or diminishes
the course, current or cross section of a watercourse, floodway or
body of water.
The movement of soil particles by the action of water, wind,
ice, or other natural forces.
A plan that is designed to minimize accelerated erosion and
sedimentation.
Existing Resource and Site Analysis Map.
Surface waters of high quality which satisfy Pennsylvania
Code Title 25, Environmental Protection, Chapter 93, Water Quality
Standards, § 93.4b(b) (relating to antidegradation).
The initial condition of a project site prior to the proposed
construction. If the initial condition of the site is undeveloped
land, the land use shall be considered as "meadow" unless the natural
land cover is proven to generate lower curve numbers or Rational "C"
values.
A general but temporary condition of partial or complete
inundation of normally dry land areas from the overflow of streams,
rivers, and other waters of this commonwealth.
Any land area susceptible to inundation by water from any
natural source or delineated as a special flood hazard area on the
applicable National Flood Insurance Program Flood Insurance Rate Map
(FIRM) prepared by the Federal Emergency Management Agency (FEMA).
Also included are areas that comprise Group 13 Soils, as listed in
Appendix A of the Pennsylvania DEP of Environmental Protection (DEP)
Technical Manual for Sewage Enforcement Officers (as amended or replaced
from time to time by DEP).
The channel of the watercourse and those portions of the
adjoining floodplains that are reasonably required to carry and discharge
the one-hundred-year-frequency 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 one-hundred-year-frequency floodway,
it is assumed—absent evidence to the contrary—that the
floodway extends from the stream to 50 feet from the top of the bank
of the stream.
Planning and activities necessary for the management of forest
land. These include timber inventory and preparation of forest management
plans, silvicultural treatment, cutting budgets, logging road design
and construction, timber harvesting, site preparation, and reforestation.
A vertical distance between the elevation of the design high-water
and the top of a dam, levee, tank, basin, or diversion ridge. The
space is required as a safety margin in a pond or basin.
A slope, usually of a road, channel, or natural ground, specified
in percent and shown on plans as specified herein.
A natural or constructed waterway, usually broad and shallow,
covered with erosion-resistant grasses, used to conduct surface water.
Replenishment of existing natural underground water supplies.
Hydrologic modeling system (HMS) adapted to the Delaware
River South Creek watershed.
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).
The hydrologic cycle or balance that sustains quality and
quantity of stormwater, baseflow, storage, and groundwater supplies
under natural conditions.
A classification of soils by the Natural Resources Conservation
Service, formerly the Soil Conservation Service, into four runoff
potential groups. The groups range from A soils, which are very permeable
and produce little runoff, to D soils, which are not very permeable
and produce much more runoff.
A graphical representation of average rainfall, rainfall
excess rates, or volumes over specified areas during successive units
of time during a storm.
A surface that prevents the percolation of water into the
ground such as building rooftops, pavement, sidewalks, driveways and
compacted earth or turf.
A retention or detention basin designed to retain stormwater
runoff and release it at a controlled rate.
Development that occurs on smaller parcels that remain undeveloped
but are within or in very close proximity to urban areas. The development
relies on existing infrastructure and does not require an extension
of water, sewer, or other public utilities.
The passing of stormwater through the soil from the surface.
A structure designed to direct runoff into the ground (e.g.,
French drains, seepage pits, seepage trench).
A surface connection to a closed drain. A structure at the
diversion end of a conduit. The upstream end of any structure through
which water may flow.
The improvement of one lot or two or more contiguous lots, tracts,
or parcels of land for any purpose involving:
A group of two or more residential or nonresidential buildings,
whether initially or cumulatively, or a single nonresidential building
on a lot or lots regardless of the number of occupants or tenure;
or
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.
A subdivision of land.
Development in accordance with Section 503(1.1) of the Pennsylvania
Municipalities Planning Code Act of 1968 (Act 247).[1]
Any activity involving grading, tilling, digging, or filling
of ground or stripping of vegetation or any other activity that causes
an alteration to the natural condition of the land.
A soil horizon or condition in the soil profile or underlying
strata which includes one of the following:
A seasonal high water table, whether perched or regional, determined
by direct observation of the water table or indicated by soil mottling.
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.
A rock formation, other stratum or soil condition which is so
slowly permeable that it effectively limits downward passage of effluent.
Any stream segment or other runoff conveyance facility used
as a reach in the Delaware River South Creek hydrologic model.
A method for calculation of velocity of flow (e.g., feet
per second) and flow rate (e.g., cubic feet per second) in open channels
based upon channel shape, roughness, depth of flow and slope. Open
channels may include closed conduits so long as the flow is not under
pressure.
Tullytown Borough, Bucks County, Pennsylvania.
See "hydrologic regime."
Pollution that enters a body of water from diffuse origins
in the watershed and does not result from confined or discrete conveyances.
Natural Resources Conservation Service (previously SCS).
A drainage element in which stormwater flows with an open
surface. Open channels include, but shall not be limited to, natural
and man-made drainageways, swales, streams, ditches, canals, and pipes
flowing partly full.
Point where water flows from a conduit, stream, or drain.
Points of water disposal from a stream, river, lake, tidewater
or artificial drain.
The parcel of land from which a land development or subdivision
originates as of the date of the original Delaware River South stormwater
ordinance adoption.
Involves the use of impervious parking areas as temporary
impoundments with controlled release rates during rainstorms.
The maximum rate of stormwater runoff from a specific storm
event.
The computer-based hydrologic modeling technique adapted
to the Delaware River South watershed for the Act 167 plan. The model
has been calibrated to reflect actual recorded flow values by adjoining
key model input parameters.
A culvert, closed conduit, or similar structure (including
appurtenances) that conveys stormwater.
The Planning Commission of Tullytown Borough.
The flood that may be expected from the most severe combination
of critical meteorological and hydrologic conditions that are reasonably
possible in any area. The PMF is derived from the probable maximum
precipitation (PMP) as determined based on data obtained from the
National Oceanographic and Atmospheric Administration (NOAA).
Undeveloped/natural condition.
Techniques employed in stormwater BMPs to provide storage
or filtering to help trap coarse materials and other pollutants before
they enter the system.
A rainfall-runoff relation used to estimate peak flow.
Undisturbed surface area or depression where stormwater collects,
and a portion of which infiltrates and replenishes the underground
and groundwater.
The process by which existing developed area is adaptively
reused, rehabilitated, restored, renovated, and/or expanded. The development
relies on existing infrastructure and does not require an extension
of water, sewer, or other public utilities.
Original documents revised to suit the as-built conditional
and subsequently provided by the engineer to the client. The engineer
takes the contractor's as-builts, reviews them in detail with
his/her own records for completeness, then either turns these over
to the client or transfers the information to a set or reproducibles,
in both cases for the client's permanent records.
The construction, alteration, or improvement exceeding 5,000
square feet of land disturbance performed on sites where existing
land use is commercial, industrial, institutional, or multifamily
residential.
Actions or proposed actions that have an impact on stormwater runoff and that are specified in § 153-700D of this chapter.
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.
An impoundment in which stormwater is stored and not released
during the storm event. Stored water may be released from the basin
at some time after the end of the storm.
The average interval, in years, within which a storm event
of a given magnitude can be expected to recur. For example, the twenty-five-year
return period rainfall would be expected to recur on the average of
once every 25 years.
A vertical pipe extending from the bottom of a pond that
is used to control the discharge rate from the pond for a specified
design storm.
Temporary ponding and gradual release of stormwater falling
directly onto flat roof surfaces by incorporating controlled-flow
roof drains into building designs.
Any part of precipitation that flows over the land surface.
Subdivision and Land Development Ordinance.
A barrier, dam, or retention or detention basin located and
designed to retain rock, sand, gravel, silt, or other material transported
by water.
The placement, discharge, or any other introduction of sediment
into the waters of the commonwealth occurring from the failure to
design, construct, implement or maintain control measures and control
facilities in accordance with the requirements of the DEP Erosion
and Sediment Pollution Control Program manual.
The process by which mineral or organic matter is accumulated
or deposited by the movement of water.
An area of excavated earth filled with loose stone or similar
coarse material, into which surface water is directed for infiltration
into the ground.
Runoff that flows over the ground surface as a thin, even
layer, not concentrated in a channel.
A method of runoff computation developed by the NRCS that
is based on relating soil type and land use/cover to a runoff parameter
called "curve number" (CN).
The zone through which contaminants are likely to migrate
and reach a drinking water well or surface water intake.
Watersheds for which the receiving waters are exceptional
value (EV) or high quality (HQ) waters.
A conveyance that is used to pass the peak discharge of the
maximum design storm controlled by the stormwater facility.
A reservoir routing procedure based on solution of the continuity
equation (inflow minus outflow equals the change in storage) with
outflow defined as a function of storage volume and depth.
The number of times that a given storm event occurs or is
exceeded on the average in a stated period of years. See "return period."
A system of pipes and/or open channels that conveys intercepted
runoff and stormwater from other sources, but excludes domestic sewage
and industrial wastes.
The total amount of precipitation reaching the ground surface.
Any structure, natural or man-made, that, due to its condition,
design, or construction, conveys, stores, or otherwise affects stormwater
runoff. Typical stormwater management facilities include, but are
not limited to, detention and retention basins, open channels, storm
sewers, pipes, and infiltration structures.
The plan for managing stormwater runoff in the Delaware River
South watershed adopted by Bucks County as required by the Act of
October 4, 1978, P.L. 864, (Act 167), and known as the "Delaware River
South Watershed Act 167 Stormwater Management Plan."
The plan prepared by the applicant or his representative
indicating how stormwater runoff will be managed at the particular
site of interest according to this chapter.
