[HISTORY: Adopted by the Borough Council of the Borough of
Avis 9-4-2001 by Ord. No. 236 (Ch. 26, Part 1, of the 1992 Code of Ordinances). Amendments
noted where applicable.]
A.
Short title. This chapter shall be known and may be cited as the
"Avis Borough Stormwater Management Ordinance."
B.
Authority. Act 247 of July 31, 1968, the Pennsylvania Municipalities
Planning Code, as amended,[1] has authorized that the governing body of each municipality
may regulate subdivision and land developments. In addition, Act 167
of October 4, 1978, the Storm Water Management Act,[2] authorizes the regulation of land and water use for flood
control and stormwater management purposes, imposing duties and conferring
powers on the Department of Environmental Protection, municipalities,
and counties.
C.
Purpose. This chapter is enacted for the following purposes:
(1)
To control accelerated runoff and erosion and sedimentation problems
at their source by regulating activities which cause such problems;
to utilize and preserve desirable existing natural drainage systems;
to encourage recharge of groundwater quality; to maintain the existing
flows and quality of streams and watercourses in the Borough; to preserve
and restore the flood-carrying capacity of streams.
(2)
To provide for the design, installation and proper maintenance of
all permanent stormwater management structures which are constructed
in the Borough.
(3)
To assure that the peak rate of stormwater runoff (peak discharge)
is no greater after development than prior to development within any
predevelopment drainage subarea.
(4)
To minimize danger to public health and safety and damages to property
by providing for management of stormwater runoff.
D.
Scope. This chapter shall apply to all land and watercourses within
the Borough in conjunction with the following activities: land development;
land disturbances and alteration; construction of additional impervious
surfaces, new structures and additions to existing structures; changes
or alterations of any watercourse or drainageway; diversion or piping
of any natural or man-made stream channel; installation of stormwater
systems or appurtenances thereto; and logging or mining operations.
E.
Relationship with other restrictions. Permits and approvals issued
pursuant to this chapter 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. If more stringent
requirements concerning regulation of stormwater, erosion and sediment
pollution control, and floodplain management are contained in the
other code, rule, act or ordinance, the more stringent regulation
shall apply.
F.
Borough liability. The degree of stormwater management sought by
the provisions of this section is considered reasonable for regulatory
purposes. This section shall not create liability on the part of the
Borough, any appointed or elected official of the Borough, the Clinton
County Conservation District, or any officer, engineer or employee
thereof for any erosion, sedimentation or flood damages that result
from reliance on this section or any administrative decision lawfully
made thereunder.
H.
References. Specific methods and publications indicated in this chapter
shall, in all cases, refer to the latest available edition and include
revisions or amendments thereto.
A.
General requirements.
(1)
From and after the date of enactment of this chapter, a stormwater
management plan and other information specified herein, shall be submitted
to the Borough for all lands subdivided or for which land development
plans are prepared after the enactment of this chapter. A stormwater
management plan and other information specified herein shall be submitted
at the same time and together with submission of a preliminary subdivision
or land development plan, along with a completed checklist supplied
by the Borough indicating the items contained within the submission.
(2)
Such plans and information shall be considered part of said zoning
and subdivision documents and shall be reviewed in accordance with
procedures established thereunder. Preliminary approval or final approval
of a subdivision or land development plan, or the issuance of a zoning
permit, shall be contingent upon the submission of a stormwater management
plan and other materials specified herein, and approval of the stormwater
management plan in accordance with provisions of this chapter.
(3)
All stormwater management plans shall be submitted to the Borough
Engineer for review and comment. Such review shall include a statement
by the Borough Engineer specifying the provisions of this chapter
which have not been met by the plan as submitted.
(4)
Once a stormwater management plan has been approved together with
a subdivision or land development plan approval, or together with
the issuance of a zoning permit, said stormwater management plan shall
be valid only for the subdivision, land development or zoning permit
approval. Any further development on the lot or lots requiring a revision
of the approved plan or other construction or activities as defined
by the Borough zoning regulations shall require the submission of
a new, amended or revised stormwater management plan and other information
specified herein.
(a)
Exemptions from plan preparation. The following activities are specifically exempt from the plan preparation and submission provisions of this chapter, but remain subject to the design standards and criteria specified in § 440-3 of this chapter (which include soil erosion requirements).
[1]
Land disturbances affecting less than 5,000 square feet.
[2]
Land disturbance associated with the construction or alteration
of a single-family house or duplex, provided that the disturbance
does not alter any stormwater conditions beyond the boundaries of
the lot or alter provisions of a previously approved stormwater management
plan for the lot or encompassing subdivision.
[3]
Use of land for gardening for home consumption.
[4]
Agriculture, when operated in accordance with a conservation
plan approved by the Clinton County Conservation District.
[5]
Forest management operations which are following the Department
of Environmental Protection management practices contained in its
publication Soil Erosion and Sedimentation Control Guidelines for
Forestry and are operating under an erosion and sedimentation control
plan approved by the Clinton County Conservation District.
B.
Plan content. The content of the plans shall consist of annotated
maps, drawings, engineering plans and construction details. Said plan
shall be prepared by a registered professional land surveyor, qualified
geologist, landscape architect, architect or engineer licensed in
the Commonwealth of Pennsylvania, with said preparer's seal and
registration number affixed to the plan. Plans for tracts of less
than 20 acres shall be drawn at a scale of one inch equals no more
than 50 feet; for tracts of 20 acres or more, plans shall be drawn
at a scale of one inch equals no more than 100 feet. Plans shall be
submitted on the following sheet sizes: 18 inches by 24 inches, 24
inches by 36 inches, or 36 inches by 42 inches. All lettering shall
be drawn to a size to be legible if the plans are reduced to half
size. All sheets comprising a submission shall be in one size.
(1)
The following information, unless specifically exempted in writing
by the Borough Engineer, must be shown on the plans, prepared in a
form which meets the requirements for recording in the office of the
Recorder of Deeds of Clinton County, Pennsylvania.
(a)
The name of the proposed development and the name and address
of the owner of the property and the individual or firm preparing
the plan.
(b)
Date of submission and revision.
(c)
Graphic and written scale.
(d)
North point.
(e)
Total tract boundary with distances marked to the nearest foot
and bearings to the nearest degree and total acreage of the tract.
(f)
Key map showing all existing natural and man-made features beyond
the property boundary affected by the project and the extent of the
watershed or subbasin which drains through the project site.
(g)
Topographic conditions of both existing and proposed elevations
at intervals of two feet for land with an average natural slope of
4% or less, and at intervals of five feet for land with an average
natural slope exceeding 4%.
(h)
Drainage areas and subareas affecting the site, including areas
necessary to determine downstream impacts analysis, where required,
for proposed stormwater management facility.
(i)
Existing and proposed use, including the total area of impervious
surfaces after construction.
