Green infrastructure is a low-impact development approach that protects and restores nature in the urban environment, blending engineered solutions with existing environmental processes. The Silva Cell is a modular suspended pavement system that uses soil to create forest-like conditions in the city, supporting large tree growth and providing powerful on-site stormwater management through absorption, evapotranspiration, and interception.

— How it works —

Meet regional stormwater requirements using underground bioretention designed for tight urban spaces. The Silva Cell is a stormwater BMP that leverages soil and trees to provide:
Water quality / pollutant control
Peak overflow reduction/flow control
Any type of soil
Grow big trees

The soil contained in the Silva Cell serves two important functions: growing large trees and treating stormwater onsite.

Interception and Evapotranspiration: Large trees intercept and evapotranspire significantly more rain than small trees. For example, a healthy 40 year old Hackberry tree is estimated to provide 14 times as much interception as a 10 year old Hackberry (McPherson et al 2006).

Long-Term Infiltration: As roots grow and then decay, they leave open channels in the soil that restore and/or enhance porosity and infiltration rates. Several studies have found a significant increase in saturated hydraulic conductivity in bioretention with plants as compared to those without (e.g. Lucas and Greenway 2011).

Water Quality Benefits: Vegetation is crucial to many water quality benefits, including removal or sequestration of dissolved nutrients, hydrocarbons, and Total Suspended Solids (TSS).

Plants also slow water flow, allowing more time for sedimentation to occur (Hunt et al 2012).

Silva Cell compared to typical bioretention systems

Unlike some bioretention systems, which leach nutrients and negatively impact receiving water bodies, Silva Cell systems also provide nutrient removal. Additional lowimpact development benefits of the system include:
- Water quality
- Peak overflow reduction
- Low/no maintenance
- May use any type of soil
- Efficient use of space

Silva Cells can be used on almost any type of site, including:
- Streets
- Plazas
- Parking areas
- Green roofs/on-structure
- "Break-out" zones.



U.S. Approvals
Canadian Approvals
City of North Vancouver
City of Calgary
City of Edmonton
Toronto Regional Conservation Authorityaccept Silva Cells as an equivalency for bioretention
Lake Simcoe Regional Conservation Authority accept Silva Cells as an equivalency for bioretention
Credit Valley Conservation Authorityaccept Silva Cells as an equivalency for bioretention