A natural watercourse.
The land area adjacent to each side of a stream, essential
to maintaining water quality, measured 150 feet from the top of the
bank.
A bridge, culvert, or other structure in excess of 100 feet
in length upstream to downstream which encloses a regulated water
of this commonwealth.
The smallest drainage unit of a watershed for which stormwater
management criteria have been established in the stormwater management
plan.
The division or redivision of a 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 of the court
for distribution to heirs or devisees, transfer of ownership or building
or lot development; provided, however, that the subdivision by lease
of land for agricultural proposes into parcels of more than 10 acres,
not involving any new street or easement of access or any residential
dwelling, shall be exempted.
A low-lying stretch of land which gathers or carries surface
water runoff.
See "forest management/timber operations."
The time for surface runoff to travel from the hydraulically
most distant point of the watershed to a point of interest within
the watershed. This time is the combined total of overland flow time
and flow time in pipes or channels, if any.
To finish the surface of a roadbed, top of embankment, or
bottom of excavation.
A river, brook, creek, or a channel or ditch for water, whether
natural or man made, with perennial or intermittent flow.
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 and underground
water, or parts thereof, whether natural or artificial, within or
on the boundaries of this commonwealth.
The surface and subsurface area surrounding a water supply
well, well field, spring, or infiltration gallery supplying a public
water system, through which contaminants are reasonably likely to
move towards and reach the water source.
Those areas that are inundated or saturated by surface water
or groundwater 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, including
swamps, marshes, bogs, ferns, and similar areas.
[1]
Editor's Note: See 53 P.S. § 10503(1.1).
A.
Requirements applicable to all stormwater management systems.
(1)
All regulated activities in the Delaware River South watershed that do not fall under the exemption criteria shown in § 153-703B shall submit a drainage plan consistent with the Delaware River South Watershed Stormwater Management Plan to the Borough for review. These criteria shall apply to the total proposed development even if development is to take place in stages. Impervious cover shall include, but not be limited to, any roof, parking or driveway areas and any new streets and sidewalks. Any areas designed to initially be gravel or crushed stone shall be assumed to be impervious for the exemption criteria.
(2)
Stormwater drainage systems shall be provided in order to permit
unimpeded flow along natural watercourses, except as modified by stormwater
management facilities or open channels consistent with this chapter.
(3)
The drainage plan must be designed consistent with the sequencing provisions of § 153-702B to ensure maintenance of the natural hydrologic regime and to promote groundwater recharge and protect groundwater and surface water quality and quantity. The drainage plan designer must proceed sequentially in accordance with § 153-702 of this chapter.
(4)
The existing points of concentrated drainage that discharge
onto adjacent property shall not be altered without permission of
the affected property owner(s) and shall be subject to any applicable
discharge criteria specified in this chapter.
(5)
Areas of existing diffused drainage discharge shall be subject
to any applicable discharge criteria in the general direction of existing
discharge, whether proposed to be concentrated or maintained as diffused
drainage areas, except as otherwise provided by this chapter. If diffused
flow is proposed to be concentrated and discharged onto adjacent property,
the applicant must document that adequate downstream conveyance facilities
exist to safely transport the concentrated discharge, or otherwise
prove that no erosion, sedimentation, flooding, or other harm will
result from the concentrated discharge.
(6)
Whenever a watercourse is located within a development site,
it shall remain open in its natural state and location and should
not be piped, impeded, or altered (except for road crossings). It
is the responsibility of the developer to stabilize existing eroded
stream/channel banks.
(7)
Where a development site is traversed by watercourses, drainage
easements shall be provided conforming to the line of such watercourses.
The terms of the easement shall prohibit excavation, the placing of
fill or structures, and any alterations that may adversely affect
the flow of stormwater within any portion of the easement.
(8)
When it can be shown that, due to topographic conditions, natural
drainageways on the site cannot adequately provide for drainage, open
channels may be constructed conforming substantially to the line and
grade of such natural drainageways. Work within natural drainageways
shall be subject to approval by the municipality and the DEP through
the joint permit application process, or, where deemed appropriate
by DEP, through the general permit process.
(9)
Any stormwater management facilities regulated by this chapter
that would be located in or adjacent to waters of the commonwealth
or wetlands shall be subject to approval by DEP through the joint
permit application process, or, where deemed appropriate by DEP, the
general permit process. When there is a question whether wetlands
may be involved, it is the responsibility of the applicant or his
agent to show that the land in question cannot be classified as wetlands;
otherwise, approval to work in the area must be obtained from DEP.
(10)
Any stormwater management facilities regulated by this chapter
that would be located on or discharged into state highway rights-of-way
shall be subject to approval by the Pennsylvania Department of Transportation
(PennDOT).
(11)
Minimization of impervious surfaces and infiltration of runoff
through seepage beds, infiltration trenches, etc., are required to
reduce the size or eliminate the need for detention facilities.
(12)
Roof drains must not be discharged to streets or roadside ditches
or connected to sanitary or storm sewers. Overland flow and infiltration/percolation
of stormwater shall be promoted where advantageous to do so. Only
when it is more advantageous to connect directly to streets or storm
sewers shall it be permitted on a case-by-case basis by the Borough.
(13)
All stormwater runoff shall be pretreated for water quality
prior to discharge to surface water or groundwater as per § 702C
and D.
B.
Nonstructural project design (sequencing to minimize stormwater impacts).
(1)
The design of all regulated activities shall include the following
steps in sequence to minimize stormwater impacts.
(a)
The applicant is required to find practicable alternatives to
the surface discharge of stormwater, the creation of impervious surfaces
and the degradation of waters of the commonwealth, and must maintain
as much as possible the natural hydrologic regime of the site.
(b)
An alternative is practicable if it is available and capable
of being done after taking into consideration cost, existing technology,
and logistics in light of overall project purposes and other municipal
requirements.
(c)
All practicable alternatives to the discharge of stormwater
are presumed to have less adverse impact on quantity and quality of
waters of the commonwealth unless otherwise demonstrated.
(2)
The applicant shall demonstrate that he/she has designed the
regulated activities in the following sequence to minimize the increases
in stormwater runoff and impacts to water quality:
(a)
Prepare an Existing Resource and Site Analysis Map (ERSAM), showing environmentally sensitive areas, including, but not limited to, steep slopes, ponds, lakes, streams, wetlands, hydric soils, vernal pools, floodplains, stream buffer zones, hydrologic soil groups A, B, C, and D, any existing recharge areas and any other natural resources identified in § 153-503C(9) of this chapter.
(b)
Prepare a draft project layout avoiding sensitive areas identified in § 153-702B(2)(d) and minimizing total site earth disturbance as much as possible. The ratio of disturbed area to the entire site area and measures taken to minimize earth disturbance shall be included in the ERSAM.
(c)
Identify site-specific existing conditions, drainage areas,
discharge points, recharge areas, and hydrologic soil groups A and
B.
(f)
Satisfy groundwater recharge (infiltration) objective (§ 153-702D) and provide for stormwater treatment prior to infiltration.
(h)
Determine what management district the site falls into (Appendix
D[2]) and conduct a pre-development runoff analysis.
[2]
Editor's Note: Appendix D is included at the end of this chapter.
(i)
Prepare final project design to maintain pre-development drainage
areas and discharge points, to minimize earth disturbance and impervious
surfaces, and to reduce runoff to the maximum extent possible, the
use of surface or point discharges.
(j)
Conduct a proposed conditions runoff analysis based on the final design and to meet the release rate and in turn the overbank flow and extreme event requirements (§ 153-702F).
(k)
Manage any remaining runoff through treatment prior to discharge,
as part of detention, bioretention, direct discharge or other structural
control.
C.
Water quality. In addition to the performance standards and design criteria requirements of this article, the applicant shall comply with the following water quality requirements of this article. Adequate storage and treatment facilities will be provided to capture and treat stormwater runoff from developed or disturbed areas. The recharge volume computed under § 153-702D may be a component of the water quality volume if the applicant chooses to manage both components in a single facility. If the recharge volume is less than the water quality volume, the remaining water quality volume may be captured and treated by methods other than recharge/infiltration BMPs. The required water quality volume (WQv) is the storage capacity needed to capture and to treat a portion of stormwater runoff from the developed areas of the site produced from 90% of the average annual rainfall (P). To achieve this goal, the following criterion is established:
|
The following calculation formula is to be used to determine
the water quality storage volume, (WQv), in acre-feet of storage for
the Delaware River South watershed:
|
|
WQv = [(P)(Rv)(A)]/12
|
|
Where:
| ||||
|
WQv
|
=
|
Water quality volume (acre-feet)
| ||
|
P
|
=
|
Rainfall amount equal to 90% of events producing this rainfall
(inches)
| ||
|
A
|
=
|
Area of the project contributing to the water quality BMP (acres)
| ||
|
Rv
|
=
|
0.05 + 0.009(I) where "I" is the percent of the area that is
impervious surface (impervious area/A*100)
| ||
|
The P value for the five PennDOT rainfall regions is shown in
Figure E-2 and Table E-5 in Appendix E.[3] Since the Delaware River South watershed is in PennDOT
Region 5, the P value to be utilized to meet this requirement is 2.04
inches.
|
(1)
Design of BMPs used for water quality control shall be in accordance
with design specifications outlined in the Pennsylvania Handbook of
Best Management Practices for Developing Areas or other applicable
manuals. The following factors shall be considered when evaluating
the suitability of BMPs used to control water quality at a given development
site:
(a)
Total contributing drainage area.
(b)
Permeability and infiltration rate of the site soils.
(c)
Slope and depth to bedrock.
