TECHNIQUES FOR DIRECTING WATER
INTO SILVA CELLS
Tuesday, June 17th, 2014
PRESENTED BY: Marcy Bean Sustainable Landscape Architect With Panelists: Peter MacDonagh, Kestrel Design Group Michael James, DeepRoot
Techniques for
Directing Water into
Silva Cells
Presentation Overview:
• Why use the Silva Cells for Stormwater Management?
• Critical Considerations for using the Silva Cells for Stormwater Management
• Method of Stormwater Capture with Case Studies
• Porous Pavement • Marq2 Streetscape
• Sheet Flow/Curb Cuts • 2nd Avenue Streetscape
• Catch Basins/Sumps • NCSU Monitoring Site
• Questions & Answers with Panelists
1 Techniques for Directing Water into Silva Cells
Why use the Silva
Cells for Stormwater
Management?
Tree Soil System – Bioretention
• TSS Removal
• Pretreatment
• Pollutant removal
• Rate Reduction
• Slow runoff, or take offline
• Storage
• Design dependent
• Tree Growth
• Evapotranspiration &
Interception
2 Image from Aurora Streetscape, Shoreline, Washington – Photo by DeepRoot
Why use the Silva
Cells for Stormwater
Management?
Critical Considerations:
• Adapt to your site
• Project Goals
• Treatment/Storage
• Design & Size per Project
• Offline
• Small storms
3 Why use the Silva Cells for Stormwater Management?
Techniques for
Directing Water into
Silva Cells
Three features in almost every
Silva Cell project for Stormwater:
• Pretreatment
• Distribution
• Overflow
4 Image from http://www.aerosnow.com/dejanaservices/catch-basin.html
Many variations available
Techniques for
Directing Water into
Silva Cells
Method of Stormwater Capture
with Case Studies
Porous Pavement
Marq2 Streetscape
Sheet Flow/Curb Cuts
2nd Avenue Streetscape
Catch Basins/Sumps
NCSU Monitoring Site
5 Techniques for Directing Water into Silva Cells
METHOD OF CAPTURE #1 –
POROUS PAVEMENT Keep it simple.
Method of Capture: Porous Pavement
Porous Pavement 7
Keep it simple.
Pretreatment Distribution Overflow
Case Study:
Porous Pavement
Marquette & 2nd Avenues (Marq2)
Minneapolis, Minnesota
On-site stormwater management
through porous pavers and
infiltration through the Silva Cell
system.
Average soil volume per tree: 587 ft3
Catchment area: 1.15 acres
Number of trees: 167
Total Silva Cells: 4,909 frames, 9,818
decks
Installation date: 2008-2009
Project Designer: SEH and URS
8 Photo taken summer 2012, Kestrel Design Group
Method of Capture: Porous Pavement
9 Marq2 Silva Cell Installation - 2009
Method of Capture: Porous Pavement
10 Marq2 Streetscape – 2009, and again in 2013
Method of Capture: Porous Pavement
11 Marq2 Silva Cell Installation, tree monitoring images by Kestrel Design Group
METHOD OF CAPTURE #2 –
SHEET FLOW / CURB CUT Raingarden concept.
Method of Capture: Sheet Flow/Curb Cut
Sheet Flow / Curb Cut 13
Raingarden concept.
Method of Capture: Sheet Flow/Curb Cut
Sheet Flow / Curb Cut 14
Raingarden concept.
Case Study:
Sheet Flow/Curb Cut
2nd Avenue Streetscape, Calgary,
Alberta
On-site stormwater management
and data monitoring through curb
cuts and distribution into the Silva
Cell system.
Average soil volume per tree: 19m3 (671
ft3)
Catchment area: 1,235 m2 (0.3 acres)
Number of trees: 7
Total Silva Cells: 470 frames, 270 decks
Installation date: June 2013
Project Designer: Kestrel Design Group &
Larson Engineering
15 Image courtesy City of Calgary
Method of Capture: Sheet Flow/Curb Cut
16 2nd Avenue Streetscape – Detail by Kestrel Design Group
Pretreatment Distribution Overflow
Method of Capture: Sheet Flow/Curb Cut
17 2nd Avenue Streetscape Construction – Photos by DeepRoot
Method of Capture: Sheet Flow/Curb Cut
18 2nd Avenue Streetscape Construction – Photos by DeepRoot
Method of Capture: Sheet Flow/Curb Cut
19 2nd Avenue Streetscape – Before and After – Photo at left by DeepRoot, photo at right courtesy City of Calgary
METHOD OF CAPTURE #3 –
CATCH BASIN Slow things down.
Method of Capture: Catch Basin
Catch Basin 21
Pretreatment Distribution Overflow
Slow things down.
Method of Capture: Catch Basin
22 Catch Basin
Pretreatment Distribution Overflow
Slow things down.
Catch Basin Schematic
23 Image from http://www.aerosnow.com/dejanaservices/catch-basin.html
Elbow
Distribute to Silva Cell system
Slow things down.
Many variations available
Case Study:
Catch Basin
North Carolina State University
Stormwater Treatment
Performance Monitoring Sites,
Wilmington, North Carolina
On-site stormwater management
and data monitoring through catch
basins and distribution through the
Silva Cell system.
Comparison of two sites, Orange Street
and Ann Street
Soil volume per tree: 750 ft3
Catchment area: ~0.10-0.12 acres
Number of trees: 1 per treatment area
Total Silva Cells: 68 frames, 34 decks
Installation date: June-July 2012
Monitoring dates: Sept 2012-July 2013
Project Designer: North Carolina State
University with Kestrel Design Group
24 Approximate drainage area for each tree, image adapted from Page, Winston and Hunt
Silva
Cells
Silva
Cells
Method of Capture: Catch Basin
25 NC State Research Site - Image from Page, Winston and Hunt
Method of Capture: Catch Basin
26 NC State Research Site – Photos by DeepRoot
Method of Capture: Catch Basin
27 NC State Research Site – Photos by DeepRoot
TECHNIQUES FOR DIRECTING WATER
INTO SILVA CELLS
Tuesday, June 17th, 2014
6/12/2014
Contact us: DeepRoot Blog:
http://www.deeproot.com/blog/ [email protected]
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