This section shall apply to the calculation of minimum lot size, development coverage and residential density. For purposes of calculating development yield, the following areas shall be subtracted from the gross acreage of a parcel to establish the minimum lot area and maximum permissible development coverage in the case of nonresidential projects requiring site plan approval, or development yield and permissible density in the case of residential subdivisions or site plans:
A.
Utility rights-of-way and designated streets. Fifty percent of any land within easements or rights-of-way for overhead utilities of 69 kilovolts or greater, or within a designated street line, shall not be counted as part of any minimum lot area requirement. No building, structure, yard or land proposed for prolonged habitual human occupancy shall be located within a utility easement; however, a road may traverse the easement.
B.
Land under water (applicable prior to development). One hundred percent of that portion of a lot subject to the following shall not be counted as part of any minimum lot area requirement: ponds: freshwater wetlands regulated by the Army Corps of Engineers; streams; and that portion of any freshwater wetland and any 100-foot control area designated by the New York State Department of Environmental Conservation. No construction shall be permitted within the limits of the freshwater wetland or stream without appropriate federal or state permits.
C.
Floodplains. Fifty percent of any land contained within the 100-year floodplain as designated on Federal Emergency Management Agency maps shall not be counted as part of any minimum lot area requirement. No construction shall be permitted within the 100-year floodplain.
D.
Steep slopes (applicable prior to development).
(2)
No construction shall be permitted on that portion of a lot with a slope in excess of 20% except for roads and driveways and supporting infrastructure as necessary to access flatter areas of the lot.
(3)
No portion of the land area of that portion of a lot with a slope in excess of 50% may be counted as part of the minimum lot area of a parcel.
E.
Rock outcrops (applicable prior to development). Not more than 50% of the area of that portion of a lot that is proposed to be disturbed with rock outcrops in excess of 50 square feet may be counted as part of the lot area of a parcel.