(d)
Seasonal high water table.
(e)
Proximity to building foundations and well heads.
(f)
Erodibility of soils.
(g)
Land availability and configuration of the topography.
(h)
Peak discharge and required volume control.
(i)
Stream bank erosion.
(j)
Efficiency of the BMPs to mitigate potential water quality problems.
(k)
The volume of runoff that will be effectively treated.
(l)
The nature of the pollutant being removed.
(m)
Maintenance requirements.
(n)
Creation/protection of aquatic and wildlife habitat.
(o)
Recreational value.
(p)
Enhancement of aesthetic and property value.
(2)
To accomplish the above, the applicant shall submit original
and innovative designs to the Borough for review and approval. Such
designs may achieve the water quality objectives through a combination
of BMPs (best management practices).
[3]
Editor's Note: Appendix E is included at the end of this chapter.
D.
Groundwater recharge (infiltration).
(1)
Infiltration BMPs shall meet the following minimum requirements: Regulated activities will be required to recharge (infiltrate) a portion of the runoff created by the development as part of an overall stormwater management plan designed for the site. The volume of runoff to be recharged shall be determined from § 153-702D(1)(b)[1] or [2] depending upon demonstrated site conditions.
(a)
Infiltration BMPs intended to receive runoff from developed
areas shall be selected based on suitability of soils and site conditions
and shall be constructed on soils that have the following characteristics:
[1]
A minimum depth of 24 inches between the bottom of the BMP and
the limiting zone.
[2]
An infiltration and/or percolation rate sufficient to accept
the additional stormwater load and drain completely as determined
by field tests conducted by the applicant's design professional.
[3]
The recharge facility shall be capable of completely infiltrating
the recharge volume within four days (96 hours).
[4]
Pretreatment shall be provided prior to infiltration.
[5]
The requirements for recharge are applied to all disturbed areas,
even if they are ultimately to be an undeveloped land use such as
grass, since studies have found that compaction of the soils during
disturbance reduces their infiltrative capacity.
(b)
The recharge volume (Re) shall be computed by first obtaining the infiltration requirement using methods in either section § 153-702D(1)(b)[1] or [2] then multiplying by the total proposed impervious area. The overall required recharge volume for a site is computed by multiplying total impervious area by the infiltration requirement.
[1]
NRCS Curve Number Equation. The following criteria shall apply.
|
The NRCS runoff shall be utilized to calculate infiltration
requirements (P) in inches.
| |
|
For zero runoff: P = I (Infiltration) = (200/CN) - 2 Equation:
702.1
|
|
Where:
| ||||
|---|---|---|---|---|
|
P
|
= I =
|
infiltration requirement (inches)
| ||
|
CN
|
=
|
SCS(NRCS) curve number of the existing conditions contributing
to the recharge facility
| ||
|
This equation can be displayed graphically in, and the infiltration
requirement can also be determined from, Figure 702-1.
| |
|
The recharge volume (Rev) required would
therefore be computed as:
| |
|
Rev = I*impervious area (SF)/12 = Cubic
Feet (CF) Equation: 702.2
|
[2]
Annual recharge water budget approach. It has been determined that infiltrating 0.5 inch of runoff from the impervious areas will aid in maintaining the hydrologic regime of the watershed. If the goals of § 153-702D(1)(b)[1] cannot be achieved, then 0.5 inch of rainfall shall be infiltrated from all impervious areas, up to an existing site conditions curve number of 77. Above a curve number of 77, Equation 702.1 or the curve in Figure 702-1 should be used to determine the infiltration requirement.
|
Where:
| ||||
|---|---|---|---|---|
|
I
|
=
|
0.5 inch
| ||
|
The recharge volume (Rev) required would
therefore be computed as:
| |
|
Rev = I*percent impervious area (SF)/12
= (CF)
| |
|
The recharge values derived from these methods are the minimum
volumes the applicant must control through an infiltration/recharge
BMP facility. However, if a site has areas of soils where additional
volume of infiltration can be achieved, the applicant is encouraged
to recharge as much of the stormwater runoff from the site as possible.
|
|
Figure 702-1
Infiltration Requirement Based Upon NRCS Curve Number
|
(2)
The general process for designing the infiltration BMP shall
be as follows: A detailed soils evaluation of the project site shall
be required to determine the suitability of recharge facilities. The
evaluation shall be performed by a qualified applicant and, at a minimum,
address soil permeability, depth to bedrock, and subgrade stability.
(a)
Analyze hydrologic soil groups as well as natural and man-made
features within the watershed to determine general areas of suitability
for infiltration practices.
(b)
Provide field tests, such as double ring infiltration tests
at the level of the proposed infiltration surface to determine the
appropriate hydraulic conductivity rate.
(c)
Design the infiltration structure for the required storm volume
based on field determined capacity at the level of the proposed infiltration
surface.
(d)
Where the recharge volume requirement cannot be physically accomplished
due to the results of the field soils testing, supporting documentation
and justification shall be supplied to the municipality with the drainage
plan.
(e)
If on-lot infiltration structures are proposed by the applicant's
design professional, it must be demonstrated to the municipality that
the soils are conducive to infiltration on the lots identified.
(3)
Extreme caution shall be exercised where infiltration is proposed
in geologically susceptible areas such as strip mine or limestone
areas. Extreme caution shall also be exercised where salt or chloride
would be a pollutant since soils do little to filter this pollutant
and it may contaminate the groundwater. Extreme caution shall be exercised
where infiltration is proposed in source water protection areas. The
qualified design professional shall evaluate the possibility of groundwater
contamination from the proposed infiltration/recharge facility and
perform a hydrogeologic justification study if necessary. The infiltration
requirement in high quality/exceptional value waters shall be subject
to the DEP's Title 25:, Chapter 93, Antidegradation Regulations.
The Borough may require the installation of an impermeable liner in
BMP and/or detention basins where the possibility of groundwater contamination
exists. A detailed hydrogeologic investigation may be required by
the Borough.
(4)
The Borough shall require the applicant to provide safeguards
against groundwater contamination for uses which may cause groundwater
contamination, should there be a mishap or spill.
(5)
Recharge/infiltration facilities shall be used in conjunction
with other innovative or traditional BMPs, stormwater control facilities,
and nonstructural stormwater management alternatives.
E.
Stream bank erosion requirements.
(1)
In addition to the water quality volume, to minimize the impact
of stormwater runoff on downstream streambank erosion, the requirement
is to design a BMP to detain the post-development two-year, twenty-four-hour
design storm to the pre-development one-year flow using the SCS Type
II distribution. Additionally, provisions shall be made (such as adding
a small orifice at the bottom of the outlet structure) so that the
post-development one-year storm takes a minimum of 24 hours to drain
from the facility from a point where the maximum volume of water from
the one-year storm is captured (i.e., the maximum water surface elevation
is achieved in the facility).
(2)
Release of water can begin at the start of the storm (i.e.,
the invert of the water quality orifice is at the invert of the facility).
The design of the facility shall consider and minimize the chances
of clogging and sedimentation. Orifices smaller than three inches'
diameter are not recommended. However, if the design engineer can
provide proof that the smaller orifices are protected from clogging
by use of trash racks, etc., smaller orifices may be permitted.
(3)
In "no detention" areas (District C) only, the objective is
not to attenuate the larger storms. This can be accomplished by configuration
of the outlet structure not to control the larger storms, or by a
bypass or channel to divert only the two-year flood into the basin
or divert flows in excess of the two-year storm away from the basin.
F.
Stormwater management districts.
(1)
Delaware River South watershed has been divided into stormwater
management districts as shown on the Watershed Map in Appendix D.[4] In addition to the requirements specified below, the water quality (§ 153-702C), groundwater recharge (§ 153-702D), and streambank erosion (§ 153-702E) requirements shall be implemented.
[4]
Editor's Note: Appendix D is included at the end of this chapter.
(2)
Standards for managing runoff from each subarea in the Delaware
River South watershed is shown below. Development sites located in
each of the A, B, or C Districts must control post-development runoff
rates to pre-development runoff rates for the design storms as follows:
|
District
|
Design Storm Post-Development
|
Design Storm Pre-Development
| |
|---|---|---|---|
|
A
|
2-year
|
1-year
| |
|
5-year
|
5-year
| ||
|
10-year
|
10-year
| ||
|
25-year
|
25-year
| ||
|
50-year
|
50-year
| ||
|
B
|
2-year
|
1-year
| |
|
5-year
|
2-year
| ||
|
10-year
|
5-year
| ||
|
25-year
|
10-year
| ||
|
50-year
|
50-year
| ||
|
C*
|
2-year
|
1-year
| |
|
5-year
|
2-year
|
|
NOTES:
| ||
|---|---|---|
|
*
|
In District C, development sites which can discharge directly to the Delaware River South main channel or major tributaries or indirectly to the main channel through an existing stormwater drainage system (i.e., storm sewer or tributary) may do so without control of post-development peak rate of runoff greater than the five-year storm. Sites in District C will still have to comply with the groundwater recharge criteria (§ 153-702D), the water quality criteria (§ 153-702C), and streambank erosion criteria (§ 153-702E). If the post-development runoff is intended to be conveyed by an existing stormwater drainage system to the main channel, assurance must be provided that such system has adequate capacity to convey the flows greater than the two-year pre-development peak flow or will be provided with improvements to furnish the required capacity. When adequate capacity of a downstream system does not exist and will not be provided through improvements, the post-development peak rate of runoff must be controlled to the pre-development peak rate as required in District A provisions (i.e., ten-year post-development flows to ten-year pre-development flows) for the specified design storms.
| |
G.
Stormwater management district implementation provisions (performance
standards).
