Barrhaven subdivision formerly in floodplain will stay dry, developer pledges

A new subdivision in Barrhaven that got the go-ahead at city hall this week used to fall within the edges of the Jock River floodplain, but the developer says it won't be a problem keeping homes high and dry.

Caivan is building new subdivision near Jock River, councillor has no concerns

Developer Caivan received zoning approval on April 25, 2019 for its new subdivision along the Jock River in Barrhaven. While it would have previously been partly inside in the river's floodplain, the developer is grading lots higher so that won't be a problem. (Kate Porter/CBC)

A new subdivision in Barrhaven that got the go-ahead at city hall this week used to fall within the edges of the Jock River floodplain, but the developer says it won't be a problem keeping homes high and dry.

Caivan is working with the Rideau Valley Conservation Authority to move land around and get properties in its new Barrhaven Conservancy development on the right side of the flood line.

It's no longer in the floodplain. We don't allow development in the floodplain.- Don Herweyer, City of Ottawa

The file received no discussion at Thursday's planning committee meeting, and Barrhaven Coun. Jan Harder, the committee's chair, has no concerns.

"[The conservation authority] would not have allowed it if it was a problem. There's a science to figuring this stuff out," she said.

Don Herweyer, the City of Ottawa's manager for development reviews in the south end, underscored that sentiment after planning committee approved the zoning.

"It's no longer in the floodplain," he said. "We don't allow development in the floodplain."

Moving land around

A small portion of the lots, however, used to see the flood line run through them.

That's a theoretical line the Rideau Valley Conservation Authority modelled in 2005 to show areas that stood a one-in-a-hundred-year chance of flooding.

Development is prohibited inside such lines.

Caivan received a permit from the conservation authority to grade those lots to a higher level — basements will be poured one foot above the flood elevation — and will have to grade lower elsewhere, in order to create extra space for water to flow.

The Rideau Valley Conservation Authority last did a floodplain map for the Jock River, which is surrounded by booming Barrhaven, in 2005. (Kate Porter/CBC)

Protected at 'high standard'

At a time when the City of Ottawa is in a state of emergency over rising flood levels, attention has turned to where homes have been built or could or should be rebuilt.

But Frank Cairo, Caivan's CEO, says buyers should have "no concern at all".

Present-day engineering and planning takes into account flood elevations, sump pumps, and stormwater management drainage, said Cairo — unlike low-lying neighbourhoods built decades ago.

"We protect these units at a very, very high standard," Cairo said. "And that's why you don't see flooding in new residential areas during these significant rain events."

Shifting floodplain lines

Cairo walked through his Barrhaven property Friday and said even with the heavy rains, there's no water near the build site. 

"Much of the area that we call floodplain has never flooded," he said, adding he believes some of the mapping overstates the flood risk near the Jock River.

The city agrees and has noted some areas of Caivan's Conservancy property could open for development if future mapping of the Jock River changes flood lines.

That happened in nearby Kars, when recent mapping saw the Rideau River's floodplain reduced slightly. Technology has made flood mapping more accurate and cheaper in recent years, and thanks to funding from the city and the federal government, the three Ottawa conservation areas have made a push to map local waterways.

As for the Jock River, that same floodplain that triggers regulatory steps is also greenspace and a major selling point for home buyers, Cairo says.

'Signature piece'

Harder called Caivan a "genius" for how considering the development's relationship to a future linear park along the river.

"I'd say this is their signature piece in the city. And they own a lot of land," she said. "I'm really [excited] about what it's going to look like."

Caivan plans to start construction in the coming months after the zoning receives full council's approval and some other conservation authority permits.


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