The standards of design in this article shall
be used to judge the adequacy of development proposals and shall be
considered to be the minimum criteria in achieving the purpose and
objectives of this chapter. Where questions should arise regarding
the interpretation of these design standards, the determination of
the Board of Supervisors shall prevail.
A.
Land. No land shall be subdivided or developed for
any purposes unless hazards to life, health, or property from flood,
fire, disease, shall have been eliminated, or adequate safeguards
against such hazards have been developed.
[Amended 6-20-2000 by Ord. No. 42]
B.
Development. Proposed projects shall be coordinated
with existing nearby neighborhoods so that the community as a whole
may develop harmoniously.
C.
Subdivisions and land developments shall be laid out
to:
D.
Thoughtful and imaginative design of streets and their
relationship to the arrangement and shape of lots is required. An
important element is the blending with topography to produce curvilinear
design and reasonable grades. The rectilinear design of streets and
lots, involving long straight sections of street should be avoided.
E.
Subdivisions shall be designed, to the greatest extent
practical, with streets following topographic highs and/or the contours
of the land to ensure conformity with topography so as to create the
least erosion potential and adequately handle surface water runoff.
F.
Construction of required improvements will be completed
under specifications of the Pennsylvania Department of Transportation,
Pennsylvania Department of Environmental Protection, Perry Conservation
District, and/or other appropriate agencies. The specifications included
herein, whichever specifications shall be more stringent, shall be
the one used.
A.
General standards. The arrangement, character, extent,
width, grade and location of all streets shall be considered in their
relation to existing and planned streets, to topographical conditions,
to public convenience and safety, and in the appropriate relation
to the proposed uses of the land to be served by such streets. The
arrangement and other design standards of streets shall conform to
the provisions found herein.
(1)
Where adjoining areas are not presently subdivided,
the arrangement of streets in the new subdivision shall extend on
the proper projection of the street right-of-way for future development
to the adjoining properties and end at the property line.
(2)
Streets in and bordering a subdivision or land development
shall be coordinated, and be of such width and grades and in such
locations as deemed necessary to accommodate prospective traffic,
and facilitate fire protection.
(3)
Existing Township roads are designated as minor streets
with a projected fifty feet of right-of-way.
(4)
Private rights-of-way of 50 feet in width may be approved for subdivisions of four lots or less. Further subdivision in excess of the initial four lots using a private rights-of-way shall not be permitted unless the initial private rights-of-way, and any extensions thereof, are improved and dedicated in accordance with all applicable construction standards in this chapter. The private rights-of-way shall meet the design standards for streets as specified in this article, except for the requirement for paving and the requirements of § 120-39B.
[Amended 10-16-2001 by Ord. No. 44[1]]
[1]
Editor's Note: This ordinance also repealed
original Section 403B, Existing Township road designation, which immediately
followed this subsection.
B.
Street widths.
(1)
Streets shall be laid out according to the following minimum schedule; however, additional street width may be required as determined by the Board of Supervisors to insure public safety and convenience in accordance with Subsection B(2) and the purpose of this chapter:
|
Street Type
|
Width
| |
|---|---|---|
|
Arterial streets
|
As determined by the
| |
|
Right-of-way Shoulders
|
Carroll Township Supervisors after consultation
with the Carroll Township Engineer and the Pennsylvania Department
of Transportation (PennDOT)
| |
|
Collector streets
| ||
|
Right-of-way
|
60 feet
| |
|
Shoulders
|
16 (8 each side) feet
| |
|
Cartway
|
24 feet
| |
|
Minor streets
| ||
|
Right-of-way
|
50 feet
| |
|
Shoulders
|
10 (5 each side) feet
| |
|
Cartway
|
20 feet
| |
|
Turnaround or cul-de-sac (diameter)
| ||
|
Right-of-way
|
100 feet
| |
|
Cartway
|
80 feet
| |
|
Alley or service drive
| ||
|
Right-of-way
|
20 feet
| |
|
Cartway
|
20 feet
|
(2)
Provision for additional street width (right-of-way,
cartway, or both) may be required when determined to be necessary
by the Carroll Township Board of Supervisors in specific cases for:
(3)
Where curbs are required the cartway width (between
curbs) shall be as indicated in the PennDOT Design Manual Part 2,
as revised.
(4)
When the subdivision or land development is proposed
fronting on an existing Township road, except for a PennDOT highway,
the required additional right-of-way shall be dedicated for all the
lots or land development proposed. The required right-of-way for all
of the property fronting on the existing Township road shall be shown
on the plat and a signed dedicators statement shall be shown on the
final plat.
(5)
Existing Township roads are considered minor streets
and require 50 feet of dedicated right-of-way. A width of 25 feet
of dedicated right-of-way from the center line of the existing pavement
is required for the entire length of the property involved.
C.
Horizontal alignment.
(1)
Intersections. Intersections involving the junction
of more than two streets are prohibited. Right-angle intersections
must be used wherever practical, however, in no case shall streets
intersect at less than 75º.
(2)
Intersection curve radii.
(a)
At intersections or streets the radius of the
curb or edge of pavement radii shall not be less than the following:
|
Intersection
|
Curb or Edge
of Pavement
(feet)
| |
|---|---|---|
|
Collector with collector street
|
35
| |
|
Collector with minor street
|
25
| |
|
Minor street with minor street
|
15
|
(b)
Property lines of corner properties adjacent
to intersections shall be substantially concentric with curb lines
or edge of pavement.
(3)
Intersection sight distance. Proper sight lines must
be maintained at all intersections.
[Amended 10-16-2001 by Ord. No. 44; 3-6-2012 by Ord. No. 59]
(a)
For intersecting street and/or driveways, the required minimum safe stopping distance shall be based upon data and specifications found in Appendix 1 (see Pa. Code Chapter 441, § 441.8, Driveway design requirements, Subsection (h), Sight distance; using applicable criteria including speed limit and road grade at the actual proposed driveway or street location).[2]
[2]
Editor’s Note: See 67 Pa. Code § 441.8. Appendix 1 is included at the end of this chapter.
(b)
Use the form provided in the Appendix 2.[3] The form shows the procedure for taking measurements and
what data is required. The information should be provided in tabular
form on the subdivision or land development plan.
[3]
Editor's Note: Appendix 2 is included at the end of this chapter.
(c)
Clear sight triangle. For the minimum sight distance measured along the center line, there must be a clear sight triangle of 150 feet for arterial and collector streets and 75 feet for all other streets. These are minimum lengths; the required length shall be in accordance with Subsection C(3)(d) and (e) below, whichever is the longer.
(d)
Where intersections occur between proposed new streets within a new
subdivision, there must be a clear sight triangle that conforms to
the standards established in PennDOT Publication 70, April 1983, “Guidelines
for Design of Local Roads and Streets,” as amended. No building
or obstruction shall be permitted in this area.
(e)
Where intersections occur between proposed new streets or driveways
providing access to separate parcels of land and state highway (legislative
routes, Pennsylvania routes and United States routes) on arterial
streets, there must be a clear sight triangle provided in accordance
with the requirements of the Pennsylvania Department of Transportation.
(4)
Streets not in alignment.
[Amended 10-16-2001 by Ord. No. 44]
(a)
The distance between the center line of streets
intersecting at grade with a local street shall be no less than 150
feet measured along the center line of the street being intersected
based on the safe stopping distance of a road with a design speed
of 25 miles per hour (mph) at a moderate grade.
(b)
The distance between the center line of streets
intersecting at grade with a collector street shall be no less than
300 feet measured along the center line of the street being intersected
based on the safe stopping distance of a road with a design speed
of 40 mph at a moderate grade.