(1)
General. Post-development peak rates of runoff from any regulated
activity shall meet the peak release rates of runoff prior to development
for the design storms specified on the Stormwater Management District
Watershed Map (Appendix D[5]) and § 153-702B of this chapter.
[5]
Editor's Note: Appendix D is included at the end of this chapter.
(2)
District boundaries. The boundaries of the stormwater management
districts are shown on an official stormwater district map that is
available for inspection at the Borough office. A copy of the map
at a reduced scale is included in this chapter, Appendix D. The exact
location of the stormwater management district boundaries, as they
apply to a given development site, shall be determined by mapping
the boundaries using the two-foot topographic contours (or most accurate
data required) provided as part of the drainage plan.
(3)
Sites located in more than one district. For a proposed development site located within two or more stormwater management district category subareas, the peak discharge rate from any subarea shall be the pre-development peak discharge for that subarea as indicated in § 153-702B. The calculated peak discharges shall apply regardless of whether the grading plan changes the drainage area by subarea. An exception to the above may be granted if discharges from multiple subareas recombine in proximity to the site. In this case, peak discharge in any direction may be a one-hundred-percent release rate, provided that the overall site discharge meets the weighted average release rate.
(4)
Off-site areas. Off-site areas that drain through a proposed
development site are not subject to release rate criteria when determining
allowable peak runoff rates. However, on-site drainage facilities
shall be designed to safely convey off-site flows through the development
site.
(5)
Site areas. Where the area of a site being impacted by a proposed
development activity differs significantly from the total site area,
only the proposed impact area utilizing stormwater management measures
shall be subject to the management district criteria. Unimpacted or
undisturbed areas that do flow into or are bypassing the stormwater
management facilities would not be subject to the management district
criteria.
(6)
No-harm option. For any proposed development site not located in a provisional direct discharge district, the applicant has the option of using a less restrictive runoff control (including no detention) if the applicant can prove that no harm would be caused by discharging at a higher runoff rate than that specified by this chapter. The no-harm option is used when an applicant can prove that the post-development hydrographs can match pre-development hydrographs, or if it can be proved that the post-development conditions will not cause increases in peaks at all points downstream. Proof of no harm would have to be shown based upon the following downstream impact evaluation which shall include a downstream hydraulic capacity analysis consistent with § 153-702G(7) to determine if adequate hydraulic capacity exists. The applicant shall submit to the Borough this evaluation of the impacts due to increased downstream stormwater flows in the watershed.
(a)
The downstream impact evaluation shall include hydrologic and
hydraulic calculations necessary to determine the impact of hydrograph
timing modifications due to the proposed development upon a dam, highway,
structure, natural point of restricted streamflow, or any stream channel
section, established with the concurrence of the Borough.
(b)
The evaluation shall continue downstream until the increase
in flow diminishes due to additional flow from tributaries and/or
stream attenuation.
(c)
The peak flow values to be used for downstream areas for the
design return period storms (two-, five-, ten-, twenty-five-, fifty-,
and one-hundred-year) shall be the values from the calibrated model
for the Delaware River South watershed. These flow values can be obtained
from the watershed plan.
(d)
Applicant-proposed runoff controls that would generate increased peak flow rates at storm drainage problem areas would, by definition, be precluded from successful attempts to prove no-harm, except in conjunction with proposed capacity improvements for the problem areas consistent with § 153-702G(7).
(e)
Financial considerations shall not constitute grounds for granting
a no-harm exemption.
(f)
Capacity improvements may be provided as necessary to implement
the no-harm option which proposes specific capacity improvements to
provide that a less stringent discharge control would not create any
harm downstream.
(7)
Downstream hydraulic capacity analysis. Any downstream capacity
hydraulic analysis conducted in accordance with this chapter shall
use the following criteria for determining adequacy for accepting
increased peak flow rates:
(a)
Natural or man-made channels or swales must be able to convey
the increased runoff associated with a one-and-half-year return period
event within their banks at velocities consistent with protection
of the channels from erosion. Acceptable velocities shall be based
upon criteria included in the Department of Environmental Protection's
Erosion and Sediment Pollution Control Program Manual.
(b)
Natural or man-made channels or swales must be able to convey
increased twenty-five-year return period runoff without creating any
hazard to persons or property.
(c)
Culverts, bridges, storm sewers or any other facilities which
must pass or convey flows from the tributary area must be designed
in accordance with the Department of Environmental Protection's
Chapter 105 regulations (if applicable) and, at minimum, pass the
increased twenty-five-year return period runoff.
(8)
Regional detention alternatives. For certain areas within the
study area, it may be more cost effective to provide one control facility
for more than one development site than to provide an individual control
facility for each development site. The initiative and funding for
any regional runoff control alternatives are the responsibility of
prospective applicants. The design of any regional control basins
must incorporate reasonable development of the entire upstream watershed.
The peak outflow of a regional basin would be determined on a case-by-case
basis using the hydrologic model of the watershed consistent with
protection of the downstream watershed areas. "Hydrologic model" refers
to the calibrated model as developed for the stormwater management
plan. It is a requirement that, even if regional basins are proposed
for the water quantity control, that the water quality, streambank
erosion and recharge criteria be accomplished on site, or as close
to the source of the runoff as possible.
H.
Design criteria for stormwater management facilities.
(1)
Any stormwater facility located on state highway rights-of-way
shall be subject to approval by the Pennsylvania Department of Transportation
(PennDOT).
(2)
Any stormwater management facility (i.e., detention basin) designed
to store runoff and requiring a berm or earthen embankment required
or regulated by this chapter shall be designed to provide an emergency
spillway to handle flow up to and including the one-hundred-year post-development
conditions. The height of embankment must be set as to provide a minimum
1.0 foot of freeboard above the maximum pool elevation computed when
the facility functions for the one-hundred-year post-development inflow.
Should any stormwater management facility require a dam safety permit
under Title 25, Environmental Protection, Chapter 105, Dam Safety
and Waterway Management, the facility shall be designed in accordance
with Chapter 105 and meet the regulations of Chapter 105 concerning
dam safety which may be required to pass storms larger than the one-hundred-year
event.
(3)
Any facilities that constitute water obstructions (e.g., culverts,
bridges, outfalls, or stream enclosures), and any work involving wetlands
as directed in DEP Chapter 105 regulations (as amended or replaced
from time to time by DEP), shall be designed in accordance with Chapter
105 and will require a permit from DEP. Any other drainage conveyance
facility that does not fall under Chapter 105 regulations must be
able to convey, without damage to the drainage structure or roadway,
runoff from the twenty-five-year design storm with a minimum 1.0 foot
of freeboard measured below the lowest point along the top of the
roadway. Roadway crossings located within designated floodplain areas
must be able to convey runoff from a one-hundred-year design storm
with a minimum 1.0 foot of freeboard measured below the lowest point
along the top of the roadway. Any facility that constitutes a dam
as defined in DEP Chapter 105 regulations may require a permit under
dam safety regulations. Any facility located within a PennDOT right-of-way
must meet PennDOT minimum design standards and permit submission requirements.
(4)
Any drainage conveyance facility and/or channel that does not
fall under Chapter 105 regulations, must be able to convey, without
damage to the drainage structure or roadway, runoff from the ten-year
design storm. Conveyance facilities to or exiting from stormwater
management facilities (i.e., detention basins) shall be designed to
convey the design flow to or from that structure. Roadway crossings
located within designated floodplain areas must be able to convey
runoff from a one-hundred-year design storm.
(5)
Storm sewers must be able to convey post-development runoff
from a one-hundred-year design storm without surcharging inlets, where
appropriate.
(6)
Adequate erosion protection shall be provided along all open
channels, and at all points of discharge.
(7)
The design of all stormwater management facilities shall incorporate
sound engineering principles and practices. The Borough shall reserve
the right to disapprove any design that would result in the creation,
exacerbation, or continuation of an adverse hydrologic or hydraulic
condition within the watershed.
(8)
On-lot drainage swales shall be designed to provide positive
conveyance of surface water from the individual lot. Each swale shall
convey stormwater from the lot to a storm sewer system, street, open
space area, or stormwater management easement.
(9)
Drainage swales necessary to control surface drainage between
lots shall be centered about the common property line.
(10)
Storm drainage system requirements.
(a)
Any proposed storm drainage plans which affect the drainage
basin in any stream or watercourse shall be approved by the Division
of Dams and Waterway Management of the Pennsylvania Department of
Environmental Protection in accordance with the Title 72, Chapter
105, as amended.
(b)
Storm sewers, culverts and related installations shall be provided
to permit the flow of natural watercourses, to ensure the drainage
of all low points (except in protected wetlands) on the subdivided
lots or developed land areas and along the line of streets, and to
intercept stormwater runoff along the streets at intervals related
to the extent and grade of the area drained. The system shall also
be designed to accommodate or receive and discharge all runoff from
adjacent upstream properties. Where adequate existing storm sewers
are readily accessible, the developer must connect new stormwater
facilities to the existing system.
(c)
Flood protection. No stormwater runoff or natural drainage water
shall be so diverted as to overload existing drainage systems, or
create flooding or the need for additional drainage structures on
other private property owners. The developer shall indemnify and/or
hold harmless the Borough against any claim of damage from any downstream
property owners that may result from the proposed development.
(d)
Whenever the location of concentrated runoff from a site is
changed due to development, the developer must secure written approval
from any adjacent downstream property owners. The developer shall
indemnify and/or hold harmless the Borough against any claim of damage
from any downstream property owners that may result from the proposed
development.
(e)
Scour and erosion prevention. In areas in which the street curbs
are not required by either this chapter or by the Borough, drainage
may be accomplished by natural or artificial swales and culverts.
