[Ord. 524, 12/15/2010, § 301]
1.
For all regulated activities, unless specifically exempted in § 26-117:
A.
Preparation and implementation of an approved SWM site plan is required.
B.
No regulated activities shall commence until the Township issues
written approval of a SWM site plan, which demonstrates compliance
with the requirements of this Part.
D.
The SWM site plan approved by Lower Swatara 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 Part 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 Part and to meet all requirements under Title
25 of the Pennsylvania Code and the Clean Streams Law, conform to
the state water quality requirements, meet all requirements under
the Storm Water Management Act and any more stringent requirements
as determined by Lower Swatara Township.
4.
Lower Swatara Township may, after consultation with PADEP and/or
DCCD, approve measures for meeting the state water quality requirements
other than those in this Part, 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 Part 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 Part and the state water quality requirements.
D.
Incorporate methods described in the Pennsylvania Stonnwater Best
Management Practices Manual (BMP Manual). If methods other than green
infrastructure and LID methods are proposed to achieve the volume
and rate controls required under this Part, the SWM site plan must
include a detailed justification demonstrating that the use of LID
and green infrastructure is not practicable.
[Added by Ord. No. 601, 7/20/2022]
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 Part.
C.
For projects that add impervious area to a parcel, the total impervious area on the parcel is subject to the requirements of this Part; except that the volume controls in § 26-118 and the peak rate controls in § 26-119 do not need to be retrofitted to existing impervious areas that are not being altered by the proposed regulated activity.
[Amended by Ord. No. 601, 7/20/2022]
7.
Stonnwater flows onto adjacent property shall not be created, increased,
decreased, relocated, or otherwise altered without written notification
to the adjacent property owner(s). Such stonnwater flows shall be
subject to the requirements of this Part.
[Added by Ord. No. 601, 7/20/2022[1]]
8.
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.
Applicant must provide an executed easement for newly concentrated
flow across adjacent properties.
9.
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 Part.
10.
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.
11.
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 drainage ways
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.
12.
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 Part, 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.
13.
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 one-hundred-year
event.
14.
Any stormwater management facilities regulated by this Part 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).
15.
When stormwater management facilities are proposed within 1,000 feet
of a downstream municipality, the stormwater analysis shall be submitted
to the downstream municipality for review and comment.
16.
Minimization of impervious surfaces and infiltration of runoff through
seepage beds, infiltration trenches, etc., are encouraged, where soil
conditions and geology permit, to reduce the size or eliminate the
need for detention facilities.
17.
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 Part.
18.
The design of facilities over karst shall include an evaluation and
implementation of measures to minimize adverse effects.
19.
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 the Township shall permit it on a case-by-case
basis.
20.
Normally dry, open top, storage facilities should completely drain
both the volume control and rate control capacities over a period
of time not less than 24 and not more than 72 hours from the end of
the design storm.
[Added by Ord. No. 601, 7/20/2022]
21.
Various BMPs and their design standards are listed in the BMP Manual.
[Added by Ord. No. 601, 7/20/2022]
[Ord. 524, 12/15/2010, § 302]
2.
The applicant must demonstrate that the following BMPs are being
utilized to the maximum extent practicable to receive consideration
for the exemptions:
A.
Design around and limit disturbance of floodplains, wetlands, natural
slopes over 15%, 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.
The applicant must demonstrate that the proposed development/additional
impervious area will not adversely impact the following:
4.
An applicant proposing regulated activities, after demonstrating compliance with § 26-116, Subsections 1, 2 and 3, may be exempted from various requirements of this Part 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 § 26-117, Subsection 3, are assumed to be met.
[Ord. 553, 4/16/2014]
A.
Minimum separation.
(1)
New impervious cover must be separated from the features listed in § 26-117, 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 runoff flow direction, 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 § 26-117, Subsection 4D(2), below;
(i)
Other features deemed relevant by the municipal governing body.
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 § 26-117, Subsection 4A(2), shall be determined from the edge, or roof drain discharge, of either the existing or proposed new impervious areas, whichever is most downslope.
(4)
The municipality reserves the right to consider existing conditions
and runoff issues in determining the needed separation area under
this section.
|
Table 1
Minimum Separation Distances
| ||
|---|---|---|
|
Minimum Separation Distance
(See Appendixes E and F)[1]
| ||
|
New Impervious Area
(square feet)
|
No Roof Drain
(feet)
|
Roof Drain
(feet)
|
|
0 to 250
|
25
|
40
|
|
251 to 500
|
50
|
75
|
|
501 to 1,000
|
75
|
110
|
|
1,001 to 1,500
|
100
|
150
|
|
1,501 to 2,000
|
125
|
190
|
|
2,001 to 2,500
|
150
|
225
|
|
2,501 to 3,000
|
175
|
260
|
|
3,001 to 4,000
|
200
|
300
|
|
4,001 to 5,000
|
225
|
340
|
|
5,001 to 10,000
|
350
|
525
|
|
Where the municipality believes that conditions present in the
receiving area (slope, soil type, existing problems, etc.) warrant
additional separation distance, the municipality may request additional
separation distance or require stormwater management controls.
| ||
[1]
Editor's Note: Said appendixes are included as attachments to this chapter.
