The primary intent of this mapping is to define and delineate the watershed of Little Pond and calculate the amount of impervious surfaces within the watershed.

To achieve this, we started with LIDAR data collected throughout the Boston area. This provided very detailed topographic data.

From this, we generated a coverage showing two-foot contour intervals throughout the area.

This, along with the paper and electronic storm drain maps from each of the three towns, was used to calculate the Little Pond watershed.

We then acquired land use data for the Boston area, part of new study by FEMA. The watershed boundary was used as a cookie cutter to extract the relevant land use data from the larger data set.

The 11 classes of land use were reduced to two, pervious and impervious, and the impervious class was plot over the orthophoto.