(c)
The distance between the center line of streets
intersecting at grade with an arterial street shall be no less than
600 feet measured along the center line of the street being intersected
based on the safe stopping distance of a road with a design speed
of 55 mph at a moderate grade.
(5)
Sight distance. Sight distance must be provided in
accordance with Pennsylvania Code Title 67, Transportation, Chapter
441, Access to and Occupancy of Highways by Driveways and Local Roads,
January 1982.
[Amended 3-6-2012 by Ord. No. 59]
(6)
Curves (horizontal).
(a)
Where connecting street lines deflect from each
other at any one point by more than 5º, the line must be connected
with a true, circular curve. The minimum radius of the center line
for the curve must be as follows:
|
Type of Street
|
Minimum Radius
(feet)
| |
|---|---|---|
|
Collector
|
300
| |
|
Minor
|
150
|
(b)
Straight portions of the street must be tangent
to the beginning or end of curves.
(7)
Culs-de-sac or dead-end streets. Culs-de-sac and dead-end
streets are prohibited unless approved by the Township Supervisors
upon written application and good cause shown and upon such terms
and conditions as the Township Supervisors may establish.
[Amended 10-16-2001 by Ord. No. 44; 3-6-2012 by Ord. No. 59]
D.
Vertical alignment.
(1)
Street grades
(a)
The grades of streets shall not be less than
the minimum or more than maximum requirements listed below:
|
Type of Street
|
Minimum
Grade
|
Maximum
Grade
| |
|---|---|---|---|
|
All streets
|
0.75%
| ||
|
Arterial streets
|
As determined by the Board of Supervisors after
consultation with the PennDOT
| ||
|
Collector streets
|
7%
| ||
|
Minor streets, alleys, etc.
|
12%
|
(b)
Vertical curves shall be used in all changes
of grade and designed for maximum visibility. Intersections shall
be approached on all sides by leveling areas not to exceed 4%. Such
leveling areas shall have a minimum length of 100 feet (measured from
the intersection center lines). The slope from the intersecting street
shall be a minimum slope of 2% for a minimum length 50 feet from the
intersection with an intersecting vertical curve.
E.
Slope of banks along streets. The slope of banks along
streets measured perpendicular to the street center line shall be
no steeper than the following:
(1)
One foot of vertical measurement for three feet horizontal
measurement for fills.
(a)
Fill requirements. If load-bearing fill greater
than 10 feet in depth is proposed, a soils investigation report shall
be submitted which shall consist of test borings, laboratory testings,
and engineering analysis to correlate surface and subsurface conditions
with the proposed grading plan. The results of the investigation shall
include data regarding the nature, distribution, and supporting ability
of existing soils and rocks on the site, conclusions and recommendations
to insure stable soil conditions, and groundwater control, as applicable.
The Township may require such supplemental reports and data as is
deemed necessary by the Township Engineer. The following provisions
shall apply to plans involving fill:
[1]
Fills toeing out on natural slopes steeper than
three horizontal to one vertical shall not be made unless approved
by the Township Engineer after receipt of a report by a registered
professional engineer, qualified in soils analysis, certifying that
he has investigated the property, made soil tests and that, in his
opinion, such steeper slopes will safely support the proposed fill.
[2]
Natural and/or existing slopes exceeding five
horizontal to one vertical shall be benched or continuously stepped
into competent materials, as determined by the Township Engineer,
prior to placing all classes of fill.
[3]
A quality control program is critical for fills.
Therefore, wherever load-bearing fill material is to be used, each
layer of compacted fill shall be tested to determine its density per
American Society of Testing Materials (ASTM) D 1556. The density of
each layer shall not be less than 95% of maximum dry density as determined
by ASTM D 1557. The maximum lift thickness shall be eight inches.
[4]
Inspections shall be conducted in accordance
with the general procedure outlined in this chapter.
[5]
Compaction test reports shall be kept on file
at the site and be subject to review at all times by the Township
Engineer. These reports shall be sent to the Township Engineer on
a weekly basis and a bound report and summary submitted within 30
days after completion of the construction.
(2)
One foot of vertical measurement for two feet of horizontal
measurement for cuts.
(a)
Cuts. Intercepting under-drains shall be required
at all locations in which subsurface water is encountered which may
permeate or endanger the subgrade of the street. Under-drains shall
be required in all cuts six feet deep and greater, and in all other
locations stipulated by the Township Engineer. Under-drains shall
be parallel to the established street grade to outlet in approved
drainage structures. Under-drains shall consist of a trench excavated
to a minimum depth of 24 inches below the elevation of the special
subgrade and to the minimum width of 18 inches in which filter fabric
and a six-inch perforated pipe under-drain shall be laid. The trench
shall be backfilled with clean No. 2-B aggregate to its full depth
around and above the laid pipe and wrapped within the fabric (geotextile)
in accordance with PennDOT Form 408, as revised to date. All underdrain
designs shall be approved by the Township Engineer.
(b)
If the length of pipe under-drain exceeds 600
feet in one run, the minimum diameter of six inches shall be increased
to eight inches beyond that point. Pipe shall meet PennDOT Form 408,
as revised to date.
F.
Partial and half-streets. The dedication of half-streets
at the perimeter of new subdivisions is prohibited.
G.
Names of streets. Names of new streets shall not duplicate
or approximate existing or platted street names, or approximate such
names by the use of suffixes such as "land," "drive," "way," "court,"
"avenue," etc. In approving the names of streets cognizance may be
given to existing or platted street names within the postal delivery
district served by the local post office. New streets shall bear the
same name or number of any continuation or alignment with an existing
or platted street.
H.
Driveways. The following standard shall apply to driveway construction
in any subdivision and land development:
[Added 3-6-2012 by Ord. No. 59; amended 11-6-2012 by Ord. No.
63]
(1)
Private driveways on corner lots shall be located at least 40 feet
from the point of intersection of the nearest street right-of-way
lines. Private driveways shall be set back a minimum of five feet
from side property lines unless a joint-use driveway is proposed.
(2)
All driveways on a state highway must have a valid highway occupancy
permit from the Pennsylvania Department of Transportation.
(3)
The minimum driveway width at the cartway edge shall be 10 feet.
The maximum driveway width at the cartway edge shall be 25 feet.
(4)
Adequate area will be provided for a turnaround so that vehicles
do not have to back onto roads. A minimum of two parking spaces per
dwelling shall be provided.
(5)
(6)
Driveway entrances.
(a)
Driveway entrances shall have a minimum edge-of-payment radius
of five feet.
(b)
Driveway entrances onto a municipal street shall be constructed
according to the municipal construction standards for such access
within the street right-of-way.
(c)
Driveway entrances onto a state street within the street right-of-way
shall be surfaced to their full width. The type of surface may be
with concrete or asphalt, constructed following the specifications
in PennDot Publication RC-25M Type 6 Shoulder (asphalt) or Type 2
Shoulder (concrete.)
(d)
Driveway entrances along streets where curbs are not required
shall be constructed to provide proper drainage along the street and
from the streets by the continuation of gutters, swales, or ditches.
Such continuation may be provided by having an approved pipe of not
less than 15 inches in diameter across such driveway entrances.
(e)
Driveway entrances along streets shall be constructed so that
the driveway meets the edge of the cartway as a continuation of at
least the slope from the crown of the street for not less than five
feet.
(f)
Driveways serving single-family residences shall intersect streets
at angles of no less than 75°. All other driveways or service
drives shall intersect streets at right angles.
(7)
Sight distance. See § 120-23C(3).