(j)
Existing soil types, Karst formations, floodplain boundaries,
sinkholes, undrained depressions, rock outcrops, streams, drainage
courses, wetlands based on existing sources and references, and vegetation.
(k)
Complete drainage systems for the site, including details for
construction. All existing drainage features which are to be incorporated
in the design shall be so identified. If the site is to be developed
in stages, a general drainage plan for the entire site shall be presented
with the first stage and appropriate development stages for the drainage
system shall be indicated.
(l)
Location and selected plant material used for vegetative filter paths to sinkholes, and the location of all notices to be posted, as specified in § 440-3B(4).
(m)
If stormwater management facilities are off site, a note on the plan referring to location and agreements indicating responsibility for conveyance to and maintenance of the facilities; all such off site facilities shall meet the design standards and criteria specified in § 440-3 and details of the facilities shall be included with the plan.
(n)
Proposed easement locations, including drainage, maintenance and access easements in conformance with § 440-3A(13) of this chapter.
(o)
A statement, signed by the landowner, acknowledging the stormwater
management system is to be maintained in accordance with the approved
ownership and maintenance program and remain in permanent fixture
which can be altered or removed only after approval of a revised plan
by the Borough of Avis.
(p)
The location of the permanent watercourse to which stormwater
from the site will drain.
(q)
The location of all erosion and sedimentation control facilities.
(r)
Horizontal and vertical profiles of all open channels, including
hydraulic capacity.
(s)
The following signature block for the registered professional
preparing the stormwater management plan:
"I, ____________________, hereby certify that the stormwater
management plan meets all design standards and criteria of the Avis
Borough Stormwater Management Ordinance."
(t)
The following signature block for the Borough Engineer reviewing
the stormwater management plan:
"I, ____________________, hereby certify that as the Avis Borough
Engineer, I have reviewed this Stormwater Management Plan.
C.
Supplemental information. In addition to the plan information enumerated in Subsection B, above, the following information shall be submitted:
(1)
A written description of:
(a)
The overall project concept.
(b)
Stormwater runoff computations as specified in § 440-3A(1), (2) and (3), and in accordance with criteria contained in Appendix A:[1]
[1]
Horizontal and vertical profiles of any existing watercourses,
drainageways, channels or streams, including hydrologic capacity.
[2]
Hydraulic, hydrologic and structural computations for all proposed
stormwater management facilities and measures.
[1]
Editor's Note: Said appendix is included as an attachment to this chapter.
(c)
Stormwater controls both during and after development.
(d)
Expected project time schedule.
(2)
The effect of the project on runoff volume, time to peak flow, and
rate of flow on adjacent property and upon an existing Borough stormwater
drainage system when such will be utilized.
(3)
Description of all watercourses, impoundments and wetlands on or
adjacent to the site or into which stormwater flows.
(4)
Soils investigation report, including boring logs, compaction requirements
and recommendations for construction of detention basins.
(5)
Karst features identification and analysis reports and a hydrogeologic assessment of the effects of runoff on sinkholes as specified in § 440-3A(8)(b) and B(3) and (5).
(6)
A soil erosion and sediment pollution control plan, including all
reviews and approvals, by the Pennsylvania Department of Environmental
Protection and/or Clinton County Conservation District.
(7)
All easements, deeds restrictions, covenants and maintenance measures of the system shall be outlined in an ownership maintenance program in accordance with § 440-3D of this chapter. For stormwater management systems to be dedicated to the Borough, a maintenance guarantee, as specified by the Pennsylvania Municipalities Planning Code,[2] may be required by the Borough of Avis.
[2]
Editor's Note: See 53 P.S. § 10101 et seq.
(8)
All permits required by the Pennsylvania Department of Environmental
Protection, Pennsylvania Department of Transportation and Army Corps
of Engineers and other regulatory agencies.
A.
Design standards. All subdivision and land development activities
involving an increase in impervious cover (i.e., reduction in permeability),
shall be conducted in conformance with the following standards:
(1)
Discharge rates of stormwater runoff.
(a)
After installation of impervious cover, peak discharges for
the one-, ten- and one-hundred-year frequency storms from the site
shall not exceed the respective peak discharge rates before development
for all drainage areas and subareas. Stormwater runoff shall be controlled
so that no downstream increases in flood damages or impairment of
streets and other public facilities occur. The Borough Engineer may
require that downstream impacts be evaluated at critical locations
such as dams, tributaries, existing developments, undersized culverts
and flood-prone areas. The applicant shall evaluate the effects of
the proposed plan on such critical locations by providing computed
water surface elevations (WSEL) for the ten- and one-hundred-year
storms. Methods of computation shall have prior approval of the Borough
Engineer. At such downstream critical locations, stormwater control
may be exercised by:
(b)
The Avis Borough Council and the Borough Engineer shall make
the final determination with respect to the degree of control required
for any site.
(2)
Groundwater recharge. The Borough of Avis may impose water quality
control measures in accordance with Appendix A, Section IV,[1] to protect against groundwater or surface water pollution
where the type of business or the nature of the runoff and soils underlying
stormwater control facilities would constitute a substantial risk
of contamination.
[1]
Editor's Note: Said appendix is included as an attachment to this chapter.
(3)
In establishing the watershed conditions for calculating runoff prior
to development, the following assumptions shall apply:
(a)
Woodland or meadow in good condition shall be used for all undeveloped
areas.
(b)
Average antecedent moisture conditions as defined by the Natural
Resources Conservation Service (NRCS).
(c)
Drainage area reductions equal to the area of undrained depressions
or pond factor adjustments in accordance with the NRCS TR 55 procedure
shall be applied in determining predevelopment peak discharges from
Karst geologic areas.
(4)
All plans and designs for stormwater management facilities shall
be reviewed by the Borough Engineer. Plans for facilities other than
storm sewers may determine stormwater peak discharge and runoff by
the use of the Soil Cover Complex Method as set forth in Urban Hydrology
for Small Watersheds, Technical Release No. 55 (TR 55), and Technical
Release No. 20 (TR 20), latest revisions, with specific attention
given to antecedent moisture conditions, flood routing and peak discharge
specifications included therein, and National Hydrology Engineering
Handbook, Section 4, both by United States Department of Agriculture,
Natural Resources Conservation Service (NRCS). The Borough Engineer
may permit the use of the Modified Rational Method or other methods
for calculating of the storage capacity of a stormwater control facilities.
(a)
Acceptable runoff coefficient values for use in the Rational
Method, and permissible curve numbers for TR 55, maximum velocities,
and suggested roughness coefficients and permissible velocities for
channels are identified in Tables A-2 through A-5 of Appendix A, Section
I.[2]
[2]
Editor's Note: Said appendix is included as an attachment to this chapter.
