Impervious Surface Ratio (ISR) Worksheet

February 9, 2023

Method of Calculation
IMPERVIOUS SURFACE- "Any hard-surfaced, man-mad area that does not readily absorb or retain water, including but not limited to building roofs, parking and driveway areas, sidewalk and paved recreational facilities."
IMPERVIOUS SURFACE RATIO (ISR)- "The total area of impervious surfaces divided by the net area (excluding right-of-way) of the lot."
LOT AREA- "The total horizontal area included within the list lines of the lot. No public right-of-way or access easement for a public street or handle of panhandle lot shall be included in the calculation of the lot area, nor shall the public right-of-way cross the lost area."
Lot information:
Name
First Last
Phone
Address * Required
Street Address Address Line 2 City State / Province / Region ZIP / Postal Code
Email
Site Identification: * Required
Lot Area: * Required
sq.ft.
Description of Project: * Required
Permit application number, if applicable
Building Footprint: * Required
sq.ft.
Parking & Drive Areas: * Required
sq.ft.
Access Easements: * Required
sq.ft.
Walkways: * Required
sq.ft.
Other:
sq.ft.
If you chose "Other" Above, please describe impervious surfaces you are referring to:
Total Impervious Surfaces:
Impervious Surface Ratio % * Required
Total Impervious Surfaces divided by Lot Area.
Signature * Required
By Checking the box, I certify that the calculations submitted above for the Impervious Surface Ratio are accurate and complete to the best of my knowledge.

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