Words and phrases used in this Part
1 shall be presumed to be used in their ordinary context unless such word or phrase is defined or interpreted differently within this section.
BOROUGH
The Borough Council or staff of Jefferson Borough.
CISTERN
A reservoir or tank for storing water.
CULVERT
A structure intended to convey runoff under an embankment,
and which is designed to take advantage of submergence to increase
capacity.
DESIGN STORM
The magnitude of precipitation from a storm event measured
in probability of occurrence (e.g., fifty-year storm) and duration
(e.g., 24 hours), and used in computing stormwater management control
systems.
DETENTION BASIN
A basin designed to retard stormwater runoff by temporarily
storing the runoff and releasing it at a predetermined rate. This
basin is designed to drain completely after a storm event.
DEVELOPMENT
The improvement or alteration of any lot, parcel, tract or
piece of land for residential, commercial, or industrial purposes
in any manner which increases the quantity of impervious material
cover, such as the construction or expansion of buildings, parking
facilities, streets, etc.
INFILTRATION STRUCTURES
A structure designed to direct runoff into the ground, e.g.,
seepage pits, seepage trenches, etc.
LAND DEVELOPMENT
Any subdivision or new construction or expansion of any residential,
commercial, industrial, accessory or other facility that creates an
additional area of impervious material on the parcel of 700 square
feet or more.
PEAK DISCHARGE
The maximum rate of flow of water at a given point and time
resulting from a predetermined storm.
PERSON
An individual, partnership, public or private association
or corporation, firm, trust, estate, municipality, governmental unit,
public utility or any other legal entity whatsoever. Whenever used
in any section prescribing or imposing a penalty, the term "person"
shall include the members of a partnership, the officers, agents and
servants of a corporation and the officers of a municipality.
RETENTION BASIN
A basin or pond containing a permanent pool of water and
designed to retard stormwater runoff by temporarily storing the runoff
and releasing it at a predetermined rate.
RUNOFF
That part of precipitation which flows over the land.
RUNOFF CHARACTERISTICS
The surface components on any watershed which, either individually
or in any combination thereof, directly affect the rate, amount and
direction of stormwater runoff. These may include, but are not limited
to, vegetation, soils, slopes and any type of man-made landscape alterations.
SCS
Soil Conservation Service, U.S. Department of Agriculture.
SEEPAGE PIT/SEEPAGE TRENCH
An area of excavated earth filled with loose stone or similar
material and into which surface water is directed for infiltration
into the ground.
STORMWATER
Drainage runoff from the surface of the land resulting from
precipitation or snow or ice melt.
SUBDIVISION
Same definition as that contained in the current Jefferson
Borough Subdivision and Land Development Ordinance.
TIME OF CONCENTRATION
The interval of time required for water from the most remote
portion of the drainage area to reach the point in question.
WATERSHEDS
Jefferson Borough Watershed Districts, as shown on a map
attached hereto and made a part hereof.
The following persons shall be exempted from
the requirements of this Part 1:
A. Any person who has secured a building permit prior
to the effective date of this Part 1.
B. Any person who applies for a building permit for a
single-family dwelling within a subdivision, which subdivision was
approved by the Borough Council after the effective date of this Part
1, subject to such conditions as may have been attached to said plan
at the time of approval.
C. Construction of sidewalks, driveways and curbing within
public rights-of-way existing and actually improved on the effective
date of this Part 1.
D. Use of land for gardening for home consumption.
E. Agriculture, when operated in accordance with a conservation
plan approved by the York County Conservation District.
Before the development of any tract, parcel
or piece of land within the Borough, each person desiring to develop
said land shall submit a stormwater management plan, to be approved
by the Borough, which will provide for the management of stormwater
on the land proposed for development. Said plan shall be submitted
at the same time as the subdivision or land development plan, if a
subdivision or land development plan is required to be submitted pursuant
to the Jefferson Borough Subdivision and Land Development Ordinance.
The plan shall be sealed by a professional engineer
or a professional surveyor. The engineer or surveyor shall certify
that the plan meets the minimum design requirements of this Part 1
and shall include the following:
A. Topographic features.
(1) The location of the project relative to highways,
municipalities or other identifiable landmarks.
(2) Contours at intervals of one foot. In areas of steep
slopes (greater than 15%), five-foot contour intervals may be used.
(3) Streams, lakes, ponds or other bodies of water within
or near the project.