(b)
The Rational Method may be used in lieu of the Soil Cover Complex
Method to compute design flows for the sizing of storm sewers, inlets
and swales. Methods approved by the Pennsylvania Department of Transportation
and/or Environmental Protection may be used to design the waterway
areas of bridges.
(c)
Rainfall amounts for the return periods specified shall be determined
using the Pennsylvania Department of Transportation intensity-duration-frequency
curves presented in Appendix A, Section 1, as Figure A-1.[3] Rainfall duration for hydrography generation shall be
selected for the specified recurrence intervals on the basis of twice
the computed time of concentration for the given watershed and subwatersheds.
In no case shall the duration be less than one hour.
[3]
Editor's Note: Said appendix is included as an attachment to this chapter.
(d)
In order to reduce runoff volumes from developed areas and encourage
groundwater recharge, underground basin drains, infiltration trenches
and cisterns are permitted, to which roof leaders may be connected.
These drains consist of stone-filled basins which temporarily store
and release water below ground surface. Plans for such facilities
shall be submitted to the Borough for approval, and the basins shall
be used only in those areas where soils, geologic and water table
conditions permit. Performance criteria which govern the location,
design, construction and maintenance of these infiltration facilities
are contained in Appendix A, Section IV.[4] Suggested guidelines are contained in Standards and Specifications
for Infiltration Practices, Maryland Department of Natural Resources,
Water Resources administration, February 1984.
[4]
Editor's Note: Said appendix is included as an attachment to this chapter.
(5)
Stormwater management facilities and related installations shall
be provided:
(a)
To permit unimpeded flow of natural watercourses. Such flow
may be redirected as required, subject to the approval of the Department
of Environmental Protection and the Borough.
(b)
To insure adequate drainage of all low points along the curbline
of streets.
(c)
To intercept stormwater runoff along streets at intervals reasonably related to the extent and grade of the area drained, and to prevent substantial flow of water across intersections or flooded intersections during storms, in accordance with the procedures contained in Design Manual Part 2 (DM-2), Chapter 10, of the Pennsylvania Department of Transportation.
(d)
To insure adequate and unimpeded flow of stormwater under driveways
in, near or across natural watercourses or drainage swales. Suitable
pipes or other waterways shall be provided as necessary.
(e)
To properly drain stormwater runoff from all land development
projects. All lot and open areas shall be designed to drain to the
nearest practical street or drainage system, existing or proposed,
as defined by the Borough Engineer, with no impact on adjoining properties,
unless an area specifically designed for stormwater detention is provided.
(6)
Storm sewers and related installations:
(a)
Storm sewers, where required by zoning and land use densities,
shall be placed under or immediately adjacent to the roadway side
of the curb, or as directed by the Borough, when parallel to the street
within the right-of-way. When located in undedicated land, they shall
be placed within a drainage easement not less than 20 feet wide as
approved by the Borough Engineer. The use of properly designed, graded
and turfed drainage swales is encouraged in lieu of storm sewers in
commercial and industrial areas and, where approved by the Borough
Engineer, in residential areas. Such swales shall be designed not
only to carry the required discharge without excessive erosion, but
also to increase the time of concentration, reduce the peak discharge
and velocity, and permit the water to percolate into the soil, where
appropriate. Criteria related to the use and design of drainage swales
are contained in Appendix A, Section II.[5]
[5]
Editor's Note: Said appendix is included as an attachment to this chapter.
(b)
The design capacity of storm sewer and drainage swales shall
be determined in accordance with the ten-year frequency storm of the
duration equal to the time of concentration. Storm drainage systems
shall be designed without surcharging inlets to provide controlled
conveyance of the ten-year storm into a detention basin or similar
facility utilized to control the rate of runoff. Conveyance of storms
to the stormwater pond, up to and including the one-hundred-year frequency,
shall be provided so as not to endanger life or seriously damage property.
(c)
Inlet types and inlet assemblies shall conform to the Pennsylvania
Department of Transportation Standards for Roadway Construction as
approved by the Borough Engineer.
[1]
Inlets shall, at a minimum, be located at the lowest point of
street intersections to intercept the stormwater before it reaches
pedestrian crossings, or at sag points of vertical curves in the street
alignment which provide a natural point of ponding of surface stormwater.
[2]
Where the Borough deems it necessary because of special land
requirements, special inlets may be approved.
[3]
The interval between inlets collecting stormwater runoff shall
be determined in accordance with DM-2, Chapter 10, Section 5, Capacity
of Waterway Areas. In curbed sections, the maximum encroachment of
water on the roadway pavement shall not exceed half of a through traffic
lane or one inch less than the depth of curb during the ten-year design
storm of five-minute duration. Inlets shall be provided to control
the encroachment of water on the pavement. When inlets are used in
a storm system within the right-of-way limits of a street in lieu
of manholes, the spacing of such inlets shall not exceed the maximum
distance of 450 feet.
(d)
Accessible drainage structures shall be located on a continuous
storm sewer system at all vertical dislocations, at all locations
where a transition in storm sewer pipe sizing is required, at all
vertical and horizontal angle points exceeding 5°, and at all
points of convergence of two or more influent storm sewer mains. The
construction locations of accessible drainage structures shall be
as indicated on the subdivision drainage plan or area drainage plan
approved by the Borough.
(e)
When evidence available to the Borough indicates that existing storm sewers have sufficient capacity as determined by hydrograph summation and are accessible, the subdivider may connect their stormwater facilities to the existing storm sewers so long as the peak rate of discharge does not exceed the amount permitted by Subsection A(1) of this section. Facilities will be considered available even though the developer must acquire rights-of-way or easements in order to connect.
(7)
Bridges and culverts shall have ample waterway to carry expected
flows, based on a minimum storm frequency of 10 years for driveways,
25 years for local streets, 50 years for collector streets, and 100
years for arterials, or as required by the Borough Engineer. Bridge
and/or culvert construction shall be in accordance with the Pennsylvania
Department of Transportation specifications.
(a)
The design criteria contained in this section are intended for
use in conjunction with the Chapter 105 regulations of the Pennsylvania
Department of Environmental Protection entitled "Water Obstructions
and Encroachments." All information and regulations contained in Chapter
105 shall be considered to be incorporated into this section as if
reproduced in full. A DEP permit in accordance with Chapter 105 shall
be required for any obstruction or encroachment in the regulated waters
of the commonwealth, prior to the approval of the stormwater plan.
All areas of the Borough shall be classified as rural, suburban or
urban, as determined by the Borough Engineer (see DEP § 105.161[6]) for bridge and culvert designs. In the event any question
or conflict arises between this section and the DEP Chapter 105 regulations,
the design criteria contained in the DEP regulations shall govern.
[6]
Editor's Note: See 25 Pa. Code § 105.161.
(b)
Refer to Appendix A, Section II,[7] for additional design criteria.