(8)
Clear sight triangle. Clear sight triangle shall be 75 feet in each
direction along the street and 10 feet back from the edge of the cartway.
(9)
Driveway profile. Driveway profiles shall provide efficient access
to the abutting residential street, allow for low-speed ninety-degree
turns into the driveway, and provide safe access to the residential
garage or parking area. The following standards shall apply:
(a)
Driveway grades shall not exceed 10% for the first 18 feet from
the street edge of pavement.
(b)
Driveways serving residential dwellings shall not exceed 20%.
(c)
If not jointly used, a driveway may not be placed closer than
five feet to an adjoining property line.
(d)
New driveways may not be placed closer than 50 feet to another
driveway.
(e)
New driveways shall be designed to maintain the shoulder or
roadway swale without impeding the flow of runoff. Runoff shall not
be directed onto the cartway of the connection road.
Alleys shall be prohibited in residential districts
except where proven to be necessary. The applicant must submit to
the Planning Commission the justification with alternative explored
prior to review by the Planning Commission and Supervisors. All requests
must be reviewed by the Township Engineer prior to the Planning Commission
making recommendations.
A.
The minimum width of easements shall be 15 feet for
underground public utility facilities and drainage facilities and,
wherever possible, easements for public utilities shall be centered
on side or rear lot lines. Additional width may be required by the
Supervisors on recommendation of the Planning Commission and/or Engineer
depending on the purpose and use of the easement.
B.
Easements with a width of 10 feet shall be provided
as necessary for each utility within a multiple utility easement.
C.
Where a subdivision is traversed by a watercourse,
drainageway, channel or stream, there shall be provided a drainage
easement conforming substantially with the line of such watercourse,
drainageway, channel or stream, and of such width as will be adequate
to preserve the unimpeded flow of natural drainage or for the purpose
of widening, deepening, relocating or protecting such drainage facilities,
or for the purpose of installing a stormwater sewer. Drainage easement
shall be required along natural watercourses coinciding with the extent
of the one-hundred-year floodplain, but in any case not less than
50 feet in total width. Permanent drainage easements for man-made
facilities and swales shall be a minimum of 30 feet in width.
D.
When any petroleum or natural gas transmission line
traverses a subdivision or land development, the developer shall confer
with the applicable transmission or distributing company to determine
the minimum distance which shall be required between each proposed
dwelling unit and the petroleum or petroleum products or natural gas
transmission line, and provide evidence of such with the preliminary
plan submission.
E.
Whenever practicable, easements shall be parallel
with and conjunctive to property lines of the subdivision.
F.
All easement agreements shall be recorded with a reference
to the recorded easement indicated on the site plan.
Blocks shall not exceed 1,500 feet in length
and shall be of sufficient depth to permit two tiers of lots, except
as otherwise provided for in this chapter.
A.
General. All lots shall conform to the following:
(2)
Insofar as is practical, side lot lines shall be at
right angles to straight streets, and radial to curved streets.
(3)
Where there is a question as to the suitability of
a lot or lots for their intended use due to factors such as soil conditions,
rock formations, flood conditions, excessive slopes or similar circumstances,
the Planning Commission may, after adequate investigation, withhold
approval of such lots, require reconfiguration of lots, require remedial
action, or require a suitable site development plan be prepared.
(4)
Lot lines shall, to the greatest extent practical,
be laid out to follow topographic lows, drainage swales, and watercourses.
(5)
Increased building setbacks and/or deed restrictions
shall be prescribed where required by the Supervisors, on the recommendation
of the Planning Commission, to preserve natural features and preclude
potential adverse impacts related to construction in the following
areas:
(6)
No
lot shall be created which has a regularity factor of less than 0.4.
The regularity factor shall be determined by the formula:
|
Regularity =
|
16 x Land Area (in square feet)
| ||
|---|---|---|---|
|
Perimeter2 (in feet)
|
|
That part of the lot area in excess of the required lot area
may be excluded from the regularity formula in determining the regularity
factor. The perimeter containing the excess area shall not include
the required frontage.
[Added 5-3-2011 by Ord. No. 58] |
B.
Double frontage. Double frontage lots shall be avoided,
except that, where desired along arterial streets or limited access
highways, reverse frontage lots may face on an interior street, and
back on such thoroughfares. Interior lots having frontage on two streets
shall be avoided except where unusual conditions make it necessary.
Any use of double frontage lots must be justified and alternatives
explored prior to review by the Planning Commission and Supervisors.
C.
Flag lots. The use of flag lots shall be prohibited.
[Amended 10-16-2001 by Ord. No. 44; 5-3-2011 by Ord. No. 58]
D.
Access.
[Amended 10-16-2001 by Ord. No. 44; 5-3-2011 by Ord. No. 58]
(1)
Each subdivision and land development shall be designed to provide
for access to each lot or development by a public street or private
right-of-way as defined by this chapter.
(b)
Private rights-of-way.
[1]
A private right-of-way may be approved serving two lots or less,
provided that the right-of-way meets the following minimum design
and construction standards:
[2]
A private right-of-way may be approved serving three or four lots or dwelling units, provided that the right-of-way meets the design standards for a street, except for the paving and the requirements of § 120-39.
[a]
Minimum right-of-way width: 50 feet.
[b]
Minimum cartway width: 20 feet.
[c]
Shoulders: five graded shoulders (no stone).
[d]
Maximum length: 1,500 feet.
[e]
Maximum slope: 12%.
[g]
Surface: same as a street without the paving.
[h]
Turnaround: minimum one-hundred-foot diameter right-of-way
with an eighty-foot diameter cartway.
(2)
Further subdivision in excess of the initial number of lots using
a private right-of-way shall not be permitted unless the initial right-of-way,
and any extension thereof, are improved in accordance with the applicable
construction standards in this chapter.
(3)
Prior to final subdivision plan approval, the developer will submit
copies of an agreement for the maintenance and repair of the right-of-way
for review and approval by the Township Solicitor. The agreement may
be in the form of notes on the plan or a separate agreement to be
recorded with the final plan. The agreement shall include language
indicating that Carroll Township is not responsible for maintenance
or upkeep of the right-of-way.
E.
Soils analysis/sewage permit.
[Amended 6-20-2000 by Ord. No. 42; 5-3-2016 by Ord. No. 74]
(1)
Soils analysis shall be required by the Township on each proposed lot in accordance with the Rules and Regulations of the Pennsylvania Department of Environmental Protection. From the results of these tests, the lot size shall be established large enough to provide for the specified minimum area required for the absorption field as prescribed in accordance with the requirements of the Pennsylvania Department of Environmental Protection, or the specified minimum area required for other approved system, but in no case shall the lot size be less than set forth in Chapter 138, Zoning, and Subsection A of this section.
(2)
No lot or tract shall be built upon without a valid sewage disposal
permit issued by the Sewage Enforcement Officer for Carroll Township
for each existing or proposed lot within a subdivision except where
a public or common sewage system is provided or other approved system
is provided. In addition, all lots being subdivided should contain
a secondary or alternate drain field area, as determined by the Carroll
Township Sewage Enforcement Officer, for an alternate system in the
event of malfunction or failure of the primary permitted on-lot system.
The requirement of a secondary or alternate drain field may be waived
by the Carroll Township Sewage Enforcement Officer when the primary
system is an alternate approved system.
[Amended 12-2-2003 by Ord. No. 51; 3-6-2012 by Ord. No. 59]
A.
The scope of a stormwater management plan (SWMP) shall be required
for each subdivision or land development plan at both the preliminary
and final plan submittal stage. As an integral part of the SWMP, erosion
and sedimentation control measures shall be included.
B.
