[Ord. No. 6-2018, 10/23/2018]
1.
For all regulated activities, unless specifically exempted in § 26-302:
A.
Preparation and implementation of an approved SWM site plan is required.
B.
No regulated activities shall commence until South Hanover Township
issues written approval of an SWM site plan, which demonstrates compliance
with the requirements of this chapter.
D.
The SWM site plan approved by South Hanover Township shall be on
site throughout the duration of the regulated activities.
2.
For all regulated earth disturbance activities, erosion and sediment
control BMPs shall be designed, implemented, operated, and maintained
during the regulated earth disturbance activities (e.g., during construction)
to meet the purposes and requirements of this chapter and to meet
all requirements under Title 25 of the Pennsylvania Code (including,
but not limited to, Chapter 102, Erosion and Sediment Control) and
the Clean Streams Law. Various BMPs and their design standards are
listed in the Erosion and Sediment Pollution Control Program Manual
(E&S Manual), No. 363-2134-008 (April 15, 2000), as amended and
updated.
3.
For all regulated activities, stormwater BMPs shall be designed,
installed, implemented, operated, and maintained to meet the purposes
and requirements of this chapter and to meet all requirements under
Title 25 of the Pennsylvania Code and the Clean Streams Law, conform
to the state water quality requirements, and meet all requirements
under the Storm Water Management Act and any more-stringent requirements
as determined by South Hanover Township.
4.
South Hanover Township may, after consultation with PADEP and/or
DCCD, approve measures for meeting the state water quality requirements
other than those in this chapter, provided that they meet the minimum
requirements of, and do not conflict with, state law, including, but
not limited to, the Clean Streams Law.
5.
All regulated activities shall include, to the maximum extent practicable,
measures to:
A.
Protect health, safety, and property.
B.
Meet the water quality goals of this chapter by implementing measures
to:
(1)
Minimize disturbance to floodplains, wetlands, natural slopes,
existing native vegetation and woodlands.
(2)
Create, maintain, or extend riparian buffers and protect existing
forested buffers.
(3)
Provide trees and woodlands adjacent to impervious areas whenever
feasible.
(4)
Minimize the creation of impervious surfaces and the degradation
of waters of the commonwealth and promote groundwater recharge.
(5)
Protect natural systems and processes (drainageways, vegetation,
soils, and sensitive areas) and maintain, as much as possible, the
natural hydrologic regime.
(6)
Incorporate natural site elements (wetlands, stream corridors,
mature forests) as design elements.
(7)
Avoid erosive flow conditions in natural flow pathways.
(8)
Minimize soil disturbance and soil compaction.
(9)
Minimize thermal impacts to waters of the commonwealth.
(10)
Disconnect impervious surfaces by directing runoff to pervious
areas wherever possible, and decentralize and manage stormwater at
its source.
C.
Applicants are encouraged to incorporate the techniques for low-impact
development practices described in the Pennsylvania Stormwater Best
Management Practices Manual (BMP Manual) to reduce the costs of complying
with the requirements of this chapter and the state water quality
requirements.
6.
Impervious areas.
A.
The measurement of impervious areas shall include all of the impervious
areas in the total proposed development, even if development is to
take place in stages.
B.
For development taking place in stages, the entire development plan
must be used in determining conformance with this chapter.
C.
For projects that add impervious area to a developed parcel, the
new impervious area is subject to the requirements of this chapter;
and any existing impervious area that is within the new proposed limit
of disturbance is also subject to the requirements of this chapter.
7.
If diffused flow is proposed to be concentrated and discharged onto
adjacent property, the applicant must document that adequate downstream
conveyance facilities exist to safely transport the concentrated discharge,
or otherwise prove that no erosion, sedimentation, flooding, or other
harm will result from the concentrated discharge.
A.
The applicant must provide an executed easement for newly concentrated
flow across adjacent properties.
8.
Stormwater drainage systems shall be provided in order to permit
unimpeded flow along natural watercourses, except as modified by stormwater
management facilities or open channels consistent with this chapter.
9.
