So it might seem like we’re beating the same old drum here, but I have to mention that we have now exceeded 100 Silva Cell installations (yeah!). Each of them represents a very real accomplishment for the planners, designers, and developers who saw the value in bringing long-term sustainable tree and stormwater solutions to their communities. Ultimately, our goals are not so much about gaining acceptance for the Silva Cell specifically as they are about making inroads into policy changes for soil volume targets and sustinable on-site stormwater management (what we call green utilities) at a municipal level.

In pursuit of this goal, we try to keep strategizing with forward-thinking city officials and sustainable infrastructure advocates as a top priority. While there may be no one answer to the ecological and financial challenges we’re facing in our urban areas, continuing the discussion and debate about these targets is of critical importance. Toronto, ON has already adopted an ambitious soil volume target of 1,059 ft3 (30 m3) per tree for mid- to high-rise residences, commercial, industrial and institutional developments in their Green Development Standards. They’ve approached on-site stormwater management goals with the same ambition, mandating that the same sites retain all runoff from “small design” rainfall events (typically .19,” or 5 mm) through rainwater reuse, on-site infiltration, and evapotranspiration.

Canada has been at the forefront in recognizing and accepting the role that green utilities can play in creating sustainable urban infrastructure. In addition to regulatory approval for use in Toronto’s Urban Design Streetscape Manual and the Green Development Standards, the Silva Cell has been formally approved for use in the Markham, ON Streetscape Manual. Three other applications for acceptance — in British Columbia (Langley and Kelowna) and Manitoba (Winnipeg) — are in the final stages of approval. 

We’ve had some great success in the United States, too. In September 2009 the Silva Cell received a General Use Designation by the Washington State Department of Ecology. Their identification of the Silva Cell as “functionally equivalent to a rain garden” green lights its use by designers, contractors and engineers at project sites throughout the state without the need for pre-approval. The Washington DOE is recognized as the benchmark for environemntal best practices among states in the Pacific Northwest, and we’re very excited about this approval.

Now, onward!