For any of the regulated activities of this chapter, prior to
the final approval of subdivision and/or land development plans, or
the issuance of any permit, or the commencement of any land disturbance
activity, the owner, subdivider, developer or his agent shall submit
a drainage plan for approval.
A.
Impervious cover. Any proposed regulated activity, except those defined in § 296-5D(5) and (6), which would create 10,000 square feet or less of additional impervious cover is exempt from the drainage plan preparation provisions of this chapter. All of the impervious cover added incrementally to a site above the initial 10,000 square feet shall be subject to the drainage plan preparation provisions of this chapter. If a site has previously received an exemption and is proposing additional development such that the total impervious cover on the site exceeds 10,000 square feet, the total impervious cover on the site proposed since the original ordinance date must meet the provisions of this chapter.
(1)
The date of the Township ordinance adoption of the original Act 167
Stormwater Management Ordinance shall be the starting point from which
to consider tracts as "parent tracts" in which future subdivisions
and respective impervious area computations shall be cumulatively
considered. Predevelopment impervious cover is that which is in place
as of May 18, 1989, within the Little Lehigh Creek Watershed, March
17, 1993, within the Jordan Creek Watershed, and March 1, 1995, within
the Coplay Creek Watershed. These dates reflect the original ordinance
adoption date in each watershed.
(2)
For development taking place in stages, the entire development plan
must be used in determining conformance with these criteria.
(3)
Additional impervious cover shall include, but not be limited to,
additional indoor living spaces, decks, patios, garages, driveways,
storage sheds and similar structures, any roof, parking or driveway
areas and any new streets and sidewalks constructed as part of or
for the proposed regulated activity.
(4)
Any additional areas proposed to initially be gravel, crushed stone,
porous pavement, etc., shall be assumed to be impervious for the purposes
of comparison to the exemption criteria. Any existing gravel, crushed
stone or hard packed soil areas on a site shall be considered as previous
cover for the purpose of exemption evaluation.
B.
Prior drainage plan approval. Any regulated activity for which a drainage plan was previously prepared as part of a subdivision or land development proposal that received preliminary plan approval from the Township prior to the effective date of this chapter is exempt from the drainage plan preparation provisions of this chapter, except as cited in Subsection C, provided that the approved drainage plan included design of stormwater facilities to control runoff from the site currently proposed for regulated activities consistent with ordinance provisions in effect at the time of approval and the approval has not lapsed under the Municipalities Planning Code. If significant revisions are made to the drainage plan after both the preliminary plan approval and the effective date of this chapter, preparation of a new drainage plan, subject to the provisions of this chapter, shall be required. Significant revisions would include a change in control methods or techniques, relocation or redesign of control measures or changes necessary because soil or other conditions are not as stated on the original drainage plan.
C.
These exemptions shall not relieve the applicant from implementing
such measures as are necessary to protect health, safety, property,
and state water quality requirements. These measures include adequate
and safe conveyance of stormwater on the site and as it leaves the
site. These exemptions do not relieve the applicant from the responsibility
to secure required permits or approvals for activities regulated by
any other applicable code, rule, act, or ordinance.
The following items shall be included in the drainage plan:
B.
Map(s) of the project area showing:
(1)
The location of the project relative to highways, municipalities
or other identifiable landmarks.
(2)
Existing contours at intervals of two feet. In areas of steep slopes
(greater than 15%), five-foot contour intervals may be used. Off-site
drainage areas impacting the project including topographic detail.
(3)
Streams, lakes, ponds or other bodies of water within the project
area.
(4)
Other features, including flood hazard boundaries, existing drainage
swales, wetlands, closed depressions, sinkholes and areas of natural
vegetation to be preserved.
(5)
Locations of proposed underground utilities, sewers and water lines.
The locations of all existing and proposed utilities, sanitary sewers
and water lines within 50 feet of property lines of the project site.
(6)
An overlay showing soil types and boundaries based on the Lehigh
County Soil Survey, as applicable, latest edition. Any hydric soils
present on the site should be identified as such.
(7)
Proposed changes to land surface and vegetative cover.
(8)
Proposed structures, roads, paved areas and buildings.
(9)
Final contours at intervals of two feet. In areas of steep slopes
(greater than 15%), five-foot contour intervals may be used.
(10)
Stormwater management district boundaries applicable to the
site.
(11)
A schematic showing all tributaries contributing flow to the
site and all existing man-made features beyond the property boundary
that would be affected by the project.
(12)
Clear identification of the location and nature of permanent
stormwater BMPs.
(13)
An adequate access easement around all stormwater BMPs that
would provide Township ingress to and egress from a public right-of-way.
(14)
The location of all public water supply wells within 400 feet
of the project and all private water supply wells within 100 feet
of the project.
(15)
An overlay showing geologic types, boundaries and any special
geologic features present on the site.
C.
Stormwater management controls and BMPs.
(1)
All stormwater management controls must be shown on a map and described,
including:
(a)
Groundwater recharge methods such as seepage pits, beds or trenches.
When these structures are used, the locations of septic tank infiltration
areas and wells must be shown.
(b)
Other control devices or methods such as rooftop storage, semipervious
paving materials, grass swales, parking lot ponding, vegetated strips,
detention or retention ponds, storm sewers, etc.
(2)
All calculations, assumptions and criteria used in the design of
the control device or method must be shown.
(3)
A chart describing the maximum allowable impervious cover per lot
based upon the stormwater management calculations.
(4)
All site testing data used to determine the feasibility of infiltration
on a site.
(5)
All details and specifications for the construction of the stormwater
management controls and BMPs.
D.