Where watercourses traverse a development site, drainage easements
(with a minimum width of 20 feet) shall be provided conforming to
the line of such watercourses. The terms of the easement shall prohibit
excavation, the placing of fill or structures, and any alterations
that may adversely affect the flow of stormwater within any portion
of the easement. Also, maintenance, including mowing of vegetation
within the easement, may be required, except as approved by the appropriate
governing authority.
10.
When it can be shown that, due to topographic conditions, natural
drainageways on the site cannot adequately provide for drainage, open
channels may be constructed conforming substantially to the line and
grade of such natural drainageways. Work within natural drainageways
shall be subject to approval by PADEP under regulations at 25 Pa.
Code, Chapter 105, through the joint permit application process or,
where deemed appropriate by PADEP, through the general permit process.
11.
Any stormwater management facilities or any facilities that constitute
water obstructions (e.g., culverts, bridges, outfalls, or stream enclosures,
etc.) that are regulated by this chapter, that will be located in
or adjacent to waters of the commonwealth (including wetlands), shall
be subject to approval by PADEP under regulations at 25 Pa. Code,
Chapter 105, through the joint permit application process or, where
deemed appropriate by PADEP, the general permit process. When there
is a question whether wetlands may be involved, it is the responsibility
of the applicant or his agent to show that the land in question cannot
be classified as wetlands; otherwise, approval to work in the area
must be obtained from PADEP.
12.
Should any stormwater management facility require a dam safety permit
under PADEP Chapter 105, the facility shall be designed in accordance
with Chapter 105 and meet the regulations of Chapter 105 concerning
dam safety which may be required to pass storms larger than the 100-year
event.
13.
Any stormwater management facilities regulated by this chapter that
will be located on, or discharged onto, state highway rights-of-way
shall be subject to approval by the Pennsylvania Department of Transportation
(PennDOT).
14.
When stormwater management facilities are proposed within 1,000 feet
of a downstream municipality, the stormwater analysis shall be submitted
to the downstream municipality's Engineer for review and comment.
15.
Minimization of impervious surfaces and infiltration of runoff through
seepage beds, infiltration trenches, etc., is encouraged, where soil
conditions and geology permit, to reduce the size or eliminate the
need for detention facilities.
16.
Infiltration BMPs should be dispersed throughout the site, made as
shallow as practicable, and located to maximize use of natural on-site
infiltration features while still meeting the other requirements of
this chapter.
17.
The design of facilities over karst shall include an evaluation and
implementation of measures to minimize adverse effects.
18.
Roof drains shall not be connected to streets, sanitary or storm
sewers, or roadside ditches in order to promote overland flow and
infiltration/percolation of stormwater where it is advantageous to
do so. When it is more advantageous to connect directly to streets
or storm sewers, then South Hanover Township shall permit it on a
case-by-case basis.
[Ord. No. 6-2018, 10/23/2018]
2.
South Hanover Township, at its discretion, may require an applicant
to demonstrate that the following BMPs are being utilized to the maximum
extent practicable to receive consideration for the exemptions:
A.
Limit disturbance of floodplains, wetlands, natural slopes over 30%,
existing native vegetation, and other sensitive and special-value
features.
B.
Maintain riparian and forested buffers.
C.
Limit grading and maintain nonerosive flow conditions in natural
flow paths.
D.
Maintain existing tree canopies near impervious areas.
E.
Minimize soil disturbance and reclaim disturbed areas with topsoil
and vegetation.
F.
Direct runoff to pervious areas.
3.
South Hanover Township, at its discretion, may require an applicant
to demonstrate that the proposed development/additional impervious
area will not adversely impact the following:
4.
An applicant proposing regulated activities, after demonstrating compliance with §§ 26-302, Subsections 1 and 2 may be exempted from the requirements of this chapter, according to Table 1 below and the following conditions. If the applicant requests an exemption and meets all of the conditions below, the requirements of § 26-302, Subsection 3 are assumed to be met.
[Amended by Ord. No. 6-2020, 7/14/2020]
A.
Minimum separation.
(1)
New impervious cover must be separated from the features listed in Subsection 4A(2) below by the minimum separation distances listed in Table 1.
(2)
Minimum separation distance is the shortest distance from the
edge of the proposed new impervious cover, or roof drain discharge
point, in the flow direction of runoff, to any of the following:
(a)
Perennial or intermittent streams or watercourses.
