Applicants shall determine the development capacity
of all tracts of land proposed for subdivision and/or land development
by applying the environmental adjustment factors (EAFs) identified
in this section. These EAFs modify the development capacity based
on the constraints of natural features that affect water supply, sewage
disposal, and construction of buildings and other site improvements.
A. Calculation of the developable area of a tract.
(1) The applicant shall determine the developable area
of the tract by determining the number of acres containing each natural
feature, then applying the EAFs to the acreage affected by these environmental
constraints, using the worksheet herein.
(2) Existing features.
(a)
The applicant shall provide a plan of existing
features of the subject tract that shows the boundaries and acreages
of the net tract area, all areas affected by each natural feature,
and all unconstrained areas.
(b)
Where more than one of these natural features
occupy part of a tract, that part shall be subject only to the most
restrictive factor (the factor with the lowest number).
(3) Worksheet:
(a)
Net tract area = _____ acres. [Net tract area
is the total (gross) tract area minus existing public and private
rights-of-way, utility easements, access easements, or access strips.]
(b)
Net tract area adjustment for natural features
(EAFs):
|
a.
|
Seasonal HWT
(less than 18 inches)*
|
_____ acres x 0.33 EAF
|
= _____ acres
|
|
b.
|
Seasonal HWT
(18 inches to 36 inches)*
|
_____ acres x 0.67 EAF
|
= _____
|
|
c.
|
Depth to bedrock
(less than 42 inches)*
|
_____ acres x 0.67 EAF
|
= _____ acres
|
|
d.
|
Diabase bedrock**
|
_____ acres x 0.33 EAF
|
= _____
|
|
e.
|
Slopes
(15% to 24%)
|
_____ acres x 0.33 EAF
|
= _____
|
|
f.
|
Slopes
(greater than 24%)
|
_____ acres x 0.00 EAF
|
= _____
|
|
g.
|
Floodplain
|
_____ acres x 0.00 EAF
|
= _____
|
|
h.
|
Wetlands
|
_____ acres x 0.00 EAF
|
= _____
|
|
i.
|
Watercourses
|
_____ acres x 0.00 EAF
|
= _____
|
|
j.
|
Waterbodies
|
_____ acres x 0.00 EAF
|
= _____
|
|
k.
|
Unconstrained net acreage
|
_____ acres x 1.00 EAF
|
= _____
|
|
Total Developable Area of the Tract (total of
a through k)
|
= _____ acres
|
|
NOTES:
|
|
*
|
Applies to sites with a sewage system(s) that
utilizes land for treatment and disposal purposes. For sewage systems
not utilizing land, the density factor equals 1.0.
|
|
**
|
Applies to sites with well(s) as the water source.
For a site not utilizing well(s), the density factor equals 1.0. Also,
for any zoning district that requires the use of central water and
the central supply is proposed to be from on-site well(s), the density
factor may equal 1.0, provided it can be proven to the Township's
satisfaction that the water supply will be sufficient, will not cause
any adverse effects on existing wells, and all applicable Township
ordinances are met.
|
B. Maximum tract density calculation. Maximum tract density
is the maximum number of residential dwelling units (or lots) or maximum
number of nonresidential building lots permitted on a tract in compliance
with EAF calculations.
(1) R-1 and R-2 district maximum tract density is calculated
by the following formula:
|
Maximum tract density
|
=
|
Total developable area of the tract
|
|
|
|
Minimum developable lot area
(see district standards)
|
|
NOTE:
|
---|
|
Minimum developable lot area shall be expressed
as acres or as a fraction of an acre in decimal form (e.g., two acres,
one acre, 0.5 acre, 0.25 acre, etc.).
|
(2) R-3 and R-4 district maximum tract density is calculated
by the following formula:
|
Maximum tract density = Total developable area of the tract (from Subsection A) multiplied by the density number expressed as dwelling units per acre of total developable area (e.g., 27.2 acres times four dwelling units per acre).
|
(3) Rounding. All maximum tract density values shall be
rounded down to the closest whole number (for example, 5.99 is rounded
down to five).
(4) Limitations. Maximum tract density is a calculated
maximum number that is not guaranteed to be feasible on a given site.
The tract configuration and other factors may make the maximum tract
density unattainable.
C. Calculation of the buildable area of each proposed
lot.
(1) The applicant shall determine the buildable area of
each proposed building lot by determining the area of each lot containing
each natural feature, then applying the EAFs to the areas affected
by these environmental constraints, using the worksheet herein.
(2) Existing features.
(a)
The applicant's plan shall show the existing
features of each lot, including boundaries and acreage/square footage
of all areas affected by each natural feature, and all unconstrained
areas.
