BY PETER CAULFIELD - The B.C. Water and Waste Association (BCWWA) is holding a seminar on earthquake, fire and flood emergency planning at its 2014 annual conference in May in Whistler, B.C.
The theme of the 2014 BCWWA Annual Conference is Safe, Sustainable, Secure: Water for the Future.
“Water professionals should have a plan for maintaining and restoring water and wastewater service to their communities in the event of an emergency,” said BCWWA CEO Tanja McQueen.
“And, even if they have one, it might need to be updated or reviewed. As we’ve seen with recent events, such as the mudslide in Washington, the earthquake in Christchurch (in 2011) and the Calgary flood (in 2013), our natural environment is extremely unpredictable.”
One of the seminar speakers will be Andy Dutton, City of Calgary wastewater treatment and planning engineer.
Dutton will discuss the late June 2013 flood in Calgary, when the Bow and Elbow rivers, which flow from the nearby Rocky Mountains through the city, overflowed their banks.
“When many people think of Calgary, they think of hills,” Dutton said in a phone interview before the conference.
“But, Calgary is built on a flood plain at the confluence of two rivers.”
Dutton said last year the ground was already saturated with water from the winter snow melt when a rain front settled over the city for several days.
“All the water that fell couldn’t be absorbed in the ground or handled by the rivers,” he said.
The flood was the worst to hit Calgary in many years, and the cleanup, which included the city’s water treatment facilities, took several weeks.
“Since then, we’ve been discussing how to protect Calgary’s water treatment infrastructure in the future,” said Dutton.
Some of the ideas that have been floated include a berm to stop water from flowing into the city’s water treatment plants, installing submarine walls in the underground tunnels of the treatment centres and building an underground tunnel from the Bow River to the Glenmore Reservoir, in the southwestern part of Calgary, to handle unusually high flow rates in the river channel.
“But the cost of such measures, which can be very expensive, needs to be balanced against the probability of them happening again,” he said.
“A flood like the 2013 flood can certainly happen again, but who knows when? The last time a flood of that severity took place was in the 1920s.”
Other subjects that will be discussed at the BCWWA annual conference are sustainable asset management and infrastructure renewal, and anticipated changes that will result from the implementation of the new provincial Water Sustainability Act.
The conference takes place at the Whistler Conference Centre May 3-6, as part of Drinking Water Week in British Columbia.
The earthquake, fire and flood emergency planning seminar takes place May 4.
While floods need to be responded to when they occur, the risk of them taking place, and the damage they can cause, can be mitigated at least to some extent by preparing for them before they occur.
Although British Columbia is less vulnerable to flooding than Alberta or Manitoba, flooding still takes place here.
“Most communities in B.C. that are located in river valleys or on the coast have at least some vulnerability to flooding,” said Steve Litke, senior manager with the Fraser Basin Council, a non-government organization that deals with flood prevention along the Fraser River.
“The possibility of a flood taking place in B.C. any year is about five per cent,” Litke said.
“There were serious floods on the lower Fraser River in 1894 and 1948, and a near-miss in the spring of 2007, when a storm that would have caused the river to overflow just missed the area,” he said.
The Fraser Basin is most at risk of flooding in the spring, if there’s a large amount of water in the snow pack, a rapid rate of snow melt and both happen to coincide with heavy rainfall.
The coastal areas are most in danger of flooding in the winter, when there can be storm surges from the ocean.
Litke said the council is developing a regional flood strategy.
“We’ve started the first phase, which is consulting with communities along the Fraser,” he said.
“There’s a fair bit of interest in developing a co-ordinated approach to flood management.
“We’re looking at a wide range of flood possibilities and assessing regional vulnerabilities and reviewing current flood management strategies.”