(b)
Swales or ditches.
(c)
Wetlands.
(d)
Lakes, ponds and other surface water bodies.
(e)
Storm sewer or combined sewer systems.
(f)
Public roads.
(g)
Property lines.
(h)
Cropland, pasture land, manure storage areas and other agricultural land unless the area meets the requirements of Subsection 4D(2) below.
(i)
Other features deemed relevant by the Township Board of Supervisors.
B.
Multiple impervious areas.
(1)
If the proposed new impervious area receives runoff from an
existing contiguous impervious area or contributes runoff to an existing
contiguous impervious area, the total impervious area to be considered
for this exemption shall be the new impervious area only.
(2)
If the existing and proposed new impervious areas are not contiguous,
the total impervious area to be considered for this exemption shall
be the new impervious area only. In this case, the total separation
area may include the distance between the two impervious areas.
(3)
Separation from the features listed in Subsection 4A(2) shall be determined from the edge, or roof drain discharge, of either the existing or proposed new impervious area, whichever is most downslope.
(4)
The Township reserves the right to consider existing conditions
and runoff issues in determining the needed separation area under
this section.
|
Table 1 - Minimum Separation Distances
| ||
|---|---|---|
|
New Impervious Area In Square Feet
|
Minimum Separation Distance
|
Minimum Separation Distance
|
|
No Roof Drain
|
Roof Drain
| |
|
0-250
|
25
|
40
|
|
251-500
|
50
|
75
|
|
501-1,000
|
75
|
110
|
|
1,001-1,500
|
100
|
150
|
|
1,501-2,000
|
125
|
190
|
|
2,001-2,500
|
150
|
225
|
|
2,501-3,000
|
175
|
260
|
|
3,001-4,000
|
200
|
300
|
|
4,001-5,000
|
225
|
340
|
|
Where the Township believes that the conditions of the area
receiving runoff (slope, soil erosiveness, etc.) from the new impervious
area may be an issue, the Township may request additional separation
distance.
| ||
C.
D.
Separation area.
(1)
The area separating the proposed new impervious discharge from any features such as those listed in Subsection 4A(2) must at all times meet the following criteria:
(a)
Be maintained in stable vegetative cover.
(b)
Eroded areas in the separation area must be immediately repaired.
(c)
No new impervious cover may be installed in the separation areas
unless the requirements of this ordinance are met.
(d)
Runoff in the separation area must be maintained as unconcentrated
flow.
(2)
The separation area may contain cropland, pasture land, manure
storage areas and other agricultural land provided the land is in
compliance with Title 25 Chapter 102.4.a (relating to erosion and
sediment pollution control on agricultural land) and Title 25 Chapter
91.36.a (relating to pollution control at agricultural operations)
of the Pennsylvania Code.
E.
An applicant for an exemption that cannot meet the criteria above
may qualify for reduced requirements based on the following:
(2)
Reduced requirements will be according to the following Table
2:
|
Table 2 - Reduced Stormwater Management Requirements
| |
|---|---|
|
New Impervious Area* in Square Feet Since the Date of Adoption
of this Section
|
Applicant Must Submit to the Township
|
|
0 - 1,000
| |
|
1,001 - 5,000
|
Volume controls and SWM site plan and report
|
|
>5,000
|
Rate controls, volume controls, SWM site plan and report and
record drawings
|
|
*
|
Gravel in the existing condition shall be considered pervious
and proposed gravel shall be considered impervious.
|
F.
Requirement for additional stormwater management controls.
(1)
The Township Board of Supervisors reserves the right to require
additional stormwater management controls if an exempted project is
determined to be causing adverse impacts of any kind.
G.
Obligation to meet other requirements.
(1)
Nothing in this section shall relieve the applicant of any responsibility
under other regulations such as, but not limited to, Township ordinances
or codes and state and federal regulations related to stormwater management,
NPDES permitting requirements for erosion and sediment pollution control
and post-construction stormwater management, stream and wetland encroachment
or floodplain management.
H.
Township decision.
(1)
All requests for exemptions or modifications shall be at the
discretion of the Township Board of Supervisors. Demonstration that
a proposed project meets exemption or modification requirements does
not necessarily obligate the Township Board of Supervisors to grant
the request for exemption or modification.
