In the residential zoning districts the following provisions
of this Part 9 shall apply:
The purpose of this bylaw is to preserve and enhance the landscape
by encouraging the maximum retention of natural topographic features,
such as drainage swales, streams, slopes, ridge lines, rock outcroppings,
vistas, natural plant formations and trees; to minimize water runoff
and soil erosion problems incurred in grading of steep slopes; to
encourage innovative architectural, landscaping, circulation and site
design. For the purposes of this section, the term "natural" shall
be defined as the condition of the ground surface as it exists at
the time a subdivision or development is proposed, including any man-made
alterations such as grading, excavation or filling which may have
occurred prior to the time such subdivision or development is submitted.
No land intended for subdivision or development may be regraded or
filled in such manner as to circumvent this bylaw.
The provisions of this Part
9 shall not apply to building lots in a definitive subdivision plan submitted in accordance with MGL Chapter 41 in order to obtain the protections afforded by MGL c. 40A, § 6.
The slope of land at any point, stated as a percentage, shall
be defined as the change in elevation over a horizontal distance measured
perpendicular to the contours divided by the distance over which the
change occurs multiplied by 100. The slope of land at any point may
be stated as a ratio (2:1, 3:1, 4:1, etc.). The first number of the
ratio indicates the horizontal distance and the second number indicates
the vertical rise.
All natural slopes exceeding 33% (3:1) over a horizontal distance
of 30 feet as measured perpendicular to the contour on a tract or
parcel of land intended or proposed for subdivision or on a building
lot are protected and shall remain undisturbed.
All areas with natural slopes exceeding 33% (3:1) over a horizontal
distance of 30 feet as measured perpendicular to the contour on a
tract or parcel of land intended or proposed for subdivision or development,
or on a lot intended for building purposes, shall be excluded from
the calculation of the minimum lot area required for the applicable
zoning district.