Special structures, such as check dams, drop outlets, concrete flow
channels, or other energy-dissipating structures, rip-rap or nondegradable
geotextile linings, may be required to prevent scour or erosion in
locations with large runoff quantities or steep slopes. Bituminous
paved swales will not be permitted.
(f)
All proposed streets shall be designed so as to discharge surface
water from their rights-of-way. Storm drainage improvements as deemed
necessary by the Borough shall be required along all existing streets
on which a subdivision or land development abuts.
(g)
Design criteria. Unless a more conservative design is required
by another regulation, or is required because of conditions particular
to an individual development, the following storm criteria shall be
used to design storm collection and conveyance systems.
|
Design Storm Return
(years)
| ||
|---|---|---|
|
Fixed pipe
|
10
| |
|
Total conveyance
|
100
|
(h)
Design preparation. Designs of storm drainage systems shall
be prepared by a licensed professional engineer. Complete detail calculations
shall be submitted to the Borough for review. Calculations shall cover
the entire drainage basin involved, including consideration of areas
outside the proposed subdivision or developed land areas.
(i)
Setback to boundaries. No piped storm sewer system outlet, detention
basin, or energy dissipation structure shall discharge closer than
20 feet from the boundary of any drainage easement under the control
of the developer or which may be utilized by the developer, so as
to allow for adequate space for stormwater dissipation in vegetated
land areas controlled by or available to the developer and/or to allow
adequate space for equipment access for future maintenance.
(11)
Collection system design.
(a)
The collection system shall be designed by the Rational Method
of Design in accordance with American Society of Civil Engineers Manual
No. 37, dated 1969, as amended, except where noted, using the formula
Q = CiA, unless otherwise approved by the Borough.
[1]
Capacity. "Q" is the required capacity in cubic feet per second
for the collection system at the point of design.
[2]
Runoff coefficient. "C" is the runoff coefficient applicable
to the entire drainage area. It shall be based on consideration of
soil conditions, average slope of the drainage area and the ultimate
development of the entire drainage area according to Comprehensive
Plans. For the various types of development, the runoff coefficient
shall be determined in accordance with Chapter 4, Section B., Rational
Method, of Manual No. 37, unless sufficient engineering data has been
presented to the Borough Engineer by the developer, which information
in the judgment of the Borough Engineer is sufficient to warrant the
use of an alternate runoff coefficient.
[3]
Rainfall intensity formula. "i" is the rainfall intensity in
inches per hour and shall be determined from rainfall intensity charts
for this area, based on time of concentrations, including overland
flow time, Manning's Formula for channelized flow time and pipe
flow time. The design rainfall frequency shall be taken from the PennDOT
Intensity-Duration-Frequency Field Manual, Region 5.
[a]
A five-minute storm duration shall be used if the
duration does not result in a maximum expected discharge that exceeds
the capacity of a thirty-inch pipe.
[b]
If a five-minute storm duration results in a pipe
size exceeding 30 inches, the time of concentration approach shall
be used in determining storm duration.
[c]
If a five-minute storm duration results in a pipe
size exceeding 30 inches, within any run of pipe, the time of concentration
approach may be used for sizing of pipes from that point on by adjusting
the time of concentration.
[4]
Drainage area. "A" is the drainage area, in acres, tributary
to the point of design, and shall include areas tributary from outside
sources as well as from within the subdivision or developed land areas
itself.
(b)
Collection system standards.
[1]
Curb inlets. Curb inlets shall be located at curb tangents on
the uphill side of street intersection, and at intervals along the
curbline to control the maximum amount of encroachment of runoff on
the roadway pavement so that same does not exceed 1/2 of the traveled
lane width during the design storm event. Design and location of curb
inlets shall be approved by the Borough.
[2]
State approvals. Drainage structures that are located on state
highway rights-of-way shall be approved by the Pennsylvania Department
of Transportation, and a copy of the highway occupancy permit shall
be submitted to the Borough.
[3]
Pipe materials. All storm piping shall be Class III reinforced
concrete pipe, except when pipe class and strength is required to
be increased in accordance with PennDOT specifications. Piping shall
be saw-cut at ends, as needed, and not hammered or broken. All pipe
joints and lift holes must be mortared.
[4]
Minimum pipe size. Minimum pipe size shall be 15 inches.
[5]
Inlet and manhole construction. Inlet and manhole castings and
concrete construction shall be equivalent to Pennsylvania Department
of Transportation design standards.
[6]
Roof drainage. Stormwater roof drains and pipes shall not discharge
water over sidewalks or walkways.
[7]
Open-end pipes must be fitted with concrete endwalls or wind
walls in accordance with PennDOT standards.
[8]
Open culvert endwalls or wing walls for pipes larger than 18
inches in diameter and longer than 60 feet in length shall be fitted
with durable protective grates. Design of protective grates is subject
to approval by the Borough.
[9]
Flow velocity. Storm drains shall be designed to produce a minimum
velocity of 3.0 feet per second when flowing full. The maximum permissible
velocity shall be 15.0 feet per second. However, in no case shall
the pipe slope be less than 0.5%.
[10]
Inlets and manholes shall be spaced at intervals
not exceeding 300 feet, and shall be located wherever branches are
connected or sizes are changes, and wherever there is a change in
alignment or grade. For drainage lines of at least 36 inches diameter,
inlets and manholes may be spaced at intervals of 400 feet. Manholes
shall be equipped with open grate lids.
[11]
Inlets shall be located to intercept concentrated
runoff prior to discharge over public/private rights-of-way, sidewalks,
streets, and driveways.
[12]
The capacity of all inlets shall be based on a
maximum surface flow to the inlet of 4.0 cubic feet per second, calculated
based on the design storm event. The maximum flow to inlets located
in low points (such as sag vertical curves) shall include the overland
flow directed to the inlet as well as all bypass runoff from upstream
inlets. The bypass flow from upstream inlets shall be calculated using
inlet efficiency curves included in PennDOT Design Manual Part 2,
latest edition. If the surface flow to an inlet exceeds 4.0 cubic
feet per second, additional inlets shall be provided upstream of the
inlet, to intercept the excessive surface flow.
[13]
A minimum drop of two inches shall be provided
between the inlet and outlet pipe invert elevations within all inlets
and manholes. When varying pipe sizes enter an inlet or manhole, the
elevation of the crown of all pipes shall be matched.
[14]
Storm sewer pipes shall have a minimum of 12 inches
of cover over the bell of the pipe, and in no case shall any part
of the pipe project into the road subbase or curb. Where cover is
restricted, equivalent pipe arches may be specified in lieu of circular
pipe.
[15]
The capacity of all storm sewer pipes shall be
calculated utilizing the Manning Equation for open channel flow as
applied to closed conduit flow. The Manning's roughness coefficient
shall be 0.13 for all concrete pipe. In cases where pressure flow
may occur, the hydraulic grade line shall be calculated throughout
the storm sewer system to verify that at least one foot of freeboard
will be provided in all inlets and manholes for the design storm event.
[16]
Culverts shall be designed based on procedures
contained in Hydraulic Design of Highway Culverts, HDS No. 5, U.S.
Department of Transportation, Federal Highway Administration.
[17]
Storm sewer structures (i.e., endwalls, inlets,
end sections, etc.) may not be located on top of or within 10 feet
of electric, water, sanitary sewer, and gas services and/or mains,
unless approval is received from the Borough, and from the authority
of utility having jurisdiction over same.
[18]
Storm sewer pipes must be oriented at right angles
to electric, water, sanitary sewer, and gas utilities when crossing
above or beneath same. Crossing angles of less than 90° will only
be permitted at the discretion of the Borough Engineer. When skewed
crossings are permitted, interior angles between alignment of the
storm sewer pipe and utility may not be less than 45°. Vertical
and horizontal design of storm sewers must be linear.
[19]
Where a public storm sewer system is not located
within a right-of-way, or dedicated public property, a twenty-foot-wide
easement shall be established to encompass the storm sewer system.
For multiple pipes or utilities, the width of the easement shall be
a minimum of 30 feet.
(c)
Open swales and gutters. Open swales shall be designed on the
basis of Manning's Formula as indicated for collection systems
with the following considerations:
[1]
Roughness coefficient. The roughness coefficient shall be 0.040
for earth swales.
[2]
Bank slopes. Slopes for swale banks shall not be steeper than
one vertical to three horizontal.
[3]
Flow velocity. Design velocity in grass or vegetated swales
shall not exceed four feet per second.
[4]
To minimize sheet flow of stormwater across lots located on
the lower side of roads or streets, and to divert flow away from building
areas, the cross section of the street as constructed shall provide
for parallel ditches or swales or curbing on the lower side which
shall discharge only at drainage easements, unless otherwise approved
by the Borough.
[5]
Gutters and swales adjacent to road paving shall be permitted
to carry a maximum flow of five cubic feet per second prior to discharge
away from the street surface, unless it is proven to the satisfaction
of the Borough by engineering calculations that the road slopes or
other factors would allow higher gutter or swale capacity.
[6]
Flows larger than those permitted in gutters and roadside swales
may be carried in swales outside the required road right-of-way in
separate drainage easements, or may be carried in pipes or culverts
inside or outside the required road right-of-way.
[7]
Swales shall be stabilized with vegetation or other materials,
approved by the Borough, to prevent erosion.
[8]
Swales shall be provided with underdrains as deemed necessary
by the Borough should overland seepage result in potential maintenance
problems for same. Underdrains must discharge into a natural drainage
channel or storm sewer system.
