Public Works: Fighting Floods With DIY Rain Gardens




Public Works: Fighting Floods With DIY Rain Gardens

Indianapolis helps citizens combat stormwater runoff and water contamination through landscape design.

Public Works looks at public space, urban design, and city-building innovations from around the world, and considers what Toronto might learn from them.

 Photo by Melsky, from the Torontoist Flickr Pool

Photo by Melsky, from the Torontoist Flickr Pool.

It’s one of Toronto’s newer traditions that each summer we get a smack of Old Testament rain that washes over roads, fills up parking lots, and saturates lawns. It floods our storm sewers and overflows into our rivers and our lake, sweeping garbage, oil, chemicals, and sediment along with it.

As our climate changes, and Storms of the Century become more like Storms of the Year, cities like Toronto will have to start dealing with the increase in rainfall and storm runoff. This can be, and is being, done through long-term infrastructure projects, but as every lawn, driveway, and sidewalk contributes to the runoff problem, it’s also worth considering smaller-scale solutions that can be implemented in the short-term.

Indianapolis Mayor Greg Ballard and his city’s office of sustainability, for example, are promoting the use of rain gardens to help soften the impact of stormwater on local waterways.

Rain Gardens are usually dug into low-lying ground, where they’ll catch runoff from roads, parking lots, downspouts, and driveways. Planted with deep-rooted flora, rain gardens absorb 30 per cent more water into the ground than a traditional lawn, meaning they reduce the amount of water streaming into natural waterways and overtaxed storm sewers. They also help filter out 80 per cent of the sediment and 90 per cent of contaminants and nutrients (which, yeah, can actually be a bad thing) contained in runoff, so that when storm runoff does get into the groundwater, lakes, or rivers, it isn’t as harmful to the environment.

Basically, rain gardens are great. And Mayor Ballard’s city wants to make sure private citizens, businesses, and institutions have all the knowledge they need to make their own. That means online resources involving everything from rain garden dimensions and a flow chart of the city permit process to a comprehensive list of suitable, native plants (for any Hoosiers who don’t already know about the effectiveness of Burr Sedge or Pink Turtlehead) and a table illustrating how they should be spaced.

There are different sets of plans for different types of rain gardens—bird and butterfly gardens, rain gardens in partial shade, rain gardens with low diversity of plants, and rain gardens that won’t grow too high. And while the city believes you can raise a garden with your own two mighty hands, they’ll also give you a tip sheet for hiring a professional.

Here in Toronto, we are trying. The Toronto and Region Conservation Authority (TRCA) offers guidelines for creating rain gardens, though it’s far less accessible than than the one from Indianapolis. And, as great an agency as the TRCA is, it’s just not as high-profile a champion of rain gardens as, say, a mayor’s office.

Indianapolis is getting citizens to take action—to do their part in stemming a serious urban problem and creating an attractive, ecologically friendly spot in their own yard. And they’re doing it with nothing more than very well-researched, very well-written resources on a website.