The BMP operations and management plan, as required in Article VII, describing how each permanent stormwater BMP will be operated and maintained and the identity of the person(s) responsible for operations and maintenance. A statement must be included, signed by the landowner, acknowledging that the stormwater BMPs are fixtures that cannot be altered or removed without approval by the Township.
E.
An environmental resources site design assessment that describes
the following:
(1)
The extent to which the proposed grading and impervious cover avoid
disturbance of significant environmental resources and preserve existing
site hydrology.
(2)
An assessment of whether alternative grading and impervious cover
site design could lessen the disturbance of significant environmental
resources and/or make better use of the site hydrologic resources.
(3)
A description of how the proposed stormwater management controls
and BMPs serve to mitigate any adverse impacts on environmental resources
on the site.
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Significant environmental resources considered in the site design
assessment include, but are not limited to, steep slopes, ponds, lakes,
streams, wetlands, hydric soils, floodplains, riparian vegetation,
native vegetation and special geologic features.
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A.
For regulated activities specified in § 296-5D (1) and (2):
(1)
The drainage plan shall be submitted by the developer to the Township
as part of the preliminary plan submission for the subdivision or
land development.
(2)
Five copies of the drainage plan shall be submitted.
(3)
Distribution of the drainage plan will be as follows:
(4)
Drainage plans involving more than 10,000 square feet of additional
impervious cover shall be submitted by the developer (possibly through
the Township) to the Lehigh Valley Planning Commission as part of
the preliminary plan submission. The Lehigh Valley Planning Commission
will conduct an advisory review of the drainage plan for consistency
with the Little Lehigh Creek Watershed, Coplay Creek Watershed or
the Jordan Creek Watershed Stormwater Management Plan. The LVPC will
not review details of the erosion and sedimentation plan or the BMP
operations and maintenance plan.
(a)
Two copies of the drainage plan shall be submitted.
(b)
The Lehigh Valley Planning Commission will provide written comments
to the developer and the Township, within a time frame consistent
with established procedures under the Municipalities Planning Code,
as to whether the drainage plan has been found to be consistent with
the stormwater management plan.
C.
(1)
The drainage plan shall be submitted by the developer to the Lehigh
Valley Planning Commission for coordination with the DEP permit application
process under Chapter 105 (Dam Safety and Waterway Management) or
Chapter 106 (Floodplain Management) of DEP's rules and regulations.
(2)
One copy of the drainage plan shall be submitted.
A.
The Township Engineer shall review the drainage plan, including the BMP operations and maintenance plan, for consistency with the adopted stormwater management plan as embodied by this chapter and with any permits issued by DEP. The Township Engineer shall also review the drainage plan against any additional storm drainage provisions contained in the Township Subdivision and Land Development, Chapter 312 or Chapter 350, Zoning, as applicable.
B.
The Township shall not approve any subdivision or land development [regulated activities § 296-5D(1) and (2)] or building permit application [regulated activities § 296-5D(3) and (4)] if the drainage plan has been found to be inconsistent with the stormwater management plan as determined by the Township Engineer.
C.
The Township shall notify the applicant in writing whether the drainage
plan, including the BMP operations and maintenance plan, is approved.
D.
The Township may require an as-built survey of all stormwater BMPs
and an explanation of any discrepancies with the drainage plan.
A modification to a submitted drainage plan for a proposed development site which involves a change in control methods or techniques, or which involves the relocation or redesign of control measures, or which is necessary because soil or other conditions are not as stated on the drainage plan (as determined by the Township Engineer) shall require a resubmission of the modified drainage plan consistent with § 296-22 subject to review per § 296-23 of this chapter.
A.
The Township may hear requests for waivers where it is alleged that
the provisions of this chapter inflict unnecessary hardship upon the
applicant. The waiver request shall be in writing and accompanied
by the requisite fee based upon a fee schedule adopted by the Township
Board of Commissioners. A copy of the waiver request shall be provided
to each of the following: Township Manager, Township Zoning Hearing
Board, Township Engineer, Director of Community Development, Township
Solicitor and Lehigh Valley Planning Commission. The request shall
fully document the nature of the alleged hardship.
B.
The Township may grant a waiver, provided, that all of the following
findings are made in a given case:
(1)
That there are unique physical circumstances or conditions, including
irregularity of lot size or shape, or exceptional topographical or
other physical conditions peculiar to the particular property, and
that the unnecessary hardship is due to such conditions, and not the
circumstances or conditions generally created by the provisions of
this chapter in the stormwater management district in which the property
is located;
(2)
That because of such physical circumstances or conditions there is
no possibility that the property can be developed in strict conformity
with the provisions of this chapter, including the no harm provision,
and that the authorization of a waiver is therefore necessary to enable
the reasonable use of the property;
(3)
That such unnecessary hardship has not been created by the applicant;
(4)
That the waiver, if authorized, will represent the minimum waiver
that will afford relief and will represent the least modification
possible of the regulation in issue;
(5)
That financial hardship is not the criteria for granting of a hardship
waiver.
C.
In granting any waiver, the Township Board of Commissioners or Zoning
Hearing Board may attach such reasonable conditions and safeguards
as it may deem necessary to implement the purposes of article. Such
conditions may include, but not be limited to (if recommended by the
Township Engineer), a requirement that comparable detention be located
by the applicant on lands other than those on which the waiver has
been requested, to assure that the overall detention capability of
a given subarea is not diminished and that the overall rate of runoff
is not increased as a result of the waiver. If a hardship waiver is
granted, the applicant must still manage the quantity, velocity quality
and direction of resulting storm runoff as is reasonably necessary
to prevent injury to health, safety or other property.