[7]
Editor's Note: Said appendix is included as an attachment to this chapter.
(8)
Detention or retention basins for the control of stormwater peak
discharges shall meet the following requirements:
(a)
Basins shall be installed prior to or concurrent with any earthmoving
or land disturbances which they will serve. The phasing of their construction
shall be noted in the narrative and on the plan.
(b)
The design of all facilities over limestone formations shall
include measures to prevent groundwater contamination and, where required,
sinkhole formation. Soils used for the construction of basins shall
have moderate to low erodibility factors (i.e., "K" factors of 0.32
or less).
(c)
Energy dissipators and/or level spreaders shall be installed
at points where pipes or drainageways discharge to or from basins.
Generally, outlet pipes designed to carry the predevelopment one-year
storm flow will be permitted to discharge to a stream with only an
energy dissipator; discharges to drainage swales shall be spread with
a level spreader or piped to an acceptable point of discharge downstream.
(d)
Outlet structures within detention/retention basins shall be
constructed of reinforced concrete or an approved alternate. With
the exception of those openings designed to carry perennial stream
flows, design openings shall have childproof, nonclogging trash racks
over all openings 12 inches or larger in any dimension. Outlet aprons
shall be designed as level spreaders and shall extend at a minimum
to the toe of the basin slope. Where spillways will be used to control
peak discharges in excess of the ten-year storm, the control weirs
shall be constructed to withstand the pressures of impounded waters
and convey flows at computed outlet velocities without erosion.
(e)
When the Pennsylvania Department of Environmental Protection
(DEP) requires facilities to be permitted, the designer shall submit
all information to the DEP and obtain all necessary approvals and
permits. Such facilities shall not create health or sanitation problems.
Consideration shall be given to safety standards.
(f)
Downstream analysis.
[1]
Where deemed necessary by the Borough Engineer, the applicant
shall submit an analysis of the impacts of detained stormwater flows
on downstream areas within the watershed, established with the concurrence
of the Borough Engineer. The analysis shall include hydrologic and
hydraulic calculations necessary to determine the impact of peak discharge
modifications of the proposed development on critical locations such
as dams, tributaries, existing developments, undersized culverts and
flood-prone areas.
[2]
Review and comment of the analysis by the Borough Engineer of
a downstream municipality shall be obtained when stormwater management
facilities are proposed within 1,000 feet of the affected downstream
municipality.
(g)
Detention basins may be waived by the Borough, upon recommendation of the Borough Engineer, at sites in close proximity to larger receiving streams, depending on the hydrology of the watershed. This is to facilitate drainage prior to main stream flooding. It shall be incumbent upon the applicant to demonstrate that no downstream increase in stream flooding or channel erosion will result in accordance with Subsection A(8)(f), above, and that no increases in peak discharge within the receiving stream will occur as outlined under Subsection A(1).
(h)
Multiple-use basins. The design and construction of multiple-use
stormwater detention facilities are strongly encouraged. In addition
to stormwater management, facilities should, where appropriate, allow
for recreational uses, including ballfields, play areas, picnic grounds,
etc. Provisions for parking facilities within basins and permanent
wet ponds with stormwater management capabilities may also be appropriate.
Prior approval and consultation with the Borough are required before
design. Multiple-use basins should be constructed so that potentially
dangerous conditions are not created.
(i)
Multiple-development basins. Stormwater management facilities
designed to serve more than one property or development in the same
watershed are encouraged. Staged construction of existing or proposed
multiple-use detention facilities by several developers in conjunction
with watershed development is encouraged. Each developer shall be
responsible for the incremental increase in runoff generated by the
respective development and incremental construction improvements necessary
for the overall detention facility. Prior approval and consultation
with the Borough is required before design of such facilities.
(j)
Alternative detention facilities. Alternative stormwater detention
facilities, including rooftop, subsurface basins or tanks and in-pipe
detention storage, or other approved alternative designs are permitted
as determined by the Borough Engineer.
(k)
Specific criteria related to the design of detention basins
is contained in Appendix A, Section III.[8]
[8]
Editor's Note: Said appendix is included as an attachment to this chapter.
(9)
All calculations shall be submitted to the Borough Engineer on computation
sheets for approval. If the Borough Engineer determines through review
and independent computation that the size of pipes or holding pond
is insufficient, the Borough may require the developer to increase
the size of pipes or capacity of the holding pond. If the storm drainage
system design is completed on a computer installation, sufficient
supporting data shall be provided to allow comprehensive review by
Borough officials.
(10)
Off-site improvements. Any increase in runoff may require necessary
corrective measures deemed appropriate by the Borough to alleviate
any off-site drainage problem affected by the subdivision or land
development. The costs for such measures will be borne entirely by
the developer or subdivider, including deed of easement.
(11)
When the elevation of any existing or proposed entrance to a
structure, including windows, is lower than the elevation of the public
cartway serving that site, a site plan shall be prepared which includes
construction or alteration of structures and/or grading illustrating
the method to minimize the risk of flooding from drainage moving from
the public cartway.
(12)
Natural drainageways shall be utilized to the maximum extent possible in carrying stormwater runoff, provided such use remains consistent with the purpose of this chapter specified in § 440-1C.
(13)
Stormwater management facilities located outside of existing
or proposed rights-of-way shall be located within the accessible by
easements as follows:
(a)
Drainage easements.
[1]
Where a tract is traversed by a watercourse, drainageway, channel or stream, there shall be provided a drainage easement paralleling the line of such watercourse, drainageway, channel or stream. The width of the drainage easement will be adequate to preserve the unimpeded flow of natural drainage in the one-hundred-year floodplain, in accordance with computed top widths for water surface elevations determined under Subsection A(1) of this section.
[2]
Drainage easements shall provide for occasional maintenance
and for the purpose of widening, deepening, improving or protecting
such drainage facilities.
(b)
Access easements. Where proposed stormwater management facilities
are not adjacent to proposed or existing public rights-of-way or are
not accessible due to physical constraints, as determined by the Borough
Engineer, a twenty-foot-wide passable access easement specifying rights
of entry shall be provided. Access easements shall provide for vehicle
ingress and egress on grades of less than 10% for carrying out inspection
or maintenance activities.
(c)
Maintenance easements. A maintenance easement shall be provided
which encompasses the stormwater facility and appurtenances and provides
for access for maintenance purposes. The maintenance easement must
be located at least 20 feet outside of the one-hundred-year surface
elevation and the stormwater facility and appurtenances.
(d)
Easements shall stipulate that no trees, shrubs, structures,
excavation or fill be placed, and no regrading be performed within
the area of the easement without written approval from the Borough
upon review by the Borough Engineer. Upon approval of the Borough
Engineer, such landscaping may be placed in maintenance easements,
provided it does not impede access.