(b)
Where more than one of these natural features
occupy part of a lot, that part shall be subject only to the most
restrictive factor (the factor with the lowest number).
(3) Worksheet:
(a)
Net lot area of Lot No. _____ = _____ acres
or square feet. [Net lot area is the total (gross) lot area minus
existing and proposed public and private rights-of-way, utility easements,
access easements, or access strips.]
(b)
Net lot area adjustment for natural features
(EAFs):
|
a.
|
Seasonal HWT
(less than 18 inches)*
|
_____ area x 0.33 EAF
|
= _____ area
|
|
b.
|
Seasonal HWT
(18 inches to 36 inches)*
|
_____ area x 0.67 EAF
|
= _____
|
|
c.
|
Depth to bedrock
(less than 42 inches)*
|
_____ area x 0.67 EAF
|
= _____
|
|
d.
|
Diabase bedrock**
|
_____ area x 0.33 EAF
|
= _____
|
|
e.
|
Slopes
(15% to 24%)
|
_____ area x 0.33 EAF
|
= _____
|
|
f.
|
Slopes
(greater than 24%)
|
_____ area x 0.00 EAF
|
= _____
|
|
g.
|
Floodplain
|
_____ area x 0.00 EAF
|
= _____
|
|
h.
|
Wetlands
|
_____ area x 0.00 EAF
|
= _____
|
|
i.
|
Watercourses
|
_____ area x 0.00 EAF
|
= _____
|
|
j.
|
Waterbodies
|
_____area x 0.00 EAF
|
= _____
|
|
k.
|
Unconstrained net acreage
|
_____ area x 1.00 EAF
|
= _____
|
|
Total Buildable Area of Lot No. _____ (total
of a through k)
|
= _____ (acres or square feet)
|
NOTES:
|
---|
*
|
Applies to sites with a sewage system(s) that
utilizes land for treatment and disposal purposes. For sewage systems
not utilizing land, the density factor equals 1.0.
|
**
|
Applies to sites with well(s) as the water source.
For a site not utilizing well(s), the density factor equals 1.0. Also,
for any zoning district that requires the use of central water and
the central supply is proposed to be from on-site well(s), the density
factor may equal 1.0, provided it can be proven to the Township's
satisfaction that the water supply will be sufficient, will not cause
any adverse effects on existing wells, and all applicable Township
ordinances are met.
|
D. Compliance with buildable area and lot size standards.
(1) Lot size. The lot size of each proposed lot must equal
or exceed the minimum lot size specified in the applicable zoning
district standards.
(2) Total buildable area. The total buildable area of
each proposed lot must equal or exceed the minimum buildable area
for each building lot specified in the applicable zoning district
standards.
(3) In the R-3 and R-4 districts, the minimum buildable
areas for the various dwelling types shall be equal to the minimum
lot area required for each dwelling type.
E. Evaluation of compliance with EAFs and related dimensional
standards.
(1) To facilitate evaluation of compliance with these
standards, the applicant's plan shall include a table listing the
following:
(a)
Total (gross) tract area.
(c)
Total developable area of the tract.
(d)
Maximum tract density, including the calculations required by Subsection
B.
(e)
Minimum lot size required by the applicable
zoning district.
(f)
Minimum buildable area required by the applicable
zoning district.
(g)
Lot size and buildable area proposed for each
building lot and lot proposed for purposes other than building.
(2) The applicant shall provide one copy of all the worksheets required for Subsections
A and
C for review by the Township Engineer, one copy for the Township's files, and copies for other Township advisors, when requested.
F. Natural features determination. The following procedure
shall be followed to determine the presence, location, and boundaries
of all natural features, and, except as provided for elsewhere in
this chapter, to address disputes concerning these features:
(1) The presence, location, sizes, and boundaries of any
natural feature(s) shall be determined by the applicant through on-site
survey, reference to the natural features maps contained in the Township's
Open Space Preservation Plan of 1995, and/or other resources acceptable
to the Township Engineer.
(2) The Township Engineer shall review the applicant's
information and determine the adequacy of the applicant's plan with
respect to the presence, location, and boundaries of all natural features
located on the site(s).
(3) If a dispute arises concerning the Township Engineer's
determination, the applicant shall have the burden of proving that
a different finding is warranted. The applicant shall submit to the
Township Engineer all technical information and documentation supporting
a different finding, including any information or findings from qualified
agencies such as the Soil Conservation Service. Upon review, the Township
Engineer shall make a final determination.
(4) If the Township Engineer's final determination is disputed, the applicant may appeal to the Township Zoning Hearing Board under Article
XIX of this chapter.