Basic requirements. All earthmoving activities and/or construction
activities shall be designed and constructed in a manner such that
the rate as measured in cubic feet per second of stormwater runoff
from a lot, tract or parcel shall not be greater after the activities
than prior to the activities. Such determination shall be made on
the basis of the following:
(1)
Storm sewer design: ten-year storm event.
(2)
Cross culverts design: twenty-five-year storm event.
(3)
Detention structures: See § 120-28D(1)(a) and (b).
C.
General basis of facility design.
(1)
All drainage facilities or stormwater facilities shall be designed
to carry, accommodate or handle peak runoff as tabulation in this
chapter. The computations of stormwater runoff for the event shall
be in accordance with the provisions of this chapter.
(2)
All drainage facilities, stormwater facilities and erosion and sedimentation
control facilities shall be consistent, to the extent applicable,
with the standards and specifications of the "State Erosion and Sediment
Pollution Control Program Manual."
(3)
Facilities shall be designed to accommodate existing and projected
on-site peak stormwater and projected peak stormwater from the site
of the proposed earthmoving activities or construction activities.
D.
Prime hydraulic method and criteria.
(1)
Design standard-computations for determining stormwater runoff and
for the design of stormwater management facilities shall be based
upon the Soil Cover Complex Method described in either TR-55, Urban
Hydrology for Small Watersheds; the United States Department of Agriculture,
Soil Conservation Engineering Field Manual; or the Soil Conservation
Service National Engineering Handbook, Section 4. Computations based
upon an alternative method may be accepted upon recommendation of
the Township Engineer and approval of Township Supervisors. The following
standards shall apply:
(b)
Release rates from storage structures shall be based on the
runoff from the one-, two-, five-, ten-, twenty-five-, fifty- and
one-hundred-year storm pre-developed storm events.
(c)
Storage structures shall be designed such that the post-developed
discharge will not exceed the pre-developed discharge for the like
storm event.
(d)
All storage structures or facilities will be designed with emergency
spillways sufficient to handle the one-hundred-year post-development
storm event.
(e)
Culverts, pipes, and other water-carrying structures shall be
designed to handle the runoff from the storm event.
(f)
The SWMP shall include calculations indicating velocities of
flow, grades, sizes and capacities of water-carrying structures, debris
or sedimentation basins, and retention and detention ponds and sufficient
design information to construct such facilities.
(g)
Stormwater runoff shall be based on the following twenty-four-hour
storm events:
|
Storm Frequency
(years)
|
Rainfall
(inches)
| |
|---|---|---|
|
2
|
2.5
| |
|
5
|
3.8
| |
|
10
|
4.7
| |
|
25
|
5.1
| |
|
50
|
5.8
| |
|
100
|
6.4
|
(h)
Maximum permitted velocities are as follows:
[1]
For all proposed lined water-carrying channels, complete hydraulic
calculations shall be submitted to the Carroll Township Engineer for
review. The calculations shall determine that the protection proposed
will achieve results in this required article.
[2]
Three feet per second where only sparse vegetation can be established.
[3]
Four feet per second under normal conditions where vegetation
can be established by seeding.
[4]
Five feet per second where a dense, vigorous sod can be quickly
established or with establishment of vegetation.
[5]
Six feet per second where well-established sod is in existence.
[6]
The normal maximum velocity of open channel flows shall not
exceed 10 feet per second after channel lining adjustments are made.
(i)
Energy dissipaters/erosion control devices shall be placed at
the outlets of all pipes where flow velocities exceed maximum permitted
channel velocities. Such devices shall be designed and installed in
accord with the Pennsylvania Department of Environmental Protection's
Erosion and Sediment Pollution Control Program Manual.
(j)
Vertical pipes, inlets and other surface-water-receiving structures
shall be installed with trash racks or so designed to control trash
accumulation.
(k)
Stormwater runoff channels shall be designed and installed to
avoid trapping excess sediment, except if structures are so designed
to trap sediment.
E.
Alternate hydraulic method and criteria.
(1)
General. All methods and drainage details must be approved by the
Township Engineer.
(3)
Runoff determination.
(a)
Minor watercourse and storm sewers shall be designed using the
Rational Equation:
|
Where:
|
Q = CIA
| ||
|
A is the total area contributing runoff to the point under study.
| |||
[1]
Editor's Note: Table 1 is included at the end of this chapter.
[2]
Editor's Note: Chart 1 is included at the end of this chapter.
(c)
For average velocities of overland flow, see Table 2 included at the end of this chapter.
F.
The SWMP plan shall contain the following:
(1)
A stormwater management plan.
(2)
A general description of the proposed project.
(3)
Project location on a 7.5 minute USGS map or equivalent.
(4)
Topographic features of the site and adjacent lands that are considered
to impact upon the stormwater management design.
(5)
Runoff calculations and related design computations of the total
drainage basin necessary to substantiate the proposed temporary and
permanent stormwater management facilities.
(6)
Design and specifications of temporary and permanent stormwater management
facilities.
(7)
Staging or implementation schedule for constructing the proposed
stormwater control system.
G.
Plan requirements are as follows:
(1)
A plan or plans, drawn to a scale of one inch equals 50 feet, showing
at least the following:
(a)
Name, address and telephone number of the landowner or developer
submitting the plan.
(b)
Name, address and telephone number of the engineer preparing
the plan.
(c)
North arrow, scale, graphic scale, and date of plan preparation
with revision dates, if any.
(d)
Names of adjacent or surrounding landowners.
(e)
Site boundaries, with bearings and distances.
(f)
Existing topography, existing and proposed contours at an interval
of two feet and illustrating all natural features of the area.
(g)
The location and dimensions of all existing and proposed buildings
and associated impervious areas.
(h)
Location and dimensions of existing and proposed streets and
parking areas, including showing the difference between paved and
unpaved rights-of-way and specification of the type or types of paving
material to be used.
(i)
Location and dimensions of existing and proposed lots, tracts
or parcels.
(j)
Plans and profiles showing the locations, size and capacity
of existing and proposed surface and subsurface drainage facilities
and detailed plans and profiles thereof. The plan shall also show
how the proposed drainage facilities relate to or tie into existing
facilities, both on site and off site.
(k)
Location and description of erosion and sedimentation control
facilities and devices and a description of any vegetative material
to be used.
(l)
Stormwater runoff computations for the area of the earthmoving
activities or construction activities and for the entire site. The
computations shall be prepared in accordance with the provisions of
this chapter.
(m)
Such other certificates, affidavits, endorsements or dedications
as may be required by the Township in the administration and enforcement
of this chapter.
(n)
All plan sheets, details sheets, profiles and computations shall
be sealed by a registered professional engineer.
H.
Preparation of stormwater runoff computations. All computations of
stormwater runoff shall be prepared in a clear, legible manner and
submitted to the Township, together with the herein-required stormwater
management plan. The Township shall forward the plan, together with
the computations, to the Township Engineer for review and recommendations.
I.
Use of natural or man-made systems.
(1)
Where natural swales, channels, drainageways, or easements are existing
or proposed to be used to convey stormwater, the landowner or developer
shall institute such measures as may be necessary to prevent erosion
of the natural systems. The landowner or developer shall be responsible
for maintenance of all on-site natural or man-made systems unless
or until said swales, channels, drainageways or easements have been
dedicated to and accepted by the Township. The Township Supervisors
may require dedication of swales, channels, drainageways or easements
if it is the option of the Township Supervisors that it is in the
best interests of the citizens of Carroll Township.
(2)
No earthmoving activities or construction activities shall obstruct
or cause obstruction or otherwise impede the flow of natural watercourses,
swales, channels, drainageways or easements, nor shall plantings of
an obstructive nature be permitted herein.
