MMW Proposed Underground Storm ChambersProject Information
Calculator Version: Version 2: June 2014
Project Name: MMW Proposed Underground Storm Chambers for 2016
User Name/ Company Name: Cliff Buhman/Inspec
Date: 9-5-15
Project Description: Proposed Underground Storm Chambers to replace
Existing North Detention Pond
Site Information
Retention Requirement (inches): 1.1 CIN OFCHANHASSE!PI
Site's Zip Code: 55331 RECEIVED
Annual Rainfall (inches): 29.6 SEP 0 8 2015
Phosphorus EMC (mg/p: 0.3
TSS EMC (mg/1): 54.5 CHANHASSENPLANNING DEPi
Total Site Area
Land Cover A Soils
B Soils C Soils D Soils
Total
(acres)
(acres) (acres) (acres)
(acres)
Forest/Open Space - Undisturbed, protected
forest/open space or reforested land
0
Managed Turf - disturbed, graded for yards or
other turf to be mowed/managed
10.38
10.38
Impervious Area (acres)
4.01
Total Area (acres)
14.39
Site Areas Routed to BMPs
Land Cover A Soils B Soils C Soils D Soils Total
(acres) (acres) (acres) (acres) (acres)
Forest/Open Space - Undisturbed, protected 0
forest/open space or reforested land
Managed Turf - disturbed, graded for yards or 10.38 10.38
other turf to be mowed/managed
Impervious Area (acres) 4.01
Total Area (acres) 14.39
Summary Information
Performance Goal Requirement
Performance goal volume retention requirement: 16012 ft3
Volume removed by BMPs towards performance goal: 7603 ft3
Percent volume removed towards performance goal 47 %
Annual Volume and Pollutant Load Reductions
Post development annual runoff volume
14.218
acre -ft
Annual runoff volume removed by BMPs:
4.5948
acre -ft
Percent annual runoff volume removed:
32
%
Post development annual particulate P load:
6.38
lbs
Annual particulate P removed by BMPs:
2.06
lbs
Post development annual dissolved P load:
5.22
lbs
Annual dissolved P removed by BMPs:
1.69
lbs
Percent annual total phosphorus removed:
32
%
Post development annual TSS load:
2108
lbs
Annual TSS removed by BMPs:
681
lbs
Percent annual T55 removed:
32
%
BMP Summary
De F.... ..1. rnA S��mmary
Da A:�ula4e Dhnenhnnic Summary
BMP Volume
Volume Volume
Volume
Percent
BMP Name
Capacity
Recieved Retained
Outflow
Retained
From Direct
BMP Name
(ft3)
(ft3) (113)
(ft3)
(%)
1 - Infiltration basin/Underground Infiltrati
7603
16012 7603
8409
47
Da A:�ula4e Dhnenhnnic Summary
Volume
Load From
Load
Outflow
Volume
From
Volume
Volume
Percent
From Direct
BMP Name
Upstream
Retained
outflow
Retained
Watershed
BMPs
(acre -ft)
(acre -ft)
(%)
(acre -ft)
(acre -ft)
1 - Infiltration basin/Underground Infiltrati
1 - Infiltration basin/Underground Infiltrati 14.218
0
4.5948
9.6232
32
Da A:�ula4e Dhnenhnnic Summary
Load From
Load From
Load
Outflow
Percent
BMP Name
Direct
Upstream
Retained
Load
Retained
Watershed
BMPs
(Ibs)
(lbs)
(%)
(lbs)
(lbs)
1 - Infiltration basin/Underground Infiltrati
6.38
0
2.06
4.32
32
Dissolved Phosphorus Summary
TSS Summary
Load From
Load From
Direct
Direct
Upstream
Load
Outflow
Percent
BMP Name
Watershed
BMPs
Retained
Load
Retained
(lbs)
(lbs)
(lbs)
(lbs)
M
1 - Infiltration basin/Underground Infiltrati
5.22
0
1.69
3.53
32
TSS Summary
BMP Schematic
1 -nfilt basin/
underground Infiltration
Load From
Load From
Direct
Load
Upstream
Outflow
Percent
BMP Name
Retained
Load
Retained
Watershed
BMPs
(lbs)
(lbs) (lbs)
(lbs)
M
1 - Infiltration basin/Underground Infiltrati
2108
0 681
1427
32
BMP Schematic
1 -nfilt basin/
underground Infiltration