Stormwater management system, including calculations; this shall
include existing drainage characteristics of the general area of the
project, and the effect of the proposed use and any proposed drainage
facilities on the existing drainage characteristics. The drainage
plan shall be prepared by a registered professional engineer in the
Commonwealth of Massachusetts and show existing and proposed streets,
lots, two-foot contours, and other pertinent data; drainage limits
and acreage of the area tributary to each stormwater inlet and culvert,
location and type of inlets proposed; location, size, length, invert
elevations and slope of proposed drains and culverts; structural details
of inlets, manholes, pipes, headwalls, and all other drainage structures
required to complete the plan.