ain Gardens and bioswales are some of our most effective tools in implementing sustainable water practices. In the presentation, Barrett will discuss how rain gardens and bioswales protect, restore, and mimic the natural water cycle. Additionally, Tom will explain how rain gardens and bioswales can help develop a natural solution for water efficiency, and relieve storm water management issues. Rain Gardens and bioswales create natural filters through which our rainwater can flow. We are in essence helping to remove the contaminants, while reducing the speed and volume in which the water runs to the storm drains. By choosing to create a rain garden or other environmentally responsible landscape solution, we can reduce the contaminants that collect in the sewer systems, and make a significant improvement for a cleaner and healthier environment.

1. Rain Gardens
& Bioswales
By Tom Barrett
Green Water Infrastructure, Inc.
www.ThinkGWI.com
Follow us on Twitter @TomBarrett_GWI
Tom.Barrett@ThinkGWI.com
© 2011 Tom Barrett

2. The GREEN
Economy

3. How Much Rain Falls in Chicago?
January
-
1.86" Image of Rain Falling
February
-
1.58"
March
-
2.59"
April
-
3.28"
May
-
3.75"
June
-
4.08"
July
-
3.39"
August
-
3.38"
September
-
2.91"
October
- 2.65"
November
-
2.09"
December
-
1.88"
Total
33.44"

4. How Much Water Falls in Chicago?
2,500 sq. ft. Roof
January
-
,727 gallons
2 Image of Rain Falling
February
-
,540
2
March
-
,130
4
April
- 5,735
May
-
,268
5
June
-
5,657
July
-
,470
5
August
-
,200
7
September
-
,096
5
October
-
,223
4
November
-
4,691
December
- 3,787
Total
6,525
5

5. How Much Water Falls in Chicago?
3 Acre Commercial Property
January
-
42,560 gallons
1 Image of Rain Falling
February
-
32,784
1
March
-
15,876
2
April
- 299,783
May
-
75,344
2
June
-
295,710
July
-
85,934
2
August
-
76,358
3
September
-
66,383
2
October
-
20,764
2
November
-
245,203
December
- 197,954
Total
2,954,654

6. How Much Water Falls in Chicago?
City Block
(660’ x 660’ – 10 acres)
January
-
75,195 gallons
4
February
-
42,610
4
March
-
19,581
7
April
- 999,267
May
-
17,805
9
June
-
985,690
July
-
53,105
9
August
-
,254,515
1
September
-
87,936
8
October
-
35,873
7
November
-
817,335
December
- 659,842
Total
9,848,756

7. Low Impact Site Development

8. Stormwater Mitigation
Stormwater Mitigation
Stormwater Mitigation
Stormwater Mitigation
Stormwater Mitigation

10. Peak Flow
(2,500 ft. sq. Roof)
Grass Field Roof
1 Year Storm 36 gpm 111 gpm
2 Year Storm 54 gpm 139 gpm
10 Year Storm 111 gpm 206 gpm
25 Year Storm 147 gpm 245 gpm
100 Year Storm 206 gpm 309 gpm
gpm – gallons per minute

11. Peak Flow
(1 Acre Site)
Grass Field Roof
1 Year Storm 630 gpm 1,932 gpm
2 Year Storm 942 gpm 2,424 gpm
10 Year Storm 1,932 gpm 3,588 gpm
25 Year Storm 2,556 gpm 4,266 gpm
100 Year Storm 3,588 gpm 5,388 gpm
gpm – gallons per minute

12. Change in Peak Runoff Flow Before and after Development
300%
225%
150%
75%
0%
m m m m m
S tor S tor S tor S tor S tor
ar r r r r
Ye ea Ye
a
Ye
a
Ye
a
1 2Y 10 25 0
10
Stormwater Effects of Urbanization

14. Image of Rain Falling

15. Pesticide Issues
Atrazine, Nitrogen, Phosphorous

16. Stormwater Mitigation
– Collection runoff near the
source
– Slow it down
– Soak it in
– Filter it
– Apply it to the landscape
– Create habitats

17. Simple Rain garden

18. Bioswales
Engineered Soils
Underdrain

19. Location
Plant Choices Rain gardens are often
located at the end of
a roof or drain spout.
Choose plants based on
the need for light and
soil type.
Depth Size Soil
A Rain Garden usually A tpical mix is 65%
A typical Rain Garden
five to ten percent of sand, 15% top soil,
is between four to
the impervious surface 25% organic matter.
eight inches deep.
area.
Rain Gardens

20. Rain Garden

21. Bioswales
Burnsville, Minnesota

22. Native Vegetation
www.epa.gov/greenacres/ www.for-wild.org

23. Street Edges
& Medians

24. Parking Lot
Edges

25. Parking Lot
Islands

26. Driveway
Edge

27. Neighborhoods

28. Rain Garden
Indianapolis

29. Rain Garden
Indianapolis - Fall Creek Parkway

32. Functional Landscapes

34. Thank You