Cities across the world have made stormwater management a top priority, encouraging green roofs, downspout disconnections and innovative drainage systems. In Toronto, the annual budget for stormwater management is $40 million.
To a non-expert, this may all seem fine, but we often remain unclear on why stormwater management is so important. The fact is, we can’t name the real problem in basic english without using an obscenity. And so we use euphemism, latin or greek, or technical or farming terms. And as a result, most of us wind up missing the point.
So here it is, plain and simple: stormwater management is about s**t.
Let’s back up: In most of downtown Toronto, including Roncesvalles, we have a Combined Sewer System (see image, right). Such systems combine the sanitary and stormwater flows into one pipe. When there is heavy rain, the system gets overwhelmed, and responds by dumping everything, including untreated feces and urine, into the nearest lake or river.
Shockingly, in Toronto, such sewage overflows are normal, occurring at an average rate of once per week. Sunnyside Beach is regularly closed in the summer due to fecal contamination of the lake. And when conditions are abnormal, such as during last summer’s record rainfalls, even the overflow system gets overwhelmed, and untreated human waste backs up into people’s basements. In July of 2008, the Sunnyside-Gus Ryder pool was closed after the children’s wading pool was flooded with human filth.
Climatologists forecast that the future pattern for Toronto will be increasing precipitation, in the form of hard fast downpours, with longer dry spells in between. Urban growth will further strain Toronto’s sewer systems. This means, what is abnormal today will soon become our new normal. The City of London is now spending £2 billion (that’s billion, that’s pounds) on a stormwater interceptor tunnel to reduce sewage overflows. Governments everywhere are learning how crucial it is to reduce the flow of stormwater into our sewers.
On Roncesvalles, the BIA urges the creation of a Living Sidewalk. This project would integrate Roncesvalles’ stormwater sewer with an innovative new tree planting system that would finally allow urban trees to grow to maturity, instead of dying within 5-10 years of age. The result would be that our sidewalks, instead of acting like funnels channelling water rapidly into the sewers, would become massive absorption pads, sucking up huge amounts of water and slowing the drainage process down.
This system obviously costs more to construct than the current, inadequate methods. But over the long-term, the system greatly reduces planting and maintenance costs, and allows utility companies to easily access their equipment without harming tree roots. It would not only reduce stormwater flow and sewage spills, but would absorb massive amounts of greenhouse gasses and airborne pollution, cool the street, and beautify our neighborhood. It is a cost-effective solution that beautifully and efficiently integrates the urban and natural environments.
Further reading:
City of Toronto Wet Weather Flow Master Plan
City of Toronto Stormwater Management Workshop Presentation May 7, 2008 (with good background info, plus a description of the Living, or Sustainable Sidewalk on page 43)
“In the Sewers,” the first chapter of The Big Necessity, by Rose George. (This is an informative and entertaining overview of the challenges facing our municipal water management engineers and workers — and you will learn with vivid clarity why you should never put bacon grease down the drain!)
Climate Change in Southern Ontario: Implications for Urban Forestry, February 9, 2009