Transcript Document
The DeepRoot Silva Cell Integrating Trees, Soil & Stormwater for Sustainable Development. What’s missing from this picture? “Nearly all of the associated problems result from one underlying cause: loss of the water-retaining and evapotranspirating functions of the soil and vegetation in the urban landscape.” EPA commissioned report Urban Stormwater Management in the United States, 2008. Photo courtesy of James Urban It’s all about soil... General Design Goals Water quality and Water quantity 1. Volume and time water is held at the site 2. Increase infiltration and evapo-transpiration to reduce overall surface runoff 3. Reduce pollutant load 4. Reduce water temperature Rain Garden Case Studies Check dams Surface water infiltration – Absorbing soils in planted areas or pervious pavers, and green roof areas. Pavers and green roof approach is expensive. Limited by infiltration rate of soil and subsoil. Limited storage How can we start to solve some of these problems? • Large trees • Treating stormwater as a resource • Integrating trees, soil and stormwater Grow big trees. Manage rainwater. Do it all on-site. Pervious Pavement is the simplest way to get stormwater in to Silva Cells for storage and treatment Perforated distribution pipe is installed to bring water from the catch basin through the Silva Cell system Catch Basin Queensway Installation MMarquette Street, Minneapolis Combined rain garden and below paving treatment In a suburban strip development LR Large Canopy How much soil does a tree need? Summary Cities must employ all of the design options Ponds Cisterns Green roofs Pervious pavers Rain gardens Biofiltration with trees Basic Applications Streetscapes/Plazas Break-out zones Parking lots Green walls Green roofs/on-structure All of these applications can be modified to optimize tree growth or stormwater management. Parking Lot application Use Silva Cells in parking lots to achieve green canopy cover goals and downsize the stormwater system without compromising parking spaces or utilities. Parking Lot application Wal-Mart SuperStore Parking Lot Lakeland, FL Research shows trees grow best in uncompacted soil Image courtesy of Bartlett Tree Research Laboratory (North Carolina) Flexible and modular.