(4) Other physical features, including existing drainage
swales and areas of natural vegetation to be preserved.
(5) Locations of proposed underground utilities, sewers,
and waterlines.
B. Soil series and boundaries within the area tributary
site.
C. Final topography.
(1) Changes to land surface and vegetative cover.
(2) Areas to be cut or filled.
(3) Structures, roads, paved areas and buildings.
(4) Final contours at intervals of one foot. In areas
of steep slopes (greater than 15%), five-foot contour intervals may
be used. Final contours in area of stormwater management facilities
may not exceed two-foot intervals.
D. Stormwater management controls.
(1) All stormwater management controls must be shown on
the plan and described, including:
(a)
Groundwater recharge methods, such as seepage pits, beds or trenches. The location of the proposed structure, including a detailed cross section. If these structures are proposed, the locations of septic tank infiltration areas and wells must be shown. Groundwater recharge methods must comply with the additional requirements in Subsection
F of this section.
(b)
Other control devices, such as rooftop storage,
semipervious paving materials, grass swales, parking lot ponding,
vegetated strips, detention or retention ponds, storm sewers, etc.
(c)
Basins. A cross section of the basin showing
the relationship between the existing topography and the proposed
bottom, spillway, top of embankment and the outlet structure and the
corresponding proposed finished grade elevations. A detail of the
outlet structure shall be provided, including all pertinent construction
requirements.
(d)
Schedule for installation of the control measures
and devices. In all cases, the proposed stormwater control devices
must be completed prior to the creation of additional impervious area.
(2) All calculations, assumptions and criteria used in
the design of the control device or method must be submitted with
the plan, including, but not limited to: methodology for determining
time of concentration and weighted runoff curve numbers; stage/storage/discharge
table, including sample calculations for determining discharge rates;
summary table showing predevelopment, controlled and uncontrolled
post-development peak discharge rates for all required storms; and
copies of percolation test results when required.
E. Stormwater collection system.
(1) All catch basins, pipes, swales, and other means of
conveyance of stormwater must be shown and described, including:
(a)
A plan view of the collection system showing
the location, size and material for all catch basins, ditches, swales
and pipes.
(b)
A profile of the collection system showing existing
and proposed finish grades, proposed invert elevations and slope of
each storm sewer or open channel segment.
(c)
A topographic plan showing the area tributary
to each design point in the collection system.
(2) All calculations, assumptions, and criteria used in
the design of the stormwater collection system must be submitted with
the plans.
F. Additional requirements for groundwater recharge methods.
The following requirements apply to all proposed groundwater recharge
methods of stormwater management, such as seepage pits, beds, trenches,
leaching wells and cisterns:
(1) Representative percolation tests must be made throughout
the area proposed for development. At least one percolation test must
be included in each soil series group, and at least one percolation
test must be conducted for each five lots proposed for development.
(2) Seepage pits, beds, or trenches shall not be permitted
for any development of more than five lots, without prior approval
of the Borough Council.
G. Maintenance program. A maintenance program for all stormwater management facilities must be included. This program must include the ownership of the facilities and detail the financial responsibility for any required maintenance and shall comply with the requirements of §
144-11 of this Part
1.
The stormwater collection system shall be designed
and approved based upon the following criteria:
A. General. Peak discharge shall be computed using the
rational formula:
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Q = CIA
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Where:
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Q =
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Peak discharge in cubic feet per second
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C =
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Runoff factor expressed as a percent of the
total water falling on an area
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I =
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The rate of rainfall for the time of concentration
of the drainage area in inches per hour for a given storm frequency
(rainfall intensity)
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A =
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The drainage area expressed in acres
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The runoff factor "C" is a percentage factor
which represents the proportion of the total quantity of water falling
on the area that remains as runoff.
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The runoff factors for various types of drainage
areas, as presented in Table 1, shall be used for design.
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A computation table similar to Table 2 shall
be submitted with the storm sewer design.
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Storm intensity-duration-frequency curves are
presented on Figure 1. The curves provide for variation in rainfall intensity
according to:
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(1) Storm frequency.
(a)
The following storm frequencies shall be used
for design:
[2]
Culvert cross drains: 25 years.
(b)
When a pipe or culvert is intended to convey
the discharge from a stormwater management facility, its required
capacity shall be computed by the rational method and compared to
the peak outflow from the stormwater management facility for the fifty-year
storm. The greater flow shall govern the design of the pipe or culvert.