(2)
The Township Board of Supervisors may consider any and all relevant
factors such as, but not limited to, runoff concentration, slope,
soil characteristics, existed problems, adjacent properties, sensitive
environmental features and recommendations from other Township entities
such as planning commissions, Township engineers and solicitors in
determining whether or not to grant any request for exemption or modification.
5.
The purpose of this section is to ensure consistency of stormwater
management planning between local ordinances and NPDES permitting
(when required) and to ensure that the applicant has a single and
clear set of stormwater management standards to which the applicant
is subject. South Hanover Township may accept alternative stormwater
management controls, provided that:
A.
The applicant, in consultation with South Hanover Township, PADEP
and/or DCCD, states that meeting the requirements of the volume controls
or rate controls of this chapter is not possible or creates an undue
hardship.
B.
The alternative stormwater management controls proposed by the applicant
are documented to be acceptable to South Hanover Township, PADEP and/or
DCCD for NPDES requirements pertaining to post-construction stormwater
management requirements.
6.
Forest management and timber operations are exempt from rate and
volume control requirements and SWM site plan preparation requirement
of this chapter, provided the activities are performed according to
the requirements of 25 Pa. Code, Chapter 102. It should be noted that
temporary roadways are not exempt.
7.
Activities that increase the impervious coverage, but the increase
is accounted for and managed by a stormwater management best management
practice designed and installed under an previously approved subdivision
or land development plan, are exempt from the requirements of this
chapter.
8.
Agricultural activities are exempt from the requirements of this
chapter, provided the activities are performed according to the requirements
of 25 Pa. Code, Chapter 102.
9.
High tunnels are exempt from the requirements of this chapter, provided
that the high tunnel or its flooring does not result in an impervious
area exceeding 25% of all structures located on the owner's total
contiguous land area and the high tunnel meets one of the following:
A.
The high tunnel is located at least 100 feet from any perennial stream
or watercourse, public road or neighboring property line.
B.
The high tunnel is located at least 35 feet from any perennial stream
or watercourse, public road or neighboring property line and located
on land with a slope not greater than 7%.
C.
The high tunnel is supported with a buffer or diversion system that
does not directly drain into a stream or other watercourse by managing
stormwater runoff in a manner consistent with requirements of this
chapter.
10.
Linear roadway improvement projects that create additional impervious
area are not exempt from the requirements of this chapter. However,
alternative stormwater management strategies may be applied at the
joint approval of South Hanover Township and the Dauphin County Conservation
District (if an NPDES permit is required) when site limitations (such
as limited right-of-way) and constraints (as shown and provided by
the applicant) preclude the ability of the applicant to meet the enforcement
of the stormwater management standards in this chapter. All strategies
must be consistent with PADEP's regulations, including NPDES requirements.
11.
South Hanover Township may, after an applicant has demonstrated compliance with § 26-302, Subsections 1, 2 and 3, grant a modification of the requirements of one or more provisions of this chapter if the literal enforcement will exact undue hardship because of peculiar conditions pertaining to the land in question, provided that such modification will not be contrary to the public interest and that the purpose and intent of the chapter is observed.
A.
All requests for a modification shall be in writing and shall state
in full the grounds and facts of unreasonableness or hardship on which
the request is based, the provision or provisions of the ordinance
involved, and the minimum modification necessary.
[Ord. No. 6-2018, 10/23/2018]
1.
The low-impact development practices provided in the BMP Manual and
in Appendix B of this chapter[1] shall be utilized for all regulated activities to the
maximum extent practicable.
[1]
Editor's Note: Appendix B is included as an attachment to this chapter.
2.
Stormwater runoff volume controls shall be implemented using the
Design Storm Method or the Simplified Method. For regulated activities
equal to or less than one acre, this chapter establishes no preference
for either method; therefore, the applicant may select either method
on the basis of economic considerations, the intrinsic limitations
on applicability of the analytical procedures associated with each
methodology, and other factors.
A.
The Design Storm Method (CG-1 in the BMP Manual) is applicable to
any sized regulated activity. This method requires detailed modeling
based on site conditions.
