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 regulated
earth disturbance activity, the owner, subdivider, developer or his
agent shall submit a drainage plan and receive municipal approval
of the plan.
Exemptions from the drainage plan requirements are as specified in §
225-6.
The following items shall be included in the
drainage plan:
A. General.
(1) General description of project.
(2) General description of proposed permanent stormwater
controls.
(3) The name and address of the project site, the name
and address of the owner of the property and the name of the individual
or firm preparing 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) Location 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 or Northampton County Soil Survey, as applicable, latest
edition. Any hydric soils present on the site should be identified
as such.
(7) An overlay showing geologic types, boundaries and
any special geologic features present on the site.
(8) Proposed changes to land surface and vegetative cover.
(9) Proposed structures, roads, paved areas and buildings.
(10)
Final contours at intervals of two feet. In
areas of steep slopes (greater than 15%), five-foot contour intervals
may be used.
(11)
Stormwater management district boundaries applicable
to the site.
(12)
Clear identification of the location and nature
of permanent stormwater BMPs.
(13)
An adequate access easement around all stormwater
BMPs that would provide municipal ingress to and egress from a public
right-of-way.
(14)
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.
(15)
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.
C. Stormwater management controls and BMPs.
(1) All stormwater management controls and BMPs shall
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 shall be shown.
(b)
Other control devices or methods such as roof-top
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 BMPs shall be shown.
(3) All site testing data used to determine the feasibility
of infiltration on a site.
(4) 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 Borough.
E. Environmental resources site design assessment.
(1) An environmental resources site design assessment
that describes the following:
(a)
The extent to which the proposed grading and
impervious cover avoid disturbance of significant environmental resources
and preserve existing site hydrology.
(b)
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.
(c)
A description of how the proposed stormwater
management controls and BMPs serve to mitigate any adverse impacts
on environmental resources on the site.
(2) 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.
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 Borough) shall require a resubmission of the modified drainage plan consistent with §
225-22 subject to review per §
225-23 of this chapter.