(e)
Whenever practicable, easements shall be parallel with and conjunction
to property lines of the subdivision.
(f)
All easement agreements shall be recorded with a reference to
the recorded easement indicated in the site plan.
B.
Sinkhole protection.
(1)
Stormwater from roadways, parking lots, storm sewers, roof drains or other concentrated runoff paths shall not be discharged directly into sinkholes without prior filtration in accordance with Subsection B(2) below.
(2)
Sinkholes capable of absorbing substantial amounts of stormwater
shall be protected by diverting such runoff around the sinkhole or,
upon recommended approval of the Borough Engineer, by planting and
maintaining a dense filter path of suitable vegetative material [refer
to Appendix A, Section V(D)[9]] in such manner and location to disperse and slow the
runoff to a sheet flow condition to promote the maximum possible filtration
and sedimentation of impurities. The filter path must be at least
100 feet in length and 20 feet in width. Ten-foot-wide filter paths
are acceptable if land slope is less than 2%. Filter paths shall be
designed and installed so that they filter sheet flow rather than
concentrated flow. If concentrated flow occurs, grading and shaping
or the use of best management practices such as grass waterways or
drop structures may be required. Sedimentation basins designed to
DEP Chapter 102 standards or permanent stormwater storage criteria,
and proposed vegetative filter paths, in conjunction with temporary
stone filter check dams, shall be installed prior to subdivision or
land development construction activities, where sinkholes are used
to accept stormwater discharges.
[9]
Editor's Note: Said appendix is included as an attachment to this chapter.
(3)
If increased runoff is to be discharged into a sinkhole, even in
filtered condition, a hydrogeologic assessment of the effects of such
runoff on the increased risk of land subsidence and adverse impacts
to existing sinkhole floodplains and groundwater quality shall be
made by a qualified professional and submitted with the stormwater
management plan. Such discharge shall be prohibited if the Borough
Engineer determines that such poses a hazard to life, property or
groundwater resources.
(4)
All sinkholes shall be posted by permanent on-site notices clearly
visible at the sinkhole prohibiting any disposal of refuse, rubbish,
hazardous wastes, organic matter or soil into the sinkhole. Rockfill
may be permitted in the sinkhole for the purpose of preventing dumping
of said materials.
(5)
To protect sensitive Karst areas, the Borough Engineer may require
basins to contain an impervious liner. The liner may be of the impervious
membrane type, placed in accordance with the manufacturer's recommendations,
or may be constructed by mixing bentonite, or an approved alternative,
with existing soil available at the site as approved by the Borough
Engineer.
C.
Erosion and sediment control.
(1)
All plans for erosion and sediment pollution control (E&SPC)
shall meet the requirements of the Clean Streams Law, Act of June
22, 1937, P.L. 1987 as amended, 35 P.S. § 691.1 et seq.,
and 25 Pa. Code § 102.1 et seq., Erosion and Sediment Control.
The Clinton County Erosion and Sedimentation Control Manual, if available,
shall be used as the basis for E&S design. The Clinton County
Conservation District has been delegated the authority by the Pennsylvania
Department of Environmental Protection to administer the Erosion and
Sediment Pollution Control Program in Clinton County. It shall be
the responsibility of the land developer to submit the E&SPC plan,
application and other necessary material to the Conservation District.
A copy of the transmittal letter shall be provided to the Borough.
Comments shall be received and E&SPC plan approval obtained from
the Conservation District prior to stormwater plan approval.
D.
Ownership and maintenance. Each stormwater management plan shall
contain provisions which clearly set forth the ownership and maintenance
responsibility of all permanent stormwater management and erosion
and sediment control facilities, including:
(1)
Description of maintenance requirements.
(2)
Establishment of suitable easements for access to all facilities by public officials, in accordance with Subsection A(1) of this section.
(3)
Identification of the responsible party or entity for ownership and
maintenance of both temporary and permanent stormwater management
erosion control facilities. In meeting this requirement, the following
options are hereby provided for upon approval by the Borough Engineer:
(a)
Facilities may be incorporated within individual lots so that
the respective lot owners will own and be responsible for maintenance
in accordance with recorded deed restriction. A description of the
facility or system and the terms of the required maintenance shall
be incorporated as part of the deed to the property.
(b)
Ownership and maintenance may be the responsibility of a property
owners' association. The stated responsibilities of the property owners'
association in terms of owning and maintaining the stormwater management
facilities shall be submitted with final plans for determination of
their adequacy, and upon their approval shall be recorded with the
approved subdivision plan among the deed records of Clinton County,
Pennsylvania. In addition, the approved subdivision plan and any deed
written from said plan for a lot or lots shown herein shall contain
a condition that it shall be mandatory for the owner or owners of
said lot to be members of said property owners association.
(c)
For stormwater management facilities that are proposed as part
of the site development plan, the developer will be required to execute
a developer agreement and a maintenance agreement with the Borough
for the construction and continued maintenance of the facilities prior
to the signature approval on the final plan. Access for inspection
by the Borough of all such facilities deemed critical to the public
welfare at any reasonable time shall be provided.
(d)
In the event the above priorities cannot be achieved, or where
it is required, the facilities may be dedicated to the Borough in
accordance with this chapter. As a condition of Borough acceptance
of said facilities, the applicant shall provide 15% of the cost of
improvements in the form of a maintenance bond, as estimated by the
applicant's registered professional and approved by the Borough
Engineer, to cover contingency maintenance costs for 18 months from
the date of stormwater management facilities acceptance of dedication.
The 15% bond shall be based on the construction costs of the detention
pond and outlet structure within the area dedicated to the Borough.
E.
Additional general criteria. Compliance with the provisions of this
chapter shall be in accordance with the following additional general
criteria:
(1)
Materials, workmanship and methods. All materials, workmanship and
methods of work shall comply with the Pennsylvania Department of Transportation
Form 408 specifications, as accepted and commonly used by the Borough,
and shall be considered to be incorporated into this section as if
copied in full. In the event a conflict arises between the requirements
or this section and the Form 408 specifications, the Borough Engineer
shall resolve the differences, and his opinion shall be binding.
(2)
Provide a set of approved stormwater management plan drawings showing
all approved revisions, and elevations and inverts to all manholes,
inlets, pipes and stormwater control facilities.
(3)
Maintenance inspections may be performed by the Borough to ensure
proper functioning of all stormwater management facilities. These
inspections may, at a minimum, be performed annually and/or following
major storm events.
(4)
Supplemental standards and criteria technical reference materials
incorporated into these controls for information and to govern the
design and hydrologic control provisions of this chapter are contained
in Appendix B.[10]
[10]
Editor's Note: Said appendix is included as an attachment to this chapter.
F.
Plan review.
(1)
The Borough Engineer shall review all aspects of the plan.
