THE STORMWATER CALCULATION PROCESS - Low Impact Development and Sustainable Stormwater Management - page 193

Worksheet 3. Nonstructural BMP Credits

PROTECTED AREA

1.1 Area of Protected Sensitive/Special Value Features (see WS 2) Ac.

Ac.

1.2 Area of Riparian Forest Buffer Protection

Ac.

3.1 Area of Minimum Disturbance/Reduced Grading

TOTAL

Ac.

Protected

Site Area minus

-

Area =

=

Stormwater Management Area

This is the area that requires
stormwater management

VOLUME CREDITS

3.1Minimum Soil Compaction
Lawn ft 2 ft 3

x 1/4"x 1/12 =

ft 2 ft 3

Meadow x 1/3"x 1/12 =

3.3Protect Existing Trees
For Trees within 100 feet of impervious area:
Tree Canopy

ft 3

ft 2 x 1/2"x 1/12 =

For Trees within 20 feet of impervious area:
Tree Canopy

ft 3

ft 2 x 1"x 1/12 =

5.1Disconnect Roof Leaders to Vegetated Areas
For runoff directed to areas protected under 5.8.1 and 5.8.2
Roof Area

ft 3

ft 2 x 1/3"x 1/12 =

For all other disconnected roof areas
Roof Area

ft 2

ft 3

x 1/4"x 1/12 =

5.2Disconnect Non-Roof impervious to Vegetated Areas
For Runoff directed to areas protected under 5.8.1 and 5.8.2
Impervious Area

ft 3

ft 2

x 1/3"x 1/12 =

For all other disconnected roof areas
Impervious Area

ft 3

ft 2

x 1/4"x 1/12 =

ft 3

TOTAL NON-STRUCTURAL VOLUME CREDIT*

* For use on Worksheet 5