(c)
When a pipe is part of a storm sewer system
and crosses the roadway, it shall be designed as a storm sewer with
the same design storm as the remainder of the drainage system.
(d)
Greater design frequencies may be justified
on individual projects.
(e)
A fifty-year storm frequency may be required
for design of the stormwater collection system to ensure that the
resultant stormwater runoff from the post-development storm is directed
into the management facility.
(2) Storm duration.
(a)
The time-of-concentration approach shall be
used in determining storm duration.
(b)
A minimum duration of five minutes shall be
used.
B. Inlet placement.
(1) In general, inlets shall be spaced such that, based
upon the rational method, tc = five minutes and ten-year rainfall
intensity, the area contributing to the inlet shall not produce a
peak runoff of greater than four cfs. Also, inlets shall be spaced
so that their efficiency, based upon efficiency curves published by
the Pennsylvania Department of Transportation, is not less than 65%
(Figures 2 through 6).
(2) Additional inlets shall be placed at the upper side
of street intersections to prevent stormwater from crossing an intersection.
Other devices such as high-efficiency grates or perforated pipe may
be required if conditions warrant.
C. Pipe and swale capacity. Manning's Equation shall
be used for the design of all storm sewer pipes and for open channel
design:
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Where:
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V =
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V = Velocity of the water in feet per second
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R =
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R = Hydraulic radius which is equal to the net
effective area (A) divided by the wetted perimeter (W.P.):
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A
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R =
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W.P.
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The wetted perimeter is the linear feet of the
drainage facility cross section which is wetted by the water.
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S =
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Slope of energy line (for approximation, use
water surface slope in wetted stream and stream bed slope in dry stream).
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n =
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The roughness coefficient. Roughness coefficients
are presented in Table 3.
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The maximum permitted velocity in an unlined
swale shall be 5.0 feet per second.
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D. Culverts. In all cases where drainage is picked up
by means of a headwall, and inlet or outlet conditions control, the
pipe shall be designed as a culvert. The minimum diameter of culvert
shall be 18 inches. The procedure contained in Hydraulic Engineer
Circulars No. 5 and No. 13, as prepared by the U.S. Department of
Transportation, Federal Highway Administration, Washington, D.C.,
shall be used for the design of culverts.
The plan shall be designed and approved based
upon the following criteria:
A. General. Peak discharge and runoff shall be computed
using the soil-cover complex method contained in the "Urban Hydrology
for Small Water Sheds," Technical Release No. 55, published by the
Engineering Division, Soil Conservation Service, United States Department
of Agriculture, dated January 1975, except as modified herein.
B. Outflow determination. The maximum permitted stormwater
discharge, in cubic feet per second, from any site shall not exceed
the capacity of the receiving pipe or structure, nor the calculated
peak discharge from the site at predevelopment ground cover and soil
conditions for all design storms specified below. For the purposes
of this Part 1, predevelopment ground cover conditions shall be assumed
to be "meadow," as defined in "Urban Hydrology for Small Water Sheds,"
Technical Release No. 55, published by the Engineering Division, Soil
Conservation Service, United States Department of Agriculture, dated
January 1975. The maximum permitted stormwater discharge shall be
calculated using the SCS method for twenty-four-hour rainfalls having
recurrence intervals of two, five, 10, 25 and 50 years. For the purposes
of this Part 1, the following rainfall depths shall be used for design:
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Recurrence Interval
(years)
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24-Hour Rainfall Depth
(inches)
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2
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3.1
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5
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3.9
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10
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4.8
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25
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5.3
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50
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6.1
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100
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6.8
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C. Existing runoff volume. Existing runoff volume, in inches, shall be determined using the SCS method at predevelopment conditions for the fifty-year rainfall depth listed in Subsection
B herein.
D. Future runoff volume. The future runoff volume, in inches, shall be determined using the SCS method at post-development conditions (including any future expansion) for the fifty-year rainfall depth listed in Subsection
B above.
E. Minimum required detention storage. The minimum required
detention storage shall be determined by routing the post-development
hydrograph through the stormwater management facility, using either
manual methods or computerized routing. Routing shall be based upon
the Modified Puls Method; other routing methodologies shall be subject
to the approval of the Borough Engineer.
F. Emergency spillway. Emergency spillways or overflow
structures shall be designed to pass the peak flow resulting from
a one-hundred-year twenty-four-hour design storm computed at post-development
conditions. All retention basins and detention basins shall be provided
with an emergency spillway.