J.
Use of vegetative plantings. Where vegetative plantings and materials
are used or required to be used to assist in controlling erosion and
stormwater runoff or used to prevent accelerated erosion, such plantings
and materials shall be consistent with the standards and specifications
of the Soil Erosion and Sedimentation Control Handbook and the Section
on Erosion Control and Conservation Plantings of the Agronomy Guide.
K.
Discharges.
(1)
Stormwater shall not be discharged onto adjacent properties without
the written consent of the adjacent affected landowner, except that
stormwater may be discharged onto adjacent properties without said
written consent if the discharge is to natural watercourses or to
preexisting natural drainageways and if it can be demonstrated to
the satisfaction of the Township that the discharge will not result
in property damage or threaten public safety and is at a rate not
to exceed the existing rate discharging from the property.
(2)
Where discharges are proposed to streams or watercourses, the landowner
or developer shall take any and all actions that are necessary to
assure channel stability. The landowner or developer shall obtain
all necessary permits and forward copies to Carroll Township prior
to any construction.
(3)
To the maximum extent feasible, discharges from drainage facilities
shall be at nonerosive velocities. Where nonerosive velocities are
not feasible, erosion control facilities shall be constructed that
are in accordance with the applicable standards and specifications
of the Soil Erosion and Sedimentation Control Handbook of the Perry
County Conservation District and this chapter.
L.
Other design criteria.
(1)
Where on-site storm sewers are within 1,000 feet of an existing public
storm sewer system, the Township may require the landowner or developer
to connect thereto. Drainage facilities hereafter constructed shall
be separate from and independent of sanitary sewer systems.
(2)
Inlets shall be provided in a manner so that surface water is not
carried across intersections and in a manner to prevent accumulation
of stormwater runoff in roadways.
(3)
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 properties
or public lands without Township-approved provisions being made by
the landowner or developer for properly handling and financing such
conditions.
(4)
Opening channels shall be designed so that they provide two feet
of freeboard above projected peak flow water profiles.
M.
General hydraulic design criteria.
(1)
Drainage swales and channels.
(a)
Where vegetated drainage swales are used in lieu of or in addition
to storm sewers, they shall be designed to carry the ten-year discharge
without erosion, increase the time of concentration, reduce the peak
discharge and/or velocity and permit the water to percolate into the
soil.
(b)
Swales provided in cut areas shall not encroach upon the road
shoulder during a ten-year-frequency storm of five minutes' duration.
Frequent and/or sustained flooding of the subbase shall not be permitted.
(c)
The maximum velocity as determined by Manning's equation shall not exceed the allowable velocity in Subsection D of this section. Inlets shall be provided to control the shoulder encroachment and/or water velocity.
(d)
Erosion prevention. All drainage swales and channels shall be
designed to prevent the erosion of the bed and bank areas. The flow
velocity in all vegetated drainage channels shall not exceed three
feet per second to prevent erosion. Suitable stabilization shall be
provided where required to prevent erosion during establishment of
vegetation.
(e)
The side slope for any vegetated drainage channel requiring
mowing of the vegetation shall have a maximum grade of three horizontal
feet to one vertical on those areas to be mowed.
(f)
Storm sewers or drainage swales shall discharge to a detention
or retention basin for the control of peak runoff discharge except
as provided in the plan.
(g)
Design standard. Because of the critical nature of vegetated
drainage channels, the design of all vegetated channels shall, as
a minimum, conform to the design procedures outlined in the Pennsylvania
Department of Environmental Protection's Erosion and Sediment
Pollution Control Program Manual.
(h)
Deed restrictions shall be required on property(ies) containing
drainage swales and/or perennial streams. These deed restrictions
shall specify that no property owner obstruct or alter any drainage
swale or perennial stream identified in the stormwater management/erosion
and sediment pollution control plan if such action would alter the
rational course of runoff, without the approval of the Township.
(2)
Culverts and drainage channels.
(a)
Design flow standard. Culverts and drainage channels shall be
designed to carry flow rates as outlined in this article.
(b)
The maximum permissible flow velocity shall not exceed those
outlined in Pennsylvania Department of Environmental Protection's
Erosion and Sediment Pollution Control Program Manual.
(c)
A minimum grade of 1% shall be maintained for all channel flows.
(d)
Pipe capacity. The capacity of all pipe culverts shall, as a
minimum, provide the required carrying capacity as determined by the
Manning Equation; see Pennsylvania Department of Transportation's
Design Manual 2, Chapter 10.
(e)
Design of pipe culverts shall be in accordance with Pennsylvania
Department of Transportation's Design Manual 2, Chapter 10, and
FHWA's Hydraulic Design Series No. 5, "Hydraulic Design of Highway
Culverts."
(3)
Drainage pipe criteria. Wherever possible, all storm drainpipes shall
be designed to follow straight courses. No angular deflections of
storm sewer pipe sections in excess of five degrees shall be permitted
without the installation of a storm inlet or manhole. No vertical
curves shall be permitted in the storm drainpipe system. Storm pipes
shall be either polymeric coated galvanized corrugated metal pipe,
reinforced cement concrete pipe, or PVC pipe.
(a)
Minimum grade and size. All storm drainpipes shall be designed
to maintain a minimum grade of 1/2%. All storm drainpipes shall have
a minimum inside diameter of 15 inches.
(b)
Pipe arches. Where depth or headroom is restricted, equivalent
pipe arches may be used in lieu of circular pipe. An equivalent pipe
size to a fifteen-inch circular pipe is the minimum arch permitted.
(c)
Minimum cover. A minimum of two feet of cover shall be maintained
over all storm pipes. In extreme cases, when approved by the Township
Engineer, this minimum may be reduced, but in no case shall the top
of the pipe be higher than 1/2 foot below the subgrade elevation of
the roadway.
(d)
Discharge velocity. All storm drainage piping discharging to
the ground surface shall be provided with either reinforced concrete
headwalls or end sections compatible with the pipe size involved.
A riprap apron of adequate length shall be provided at all surface
discharge points in order to minimize erosion, using the procedures
found in the Department of Environmental Protection's Erosion
and Sediment Pollution Control Program Manual.
(e)
Where the construction of endwalls is proposed at the outlet
of stormwater conveyance structures, these structures will be built
in accord with Pennsylvania Department of Transportation's Publication
408. Special care shall be used by the design engineer to select the
proper endwall to fit the conditions.
(f)
All storm sewer pipe within street cartway or other paved areas
shall be backfilled with tamped 2-RC stone placed in six-inch lifts
and compacted in accordance with PennDOT Form 408, as revised to date.
(g)
Where storm sewers and culvert pipes discharge into existing
drainage channels at an angle greater than 15° from parallel with
the downstream channel flow, the far side bank shall be stabilized
by the use of riprap or masonry and/or concrete walls. The stabilization
shall be designed to prevent erosion and frost heave under and behind
the stabilizing media.
(4)
Inlet capacity and type.
(a)
The interval between inlets collecting stormwater runoff shall
be determined in accordance with DM-2, Section 10.5, "Capacity of
Waterway Areas." Inlets shall be provided to control the encroachment
of water on the pavement.
(b)
Inlets shall be standard precast types as indicated in Pennsylvania
Department of Transportation Design Standards Publication 72-Plate
RC-34.
(c)
On a curbed roadway, all street inlet tops shall be the combination
curb and gutter inlet referred to as Pennsylvania Department of Transportation
Type "C," with a ten-inch curb reveal to allow an automatic depressed
condition to exist when used with an eight-inch curb. All inlet tops
shall be precast concrete with heavy-duty steel grating. Weep holes
shall be provided on all inlet tops. In streets, private parking areas,
yard areas and drainage swales with no curbing, Pennsylvania Department
of Transportation Type "M" inlet tops shall be used.