(1)
Do not increase the post-development total runoff volume when
compared to the predevelopment total runoff volume for the two-year/twenty-four-hour
storm event.
(2)
For hydrologic modeling purposes:
(a)
Existing nonforested pervious areas must be considered meadow
(good condition) for predevelopment hydrologic calculations.
(b)
20% of existing impervious area, when present on the proposed
project site, and contained within the new proposed limit of disturbance,
shall be considered meadow (good condition) for predevelopment hydrologic
calculations for redevelopment.
B.
The Simplified Method (CG-2 in the BMP Manual) is independent of
site conditions and should be used if the Design Storm Method is not
followed. This method is not applicable to regulated activities greater
than one acre. For new impervious surfaces:
(1)
Stormwater facilities shall capture at least the first two inches
of runoff from all new impervious surfaces.
(2)
At least the first one inch of runoff from new impervious surfaces
shall be permanently removed from the runoff flow, i.e., it shall
not be released into surface waters of the commonwealth. Removal options
include reuse, evaporation, transpiration, and infiltration.
(3)
Wherever possible, infiltration facilities should be designed
to accommodate infiltration of the entire permanently removed runoff;
however, in all cases at least the first 0.5 inch of the permanently
removed runoff should be infiltrated.
3.
All applicable worksheets from Chapter 8 of the BMP Manual must be
used when establishing volume controls.
4.
Actual field infiltration tests at the location of the proposed elevation
of the stormwater BMPs are required for all proposed infiltration
facilities. Infiltration tests shall be conducted in accordance with
the BMP Manual. Acceptable soil will have an infiltration rate of
at least 0.1 inch per hour and not more than 10 inches per hour (after
application of the appropriate safety factor from the BMP Manual).
The stabilized infiltration rate is to be determined in the same location
and within the same soil horizon as the bottom of the infiltration
facility. South Hanover Township shall be notified 24 hours prior
to infiltration tests being conducted so as to provide an opportunity
for South Hanover Township to witness the tests.
[Ord. No. 6-2018, 10/23/2018]
1.
For all lands contained within South Hanover Township, the post-development
peak discharge rates shall not exceed the predevelopment peak discharge
rates for the one-, two-, ten-, twenty-five-, fifty-, and 100-year
storms.
2.
Lands contained within Dauphin County that have had release rates
established under an approved Act 167 stormwater management plan:
A.
Post-development discharge rates shall not exceed the predevelopment
discharge rates for the one-, fifty-, and 100-year storms.
B.
For the two-, ten-, and twenty-five-year storms, the post-development
peak discharge rates shall be in accordance with the approved release
rate map for the individual watershed.
[Ord. No. 8-2022, 11/22/2022]
1.
In order to protect and improve water quality, a riparian buffer
easement shall be created and recorded as part of any subdivision
or land development that encompasses a riparian buffer.
2.
Except as otherwise required, the riparian buffer easement shall
be measured to be a minimum of 50 feet from the top of the streambanks
(on each side).
3.
Minimum management requirements for riparian buffers:
A.
Existing native vegetation shall be protected and maintained within the riparian buffer easement and in accordance with the requirements set forth in Subsection 5, below.
B.
Whenever practicable invasive vegetation shall be actively removed,
and the riparian buffer easement shall be planted with native trees,
shrubs and other vegetation to create a diverse native plant community
appropriate to the intended ecological context of the site.
4.
The riparian buffer easement shall be enforceable by the municipality
and shall be recorded in the Dauphin County Recorder of Deeds Office,
so that it shall run with the land and shall limit the use of the
property located therein. The easement shall allow for the continued
private ownership and shall count toward the minimum lot area as required
by zoning, unless otherwise specified in the municipal Zoning Ordinance.[1]
5.
Any permitted use within the riparian buffer easement shall be conducted
in a manner that will maintain the extent of the existing 100-year
floodplain, improve or maintain the stream stability, and preserve
and protect the ecological function of the floodplain and in accordance
with the riparian forest buffer management plan.
7.
Septic drainfields and sewage disposal systems shall not be permitted
within the riparian buffer easement and shall comply with setback
requirements established under 25 Pa. Code Chapter 73.