(d)
Bridges and culverts. Bridges and culverts shall be designed
in accordance with Pennsylvania Department of Transportation construction
standards. Separate design plans and specifications shall be required
for each bridge and culvert which plans and specifications shall be
subject to review and approval by the Borough.
[1]
Calculation methodology. Stormwater runoff from all development
sites shall be calculated using either the Rational Method or a soil
cover complex methodology.
I.
Any stormwater runoff calculations shall use a generally accepted
calculation technique that is based on the NRCS Soil Cover Complex
Method. Table 702-1 summarizes acceptable computation methods. It
is assumed that all methods will be selected by the applicant based
on the individual limitations and suitability of each method for a
particular site.
(1)
The Borough may allow the use of the Rational Method to estimate
peak discharges from drainage areas that contain less than 200 acres.
The Rational Method is recommended for drainage areas under 100 acres.
(2)
All calculations consistent with this chapter using the Soil
Cover Complex Method shall use the appropriate design rainfall depths
for the various return period storms according to the region for which
they are located as presented in Table E-1 in Appendix E[6] of this chapter. If a hydrologic computer model such as
HEC-1 or HEC-HMS is used for stormwater runoff calculations, then
the duration of rainfall shall be 24 hours. The SCS "S" curve shown
in Figure E-1, Appendix E, of this chapter shall be used for the rainfall
distribution.
[6]
Editor's Note: Appendix E is included at the end of this chapter.
(3)
For the purposes of pre-development flow rate determination,
undeveloped land shall be considered as "meadow" in good condition,
unless the natural ground cover generates a lower curve number or
Rational "C" value (i.e., forest), as listed in Table E-2 or E-3 in
Appendix E of this document. For areas of prior mining disturbance
(i.e., strip mining, mine spoil areas, etc.), the designer must first
identify in which mining affect area the site is located, using the
Management District Map in Appendix D.[7] The appropriate curve number or Rational "C" value from
Table E-2 or Table E-3 should then be used.
[7]
Editor's Note: Appendix D is included at the end of this chapter.
(4)
All calculations using the Rational Method shall use rainfall
intensities consistent with appropriate times of concentration for
overland flow and return periods from the Design Storm Curves from
Pennsylvania Department of Transportation Design Rainfall Curves (1986)
(Figures E-2 to E-3). Times of concentration for overland flow shall
be calculated using the methodology presented in Chapter 3 of Urban
Hydrology for Small Watersheds, NRCS, TR-55 (as amended or replaced
from time to time by NRCS). Times of concentration for channel and
pipe flow shall be computed using Manning's Equation.
(5)
Runoff Curve Numbers (CN) for both existing and proposed conditions
to be used in the Soil Cover Complex Method shall be obtained from
Table E-2 in Appendix E of this chapter.
(6)
Runoff coefficients (c) for both existing and proposed conditions
for use in the Rational Method shall be obtained from Table E-3 in
Appendix E of this chapter.
(7)
Where uniform flow is anticipated, the Manning Equation shall
be used for hydraulic computations, and to determine the capacity
of open channels, pipes, and storm sewers. Values for Manning's
roughness coefficient (n) shall be consistent with Table E-4 in Appendix
E of this chapter. Outlet structures for stormwater management facilities
shall be designed to meet the performance standards of this chapter
using any generally accepted hydraulic analysis technique or method.
(8)
The design of any stormwater detention facilities intended to
meet the performance standards of this chapter shall be verified by
routing the design storm hydrograph through these facilities using
the Storage Indication Method. For drainage areas greater than 200
acres in size, the design storm hydrograph shall be computed using
a calculation method that produces a full hydrograph. The Borough
may approve the use of any generally accepted full hydrograph approximation
technique that shall use a total runoff volume that is consistent
with the volume from a method that produces a full hydrograph.
|
Table 702-1
Acceptable Computation Methodologies for Stormwater Management
Plans
| |||
|---|---|---|---|
|
Method
|
Method Developed By
|
Applicability
| |
|
TR-20
(or commercial computer package based on TR-20)
|
USDA NRCS
|
Applicable where use of full hydrology computer model
is desirable or necessary
| |
|
TR-55
(or commercial computer package based on TR-55)
|
USDA NRCS
|
Applicable for land development plans within limitations
described in TR-55
| |
|
HEC-1, HEC-HMS
|
US Army Corps of Engineers
|
Applicable where use of full hydrologic computer model
is desirable or necessary
| |
|
PSRM
|
Penn State University
|
Applicable where use of a hydrologic computer model
is desirable or necessary; simpler than TR-20 or HEC-1
| |
|
Rational Method
(or commercial computer package based on Rational Method)
|
Emil Kuichling (1889)
|
For sites less than 200 acres, or as approved by the
Borough and/or Borough Engineer
| |
|
Other methods
|
Varies
|
Other computation methodologies approved by the municipality
and/or Borough Engineer
| |
J.
Erosion and sedimentation requirements.
(1)
Whenever the vegetation and topography are to be disturbed, such activity must be in conformance with Chapter 102, Title 25, Rules and Regulations, Part I, Commonwealth of Pennsylvania, Department of Environmental Protection, Subpart C, Protection of Natural Resources, Article II, Water Resources, Chapter 102, Erosion Control, and in accordance with the Bucks County Conservation District.
(2)
Additional erosion and sedimentation control design standards
and criteria that must be applied where infiltration BMPs are proposed
shall include the following:
(a)
Areas proposed for infiltration BMPs shall be protected from
sedimentation and compaction during the construction phase, so as
to maintain their maximum infiltration capacity.
(b)
Infiltration BMPs shall not be constructed nor receive runoff
until the entire contributory drainage area to the infiltration BMP
has received final stabilization.
K.
Delaware Canal areas. Development on lands adjacent to the Delaware
Canal which propose to discharge stormwater into the canal must obtain
special right-of-way approval from the Department of Conservation
and Natural Resources (DCNR). The DCNR has established a separate
policy for granting right-of-way for stormwater drainage into the
Delaware Canal, which shall be used in conjunction with this chapter.
A.
General requirements. For any of the activities regulated by this
article, the preliminary or final approval of subdivision and/or land
development plans, the issuance of any building or occupancy permit,
or the commencement of any land disturbance activity may not proceed
until the applicant or his/her agent has received written approval
of a drainage plan from the Borough.
B.
Exemptions.
(1)
Any regulated activity that meets the exception criteria in the following table is exempt from the provisions of this section. This criteria shall apply to the total development even if development is to take place in phases. The date of the Borough ordinance adoption shall be the starting point from which to consider tracts as "parent tracts" in which future subdivisions and respective impervious area computations shall be cumulatively considered. An exemption shall not relieve the applicant from implementing such measures as are necessary to protect health, safety, and property. This exemption shall not relieve the applicant from meeting the special requirements for watersheds drainage to high quality (HQ) or exceptional value (EV) waters [§ 153-702A(13)] and requirements for groundwater recharge (§ 153-702D), water quality (§ 153-702C) and streambank erosion (§ 153-702E).
|
Stormwater Management Exemption Criteria
| ||
|---|---|---|
|
Total Parcel Size
(acres)
|
Impervious Area Exemption
(square feet)
| |
|
Less than or equal to 1/4
|
1,200
| |
|
More than 1/4 to 1
|
2,500
| |
|
More than 1
|
5,000
| |
(2)
Exemptions shall be at the discretion of the Borough upon review
of site conditions, topography, soils, and other factors as desired
appropriate.
C.
Drainage plan contents. The drainage plan shall consist of all applicable
calculations, maps, and plans. A note on the maps shall refer to the
associated computations and erosion and sedimentation control plan
by title and date. The cover sheet of the computations and erosion
and sedimentation control plan shall refer to the associated maps
by title and date. All drainage plan materials shall be submitted
to the Borough in a format that is clear, concise, legible, neat,
and well organized; otherwise, the drainage plan shall be disapproved
and returned to the applicant. The following items shall be included
in the drainage plan:
(1)
General.
(a)
General description of the project.
(b)
General description of permanent stormwater management techniques,
including construction specifications of the materials to be used
for stormwater management facilities.
(c)
Complete hydrologic, hydraulic, and structural computations
for all stormwater management facilities.
(d)
An erosion and sediment control plan, including all reviews
and approvals by the Conservation District.
(e)
A general description of nonpoint source pollution controls.
(2)
Maps. Map(s) of the project area shall be submitted on twenty-four-inch
by thirty-six-inch sheets and shall be prepared in a form that meets
the requirements for recording at the offices of the Recorder of Deeds
of Bucks County. The contents of the map(s) shall include, but not
be limited to:
(a)
The location of the project relative to highways, municipalities,
or other identifiable landmarks.
(b)
Existing contours at intervals of two feet. In areas of steep
slopes (greater than 15%), five-foot contour intervals may be used.
(c)
Existing streams, lakes, ponds, or other bodies of water within
the project area.
(d)
Other physical features, including flood hazard boundaries,
sinkholes, streams, existing drainage courses, areas of natural vegetation
to be preserved, and the total extent of the upstream area draining
through the site.
(e)
The locations of all existing and proposed utilities, sanitary
sewers, and water lines within 50 feet of property lines.
(f)
An overlay showing soil names and boundaries.
(g)
Proposed changes to the land surface and vegetative cover, including
limits of earth disturbance and the type and amount of impervious
area that would be added.
(h)
Proposed structures, roads, paved areas, and buildings.
(i)
Final contours at intervals of two feet. In areas of steep slopes
(greater than 15%), five-foot contour intervals may be used.
(j)
The name of the development, the name and address of the owner
of the property, and the name of the individual or firm preparing
the plan.
(k)
The date of submission.
