Flood protection projects in Chilliwack are so far holding back the rising elevations of the mighty Fraser River.
But much more water is on its way.
With a “high stream flow advisory” issued Sunday, officials are keeping a watchful eye on potential flooding at Carey Point — a vulnerable area outside the city’s dike system. They’ve also issued an “evacuation alert” for all residents living outside the dike, meaning those residents should be prepared to evacuate on short notice.
The river rose quickly over the weekend because of heavy rains up north.
Chilliwack MLA John Les has cancelled a trip to northeast B.C. because of the threat. The Fraser River is expected to hit high-water levels not seen in 40 years.
“I remember 1972 and the water (then) was much higher than five years ago,” Les told The Progress. “I think I need to stick around here.”
The waters could reach 6.5 to 7 metres at the Mission gauge by the weekend, according to predictions by the BC River Forecast Centre, with estimates of 12,000 to 13,000 cubic metres of water per second at Hope.
“By the end of this week, we could easily see everything outside the dike flooded and a large amount of seepage inside,” Les said.
Despite the rising water, both the recently constructed check dam and berm structure are holding up well so far, said Will Davis, chair of the Carey Point Improvement Society, on Monday morning.
“That did take us off guard,” Davis told The Progress. “But so far the berm and the check dam are doing what they are supposed to be doing.
“Unfortunately these are Band-Aid solutions to the bigger problem we’re facing of constant erosion.”
One last rush from the snow melt mixed with rain is coming down the Fraser from the upper watersheds, but they don’t know when it will arrive exactly.
Regular dike patrols have begun, and the city will activate an Emergency Operations Centre. According to its response chart, flooding of the unprotected areas could start at six metres.
The arrow hit 5.8 metres Monday morning.
Last year at this time, some residential properties outside the dike had to be sandbagged. Some properties are nearing that point again.
Last week they were losing about 24 feet a day to erosion, or a foot an hour near Carey Point. It was “alarming” to look at the comparison photos of what’s been lost, said Davis.
The erosion is caused by a shifting scour hole that resulted in a significant amount of land falling into the river from Carey Point to Island 22.
“The erosion has actually slowed down with the arrival of the high water,” said Davis. “So in a roundabout way we’re happy the high water is keeping the erosion at bay.”
They are starting to see some seepage, which is typical. There are about 15 properties in the unprotected area outside the dike, which covers about 350 acres of agricultural land.
In the long term they’ll most likely have to move the berm closer to the dike.
“We started out a couple hundred feet from the river. And because of the erosion now it’s closer to 60,” he said.
But the situation is better than last year, because the water hasn’t reached the dike yet.
“That’s all because of the berm and the check dam,” Davis said. “They’re helping everyone.”
The berm was originally constructed in 1997 by the province. It failed last year during a prolonged period of high water. Neither city nor provincial officials claimed responsibility for the orphaned structure, despite ongoing requests by affected property owners to reconstruct it.
The intense negotiations and ongoing meetings yielded results.
The berm was rebuilt this winter by the society formed by group of affected property owners, with the province and the City of Chilliwack chipping in $25,000 each, while residents put in $70,000 to $85,000 in cash and in-kind donations.
City of Chilliwack also built a separate structure to keep flows away from the city dike, an engineered check dam at the Orchard Slough, for about $100,000. Both structures were completed in May.