G. Minimum bottom slope. All detention basins shall have
a minimum bottom slope of 2%, unless a paved low-flow channel is provided.
H. Maximum depth. The permitted depth for detention or
retention basins shall be six feet, measured from the bottom of the
emergency spillway to the lowest point in the basin.
I. Side slopes. The maximum permitted side slopes for
detention or retention basins shall be four horizontal to one vertical.
J. Location. All stormwater management facilities are
considered structures and must comply with building setback requirements.
K. Fencing. Any stormwater detention/retention facility
that is designed so that it retains water on a temporary basis, located
in or adjacent to a residential, agricultural or conservation zone,
shall be subject to the following fencing requirements:
(1) Stormwater facility must be completely surrounded
by a fence or wall of not less than four feet in height, which shall
be so constructed as not to have openings, holes or gaps larger than
two inches in any dimension (including the distance between horizontal
or vertical pickets in a picket fence).
(2) All gates or doors opening through such enclosure
shall be equipped with a self-closing and self-latching device for
keeping the gate or door securely closed at all times.
Fees covering costs to the Borough for plan
reviews, permit issuance, and inspections shall be established by
resolution of the Borough Council. No permit to begin any work on
the project shall be issued until the required fees have been paid.
A. The fees payable by an applicant shall, at a minimum,
cover:
(1) The review of the stormwater management/erosion and
sedimentation control plan.
B. In addition to the fees required in Subsections
A(1) and
(2) of this section, the applicant shall deposit with the Borough before a permit shall be issued, a sum set by resolution. The sum deposited by the applicant shall be used by the Borough to cover the following costs:
(1) The inspection of required controls and improvements
during construction;
(2) The final inspection upon completion of the controls
and improvements required in the plan; and
(3) Any additional work required to enforce the permit
provisions, correct violations, and assure the completion of stipulated
remedial actions.
C. Any additional costs incurred by the Borough in the administration of this Part
1 not paid by the applicant pursuant to Subsection
B of this section shall be charged to the applicant and shall be paid promptly by the applicant. Upon completion of the construction of the stormwater management facility and upon final approval by the Borough Engineer, any moneys in excess of Township costs or expenses deposited by the applicant pursuant to Subsection
B of this section shall be refunded to the applicant.
Any development activity conducted in violation
of the provision of this Part 1 is hereby declared to be a public
nuisance. Suits to restrain, prevent or abate violation of this Part
1 may be instituted in equity or at law by the Borough or by an aggrieved
person.
[Amended 2-2-2009 by Ord.
No. 2009-01]
Any person violating any of the terms or provisions
of this Part 1 shall be fined in a sum not exceeding $1,000 following
conviction in summary proceedings commenced by the Borough before
any District Magisterial Judge. Each day's violation shall constitute
a separate offense for the purpose of commencing summary proceedings.
Upon judgment against any person by summary conviction, or by proceedings
by summons or default of the fine imposed and costs, said person may
be sentenced to the York County jail for a period not exceeding 30
days.
Any person aggrieved by any decision of the
Borough may appeal to the Court of Common Pleas of York County, Pennsylvania,
within the time allowed by law for such an appeal.
The provisions of these regulations are intended
as a minimum standard for the protection of the public health, safety
and welfare. If the literal compliance with any mandatory provision
of these regulations is shown by the applicant, to the satisfaction
of the Borough Engineer and the Borough Council, to be unreasonable
or to cause undue hardship as it applies to a particular property,
or if the applicant shows that an alternative proposal will allow
for equal or better results, the Borough Council may grant a waiver
from such mandatory provision. However, the granting of a waiver shall
not have the effect of making null and void the intent and purpose
of this Part 1. In granting waivers, the Borough Council may impose
such conditions as will, in its judgment, secure substantially the
objectives of the standards and requirements of this Part 1.
This Part
1 is enacted by Jefferson Borough pursuant to authority vested in boroughs by the Borough Code, §§ 45101 through 48501; the terms and provisions of the Pennsylvania Municipalities Planning Code, 53 P.S. §§ 10101 through 11202, and to carry out the express intent of the Legislature of the Commonwealth of Pennsylvania as set forth in the Stormwater Management Act, No. 1978-167, 32 P.S. §§ 680.1 through 680.17, approved October 4, 1978.