(l)
A graphic and written scale of one inch equals no more than
50 feet; for tracts of 20 acres or more, the scale shall be one inch
equals no more than 100 feet.
(m)
A North arrow.
(n)
The total tract boundary and size with distances marked to the
nearest foot and bearings to the nearest degree.
(o)
Existing and proposed land use(s).
(p)
A key map showing all existing man-made features beyond the
property boundary that would be affected by the project.
(q)
Location of all open channels.
(r)
Overland drainage paths.
(s)
A minimum fifteen-foot-wide access easement around all stormwater
management facilities that would provide ingress to and egress from
a public right-of-way.
(t)
The location of all erosion and sedimentation control facilities.
(u)
A note on the plan indicating the location and responsibility
for maintenance of stormwater management facilities that would be
located off site. All off-site facilities shall meet the performance
standards and design criteria specified in this chapter.
(v)
A statement, signed by the landowner, acknowledging the stormwater
management system to be a permanent fixture that can be altered or
removed only after approval of a revised plan by the municipality,
which shall be recorded with the record plan and which shall be applicable
to all future landowners.
(w)
The following signature block for the Design Engineer: (Design
Engineer), on this date (date of signature), has reviewed and hereby
certifies that the drainage plan meets all design standards and criteria
of the Delaware River South Watershed Act 167 Stormwater Management
Ordinance.
(3)
Supplemental information.
(a)
A written description of the following information shall be
submitted.
[1]
The overall stormwater management concept for the project designed in accordance with § 153-702B.
[2]
Stormwater runoff computations as specified in this chapter.
[3]
Stormwater management techniques to be applied both during and
after development.
[4]
Expected project time schedule.
[5]
Development stages (project phases) if so proposed.
(b)
A soil erosion and sedimentation control plan, where applicable,
including all reviews and approvals, as required by DEP.
(c)
A geologic assessment of the effects of runoff on sinkholes
as specified in this chapter.
(d)
The effect of the project (in terms of runoff volumes and peak
flows) on adjacent properties and on any existing municipal stormwater
collection system that may receive runoff from the project site.
(e)
A declaration of adequacy and highway occupancy permit from
the PennDOT district office when utilization of a PennDOT storm drainage
system is proposed.
(4)
Stormwater management facilities.
(a)
All stormwater management facilities must be located on a plan
and described in detail.
(b)
When groundwater recharge methods such as seepage pits, beds
or trenches are used, the locations of existing and proposed septic
tank infiltration areas and wells must be shown.
(c)
All calculations, assumptions, and criteria used in the design
of the stormwater management facilities must be shown.
D.
Plan submission. For all activities regulated by this chapter, the
steps below shall be followed for submission. For any activities that
require a DEP joint permit application and are regulated under Chapter
105 (Dam Safety and Waterway Management) or Chapter 106 (Floodplain
Management) of DEP's rules and regulations, require a PennDOT
highway occupancy permit, or require any other permit under applicable
state or federal regulations, the proof of application for that, the
permit(s), shall be part of the plan. The plan shall be coordinated
with the state and federal permit process.
E.
Drainage plan review.
(1)
The Borough Engineer shall review the drainage plan for consistency
with the adopted Delaware River South Watershed Act 167 Stormwater
Management Plan. The Borough shall require receipt of a complete plan,
as specified in this chapter.
(2)
The Borough Engineer shall review the drainage plan for any
subdivision or land development against the municipal subdivision
and land development ordinance provisions not superseded by this chapter.
(3)
For activities regulated by this chapter, the Borough Engineer
shall notify the Borough, in writing, whether the drainage plan is
consistent with the stormwater management plan. Should the drainage
plan be determined to be consistent with the stormwater management
plan, the Borough Engineer will forward a review letter to the applicant
with a copy to the Borough.
(4)
Should the drainage plan be determined to be inconsistent or
noncompliant with the stormwater management plan, the Borough Engineer
will forward a letter to the applicant with a copy to the Borough
citing the reason(s) for the inconsistency or noncompliance. Any drainage
plans receiving this decision may be revised by the applicant and
resubmitted for reevaluation. The Borough will not grant approval
to the proposal until its drainage plan is deemed consistent with
this chapter.
(5)
For regulated activities specified in § 153-700D of this chapter, the Borough Engineer shall notify the Borough Zoning Officer, in writing, within a time frame consistent with the Borough Building Code and/or this chapter, whether the drainage plan is consistent with the stormwater management plan and forward a copy of the approval/disapproval letter to the applicant. Any disapproved drainage plan may be revised by the applicant and resubmitted consistent with this chapter.
(6)
For regulated activities requiring a DEP joint permit application,
the Borough Engineer shall notify DEP whether the drainage plan is
consistent with the stormwater management plan and forward a copy
of the review letter to the Borough and the applicant. DEP may consider
the Borough Engineer's review comments in determining whether
to issue a permit.
(7)
The Borough shall not approve any subdivision or land development for regulated activities specified in § 153-700D of this chapter if the drainage plan has been found to be inconsistent with the stormwater management plan, as determined by the Borough Engineer. All required permits from DEP must be obtained prior to approval of any subdivision or land development.
(8)
The Borough Zoning Officer shall not issue a building permit for any regulated activity specified in § 153-700D of this chapter if the drainage plan has been found to be inconsistent with the stormwater management plan, as determined by the Borough Engineer, or without considering the comments of the Borough Engineer. All required permits from DEP must be obtained prior to issuance of a building permit.
(9)
The applicant shall be responsible for completing record drawings
of all stormwater management facilities included in the approved drainage
plan. The record drawings and an explanation of any discrepancies
with the design plans shall be submitted to the Borough Engineer for
final approval. In no case shall the Borough approve the record drawings
until the Borough receives copies of any applicable permits approved
by PennDOT and DEP.
(10)
The Borough's approval of a drainage plan shall be valid for a period not to exceed one. This one-year time period shall commence on the date that the Borough signs the approved drainage plan. If stormwater management facilities included in the approved drainage plan have not been constructed, or if constructed, and record drawings of these facilities have not been approved within this one-year time period, then the Borough may consider the drainage plan disapproved and may revoke any and all permits. Drainage plans that are considered disapproved by the Borough shall be resubmitted in accordance with § 153-703G of this chapter.
F.
Modification of plans.
(1)
A modification to a submitted drainage plan for a development site that involves a change in stormwater management facilities or techniques, or that involves the relocation or redesign of stormwater management facilities, or that is necessary because soil or other conditions are not as stated on the drainage plan as determined by the Borough Engineer, shall require a resubmission of the modified drainage plan consistent with § 153-703D of this chapter and be subject to review as specified in § 153-703E of this chapter.
(2)
A modification to an already approved or disapproved drainage
plan shall be submitted to the Borough, accompanied by the applicable
fee. A modification to a drainage plan for which a formal action has
not been taken by the Borough shall be submitted to the Borough, accompanied
by the applicable Borough review fee.
G.
Resubmission of disapproved drainage plans. A disapproved drainage plan may be resubmitted, with the revisions addressing the Borough Engineer's concerns documented, in writing, addressed to the Borough in accordance with § 153-703D of this chapter, and distributed accordingly, and be subject to review as specified in § 153-703E of this chapter. The applicable Borough review fee must accompany a resubmission of a disapproved drainage plan.
A.
The Borough Engineer or his/her Borough assignee shall observe all
phases of the installation of the permanent stormwater management
facilities as deemed appropriate by the Borough Engineer.
B.
During any stage of the work, if the Borough Engineer determines
that the permanent stormwater management facilities are not being
installed in accordance with the approved stormwater management plan,
the Borough shall revoke any existing permits until a revised drainage
plan is submitted and approved, as specified in this chapter.
A.
General. The fee required by this chapter is the Borough review fee.
The Borough review fee shall be established by the Borough to defray
review costs incurred by the Borough and the Borough Engineer. All
fees shall be paid by the applicant.
B.
Borough drainage plan review fee. The Borough shall establish a review
fee schedule by resolution of the Borough Council based on the size
of the regulated activity and based on the Borough's costs for
reviewing drainage plans. The Borough shall periodically update the
review fee schedule to ensure that review costs are adequately reimbursed.
C.
Expenses covered by fees. The fees required by this chapter shall,
at a minimum, cover:
(1)
Administrative costs.
(2)
The review of the drainage plan by the Borough and the Borough
Engineer.
(3)
The site inspections.
(4)
The inspection of stormwater management facilities and drainage
improvements during construction.
(5)
The final inspection upon completion of the stormwater management
facilities and drainage improvements presented in the drainage plan.
(6)
Any additional work required to enforce any permit provisions
regulated by this chapter, correct violations, and ensure proper completion
of stipulated remedial actions.
A.
Performance guarantee. The applicant should provide a financial guarantee
to the Borough for the timely installation and proper construction
of all stormwater management controls as required by the approved
Delaware River South Stormwater Management Plan and this chapter equal
to the full construction cost of the required controls.
B.
Maintenance responsibilities.
(1)
The drainage plan for the development site shall contain an
operation and maintenance plan prepared by the applicant and approved
by the Borough Engineer. The operation and maintenance plan shall
outline required routine maintenance actions and schedules necessary
to ensure proper operation of the facility(ies).
(2)
The drainage plan for the development site shall establish responsibilities
for the continuing operating and maintenance of all proposed stormwater
control facilities, consistent with the following principals:
(a)
If a development consists of structures or lots that are to
be separately owned and in which streets, sewers, and other public
improvements are to be dedicated to the Borough, stormwater control
facilities may also be dedicated to and maintained by the Borough.
