Waterloo Region got 56 millimetres of rain between Thursday and Saturday evening, an amount equivalent to almost a month's worth of rain. 

So if that left you with a soggy yard, a local award-winning landscaper says a rain garden could help your waterlogged lawn, and your municipality. 

Rain gardens look just like a regular garden, but are designed to capture and filter stormwater, said Jeff Thompson, an environmental biologist and president of the Waterloo chapter of Landscape Ontario. 

"They actually help protect the creeks and streams from this big influx of stormwater during a storm.

"The stormwater takes with it everything it touches, pollutants enter our water and then we want to draw that same water back and drink it, so we have to spend more and more money to treat it and turn it into drinking water."

Porous soil and deep roots

Rain gardens are made by digging a deep hole, between half a meter and a meter deep, filling it with a porous biological soil mix, and replacing grass with native shrubs and wildflowers. 

A good rain garden captures water from rain spouts pointed in its direction, and filters it down into the local aquifer.

Native plant species are key, said Thompson, because they will thrive in typical conditions and have deep root systems.

"Some of these root systems go down 13 feet deep," said Thompson. "And there's the added benefit that these are all pollinator plants."

Examples of those plants include: prairie dock, pale purple coneflower, little blue stem and big blue stem grasses. 

Rain gardens can be as small as a single plant, or as large as you like, provided they're at least three meters away from a building foundation, four meters away from a septic bed and 30 meters away from any wells – to prevent contamination.

Thompson also advises against planting one in the lowest-lying part of your yard, where water already collects. That pooling water means the area is already oversaturated and can't take on more water. 

Growing trend

Though Thompson has been designing rain gardens for the last 20 years, the trend is only recently starting to catch on. 

He says that's because there's been a change in tactics at the provincial level, with renewed interest in infiltrating stormwater, rather than having it spill off properties on to roads and in to creeks and streams. 

Rain gardens are now listed as a best management practice by the City of Kitchener for managing stormwater, and residential property owners can get a rebate on the stormwater part of their utility bills, of up to 45 per cent. 

Corrections

  • An earlier version of this story included a photo attributed to Jeff Thompson. In fact, it the photo was not taken by Thompson and has been replaced.
    May 09, 2017 10:05 AM ET