Flood berms divide communities
Some say barriers essential, others argue they serve no purpose, Meghan Potkins writes
In the spring, Charlie Lund can’t walk down the street in his Sunnyside neighbourhood without someone stopping him to ask if he thinks the river looks high, or if he’s worried about rain this year.
Lund says he doesn’t mind the questions.
He was there in 2013 when the Bow River, swollen by torrents of rain, poured water and mud into the neighbourhood. He knows why people are worried.
“You can feel the anxiety in the community,” he says.
Five years on and the hardest part for Calgarians living in the city’s river-hugging neighbourhoods is the knowledge that they would still be vulnerable in the event of another flood.
Even with several multi-million dollar flood mitigation projects underway, the cornerstones of Calgary’s flood-proofing plan remain incomplete.
Namely, two major upstream reservoir projects: one on the Elbow and one on the Bow.
And inside city boundaries, parts of a network of earthen flood barriers designed to keep rising waters at bay are still in the design phase.
Two long flood barriers will eventually shield the downtown: one stretching from the Peace Bridge to Eau Claire Plaza, and a second, stretching east from Eau Claire to Reconciliation Bridge. The first barrier is nearly completed; the second won’t be completed until 2022.
But it’s the barriers protecting residential neighbourhoods, including Sunnyside, Bowness and Inglewood, that are proving more controversial.
River communities are divided on the effectiveness of the barriers: some residents say they ’re unnecessary or obstructive, while others argue the proposed barriers don’t go high enough.
Lund falls squarely in the second camp.
The retired chemical engineer is the chair of Hillhurst- Sunnyside’s flood committee. He has devoted himself since 2013 to the task of understanding local hydrology and river flow rates, as well as the idiosyncrasies of Calgary’s storm water and sanitary systems.
After his own home flooded in 2013 — not from overland flooding like some of his neighbours, but from sanitary backup — Lund decided to learn as much as he could about Sunnyside’s flood vulnerabilities.
“It’s part out of self-interest, but I’m doing this because this is how I react to traumatic events like 2013,” Lund says. “I spend time trying to make sure it doesn’t happen again.”
He’s attended public engagement sessions, met with city engineers and talked to councillors. In the process, he’s become convinced the city’s flood mitigation plans for Sunnyside — specifically when it comes to the proposed barrier heights — don’t go far enough.
Lund points to the new downtown berms as well as riverbank reconstruction at Prince’s Island Park that could further restrict the flow of the Bow River, forcing more water towards Sunnyside in the event of another flood.
“The city isn’t planning on substantially raising our berm and this is a great concern to me and to others in our community,” Lund says.
“Because there have been other changes made to the river, that means if we had the same flow down the river as we did in 2013, we would face catastrophic damage as a result of these other changes without having a higher berm.”
Currently, the city is proposing to raise parts of Sunnyside’s berm to bring it up to a one-in-20 year flood defence. However, some extra protection could be afforded with a half-a-metre of buffer, described as “freeboard,” to account for waves, trees and debris carried by the river.
Calgary’s 2013 flood, often described as a one-in-100 year event, is now considered to be closer to a one-in-70 year event due to changing averages over time.
And there’s nothing to say Calgary won’t see an even bigger flood in the future, Lund says.
“It’s a probability game. There can always be a bigger flood.”
The city has promised public consultations on flood barriers, but municipal engineers say they must weigh costs and benefits when it comes to setting the heights.
“It costs more to raise it up higher and it has to be longer when you go higher because there’s usually a larger spill-point, so you have to extend it longer as well,” says Sandra Davis with the city’s river engineering department.
“Also, looking at equity of protection across the whole city, we want to be able to ensure that we can provide similar protection to all communities. And if we start talking about building barriers to a greater flood level, say the one-in-100 flood, there’s a lot more communities that start coming into play, where we would need berms to prevent that sort of flooding.”
But the city says Sunnyside will be protected through a combination of flood barriers and critical upgrades to the stormwater and sanitary systems.
And all the river communities will benefit from improvements to the Glenmore Dam that will increase its capacity when construction is complete sometime next year.
In the meantime, a deal struck between the province and TransAlta allows for more water storage at the Ghost Reservoir, just west of the city on the Bow River, during flood events.
But municipal engineers acknowledge the most important part of Calgary ’s flood defence plan remains the upstream reservoirs, including the Springbank project and a yet-to-be-determined reservoir project on the Bow.
So how would Calgary fare today if another 2013-level flood hit the city?
“We know with everything that’s been put in place since 2013, we’ve dropped our damages by about a third,” Davis says.
Bowness resident Jean Woeller agrees that the upstream reservoirs are needed, but she’s not at all convinced that flood barriers need to be built in her neighbourhood.
Woeller moved into her Bow Crescent home, which backs onto the Bow River, in 2016. Only afterwards did she learn that the city was planing to build a berm that could cut across her property and the properties of more than 90 of her neighbours.
“To be honest with you, I’m not sure we would have bought this house, because we’re potentially facing four years of construction,” Woeller says.
She’s only seen conceptual drawings for the berm, but says it appears to divide her property, putting nearly two-thirds of her yard behind the barrier.
In 2013, “our house (and) most properties were flooded by groundwater and sewer backflow and not overland flooding,” Woeller says. “So, the city is taking on this huge project. They’re putting property owners in an uncomfortable situation, with potentially four years of construction, and we’re really not sure what the benefit is. Our basements may very well still be flooded.”
While river communities grapple with the changes coming to their neighbourhoods, experts with the province are currently re-drawing flood zone maps, which haven’t been updated since 1983.
“The weather has changed, the hydrology has changed, the rivers have changed since then, so they’ve updated them and we’re expecting to see those new maps hopefully this year sometime,” Davis says.
“We’re expecting the floodway to change. So, we’re not sure where the new floodway will be.”
Davis says there could be new regulations coming for buildings constructed in flood zones.
“We know that in this region, extreme weather events and floods are expected to get more intense and more frequent by the end of the next century.
“Looking forward to that, does it make sense now to have stricter regulations and make people build up higher?”
Davis says planners are looking at things like whether it makes sense to allow bedrooms to be built in basements in flood zones or whether basements should be allowed at all in some flood-prone areas.
She says the city is also looking at the implications for land use, asking whether certain uses that might be difficult to evacuate during an emergency, like daycares, should be permitted in flood zones.
“Those are some of the things that we’ve started to explore,” she says.
WATCH FOR SPECIAL CONTENT RELATED TO THE FIFTH ANNIVERSARY OF THE 2013 FLOOD IN THE HERALD AND AT CALGARYHERALD.COM UNTIL JUNE 21.