Berms and bypasses, with a combined price tag as high as $830-million, should be built quickly to help protect southern Alberta communities from future deluges, a flood mitigation symposium has heard.
Richard Lindseth – an architect speaking on behalf of a three-member, government-appointed flood mitigation panel – said on Friday that three berms with dry ponds should be constructed in the headwaters of the Elbow and Highwood rivers, on the eastern edge of the Rocky Mountains.
The projects should be completed in an “expedited” manner, Mr. Lindseth told the symposium, convened to share ideas on how to reduce the impact of floods such as the devastating one that washed through huge parts of southern Alberta in June.
Mr. Lindseth stressed that his panel’s ideas would be just part of an Alberta-wide strategy. Other speakers highlighted the need for improved flood forecasting and mapping, individual preparedness and insurance policies.
The flood mitigation panel has picked locations for the headwater berms – one on the Highwood and two on the Elbow – that are far away from population centres and would have a minimal impact on existing infrastructure.
The berms would not affect water flows in normal circumstances.
But those alone would not be enough if a major rain storm hit further east in the foothills and sent water flowing into Calgary and other municipalities.
The panel also recommends building channels to divert water in more populated areas.
In High River, a town south of Calgary that was devastated when the Highwood River spilled its banks, “the general notion is that this would be an overland bypass,” not unlike what exists in Winnipeg.
The bypass in Calgary would run underground like “a very large storm sewer” taking water from the Elbow River at the western end of the Glenmore Reservoir to the much larger Bow River. There would be a diffusion system so that too much water is not fed into the Bow at once.
The berm and the bypass systems together would cost between $660-million and $830-million, Mr. Lindseth estimates.
The province has pegged the overall flood damage tab at between $5-billion and $6-billion, but Premier Alison Redford cautioned on Friday that it is still early in the recovery process.
For now, the panel’s work has focused on the Elbow and Highwood rivers, but Mr. Lindseth said in the future it will look at how to manage flows on the Bow – an issue raised at the symposium by residents of the Bowness neighbourhood in northwest Calgary, which was hit hard in the flood.
Measures taken in Alberta could affect the entire river system that stretches across the Prairies, Mr. Lindseth said.
“These rivers and anything we do on them can affect anything downstream and eventually the rivers that flow into the Hudson Bay,” he said. “The system has to be comprehensive. We’re simply a part of it and the system has to be ever-cognizant of the consequences that we may bring in everything we do.”
That’s why each municipality should look beyond its own interests when asking the province for its allotment of recovery money, Ms. Redford said, urging the province to pull together with a co-ordinated approach.
“While some solutions will need to be local, we need to consider the whole watershed,” she said.
“Because if we have a whole bunch of communities across the province that all make individual decisions without taking into account how those projects affect the rest of the watershed, we have not made progress.”
Closer to home, Barrie Brand of the Alberta Emergency Management Agency recommended Albertans have a kit ready so they will be set for 72 hours in the event of an emergency.
Drinking water is crucial, but items such as flashlights, toilet paper and a flash drive with important information should also be included.
Insurance must be looked at after the flood, said Kim Sturgess of Alberta WaterSMART, a strategic and engineering consulting company focused on the province’s water resources.
“The insurance issue is hitting home for all of us,” she said, noting her own coverage for sewage backup will drop to $15,000 from $120,000.
Ms. Sturgess said she will not keep anything worth more than $15,000 in her basement.
She also said coverage for overland flooding – not included in typical policies – is an issue that deserves serious thought.
Ms. Redford described flood mitigation as “layers of readiness” rather than one “silver bullet.”
“Many Albertans will remember 2013 truly as the year that life changed,” she said.
“The flooding that struck Alberta this year reminded us all of the power and the startling brutality of water, frankly, just as droughts have in previous years.”