Coefficients of Imperviousness

Standard NEMO Impervious Surface Buildout

Reference: NEMO technical paper #4. Do It Yourself! Zoning-Based Impervious Surface Build-out Analysis.



The results of this technique are show here on the left, for the town of Old Saybrook, CT. Estimates of % impervious cover are averaged by local watershed (thick black lines), and depicted in the “stoplight” color scheme shown on the key.

This current snapshot can be compared with a zoning-based build-out analysis, which estimates future imperviousness based on zoning designations. The same technique is used, except that imperviousness land cover/land use coefficients are applied not to the remote sensing-based land cover, but to zoning categories (i.e., all rural residential, 2 acre areas will have x % of impervious surface).