(d)
In traffic lanes where grates are used, the grates must be bicycle
safe.
(5)
Detention, retention and infiltration facilities.
(a)
Detention, retention and infiltration facilities, including
but not limited to seepage pits, ponds and drains, may be used to
control or reduce on-site runoff. Where such facilities are proposed
for use, detailed design drawings shall be submitted with the stormwater
management plan required in this chapter, and such facilities shall
be consistent with the standards and specifications of this chapter.
(b)
Where rooftop retention and/or detention of stormwater is proposed,
the landowner or developer shall assure that the structure will withstand
the stress and shall be responsible for maintaining any outflow structures.
In addition, the landowner or developer shall submit a signed statement
from a registered professional engineer that the structure can support
the roof loadings.
(c)
Where on-site detention, retention or infiltration facilities
are proposed, the Township Supervisors may require the landowner or
developer to pay a fee to the Township in lieu of installing the facilities
so that the Township can construct or have constructed off-site facilities
to control runoff from the site. Where such a fee is levied by the
Township, the fee shall be equal to no more than the estimated costs
that the landowner or developer would have incurred to install or
construct said on-site facilities. Such estimated costs shall be prepared
by the Township Engineer.
(6)
Design of detention basins. All detention basins shall be designed
as per the procedures developed by the U.S. Department of Agriculture,
Soil Conservation Service,[3] as outlined in its Technical Release No. 55, Urban Hydrology
for Small Watersheds, or by use of a method of plotting flood stages
based on the Rational Method, where drainage areas are less than 20
acres. All detention basins shall meet the general criteria as follows:
(a)
Detention basins shall not be located within floodplains, nor
within areas of floodplain soils, with the exception that areas of
alluvial soils may be utilized if proof is accepted that the area
is not subject to flooding.
(b)
Detention basins shall be designed to facilitate regular maintenance,
mowing, and periodic desilting and reseeding.
(c)
Whenever possible, the side slopes and basin shape shall conform
to the natural topography. When such design is impracticable, the
construction of the basin shall utilize slopes as flat as possible
to blend the structure into the terrain.
(d)
In residential developments, shallow broad basins may be provided
for recreational use.
(e)
Lakes and ponds:
[1]
Existing or proposed lakes and ponds may be used for stormwater
detention, provided that the design criteria herein are met and are
in accordance with DEP, Chapter 105, Permit Requirements.
[2]
All related basin structural components shall be constructed
of reinforced concrete.
[3]
The minimum level and the size of the permanent pool shall be
adequate to deter the growth of undesirable vegetation and mosquitoes.
[3]
Editor's Note: Now the Natural Resources Conservation
Service.
(7)
Basin design criteria.
(a)
Riser. A precast inlet riser may be provided at the outlet of
detention basins. The riser shall be constructed of metal or concrete
as approved by the Township Engineer. A one-foot minimum freeboard
shall be provided between the top of the riser and the crest elevation
of the emergency spillway. The riser shall be designed so that the
rate of outflow is controlled by the pipe barrel through the basin
berm when the depth of the water within the basin exceeds the height
of the riser or by accurately sized orifices. A trash rack or similar
appurtenance shall be provided to prevent children and debris from
entering the riser where openings greater than 12 inches in diameter
are used. The base shall be of sufficient weight to prevent flotation
of the riser.
(b)
Maximum depth of detention basins. In general, the maximum depth
of water in a detention basin measured to the invert of the emergency
spillway shall not exceed five feet.
(c)
Emergency spillways shall be designed and constructed in accord
with the Pennsylvania Department of Environmental Protection's
Erosion and Sediment Pollution Control Program Manual.
(d)
Antiseep collars. Antiseep collars shall be installed around
the principal pipe barrel within the normal saturation zone of the
detention basin berms. The antiseep collars and their connections
to the pipe barrel shall be watertight. The anitseep collars shall
extend a minimum of two feet beyond the outside of the principal pipe
barrel. The spacing between collars shall be designed by a professional
engineer and supporting calculation submitted to Carroll Township.
(e)
Freeboard. Freeboard is the difference between the design flow
elevations in the emergency spillway and the top of the settled detention
basin embankment. The minimum freeboard shall be one foot.
(f)
Slope of detention basin embankment. The top or toe of any slope
shall be located a minimum of 10 feet from any property line. Whenever
possible, the side slopes and basin shape shall be amenable to the
natural topography. Straight side slopes and rectangular basins shall
be avoided whenever possible.
[1]
Exterior slopes of compacted soil shall not exceed one foot
vertical for three feet horizontal and may be further reduced if the
soil has unstable characteristics.
[2]
Interior slopes of the basin shall not exceed one foot vertical
for three feet horizontal, except with approval of the Township.
(g)
Width of berm. The minimum top width of detention basin berms
shall be 10 feet.
(h)
Slope of basin bottom. In order to insure proper drainage of
the detention basin, a minimum grade of 2% shall be maintained for
all sheet flow.
[1]
Inlet and outlet structures shall be located at maximum distances
from one another. The Township Engineer may require a rock filter
berm or rock-filled gabions between inlet and outlet areas when the
distance is deemed insufficient for sediment trapping. All shall discharge
to areas of the basin which slope downward to lower elevations of
the basin.
[2]
A collecting swale and/or underdrain shall be provided to drain
basins intended for recreational use where the slope of the basin
bottom may be reduced to 1%.
[3]
The bottom of the detention pond may have a flat slope if infiltration
is proposed in the pond.
(i)
Energy dissipaters. Energy-dissipating devices (riprap, end
sills, etc.) shall be placed at all basin outlets. Level spreaders
shall be provided to spread discharges across drainage swales to prevent
concentrated and erosive flows.
(j)
The distance from the highest free water surface of any detention
basin or drainage facility to a dwelling unit shall be a minimum of
100 feet.
(k)
Fence or screening.
[1]
The developer shall submit a plan to address the protection
of all stormwater and erosion facilities, including temporary and/or
permanent fencing, gates and spillway protection.
[2]
The fence shall be chain-linked a minimum of four feet high
with access gates and protection of the emergency spillway from debris.
[3]
A vegetative screening of suitable landscaping plan material
in or around a detention basin may also be required. Vegetative screening
should generally provide a barrier to prevent entrance to and effectively
naturalize the appearance of the detention basin area.
(l)
Landscaping and grading of detention basins. All landscaping
and grading standards particularly applicable to detention basins
shall be approved by Carroll Township.
(m)
A soil investigation report shall be prepared for stormwater
detention basins and other structures as required by the Township
Engineer. The report shall identify unsuitable conditions, recommend
remedial actions, and determine potential risks to proposed improvements.
[1]
A minimum of three soil borings shall be required at the emergency
spillway, the pool or borrow area, and the center line of the dam
at the barrel. In any case, the Township reserves the right to require
additional soil borings.
[2]
The minimum soil boring depth shall be to the seasonal high
water table or five feet below the bottom of the stormwater management
facility, whichever is greater, or to refusal.
(n)
A quality control program is critical for embankment fills.
Therefore:
[1]
Wherever embankment fill material in excess of three feet is
to be used, each layer of compacted fill shall be tested to determine
its density per ASTM D1556. The density of each layer shall not be
less than 95% of maximum dry density as determined by ASTM D1557.
[2]
Inspections shall be conducted by the Township Engineer.
[3]
Compaction test reports shall be kept on file at the site and
be subject to review at all times by the Township Engineer.
