2. The Green Corridor Project
Green Infrastructure and Stormwater Pre-Treatment Concept
“Silva Cell” Crate System
“Freno” Modular Flow-Through Planters
Micro-Pool Stormwater Swale
Streetscape Planting Concepts

4. Design Considerations: Expected Pollutants
Landscaping sites (fertilizers -- phosphorus and nitrogen): greater cell depth will help filter these.
Studies show that removal of these pollutants increases with the depth of the bio-retention cell, reaching removal levels up to 80% for phosphorus and 60% for nitrogen (TKN) with sufficient depth (study results relating to nitrogen vary).
Parking lot or streetscape applications (metals, oils, grease and solids): Thicker mulch layer
Studies support that a significant mulch layer will effectively remove greater than 90% of copper, zinc and lead.
In urban areas where heavy metals are the focal pollutants, shallow bioretention facilities with a significant mulch layer may be recommended. In residential areas, however, where the primary pollutants of concern are nitrogen and phosphorus, the depth dependence will require deeper cells that reach approximately 2 to 3 feet

5. Bio-retention removes Pollutants (survey of studies)
Pollutant Removal
Copper
43%-97%
Lead
70%-95%
Zinc
64%-95%
Phosphorus
65%-87%
Total Kjeldahl Nitrogen (TKN)
52-67%
Ammonium (NH4+ )
92%
Nitrate (NO3-)
15%-16%
Total nitrogen (TN)
49%
Calcium
27%
Bioretention BMP,

6. Fairfax Boulevard Stormwater Pre-Treatment Filtration Based System
Filtration Systems provide temporary storage and filtration of stormwater, contributing to:
Water quality control
Percentage Reduction of Stormwater Volume
Channel protection,
Overbank protection, and
Extreme flood control
Used where soils are not suitable for infiltration
The system stores and treats stormwater before returning it to the stormwater drainage system typically through a perforated under-drain.
Use of small scale, natural drainage features to slow, clean and capture runoff to reduce the impacts of development on rivers, streams, lakes, coastal waters, and ground water.

7. “Silva Cell” Crate System
Fairfax Boulevard
Lancaster Cir. To 6th Ave
“Silva Cell” Crate System
Suspended Concrete and Brick Paving
Stormwater Distribution/Irrigation Lines
“Silva Cell” Structural Crates Containing Uncompacted Engineered Soils for Tree Root Growth and Water Retention
Perforated Under Drains for
Large Storm Events
Geomembrane Liner to prevent Infiltration beyond the Structural Crate System
Connection to the Underground Storm Sewer System

8. How the “Silva Cell” Crates works

10. Washington DC- SW 1st street- Silva Cells 2008- 2010

11. City of Charlotte Soil Vaults- 1985
Willow Oak (Quercus phellos) Planted 1985, 25 years old in 2010
Avg DBH 16 inches; Avg 44 feet; Avg Soil Volume 700 cubic feet

12. Modular Flow-Through Planters
Fairfax Boulevard
6th Ave. to 12th Ave.
Modular Flow-Through Planters
Precast Concrete Curb Drain/Inlet
Gravel Filter Strip
Herbaceous Plantings
2 inch Mulch Layer
Engineered Soils
Sand and Gravel Drainage Bed
Overflow Drain for Large Storm Events
Perforated Under Drains
Geomembrane Liner to prevent Infiltration beyond the Flow-Through Planter
Modular Precast Concrete Flow-Through
Planter Walls
Connection to the Underground Storm Sewer System

13. “Freno” Modular Flow-Through Planters

15. Life Cycle Benefits
As a modular system the Freno Flow-Through Planter can be removed and reused.
Similarly, components can be removed and reconfigured if the site is redesigned.
The system can be repaired with replacement parts if accidental damage occurs.

16. Suggested Modular Flow-Through Planter Maintenance
Activity
Schedule
Water plants daily for 2 weeks
At project completion
Inspect soil and repair eroded areas
Remove litter and debris
Re-mulch void areas
As Needed
Remove and replace dead and diseased vegetation
Twice per year
Add mulch
Cut back herbaceous plantings during winter dormancy
Once per year
Test soil treatment performance and replace soil/plants
Testing 3 years
As needed (7-10years)
Bioretention BMP,

17. 6th Ave. to Fairfax Crossing
Fairfax Boulevard
6th Ave. to Fairfax Crossing
Micro-Pool
Stormwater Swale
Landscape Micro-Pool Plantings w/ Street Trees
Weir Wall Spillways
3 ft. Turf Filter Strip
Herbaceous Plantings with Formal Planting Border
Perforated Under Drains
Overflow Drain for Large Storm Events
Connection to the Underground Storm Sewer System

18. Layered and “Over” Planting Approach to Micro-Pool Planting

19. Suggested Micro-Pool Weir Planting Maintenance
Activity
Schedule
Water plants daily for 2 weeks
At project completion
Inspect soil and repair eroded areas
Remove litter and debris
Re-mulch void areas
As Needed
Mow monthly for the First year
First year Only
Add mulch
Mow and/or cut back plantings during winter dormancy
Selectively Remove Invasive exotic Plants
Once per year
Re-plant eroded and bare areas after large storm events
As needed
Bioretention BMP,

20. The Key to the Overall Success of the Micro-Pool Planting is to not over maintain after the First Year
Mow and/or cutback once a year
No irrigation needed
No fertilizing needed

21. Bio-diverse Planting of Street Trees

22. Layered and “Over” Planting Modular Flow-Through Planters

23. Micro-Pool Strategic Combination Plantings

24. Brick and Concrete Paving between Lancaster Cir. And 6th Ave.