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 control, peak overflow reduction and flow control to grow big trees in hardscape environments.

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).