Are Grass Driveways the new trend?
by Franke James
Are “Grass Driveways” the new trend? Are we likely to see them pop up in neighborhoods across the country?
A few days ago, I would have said we’re years off from that ‘green dream’, but now a commercial homebuilder in Ontario, Marshall Homes, has me rethinking that assumption. They are testing the viability of grass driveways (also known as green driveways) as part of a LEED case study. Apparently they are waiting to see how the grass driveway performs in the winter.
They could have checked with us! We’ve been through all four seasons. The big thing people worry about is snow. Well, you can shovel a grass driveway. You can even use a snowblower on it, because the grass roots are protected by the plastic cells (in our case, Permaturf.) For us, there are many upsides and only one downside in a grass driveway. It’s an annoying secret you might not have thought about.
When we built our drought-tolerant grass driveway in 2007 we were the 1st pilot project in North York. (You can read about how we secured a permit and built the green driveway in this series of step-by-step articles.) I thought what we were doing was so unique that only devoted environmentalists would go this route — but apparently not! I guess we’ll have to get comfortable with the fact that we’re trendsetters.
Grass driveways (which incorporate high-tech plastic pavers) have been around for over a decade but mass adoption has been slow in coming. Now with growing concern over global warming and the impact of polluted stormwater that could be changing. (Riversides.org reports that stormwater is the leading cause of water pollution in urban areas.)
We used PermaTURF plastic pavers which snap together easily to create an interlocking load-bearing surface that is drivable and can support large vehicles and trucks. Below are two photos from our installation. We built it in a long weekend.
What is motivating builders to consider innovative environmental solutions?
In the case of Toronto builders, one reason may be the Toronto Green Development Standards 2007 (GDS). The GDS performance targets include minimizing stormwater that leaves the site. So, grass driveways (or permeable surfaces) clearly help satisfy the need for stormwater management solutions.
Marshall Homes, which is based in Oshawa, has joined the Canada Green Building Council’s LEED for Homes Pilot Project. In a Toronto Sun article, company president Craig Marshall said, “It’s all about water infiltration into the ground instead of running out onto the street and down into our sewers and into our lakes and rivers. The more groundwater you can keep on the site, the less damage it’s going to do to the environment and the habitats of fish and things in the rivers and lakes.”
Runoff from interlock driveway versus grass driveway
Craig Marshall is right. A big environmental advantage of a green driveway is permeability. In Paradise Unpaved, I compared the stormwater runoff from our former interlock driveway versus our new green driveway and garden. I found that about 75% of the total annual runoff was diverted from the sewers and now recharges the groundwater and nourishes plants and trees. But we are just one home. Would more permeable surfaces save the city really significant money?
Chicago’s Green Alleys
Chicago thinks permeable surfaces will save money. Their Green Alleys project aims to replace 1,900 miles of alleyways (more than any other city in the world), with permeable alleys. The program is designed to help manage stormwater, reduce the urban heat island effect and incorporate recycled materials (such as tires) into the permeable pavers. It’s an urgent initiative for the city. Their alleys are lacking proper sewer connections which cause serious flooding issues for homes nearby. The city realized that permeable alleyways would be a more cost-effective solution than expensive sewer hookups.
What is the price tag to handle stormwater runoff?
You may never have thought about stormwater management. The City of Toronto has been providing information about it for years, trying to educate businesses on how they can help. Here are tips from 2000 that include permeable pavers.
But serious measures have not been taken, and the costs are mounting. A recent Toronto Star article ‘Lake cleanup viable if city handles runoff’ highlights the importance of Toronto finding a solution to polluted stormwater runoff.
“The Don and Inner Harbour have some 50 points where combined storm water and sanitary sewers can overflow during heavy rains, discharging polluted runoff directly into the waterway. Underground storage tanks would catch runoff and later send it to upgraded sewage treatment plants — a project that carries a price tag of roughly $400 million to $500 million.”
Wow! $500 million to handle stormwater runoff? It makes you wonder how much lower the price tag (and cleaner the lakes) would be if more driveways, alleys, sidewalks and eventually even roads, were converted to permeable materials. (Permeable concrete is being tested for use on city roads, though it’s still a ways off.)
But putting aside number-crunching and environmental benefits, some people just want a grass driveway because it’s beautiful!
“Your [Paradise Unpaved] story made me want to buy a house just to turn the driveway into a garden.” Connor McCall
I think Marshall Homes may be on to something, don’t you?
(Are you wondering about that cute little car on our grass driveway, and whether we changed our minds about car ownership? No. We don’t own a car and we are very happy with our decision to walk, run, cycle, TTC, occasionally cab, and use VIA Rail to get around.)