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 §
26-6.
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) Locations of proposed underground utilities, sewers and waterlines.
The locations of all existing and proposed utilities, sanitary sewers
and waterlines 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.
An overlay showing geologic types, boundaries and any special geologic
features present on the site.
(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)
Clear identification of the location and nature of permanent
stormwater BMPs.
(12)
An adequate access easement around all stormwater BMPs that
would provide municipal ingress to and egress from a public right-of-way.
(13)
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.
(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.
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 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 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 municipality.
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 municipality) shall require a resubmission of the modified drainage plan consistent with §
26-27 subject to review per §
26-28 of this chapter.
A modification to a submitted SWM site plan that involves a
change in SWM BMPs or techniques, or that involves the relocation
or redesign of SWM BMPs, or that is necessary because soil or other
conditions are not as stated on the SWM site plan as determined by
the municipality shall require a resubmission of the modified SWM
site plan in accordance with this article. The applicable review must
accompany a resubmission of a disapproved SWM site plan.
The municipality's approval of an SWM site plan authorizes the regulated activities contained in the SWM site plan for a maximum term of validity of five years following the date of approval. The municipality may specify a term of validity shorter than five years in the approval for any specific SWM site plan. Terms of validity shall commence on the date the municipality signs the approval for an SWM site plan. If an approved SWM site plan is not completed according to §
26-30 within the term of validity, then the municipality may consider the SWM site plan disapproved and may revoke any and all permits. SWM site plans that are considered disapproved by the municipality shall be resubmitted in accordance with §
26-28 of this chapter.