[4]
When rock is encountered during the excavation of a pond, it
shall be removed to an elevation of at least 12 inches below the proposed
basin floor.
[5]
Temporary and permanent grasses or stabilization measures shall
be established on the sides and base of all earth basins within 15
days of construction.
(o)
Design information. As part of the stormwater management/erosion
and sediment pollution control plan, all design information shall
be submitted, including, but not limited to, the following:
[1]
General description of proposed facilities and the operation
of the runoff control measures.
[2]
All computations of the stormwater runoff before, during, and
after construction, including all supporting material.
[3]
A detail of the berm embankment and outlet structure indicating
the embankment top elevation, embankment side slopes, top width of
embankment, emergency spillway elevation, perforated riser dimensions,
pipe barrel dimensions, and dimensions and spacing of antiseep collars.
[4]
Design computations for the pipe barrel and riser.
[5]
A plot of the stage storage and stage discharge (acre-feet versus
elevation) and all supporting computations.
[6]
Flood routing computations.
[7]
A detailed plan of the trash rack and antivortex device.
[8]
A plan, at a scale of one inch equals 50 feet, showing the grading,
landscaping, and fencing around the detention basin.
[9]
Soils investigation report, where required.
(8)
Design of seepage pits and seepage trenches for infiltration of roof
drainage. The design may be in accordance with the guidelines in the
state BMP Manual or shall meet the following criteria. An operation
and maintenance plan shall be provided and notes added to the plan
to ensure the long-term integrity of these systems. Site-specific
soil investigations shall be required to demonstrate suitable soil
conditions exist for use of these systems; testing should be in accordance
with the guidelines of the BMP Manual. These structures shall be designed
to assimilate, in 72 hours, a volume of water equal to 0.2 cubic feet
per square foot of roof coverage (i.e., length times width of building
space covered) and to assimilate in two hours a volume equal to 0.1
cubic feet per square foot of roof coverage.
(a)
Runoff control capacity may be distributed among several seepage
pits, trenches, or runoff control berms so long as total assimilative
capacity of all structures equals the required volume.
(b)
Seepage pits connected to roof drains should be located at least
10 feet from basement walls and downhill from the building in the
direction of groundwater flow.
(c)
The bottom of a seepage pit should be at least two feet above
seasonal high water table and bedrock or be shown to be otherwise
capable of handling required design volumes.
(d)
The soils on which a seepage pit or trench are located shall
have a minimum infiltration rate of 0.27 inches per hour based upon
soils data obtained by direct testing methods.
(e)
The porosity of the gravel or rock to be used in seepage pits
must be specified on the plan. The rock or gravel shall be covered
with a ground stabilization fabric [trade names: Mirafi 500 (Monsanto),
Typer (Dupont), Bidim, Supsc, or equivalent].
(f)
Where adequate seepage pit capacity is difficult to achieve
with a rock-filled pit, a concrete (or equivalent material) culvert
pipe with a lid may be placed vertically over a stone bed to provide
storage capacity; alternatively, a septic tank-type structure operating
as a cistern with discharge to the seepage pit may be used.
(g)
The longer dimension of seepage pits or seepage trenches should
parallel the slope where slopes exceed 5%.
(h)
Seepage pits or seepage trenches shall not be installed on slopes
greater than 20% and shall be kept away from man-made grades.
(i)
The use of a perforated or porous pipe leading to the seepage
pit is encouraged.
(j)
In all cases, an overflow system should be provided to accommodate
heavy rains in excess of the design criteria.
(k)
Seepage pits or the drains to them must contain a sediment trap
which can be maintained regularly by the owner. All downspouts should
have leaf strains to prevent leaves from clogging the seepage pit.
(9)
Design of seepage pits and seepage trenches, other than roof drainage.
The design may be in accordance with the guidelines in the state BMP
Manual or shall meet the following criteria. An operation and maintenance
plan shall be provided and notes added to the plan to ensure the long-term
integrity of these systems. Site-specific soil investigations shall
be required to demonstrate suitable soil conditions exist for use
of these systems; testing should be in accordance with the guidelines
of the BMP Manual.
(a)
Where seepage pits or trenches will be used for infiltration
of flows from grassed areas or street runoff, their design shall generally
follow the guidelines of this article. It is also suggested that:
(10)
Design of cisterns for water storage facilities. The design
may be in accordance with the guidelines in the state BMP Manual or
shall meet the following criteria. An operation and maintenance plan
shall be provided and notes added to the plan to ensure the long-term
integrity of these systems. Site-specific soil investigations shall
be required to demonstrate suitable soil conditions exist for use
of these systems; testing should be in accordance with the guidelines
of the BMP Manual.
(a)
These structures shall either be located within a building or
below frost level where they will be protected against freezing. They
shall be designed to hold 0.2 cubic feet of water per square foot
of roof coverage.
(b)
Access to the structures by insect or animal vectors shall be
controlled by screens or other obstructions.
(c)
Facilities should have a means of access for cleanout of accumulated
debris or sediment.
(d)
Facilities to be used for nonpotable water supply purposes shall
comply with plumbing code regulations for cross-connections.
(e)
Septic tank-type structures are recommended for smaller facilities.
(f)
Rooftop storage must comply with all building code regulations
on load limitations and other related factors.
(g)
All water storage facilities shall be equipped to divert flows
in excess of their holding capacity to appropriate areas of discharge.
If water stored in a cistern will be used for nonpotable water supply
purposes, the facility shall be designed to drain down through a seepage
bed within 72 hours.
A.
General. In order to provide more suitable sites for
building and other uses, improve surface drainage and control erosion
the following requirements shall be met:
(1)
All lots, tracts or parcels shall be graded to provide
proper drainage away from buildings and dispose of it without ponding,
and all land within a development shall be graded to drain and dispose
of surface water without ponding except where approved by the Carroll
Township Board of Supervisors.
(2)
All drainage provisions shall be of such design to
adequately handle the surface runoff and carry it to the nearest suitable
outlet such as a curbed street, storm drain, or natural watercourse.
Where drainage swales are used to divert surface waters away for buildings,
they shall be sodded or planted as required, and shall be of such
slope, shape and size as to conform with the requirements established
by the Carroll Township Board of Supervisors.
(3)
Concentration of surface water runoff shall only be
permitted in swales or watercourses.
(4)
Driveways and streets shall be designed and constructed
to prevent water runoff from flowing directly onto intersecting streets.
(5)
Excavation and fills:
(a)
Cut and fill slopes shall not be steeper than specified in § 120-23E unless stabilized by a retaining wall or cribbing except an approved by the Carroll Township Board of Supervisors when handled under special conditions.
(b)
Adequate provisions shall be made to prevent
surface water from damaging the cut face of excavations of the sloping
surfaces of fills.
(c)
Cut and fills shall not endanger adjoining property.
(d)
Fill shall be placed and compacted so as to
minimize sliding or erosion of the soil.
(e)
Fill shall not encroach on natural watercourses
or constructed channels.
(f)
Fill placed adjacent to natural watercourses
or constructed channels shall have suitable protection against erosion
during periods of flooding.
(g)
Grading shall not be done in such a way so as
to divert water onto the property of another landowner.
(h)
During grading operations, necessary measures
for dust control shall be exercised.
(i)
Grading equipment will not be allowed to cross
flowing streams. Provision will be made for the installation of culverts
or bridges and the necessary DEP permits must be obtained.
A.
General. These erosion and sedimentation control measures
shall meet the requirements of this chapter and the "Soil Erosion
and Sedimentation Control Handbook" of the Perry County Conservation
District, as revised to date. All erosion control plans shall be submitted
to the Perry County Conservation District for review, comment and
approval.
