City keeping close eye on Third Street due to slope instability

The sewer line under Third Street West will be moved this year to get it away from the fragile Columbia River bank.

There are noticeable dips in Third Street West as it passes Mountain View Elementary. The City of Revelstoke is monitoring the street.

The sewer line under Third Street West will be moved this year to get it away from the fragile Columbia River bank.

“It’s something we’ve been monitoring for a couple of years,” said Mike Thomas, the city’s director of engineering. “We have a capital project in the budget specifically to move the sewer, which is right on the downhill side, under the pavement.”

I spoke to Thomas after receiving several comments that the portion of Third Street West alongside the Mountain View Elementary site was collapsing into the river. I walked up and down the street and it dips noticeably at some points on the river side.

Thomas said the city was monitoring the hillside above the river, and that it had lowered about 15 centimetres in places.

The city’s priority is to move the sewer line, which is feeling the effect of the shifting hillside.

The city has $120,000 included in this year’s sewer budget to do the work.

When asked about the risk of the street collapsing, Thomas said nothing was imminent.

“From what we’re seeing, it’s a slow movement of the hillside,” he said. “There’s no evidence on the hillside of impending collapse.”

Thomas said it was the city’s responsibility to stabilize the hillside, and not BC Hydro’s. BC Hydro has placed rip rap along the river to stabilize the shore near the Revelstoke Golf Club.

“It’s not something we can attribute to the increased flows from Revelstoke 5 or 6,” he said. “This is just the gradual movement of the slope. Communities up and down the Columbia are seeing the same thing.”

A potential long-term solution is to narrow Third Street West, he added.

He said a similar issue is occurring on Red Devil Hill, which is also sinking slightly.

Revelstoke roads sinking into the river is nothing new. A whole swath of central Revelstoke was washed away more than a century ago, and old maps still show sections of street that no longer exist.