(2)
The Borough Engineer shall review the plan for any subdivision or land development against the Borough Subdivision and Land Development Ordinance (Chapter 460) provisions and the provisions of this chapter.
(3)
For activities regulated by this chapter, the Borough Engineer shall
notify the Borough, in writing, within 90 calendar days whether the
plan is consistent with this chapter. Should the plan be determined
to be consistent, the Borough Engineer or designated representative
will forward an approval letter to the Borough Secretary. Should the
plan be determined to be inconsistent with this chapter, the Borough
Engineer will forward a disapproval letter to the Borough Secretary
and developer citing the reason(s) for the disapproval. Any disapproved
plans may be revised by the developer and resubmitted consistent with
this chapter.
(4)
For activities involving the construction of new or additional impervious
or semi-impervious surfaces (driveways, parking lots, etc.) and/or
construction of new buildings or additions to existing buildings,
the Borough Engineer shall notify the Borough Building Permit Officer,
in writing, whether the plan is consistent with this chapter and forward
a copy of the approval/disapproval letter to the developer. Any disapproved
plan may be revised by the developer and resubmitted consistent with
this chapter.
(5)
For any activities requiring a Pennsylvania DEP joint permit application,
the Borough Engineer shall notify Pennsylvania DEP whether the plan
is consistent with this chapter and forward a copy of the review letter
to the Borough Secretary and the developer. Pennsylvania DEP may consider
the Borough Engineer's review comments in determining whether
to issue a permit.
(6)
The Borough of Avis shall not approve any subdivision or land development
affected by this chapter if the plan has been found to be inconsistent
with this chapter, as determined by the Borough Engineer. All required
permits from Pennsylvania DEP must be obtained prior to approval.
(7)
The Borough Building Permit Office shall not issue a building permit
for any construction of new or additional impervious or semi-impervious
surfaces and/or construction of new buildings or additions to existing
buildings if the plan is found to be inconsistent with this chapter,
as determined by the Borough Engineer or designated representative.
All required permits from Pennsylvania DEP must be obtained prior
to issuance of a building permit.
(8)
The developer shall be responsible for completing an as-built survey
of all facilities included in the plan. The as-built survey and an
explanation of any discrepancies with the design plan shall be submitted
to the Borough Engineer for final approval. In no case shall the Borough
Engineer approve the as-built survey until the Borough Engineer receives
a copy of an approved declaration of adequacy, highway occupancy permit
from the Pennsylvania Department of Transportation district office
and any applicable permits from Pennsylvania DEP.
(9)
The Borough of Avis' approval of a plan shall be valid for a period not to exceed one year. This one-year time period shall commence on the date that the Borough signs the plan. If the stormwater management facilities in the approved plan have not been constructed, or if an as-built survey of these facilities has not been approved within this one-year period, then the Borough Engineer may consider the plan disapproved and may recommend that the Borough revoke any and all permits. Plans that are considered disapproved by the Borough Engineer shall be resubmitted in accordance with Subsection H of this section.
G.
Modification of plans. A modification to a submitted drainage plan for a development site that involves a change in stormwater management facilities or techniques or that involves a relocation or redesign of stormwater management facilities, or that is necessary because soil or other conditions are not as stated on the plan (as determined by the Borough Engineer), shall require resubmission of the modified plan consistent with §§ 440-1 and 440-2 of this chapter and be subject to review as specified in Subsection F of this section. A modification to an already approved or disapproved plan shall be submitted to the Borough Engineer, accompanied by the applicable review fee. A modification to a plan for which a formal action has not been taken by the Borough Engineer shall be submitted to the Borough Engineer, accompanied by the applicable review fee.
H.
Resubmission of disapproved drainage plans. A disapproved drainage plan may be resubmitted with the revisions addressing the Borough Engineer's concerns documented, in writing, to the Borough Engineer in accordance with Subsections A through E of this section and be subject to review as specified in Subsection F of this section. The Borough Engineer's fee must accompany a resubmission of a disapproved plan.
A.
Scheduled inspections.
(1)
The Borough Engineer shall inspect all phases of the installation
of the permanent stormwater management facilities.
(2)
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 plans, the Borough of Avis
shall revoke any existing permits until a revised plan is submitted
and approved as specified in this chapter.
A.
General. The fees required by this chapter are an application fee,
Borough review fee and inspection fee. All fees shall be paid by the
applicant/developer.
B.
Borough Engineer or designated representative drainage plan review
fee. An application/review fee of $300 shall be paid by applicant/developer
at the time of submission of application. Should no application fee
accompany any application, said application shall be denied and returned
to the applicant/developer.
C.
Review and inspection fees. The review and inspection fees shall
be the actual costs incurred by the Borough of Avis for review and
inspection by its Borough Engineer. Prior to any review by the Borough
Engineer, an applicant/developer shall provide to the Borough of Avis
an amount equal to 10% of the actual cost of installation of the stormwater
drainage system(s) proposed in the application and/or plan. If actual
review and inspection costs exceed 10% of the installation cost for
said stormwater drainage system(s), applicant/developer shall be responsible
for the difference prior to final approval by the Borough of Avis
or its Engineer. Should actual costs be less than 10% of the installation
cost for any stormwater drainage system(s), the Borough of Avis shall
reimburse the applicant/developer the difference.
D.
Expenses covered by review and inspection fees. The fees required
for review and inspection cover:
(1)
The review of the plan by the Borough Engineer.
(2)
Site inspection.
(3)
Inspection of stormwater management facilities and drainage improvements
during construction.
(4)
Final inspection upon completion of the stormwater management facilities
and drainage improvements presented in the plan.
(5)
Any additional work required to enforce any permit provisions regulated
by this chapter, correct violations and assure proper completion of
stipulated remedial actions.
E.
Amendment of fee schedule. Council for the Borough of Avis may, from
time to time, by resolution, revise the application/review and inspection
fee amounts.
A.
Maintenance responsibilities.
(1)
The stormwater management plan for the development site shall contain
an operation and maintenance plan prepared by the developer and approved
by the Borough Engineer. The operation and maintenance plan shall
outline required routine maintenance actions and schedules necessary
to insure proper operation of the facility or facilities.
(2)
The stormwater management plan for the development site shall establish
responsibilities for the continuing operation and maintenance of all
proposed stormwater control facilities consistent with the following
principles:
(a)
If a development consists of structures or lots which are to
be separately owned and in which streets, sewers and other public
improvements are to be dedicated to the Borough of Avis, stormwater
control facilities should also be dedicated to and maintained by the
Borough of Avis.
(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 should be the responsibility of the owner or private management
entity.
(3)
The Council for the Borough of Avis, upon recommendation of the Borough
Engineer, shall make the final determination on the continuing maintenance
responsibilities prior to final approval of the stormwater management
plan. The Council for the Borough of Avis reserves the right to accept
the ownership and operating responsibility for any or all of the stormwater
management controls.