(b)
If a development site is to be maintained in a single ownership
or if sewers and other public improvements are to be privately owned
and maintained, then the ownership and maintenance of stormwater control
facilities may be the responsibility of the owner or private management
entity.
(3)
The Borough, upon recommendation of the Borough Engineer, shall
make the final determination on the continuing maintenance responsibilities
prior to final approval of the drainage plan. The Borough reserves
the right to accept the ownership and operating responsibility for
any or all of the stormwater management controls.
C.
Maintenance agreement for privately owned stormwater facilities.
(1)
Prior to final approval of the site's stormwater management
plan, the applicant shall sign and record the maintenance agreement
contained in Appendix F,[1] which is attached and made part hereof, covering all stormwater
control facilities that are to be privately owned.
[1]
Editor's Note: Appendix F is included at the end of this chapter.
(2)
Other items may be included in the agreement where determined
necessary to guarantee the satisfactory maintenance of all facilities.
The maintenance agreement shall be subject to the review and approval
of the Borough.
D.
Borough stormwater maintenance fund.
(1)
Persons installing stormwater management facilities and best
management practices shall be required to pay a specified amount to
the Borough stormwater maintenance fund to help defray costs of periodic
inspections and maintenance expenses. The amount of the deposit shall
be determined as follows:
(a)
If the stormwater management facilities and best management
practices are to be privately owned and maintained, the deposit shall
cover the cost of periodic inspections performed by the Borough for
a period of 10 years, as estimated by the Borough Engineer. After
that period of time, inspections will be performed at the expense
of the Borough.
(b)
If the stormwater management facilities and best management
practices are to be owned and maintained by the Borough, the deposit
shall cover the estimated costs for maintenance and inspections for
10 years. The Borough Engineer will establish the estimated costs
utilizing information submitted by the applicant.
(c)
The amount of the deposit to the fund shall be converted to
present worth of the annual series values. The Borough Engineer shall
determine the present worth equivalents, which shall be subject to
the approval of the governing body.
(2)
If a stormwater management facility and best management practices
are proposed that also serve as a recreation facility (e.g., ballfield,
lake), the Borough may reduce or waive the amount of the maintenance
fund deposit based upon the value of the land for public recreation
purpose.
E.
Plan requirements.
(1)
All plans shall include a plan note stating that the Borough
shall have the right to enter private property to inspect and repair,
if necessary, any stormwater management facility.
(2)
All plans shall note that the stormwater management facilities
are a permanent part of the development and shall not be removed,
altered, or modified.
A.
Right of entry. Upon presentation of proper credentials, duly authorized
representatives of the Borough may enter at reasonable times upon
any property within the Borough to inspect the condition of the stormwater
structures and facilities in regard to any aspect regulated by this
article.
B.
Notification. In the event that a person fails to comply with the
requirements of this article, or fails to conform to the requirements
of any permit issued hereunder, the Borough shall provide written
notification of the violation. Such notification shall set forth the
nature of the violation(s) and establish a time limit for correction
of these violation(s). Failure to comply within the time specified
shall subject such person to the penalty provisions of this article.
All such penalties shall be deemed cumulative and present by the Borough
from pursuing any and all remedies. It shall be the responsibility
of the owner of the real property on which any regulated activity
is proposed to occur, is occurring, or has occurred, to comply with
the terms and conditions of this chapter.
C.
Enforcement. The Borough is hereby authorized and directed to enforce
all of the provisions of this article. All inspections regarding compliance
with the drainage plan shall be the responsibility of the Borough
Engineer or other qualified persons designated by the Borough.
(1)
A set of design plans approved by the Borough shall be on file
at the site throughout the duration of the construction activity.
Periodic inspections may be made by the Borough or designee during
construction.
(2)
Adherence to approved plan. It shall be unlawful for any person, firm, or corporation to undertake any regulated activity under § 153-700D on any property except as provided for in the approved drainage plan and pursuant to the requirements of this chapter. It shall be unlawful to alter or remove any control structure required by the drainage plan pursuant to this article or to allow the property to remain in a condition which does not conform to the approved drainage plan.
(3)
At the completion of the project, and as a prerequisite for
the release of the performance guarantee, the applicant shall:
(a)
Provide a certification of completion from an engineer, surveyor
or other qualified person verifying that all permanent facilities
have been constructed according to the plans and specifications and
approved revisions thereto.
(b)
Provide a set of as-built (record) drawings.
(c)
After receipt of the certification by the Borough, a final inspection
shall be conducted by the Borough Engineer or designated representative
to certify compliance with this chapter.
(4)
Suspension and revocation of permits.
(a)
Any permit issued under this chapter may be suspended or revoked
by the governing body for:
[1]
Noncompliance with or failure to implement any provision of
the permit.
[2]
A violation of any provision of this chapter or any other applicable
law, ordinance, rule or regulation relating to the project.
[3]
The creation of any condition or the commission of any act during
construction or development that constitutes or creates a hazard,
nuisance, or pollution or which endangers the life or property of
others.
(b)
A suspended permit shall be reinstated by the Borough Council
when:
[1]
The Borough Engineer or his/her designee has inspected and approved
the corrections to the stormwater management and erosion and sediment
pollution control measure(s), or the elimination of the hazard or
nuisance; and/or
[2]
The Borough Council is satisfied that the violation of the ordinance,
law, or rule and regulation has been corrected.
(c)
A permit that has been revoked by the Borough Council cannot
be reinstated. The applicant may apply for a new permit under the
procedures outlined in this article.
(d)
Prior to revocation or suspension of a permit, the Borough Council
will schedule a hearing to discuss the noncompliance if there is no
immediate danger to life, public health, or property.
(5)
Occupancy permit. An occupancy permit shall not be issued unless
the certification of compliance has been secured. The occupancy permit
shall be required for each lot owner and/or applicant for all subdivisions
and land development in the Borough.
E.
Penalties.
(1)
Anyone violating the provisions of this article shall be subject
to a fine as set through adoption of a resolution by Council. Each
day that the violation continues shall be a separate offense.
(2)
In addition, the Borough, through its solicitor, may institute
injunctive, mandamus, or any other appropriate action or proceeding
at law or in equity for the enforcement of this article. Any court
of competent jurisdiction shall have the right to issue restraining
orders, temporary or permanent injunctions, mandamus, or other appropriate
forms of remedy or relief.
F.
Appeals.
(1)
Any person aggrieved by any action of Tullytown Borough or its
designee may appeal to the Tullytown Borough Zoning Hearing Board
within 30 days of that action.
(2)
Any person aggrieved by any decision of the Borough Council
may appeal to the County Court of Common Pleas of Bucks County within
30 days of the municipal decision.
[Added 11-13-2007 by Ord. No. 312]
A.
Prohibited discharges.
(1)
No person in the municipality shall allow, or cause to allow, stormwater discharges into the municipality's separate storm sewer system which are not composed entirely of stormwater, except as provided in Subsection B below, and discharges allowed under a state or federal permit.
(2)
Discharges that may be allowed based on a finding by the municipality
that the discharge(s) do not significantly contribute to pollution
to surface waters of the commonwealth are:
(a)
Discharges from fire-fighting activities.
(b)
Potable water sources, including dechlorinated water line and
fire hydrant flushings.
(c)
Irrigation drainage.
(d)
Routine external building washdown (which does not use detergents
or other compounds).
(e)
Air-conditioning condensate.
(f)
Water from individual residential car washing.
(g)
Springs.
(h)
Water from crawl space pumps.
(i)
Uncontaminated water from foundation or from footing drains.
(j)
Flows from riparian habitats and wetlands.
(k)
Lawn watering.
(l)
Pavement washwaters where spills or leaks of toxic or hazardous
materials have not occurred (unless all spill material has been removed)
and where detergents are not used.
(m)
Dechlorinated swimming pool discharges.
(n)
Uncontaminated groundwater.
(3)
In the event that the municipality determines that any of the discharges identified in § 153-708A(2) herein significantly contribute to pollution of waters of the commonwealth, or is so notified by DEP, the municipality will notify the responsible person to cease the discharge.
(4)
Upon notice provided by the municipality under § 153-708A(3) herein, the discharger will have a reasonable time, as determined by the municipality, to cease the discharge consistent with the degree of pollution caused by the discharge.
(5)
Nothing in this section shall affect a discharger's responsibilities
under state law.
B.
Prohibited connections. The following connections are prohibited, except as provided in § 153-708A(2) above:
(1)
Any drain or conveyance, whether on the surface or subsurface,
which allows any nonstormwater discharge, including sewage, process
wastewater, and washwater, to enter the separate storm sewer system,
and any connections to the storm drain system from indoor drains and
sinks; and
(2)
Any drain or conveyance connected from a commercial or industrial
land use to the separate storm sewer system, which has not been documented
in plans, maps, or equivalent records, and approved by the municipality.
C.
Roof drains.
(1)
Roof drains shall not be connected to streets, sanitary or storm
sewers or roadside ditches in order to promote overland flow and infiltration/percolation
of stormwater where advantageous to do so.
(2)
When it is more advantageous to connect directly to streets
or storm sewers, connections of roof drains to streets or roadside
ditches may be permitted on a case-by-case basis as determined by
the municipality.
(3)
Roof drains shall discharge to infiltration areas or vegetative
BMPs to the maximum extent practicable.
D.
Alteration of BMPs.
(1)
No person shall modify, remove, fill, landscape or alter any
existing stormwater control or BMP, unless it is part of an approved
maintenance program, without the written approval of the municipality.
(2)
No person shall place any structure, fill, landscaping or vegetation
into a stormwater control or BMP or within a drainage easement, which
would limit or alter the functioning of the stormwater control or
BMP, without the written approval of the municipality.
