Reverse-slope driveways create ideal conditions for water damage. Links related to water damage also featured here.

I’ve been following with interest recent online discussions regarding extreme weather and climate change.

A July 11, 2013 CBC article suggests that “soft engineering” including urban parks and porous pavement might help, although costly sewers would nonetheless still need to be replaced.

The article quotes Jane Wolff, an associate professor of landscape architecture and design at the University of Toronto.

Wolff remarks that outdated engineering approaches are a major cause of the inability of big cities to deal with higher than average rainfall.

Soft engineering

The article quotes Wolff as noting that “The logic of 19th- and 20th-century engineering was to get water away from buildings and structures as quickly as possible.”

“So roofs and streets,” adds Wolff, “are made from impermeable material and water is funneled into drains towards an end point like lakes and rivers. But now people are starting to talk about the fact that maybe these highly engineered systems, designed to get water out of city very quickly, are not serving us that well anymore.”

The July 11, 2013 CBC article adds:

“Wolff says that municipalities need to integrate ‘soft engineering’ elements into development plans such as encouraging green roofs and porous parking lots, increasing the number of trees in highly urban areas, and using vacant suburban land as reservoirs during storm events to ‘slow the flow of rainwater down and ease the pressure on sewer systems that are being overwhelmed by intense, unpredictable storms.'”

Extreme weather events will become more likely, July 14, 2013 Globe and Mail article notes

A July 14, 2013 Globe and Mail article by David Miller addresses similar themes:

“As the climate changes, extreme weather events will become far more likely. Municipal infrastructure was built on the assumption that such storms were infrequent. It’s an expensive but critical task to plan for such events and rebuild our infrastructure to cope with them. Electricity is a perfect example – the need for a feed-in tariff like Germany’s is often justified by the jobs and economic boost it provides, but its biggest benefit might be to create a truly resilient electricity grid, offering the chance for each building to literally become its own power plant.

“As we rebuild this infrastructure, which will require significant public investment, we need to keep modern green lessons in mind. We need an adaptation strategy – Toronto’s is called ‘Ahead of the Storm.’ We need to act in numerous ways at the same time.

“And, critically, we need to remember that natural systems work, so they should be incorporated in our plans – expanding hard infrastructure, such as sewers, isn’t always the right way to cope with flooding. Settling ponds, green roofs, downspout disconnections, tree bylaws and requirements for permeable paving all have their places, as do innovations such as the Gowanus Sponge Park in Brooklyn, New York. The preservation of green space itself, including planting huge numbers of new trees in our cities, is of great importance. We have allowed too much of our land to be paved over, including mistakes like reverse-slope driveways, leading to extreme flooding problems for affected homeowners.

Reverse-slope driveways

The reference to reverse-sloped driveways stopped me in my tracks.

If you seek to buy a new house in any area that has in the past been associated with water damage related to extreme weather events, it may be helpful to consider what a reverse-slope driveway entails. During severe weather, such a design feature may open the way to overland flooding of the house.

Strategies to prevent water damage

A Utilities Kingston document describes ways to minimize basement water damage.

A June 19, 2013 Water Infrastructure Management, City of Toronto document also addresses the topic.

As well, the Toronto Water web page provides information for Toronto residents.

An October 2011 Claims Canada document provides additional background.