B.
Maintenance agreement for stormwater facilities dedicated to the
Borough of Avis. Any persons installing stormwater storage facilities
which are dedicated to and accepted by the Council for the Borough
of Avis shall pay a deposit, the amount of which shall be determined
from time to time by Borough Council, which shall cover the estimated
costs for maintenance and inspections of the facilities for 10 years.
The Borough Engineer shall establish the estimated cost utilizing
information submitted by the applicant.
C.
Maintenance agreement for privately owned stormwater facilities.
(1)
Prior to final approval of the site's stormwater management
plan, the property owner shall sign and record a maintenance agreement
covering all stormwater control facilities which are to be privately
owned. The agreement shall stipulate that:
(a)
The owner shall maintain all facilities in accordance with the
approved maintenance schedule and shall keep all facilities in a safe
and attractive manner.
(b)
The owner shall convey to the Borough of Avis easements and/or
rights-of-way to assure access for periodic inspections by the Borough
of Avis and maintenance, if required.
(c)
The owner shall keep on file with the Borough of Avis the name,
address and telephone number of the person or company responsible
for maintenance activities; in the event of a change, new information
will be submitted to the Borough of Avis within 10 days of the change.
(d)
If the owner fails to maintain the stormwater control facilities
following due notice by the Borough of Avis to correct the problem(s),
the Borough of Avis may perform the necessary maintenance work or
corrective work and the owner shall reimburse the Borough of Avis
for all costs.
(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
Solicitor and Borough Council.
A.
Right of entry.
(1)
The Borough of Avis, by its duly authorized agents, shall have the
right of access at all reasonable times to enter upon any property
within the Borough of Avis to investigate or ascertain the condition
of the subject property in regard to any aspect and regulated by this
chapter.
(2)
As used in Subsection A(1), above, "reasonable times" shall be defined as being between the hours of 9:00 a.m. and 5:00 p.m. Monday through Saturday, or whenever an emergency situation eminently dangerous to the public health, safety or welfare presents itself.
(3)
Upon the failure or refusal of any owner or occupant of property
to allow duly authorized agents of the Borough of Avis to inspect
said premises at a reasonable time to assure compliance with this
chapter, the duly authorized agents and/or law enforcement officers
of the Borough of Avis are hereby authorized to obtain a search warrant
for the inspection of said premises, pursuant to the procedures of
Pa. R.C.P. 2000, et seq.
B.
Notification. In the event that a person fails to comply with the
requirements of this chapter, or fails to conform to the requirements
of any permit issued hereunder, the Borough of Avis shall provide
written notification of the violation. Such notification shall set
forth the nature of the violation(s). The notice will also direct
the responsible party to comply with all the terms of the chapter
within seven days, or such additional period not to exceed 30 days
as Borough Council or its designated representative deems appropriate.
Such notice may be delivered by the United States mail, first class,
postage prepaid, or by certified or registered mail, or by personal
service, or, if the property is occupied, by posting the notice at
a conspicuous place upon the affected property. Any person/entity
which fails to comply within the time specified shall be subject to
the penalty provisions of this chapter. All such penalties shall be
deemed cumulative and shall not prevent the Borough of Avis from pursuing
any and all other remedies. It shall be the responsibility of the
owner of the real property on which any activity subject to this chapter
is proposed to occur, is occurring, or has occurred, to comply with
the terms and conditions of this chapter.
C.
Penalties.
(1)
Any violation of any provision of this chapter shall be deemed a
public nuisance.
(2)
Each day a violation occurs shall be deemed a separate violation.
(3)
Any person/entity who or which has violated any provisions of this
chapter, shall, upon a judicial determination thereof, be subject
to civil judgment for each such violation of not more than $1,000,
plus costs of suit. Each day that a violation occurs shall constitute
a separate offense. All fines shall be paid to the Borough of Avis
for its general use.
(4)
The Borough of Avis, through its Borough Council or its designated
representative may, in addition, institute injunctive, mandamus or
any other appropriate action or proceeding at law or in equity for
the enforcement of this chapter. 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.
(5)
The Borough of Avis may, in addition to any formal legal proceedings,
take any actions necessary to remove any public nuisance caused by
violation of this chapter. The costs of removal of the public nuisance/violation
shall be in addition to any penalties for violations for failure to
comply.
(6)
The cost of removal, fine and penalties hereinabove mentioned may
be entered by the Borough of Avis as a lien against such property
in accordance with existing provisions of law.
A.
Language interpretations. For the purposes of this chapter, 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" are mandatory; the words "may" and "should"
are permissive.
(5)
The words "used" or "occupied" include the words "intended, designed,
maintained or arranged to be used in occupied."
B.
ALLUVIAL SOILS
ALTERATION
APPLICANT
BOROUGH
CARBONATE
CHANNEL
CLOSED OR UNDRAINED DEPRESSION
CONSERVATION DISTRICT
CULVERT
DAM
DBH - DIAMETER AT BREAST HEIGHT
DESIGN STORM
DETENTION BASIN
DEVELOPER
EASEMENT
EROSION
FLOODPLAIN
GABION
GEOLOGIC FORMATION
GEOLOGIC MEMBER
GHOST LAKE
GRADING
GROUNDWATER RECHARGE
IMPERVIOUS AREA
IMPERVIOUS SURFACE
INFILTRATION STRUCTURE
KARST
LAND DISTURBANCE
LEVEL SPREADER
LINEAMENTS
LOW FLOW CHANNEL
NRCS
PEAK DISCHARGE
PENNSYLVANIA MUNICIPALITIES PLANNING CODE
REGISTERED PROFESSIONAL
RETENTION BASIN
RIPRAP
RUNOFF
SEDIMENTATION
SEDIMENT BASIN
SHEET FLOW
SINKHOLE
SINKHOLE FLOODPLAIN
SOIL COVER COMPLEX METHOD
STORM SEWER
STORMWATER
STRATA
STRATIGRAPHIC UNIT
SWALE
TOPOGRAPHY
USDA
WATERSHED
WETLANDS
Definitions. The following words and phrases when used in this chapter
shall have, unless the context clearly indicates otherwise, the meanings
given to them in this subsection. All words and terms not defined
herein shall be used with a meaning of standard usage.
Those areas delineated pursuant to the Clinton County, Pennsylvania,
Soil Survey, August 1981, and subsequent revisions.
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 developer who has filed an application for
a zoning permit or subdivision approval.
The Borough of Avis, Clinton County, Pennsylvania.
A sediment formed by the organic or inorganic precipitation
of mineral compounds characterized by the fundamental chemical ion
CO3. The principal element in limestone and
dolomite strata.
A perceptible natural or artificial waterway which periodically
or continuously contains moving water having a definite bed and banks
which confine the water.