(1)
The Carroll Township Board of Supervisors shall not
issue a building permit to those engaged in earth moving activities
requiring a Department of Environmental Protection permit until the
Department has issued a permit and/or plans are completed in accordance
with Chapter 102, Rules and Regulations of DEP as amended.
(2)
Further, under the requirements noted above, the Carroll
Township Board of Supervisors which issues building permits shall
notify the Department of Environmental Protection immediately upon
receipt of an application for a building permit involving earth moving
activity which disturbs the cover of 25 acres or more of land.
B.
Standards. The following are the minimum requirements
for erosion control on construction projects in Carroll Township:
(1)
No changes shall be made in the contour of the land;
no grading excavating, removal or disturbance of the topsoil, trees
or other vegetative cover of the land shall be commenced until such
time that a plan for minimizing erosion and sedimentation has been
processed with and reviewed by the Carroll Township Planning Commission,
or there has been a determination by the Carroll Township Planning
Commission, and the Carroll Township Board of Supervisors that such
plans are not necessary. Appropriate earthmoving permits from the
Department of Environmental Protection shall be required.
(2)
No subdivision or land development plan shall be approved
unless there has been a plan approved by the Carroll Township Board
of Supervisors and the Perry County Conservation District that provides
for minimizing erosion and sedimentation consistent with this chapter,
and an improvement bond or other acceptable securities are deposited
with the Township in the form of an escrow guarantee which will ensure
installation and completion of the required improvements; or there
has been a determination by the Carroll Township Board of Supervisors
that a plan for minimizing erosion and sedimentation is not necessary.
(3)
Measures used to control erosion and stormwater and
reduce sedimentation shall as a minimum meet the standards and specifications
of the Perry County Conservation District, and the Rules and Regulations
of the Department of Environmental Protection, Chapter 102, and the
Pennsylvania Clean Streams Law, Act 222, July 31, 1970, as amended.
The Perry County Conservation District shall ensure compliance with
the appropriate specifications, copies of which are available from
the Conservation District.
(4)
A plot plan restriction requiring compliance with
the erosion and sediment control plan for construction of on-lot improvement
(buildings, driveways, etc.) shall be included on the final plan.
C.
Guidelines. The following measures are effective in
minimizing erosion and sedimentation, where applicable:
(1)
Stripping of vegetation, regrading, or other development
shall be done in such a way that will minimize erosion. For that area
of land which must be cleared of trees and other vegetation to allow
construction of buildings and other improvements, the limits of clearing
shall include only:
(a)
Dedicated streets, public service or utility
easements.
(b)
Building roof coverage area plus 25 feet on
all sides for construction activity.
(c)
Driveways, alleyways, walkways and ancillary
structures, such as patios.
(d)
Parking lots, except that the area subtracted
for parking space shall not include any trees which are unique by
reason of size, age or some other outstanding quality, such as rarity
or status as a landmark or species specimen.
(e)
Other land area necessary to construct the proposed
buildings, and other improvements.
(2)
Development plans shall preserve salient natural features,
keep cut-fill operations to a minimum, and ensure conformity with
topography so as to create the least erosion potential and adequately
handle the volume and velocity of surface water runoff.
(3)
Whenever feasible, natural vegetation shall be retained,
protected, and supplemented.
(4)
The disturbed area and the duration of exposure shall
be kept to a practical minimum.
(5)
Disturbed soils shall be stabilized as quickly as
practicable.
(6)
Temporary vegetation and/or mulching shall be used
to protect exposed critical areas during development.
(7)
The permanent (final) vegetation and structural erosion
control and drainage measures shall be installed as, soon as practical
in the development.
(8)
Provisions shall be made to effectively accommodate
the increased runoff caused by changed soil and surface conditions
during and after development. Where necessary, the rate of surface
water runoff shall be structurally retarded.
(9)
Sediment in the runoff water shall be trapped until
the disturbed area is stabilized by the use of debris or sediment
basins, silt traps or similar measures.
A.
Whenever sedimentation is caused by stripping vegetation,
regrading or other development, it shall be the responsibility of
the person, corporation, or others causing such sedimentation to remove
it from all adjoining surfaces, drainage systems and watercourses,
and to repair any damage at his expense within seven calendar days.
B.
Maintenance of all drainage facilities and watercourses
within any subdivision or land development is the responsibility of
the developer until they are accepted by the Township or some other
official agency, after which they become the responsibility of the
accepting agency.
C.
It is the responsibility of any person, corporation
or other entity doing any act on or across a communal stream, watercourse
or swale or upon the floodplain or right-of-way thereof, to maintain
as nearly as possible in its present state the stream, watercourse,
swale, floodplain or right-of-way during the activity and to return
it to original or equal condition after such activity is completed.
Prior to the start of any earth moving active the applicant must process
a DEP water encroachment permit.
D.
Maintenance of drainage facilities or watercourses
originating completely on private property is the responsibility of
the owner to their point of open discharge at the property line or
at a communal watercourse within the property.
E.
No person, corporation or other entity shall block,
impede the flow of, alter, construct any structure, or deposit any
material or thing, or commit any act which will affect normal flood
flow in any communal stream or watercourses.
F.
Where a subdivision is traversed by a watercourse, there shall be provided a drainage easement or right-of-way, conforming substantially with the line of such watercourse, and of such width as will be adequate to preserve natural drainage in accordance with § 120-25 of this chapter.
G.
Each person, corporation or other entity which makes
any surface changes shall be required to:
(1)
Collect on-site surface runoff and dispose of it to
the point of discharge into the common natural watercourse of the
drainage area.
(2)
Handle existing and potential off-site runoff through
the development by designing to adequately handle storm runoff from
a fully developed area upstream.
(3)
Pay the total cost of off-site improvements including
easement cost, if applicable, to the common natural watercourse, based
on a fully developed drainage area.
(4)
Provide and install at his expense, in accordance
with Township requirements, all drainage, and erosion control improvements
both temporary and permanent.
H.
Easements for such common natural watercourse improvements
shall be maintained by the individual property owners.
A.
Each SWMP shall contain provisions which clearly set
forth the ownership and maintenance responsibility of all permanent
stormwater management facilities, including:
(1)
Description of maintenance requirements.
(2)
Establishment of suitable easements for access to
all facilities by both county and Township officials.
(3)
Identification of the responsible party or entity
for ownership and maintenance of both temporary and permanent stormwater
management and erosion control facilities. In meeting this requirement,
the following priority is herein established:
(a)
As a first priority, the facilities should be
incorporated within individual lots so that the respective lot owners
will own and be responsible for maintenance in accordance with recorded
deed restriction.
(b)
As a second priority, in the event that the
first priority cannot be achieved, ownership and maintenance should
be the responsibility of a homeowners' association. The stated responsibilities
of the homeowners' 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 Perry 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 homeowners' association.
B.
All provisions of the Soil Erosion and Sedimentation
Control Handbook as prepared by the Cumberland, Dauphin and Perry
County Conservation District shall apply.
In the event that water is to be provided by
a means other than private wells, owned and maintained by the individual
owner of lots within a subdivision or land development, the applicants
shall present evidence to the governing body and the planning agency
that the subdivision or development is to be supplied by a certified
public utility, a bona fide cooperative association, or by municipal
corporation authority or utility. A copy of the certificate of public
convenience under the Pennsylvania Public Utilities Commission, or
an application for such certificate, a cooperative agreement or a
commitment, or an agreement to serve the area in question, whichever
is appropriate, shall be evidence of the supply of water as set forth
above other than by means of private wells.
