2020-08-03 Lot-by-Lot Summary
4 Allen Place, Northampton, MA 01060 (413) 582-7000 bdg@berkshiredesign.com
Berkshire
Design
Group
August 3, 2020
Doug McDonald
Northampton DPW
RE: Burts Bog Conservation and Limited Development Project
Summary of Stormwater-Related Elements – Revised from 2017-06-08
Dear Doug:
In accordance with permit condition 5 of the Amendment to the permit (10/24/19), BDG has put together a
revised summary of the development and stormwater system by lot.
Table 1 summarizes the area of each development lot, as well as the breakdown of proposed groundcover for
each lot.
Table 1 – Groundcover Summary
Groundcover Breakdown
Lot Number Lot Area Impervious Woods Grass
sq. ft. sq. ft. sq. ft. sq. ft.
1
12,014
3,540
1,410
7,064
2
15,062
2,055
8,250
4,757
3
10,120
3,336
2,160
4,624
4
17,150
3,714
3,650
9,786
5
7,053
1,327 0
5,726
6
17,150
2,350
2,730
12,070
7
6,616
2,786 0
3,830
8
17,150
3,061
5,710
8,379
9
8,594
1,895 0
6,699
10
25,244
3,903
8,700
12,641
Total
136,153
27,967
32,610
75,576
August 3, 2020
Burts Bog Conservation and Limited Development Project
Summary of Stormwater-Related Elements (revised from 2017-06-08)
Page 2 of 2
4 Allen Place, Northampton, MA 01060 (413) 582-7000 bdg@berkshiredesign.com
Table 2 summarizes the impervious area captured by each stormwater basin, and the basin’s critical design
dimensions.
Table 2 – Basin Summary
Basin ID Lot Numbers
Impervious
Surface
Flowing to
Detention Basin
Detention Basin Outlet Detention
Basin
Storage
100-year
elevation Orifice Weir
sq. ft. cu. ft.
1 and 2 0 - - - - -
3 and 4 (part) 0 - - - - -
1
Part of lot 4, 5,
6, 7, 8, 9 and
part of 10
12,815 5” @
309.8 - Weir @
311.0
5,352 cf @
312.0 311.92
2 10 3,660 5” @
312.0
8” notch
@ 312.5
Weir @
313.2
3,250 cf @
313.4 313.26
Table 3 summarizes the stormwater components on each lot.
Table 3 – Stormwater Components by lot
Lot Number Stormwater Management Component
1 2
1 - -
2 Culvert -
3 Gravel diaphragm Stormwater piping
4 Gravel diaphragm Culvert outlet and stormwater
piping
5 Gravel diaphragm -
6 Gravel diaphragm Detention basin
and outlet
7 Gravel diaphragm -
8 Gravel diaphragm Detention basin
9 Gravel diaphragm -
10 Gravel diaphragm Detention basin and outlet