In a Karst geologic area, a distinct bowl-shaped depression
in the land surface; size and amplitude are variable; drainage is
internal. It differs from a sinkhole in that the ground surface is
unbroken and usually occurs in greater density per unit area.
The Clinton 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 to other purposes which does or may impound water or another
fluid or semifluid.
The diameter of a tree at a height of 4 1/2 feet above
the ground, on the uphill side.
The magnitude of precipitation from a storm event measured
in probability of occurrence (e.g., ten-year storm) and duration (e.g.,
24 hours), and used in designing stormwater management control systems.
A pond or basin designed to retard stormwater runoff by temporarily
storing the runoff and releasing it at a predetermined rate. A detention
pond may be designed to drain completely after a storm event (dry
pond), or it may be designed to contain a permanent pool of water
(wet pond).
A person or persons, partnership, association, corporation
or other entity, or any responsible person therein or agent thereof,
who undertakes the activities covered by this chapter.
A recorded agreement of right-of-way granted, but not dedicated,
for limited use of private land for a public or quasi-public purpose,
identified on the final plan, and within which the owner of the property
shall not erect any permanent structures, but shall have the right
to make any other use of the land which is not inconsistent with the
rights of the grantee.
The removal of soil, stone and other surface materials by
the action of natural elements.
A floodplain or flood hazard area is that land within the
Borough adjoining any watercourse subject to a one-hundred-year recurrence
interval flood as delineated by a study prepared by any federal, state,
or county agency, a registered professional engineer experienced in
the preparation of hydrological and hydraulic studies and the determination
of flood boundary lines, or the area denoted as having alluvial soils
on the most recent soil survey of the Natural Resources Conservation
Service (NRCS), United States Department of Agriculture.
A large rectangular box of heavy gage wire mesh which holds
large cobbles and boulders. Used in streams and ponds to change flow
patterns, stabilize banks or prevent erosion.
The basic or fundamental rock stratigraphic unit in the local
classification of rocks, consisting of a body of rock (usually a sedimentary
stratum or strata but also igneous or metamorphic) generally characterized
by some degree of internal lithologic homogeneity or distinctive lithologic
features (such as chemical composition, structures, textures, gross
aspect of fossils or time of deposition). Typically used for mapping
the geology of an area.
A rock stratigraphic unit which is subordinate (a subject)
of a formation. This unit is not necessarily mappable and is usually
a unified subdivision of local extent that may or may not be contained
in more than one formation.
A body of standing water occurring in a sinkhole or closed
depression of a Karst region that is usually visible after sufficient
precipitation has occurred. They may form from slow permeability of
soils, rises in the water table or the development of a natural liner
of slow permeable clays or soils.
The act of excavating and/or filling land for the purpose
of changing natural slope.
Replenish of existing natural underground water supplies.
Impermeable surfaces, such as pavement or rooftops, which
limit the infiltration of water into the soil, as outlined in Table
A-2 of Appendix A, Section I.[1]
A surface which limits the penetration of water into the
ground.
A structure designed to direct runoff into the ground, such
as French drains, seepage pits or seepage trenches.
A type of typography that is formed over limestone, dolomite
or gypsum by bedrock solution, and that is characterized by closed
depressions or sinkholes, caves and underground drainage (from AGI,
Glossary of Geology, 1972).
Any activity involving grading, tilling, digging or filling
of ground or stripping of vegetation or any other activity which causes
land to be exposed to erosion.
A device used to spread out stormwater runoff uniformly over
the ground surface as sheet flow (i.e., not through channels). The
purpose of level spreaders are to prevent concentrated, erosive flows
from occurring and to enhance infiltration.
Straight or gently curved lengthy features frequently expressed
topographically as depressions or lines on the earth's surface.
They can be more easily observed at a height of 100 meters or more
and are usually found by researching aerial photographs or satellite
photography. They are usually located in areas of faulting or in dense
jointing along some rock stratigraphy.
An incised or paved channel from inlet to outlet in a dry
basin which is designated to carry low runoff flows and/or base flow
directly to the outlet without detention.
Natural Resources Conservation Service (NRCS), United States
Department of Agriculture.
The maximum rate of flow of water at a given point and time
resulting from a storm event.
Act of 1968, July 31, P.L. 805, as amended (53 P.S. 10101
et seq.).
An individual registered in and licensed by the Commonwealth
of Pennsylvania, including, for the purposes of this chapter, land
surveyors, landscape architects, architects and engineers.
A basin in which the runoff from a given flood event is stored
and is not discharged into the downstream drainage system during the
flood event.
A combination of large stone, cobbles and boulders used to
line channels, stabilize banks and reduce runoff velocities.
That part of precipitation which flows over the land.
The process by which mineral or organic matter is accumulated
or deposited by the movement of water.
A barrier, dam, retention or detention basin located and
designed to retain rock, sand, gravel, silt or other water transported
material.
Runoff which flows over the ground surface as a thin, even
layer, not concentrated in a channel. Flow depth is generally 0.1
feet or less.
A localized, gradual or rapid sinking of the land surface
to a variable depth, occurring in areas of carbonate bedrock; generally
characterized by a roughly circular outline, a distant breaking of
the ground surface and downward movement of soil into bedrock voids.
The area inundated by the one-hundred-year, twenty-four-hour
storm, assuming no drainage from the sinkhole or closed depression
based upon anticipated runoff volumes with maximum development permitted
by zoning within the catchment area or area draining to the sinkhole.
A method of runoff computation developed by NRCS, and found
in its publication Urban Hydrology for Small Watersheds, Technical
Release No. 55, as revised.
A system of pipes or other conduits which carries intercepted
surface runoff, street water and other wash water or drainage, excluding
domestic sewage and industrial wastes.
The drainage runoff from the surface of the land resulting
from precipitation, snow or ice melt.
Tubular or sheet-like mass, distinct layers of homogenous
or gradational sedimentary material (consolidated rock or unconsolidated
earth) of any thickness, visually separable from other layers above
and below by a discrete change in the character of the material deposited
or by a sharp physical break, deposition or both.
A stratum or body of strata recognized as a unit in the classification
of the rocks of the earth's crust with respect to any specific
rock character, property, attribute or for any purpose such as description,
mapping and correlation.
A low-lying vegetated stretch of land or wide shallow ditch,
usually grassed or paved, which gathers or carries surface water runoff.
The general configuration of a land surface or any part of
the earth's surface, including its relief and position of its
natural and man-made features. The natural or physical surface features
of a region, considered collectively as to its form.
United States Department of Agriculture.
The entire region or area drained by a river or other body
of water, whether natural or artificial; a drainage basin or subbasin.
Those areas defined in the Federal Manual for Identifying
and Delineating Jurisdictional Wetlands, latest edition.
[1]
Editor's Note: Said appendix is included as an attachment to this chapter.
