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flood proofing

Toronto’s Evergreen Brickworks, formerly an abandoned brick factory which has been transformed into a vibrant public space, was flooded twice this year. Located in the floodplain of the Lower Don River, the site was redesigned to bounce back quickly from inevitable flooding.

When Toronto's Don River breached its banks and flooded the Evergreen Brick Works twice this year, David Stonehouse didn't panic. In fact, the historic site's general manager simply turned to his flood-response playbook and began taking action.

"We're in what is the most flood-prone property within the jurisdiction of the Toronto and Region Conservation Authority, but when we had the two floods, we didn't lose any electrical equipment," Mr. Stonehouse explains. "The only thing we lost was the elevator, which we had to repair."

Other commercial property owners and managers – particularly across other sites in Toronto that were ravaged when more than 100 millimetres of rain fell in a little more than three hours in a single day last July – might wonder how Evergreen managed to weather the worst of the storm and bounce back so quickly. The site was operational within 48 hours and fully open within just seven days.

Chalk it up to comprehensive flood-mitigation features incorporated into Evergreen's redesign when the former brick-making complex was converted into a mixed-use cultural facility in 2010.

Features such as a first floor coated only in concrete (carpet and drywall are nowhere to be found at ground level), special floor drains that allow for rapid water clean-up, electrical outlets positioned more than a metre above the ground and key mechanical systems located well above typical flood levels all helped to mitigate much of the damage, not to mention saving hundreds of thousands of dollars in potential clean-up costs.

In addition, architects and engineers added drainage channels around the property to funnel water to a nearby pond, as well as another unique feature.

"Our design included an emergency refuge centre on the second floor with supplies and communications," explains architect Michael Leckman of Toronto's Diamond Schmitt Architects, which designed Evergreen's 55,000-square-foot Centre for Green Cities building.

Flood mitigation became a hot topic this year as devastating flooding in Calgary, High River, Alta., and Toronto – not to mention the frequent flooding that affects cities such as Winnipeg – put a spotlight on the need to prepare commercial properties for the worst. And after fire, water damage tops the list.

The trouble is, many commercial property owners and managers simply aren't prepared to handle a worst-case flooding scenario, either on a proactive basis by using more durable materials at ground level as in Evergreen's case, or by preparing contingency and evacuation plans in the case of a debilitating flood that takes their buildings out of commission for an extended period of time.

They fail to prepare at their own peril, says Blair Feltmate, program director of the University of Waterloo's Sustainability Practice and the chair of the Climate Change Adaptation Project Canada.

He warns that climate change is a clear and present danger, bringing with it a combination of warmer, wetter weather. Flooding, he predicts, will be a fact of life for the foreseeable future.

"Senior managers need to realize that climate change is real and is here to stay," Dr. Feltmate says. "Then they need to work with people such as operations managers and risk analysts, identify key vulnerabilities in response to extreme events like more water, hotter weather and higher winds. In many cases we'll need to invent the solutions to these problems."

Flood-mitigation measures at the municipal level are numerous and varied. In Toronto, for example, the city's long-term Wet Weather Flow Master Plan calls for an increase in everything from the number of green roofs to the local tree canopy, all of which help to absorb water in the event of major rainstorms.

Other municipalities are taking proactive steps, as well. Take the redevelopment of Calgary's East Village, a 49-acre community being revitalized by Calgary Municipal Land Corp. (CMLC), a neighbourhood bound by the mighty Bow and Elbow Rivers.

When the CMLC and its partners began drawing up plans for the new East Village in 2007, they understood that special measures were needed to gird against possible flooding.

As such, the developer raised the banks along the Bow by 1.5 metres, added a series of picturesque basalt steps to buttress those banks as part of the first half of its $26-million RiverWalk infrastructure program – a broad promenade that will also include a cycling pathway – and effectively created a barrier between the river and the rest of the community. The East Village's master plan also emphasizes pulling key amenities such as public buildings back from the river's edge and to higher elevations.

The plan was successful and the heightened banks held back the Bow's surging waters as Calgary dealt with last summer's catastrophic deluge. At the other side of the East Village, however, the banks of the Elbow River – which had not been reinforced the same way – did breach, resulting in extensive flooding across the neighbourhood. According to Susan Veres, CMLC's vice-president of marketing and communications, the organization will need to take action to study how the Elbow River can be reinforced in a similar way.

In Saskatoon, flooding has been an ongoing problem, but not just from an overflowing South Saskatchewan River.

Sanitary sewer backups following heavy rainstorms used to wreak havoc in basements across the city. That was until local officials developed a plan in 2007 to install what they call "super pipes," essentially large underground reservoirs that channel rainwater to depths below that of any area basement, then hold the water until it can be conveyed into local river systems following a large rainstorm.

As Galen Heinrichs, Saskatoon's water and sewer engineering manager, explains, the addition of super-pipe infrastructure has been largely effective in preventing nasty sewage backups in the approximately eight locations in which they've been installed across the city so far.

Saskatoon has also launched a project to divert water and sewage from more heavily populated downtown neighbourhoods to processing plants in the less dense suburbs to help mitigate flood risks.

"With a bit of creativity, you can come up with an infrastructure solution that will lower the risk of flooding," Mr. Heinrichs advises. "You need to think outside the box and look at measures like these that might be useful."

While some municipalities may be taking flood risks seriously, not all commercial property stakeholders have fully grasped the need for immediate action, according to Mr. Leckman. He points out that flood mitigation measures are typically not top of mind with Diamond Schmitt's clients – a consideration that will need to enter into their property-development plans in years ahead.

"I think 2013 was a wake-up call for all property owners about their flood proofing," he says. "What we saw this year was how many more people were vulnerable to [flooding] than anyone could have expected. No one is really prepared in a non-flood zone for this, especially not in the centre of a city. I'm sure people are rethinking their threshold and their next steps."

Ready for disaster?

Not sure how to prepare your commercial property for a major catastrophe such as a flood?

John Stephenson, vice-president of property management services with Mississauga, Ont.-based emergency restoration firm FirstOnSite Restoration, offers these key tips to put your property on the path to disaster readiness:

– Conduct a property risk assessment that covers all internal and external risks including environmental, topographical and residing property risks;

– Create an overall emergency response plan with all necessary emergency support numbers accessible 24/7, regardless of your location;

– Test your plan by conducting a mock disaster recovery exercise and be sure to include your external emergency response partners such as your emergency restoration partner, security company, cleaning company and any other potential support contractors.

– Then review your plan annually and revise it based on the result of that mock exercise.

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