This document provides an overview of various bioretention techniques for managing stormwater runoff, including rain gardens, stormwater planters, swales, vegetated filter strips, and green streets approaches. It explains how each technique works to collect, absorb, and filter runoff while reducing pollutants. The document also discusses the importance of reducing runoff volumes, not just delaying it, to fully restore water quality and balances in the environment.

1. Bioretention Overview
Sustainability for all the places between the buildings.
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2. Rain Gardens
• Planted, bowl‐shaped area designed to collect and
absorb runoff and reduce polllutants.
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3. Rain Gardens
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4. Rain Gardens
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5. Rain Gardens
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6. Stormwater Planters
• Structural container with soil and plants built to collect
and slow runoff and reduce pollutants.
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7. Stormwater Planters
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8. Stormwater Planters
Courtesy of Ken Cook of Flickr
Courtesy of Davidsilver of Flickr
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9. Swales (aka Bioswales)
• Long, planted, open channel that carries, slows and
absorbs stormwater and filters out pollutants.
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10. Swales (aka Bioswales)
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11. Swales
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12. Swales (aka Bioswales)
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13. When is a swale really a rain garden?
• When water ponds in the facility instead of flowing
through it:
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14. When is a swale really a rain garden?
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15. Green Streets can be Swales
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16. Vegetated Filter Strip
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17. Vegetated Filter Strips
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18. Vegetated Filter Strips
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19. Vegetated Filter Strips
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20. Green Streets can be Rain Gardens
• Street designed to capture, absorb and filter runoff using
rain gardens, planters, swales, porous pavement, tree
canopy and other methods.
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21. Green Streets can be Planters and Tree Canopy
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22. Green Streets can be Porous Pavement
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23. X” rainfall
yearly avg
0.005% runoff
40% evaporation
35% groundwater
(deep infiltration)
The Water Balance Model
Water Quantity Before
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24. X” rainfall
yearly avg
Reduced reduced evapo-
infiltration ration
98% runoff
infiltration
No
2% evaporation
The Water Balance Model
Water Quantity After
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25. Water Quality Before
Some sediment
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26. Water Quality After
Sediment (air particulates)
Nutrients
Feces
Other debris
Runoff volumes
Sediment/turbidity
Hydrocarbons
Heavy metals (particles & soluble)
Other chemicals
Runoff volume
Sediment/turbidity
fertilizers
pesticides
herbicides
Runoff volume
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27. Sediment/turbidity?
Hydrocarbons
Heavy metals (particles & solubl
Other chemicals
Runoff volume
Bioretention
Water Quality &
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28. Hey! What about detention ponds?
They look pretty green?
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29. Detention ponds are not LID or… why you must
reduce runoff volume to restore water quality
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30. Detention ponds
are not low impact development
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31. Detention ponds
are not low impact development
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32. Detention ponds
are not low impact development
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33. Detention ponds
are not low impact development
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34. Detention ponds
are not low impact development
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35. Detention ponds
are not low impact development
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36. Detention ponds
are not low impact development
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37. Detention ponds
are not low impact development
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38. Detention ponds
are not low impact development
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39. Runoff Volume & Duration
from a Watershed Perspective
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