C.
D.
Separation area.
(1)
The area separating the proposed new impervious discharge from any features such as those listed in § 26-117, 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 chapter 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 uses, provided that 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.
The separation area may contain cropland, pasture land, manure storage
areas and other agricultural land, provided that 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.
(2)
Reduced requirements will be according to Table 2:
|
Table 2
Reduced Stormwater Management Requirements
| |
|---|---|
|
New Impervious Area1
(square feet)
|
Applicant Must Submit to the Township
|
|
0 to 1,000
|
—
|
|
1,000 to 5,000
|
Volume controls and SWM site plan and report
|
|
More than 5,000
|
Rate controls, volume controls, SWM site plan and report and
record drawings
|
|
NOTES:
| |
|---|---|
|
1
|
Existing gravel and proposed gravel shall be considered to be
impervious.
|
F.
Requirement for additional stormwater management controls. The municipal
governing body 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. Nothing in this section shall
relieve the applicant of any responsibility under other regulations,
such as, but not limited to, municipal 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.
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. The Township may accept alternative stormwater management
controls provided that:
A.
The applicant, in consultation with the Township, PADEP and/or DCCD,
states that meeting the requirements of the volume controls or rate
controls of this Part is not possible or creates an undue hardship.
B.
The alternative stormwater management controls, proposed by the applicant,
are documented to be acceptable to the Township, PADEP and/or DCCD
for NPDES requirements pertaining to postconstruction 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 Part, 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.
Agricultural activities are exempt from the requirements of this
Part, provided the activities are performed according to the requirements
of 25 Pa. Code, Chapter 102.
8.
Linear roadway improvement projects that create additional impervious
area are not exempt from the requirements of this Part. However, alternative
stormwater management strategies may be applied at the joint approval
of the 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 Part. All strategies must be consistent
with PADEP's regulations, including NPDES requirements.
9.
Lower Swatara Township may, after an applicant has demonstrated compliance with Subsections 1, 2, and 3, grant a modification of the requirements of one or more provisions of this Part 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 this Part 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 Part involved,
and the minimum modification necessary.
10.
Municipal decision.
[Ord. 553, 4/16/2014]
A.
All requests for exemptions or modifications during the building
permit application process shall be at the discretion of the municipal
governing body. Demonstration that a proposed project meets exemption
or modification requirements does not necessarily obligate the municipal
governing body to grant the request for exemption or modification.
B.
The municipal governing body may consider any and all relevant factors,
such as, but not limited to, runoff concentration, slope, soil characteristics,
existing problems, adjacent properties, sensitive environmental features
and recommendations from other municipal entities such as planning
commissions, municipal engineers and solicitors in determining whether
or not to grant any request for exemption or modification.
[Ord. 524, 12/15/2010, § 303]
1.
The low-impact development practices provided in the BMP Manual and
in Appendix B[1] of this Part 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 Part 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)
Twenty percent 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 when 5,000 square feet or greater
of new impervious surface is added. Infiltration tests shall be conducted
in accordance with BMP Manual. Lower Swatara Township shall be notified
24 hours prior to infiltration tests being conducted to provide an
opportunity for Lower Swatara Township to witness the tests.
[Ord. 524, 12/15/2010, § 304]
1.
Lands contained within Lower Swatara Township that have not 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-, two-, ten-, twenty-five-, fifty-, and
one-hundred-year storms.
2.
Lands contained within Lower Swatara Township 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-year, fifty-year, and one-hundred-year
storms.
B.
For the two-year, ten-year, 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.
3.
More stringent criteria may be required by Lower Swatara Township
in sensitive areas where stormwater problems presently exist.
[Added by Ord. No. 601, 7/20/2022]
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 required by 25 Pa. Code Chapter 102, the riparian buffer
easement shall be measured to be the greater of the limit of the 100-year
floodplain or a minimum of 35 feet from the top of the streambank
(on each side).
3.
Minimum Management Requirements for Riparian Buffers.
A.
Existing native vegetation shall be protected and maintained within
the riparian buffer easement.
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 Township
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 a required
by zoning, unless otherwise specified in the Lower Swatara Township
Zoning Ordinance.
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.
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.
