The City of Calgary is breaking ground on a new flood mitigation project along the Bow River, meant to protect the communities of Hillhurst and Sunnyside after the communities were devastated by flooding 11 years ago.
Calgary saw more than $6 billion in damages and more than 100,000 people evacuated in the June 2013 floods, which kickstarted a series of flood mitigation projects throughout the city in the years following.
At 2.4-km long with an estimated cost of $50 million, the Sunnyside Flood Barrier project is set to be built on the north side of the Bow River between 14 Street N.W. and Centre Street.
“This barrier will minimize the need for individual response and provide security in a way that is proactive and protects us long into the future,” Mayor Jyoti Gondek said during a groundbreaking ceremony Thursday.
According to the city, the barrier will use a combination of permanent and sheet flood walls, as well as temporary features like sandbags, and demountable flood walls to be used when river flows increase.
It is expected to protect the communities against a one-in-100-year flood, similar to the levels in 2013.
While it is higher protection than the originally planned one-in-20-year flood protection, it is less than the one-in-200-year flood protection for which community organizations have been advocating.
“That’s where we’ve landed,” said Charlie Lund, chair of the Hillhurst-Sunnyside Community Association’s flood committee. “That provides very good protection, perhaps not excellent protection, but we’re going to feel very well protected when this is complete.”
The first phase of construction is expected to begin next week, with closures along the river pathway and in the eastbound lanes of Memorial Drive between 14 Street and 10 Street N.W.
Both eastbound lanes of Memorial Drive will be closed between Centre St and 9 Street N.W. later this month, and the closures are expected to last until the fall.
“While there will be short-term inconveniences , the long-term benefits will significantly outweigh them,” City of Calgary infrastructure services general manager Michael Thompson said.
The project is also set to include improvements to the pathway network on the north side of the Bow River, but will require the removal of 337 trees, 22 of which have already been removed.
The city said removing trees is a last resort, and that the project will see the replanting of 280 new trees, flowers and shrubs.
The project is expected to be complete in 2026, and will require on and off disruptions along Memorial Drive and the pathway network for the next two years.