City to cap basement drains

In the overall scheme of a spring flood fight, having to leave your house to do your laundry may not seem like a major inconvenience.

But that's what several hundred Winnipeggers may have to do during the month of April due to a little-known flood-mitigation measure known as drain capping.

Beginning this week, plumbers will begin sealing off the basement drains inside approximately 280 low-lying properties in Winnipeg.

The move is a purely precautionary measure, aimed at preventing river water from inundating the city's sewer system in the unlikely -- but not impossible -- event a sandbag dike fails to hold back spring floodwaters.

"This is something we did in 1997, before we had a flood manual. We also did it in 2009," said Grant Mohr, the city's flood-protection engineer.

The city is preparing to protect as many as 688 homes against the prospect of a flood on the scale of the 1997 Flood of the Century, which saw the Red River peak at 24.5 feet above normal winter ice levels at the James Avenue monitoring station.

It's far more likely the river will crest somewhere between 20 and 23 feet. In 2009, the peak was 22.6 feet.

Nonetheless, the city is preparing for not just a worst-case scenario, but a wide variety of unpleasant surprises that range from minor overland flooding to catastrophic dike failures.

Hence the need to cap basement drains well before the river begins to rise. The city is paying for the temporary caps to be installed over the next three weeks and then remove the caps once the flood threat subsides.

"Because it takes us time to do this work, we have to go ahead now," Mohr said.

If sandbag dikes are built properly and the flood forecast holds, it's likely none of the drains will actually be put to use. But the city has learned it's better to be safe than sorry when it comes to flood mitigation.

Individual homeowners may grumble about not being able to use basement appliances for a few weeks, but few have registered complaints, Mohr said.

"The vast majority of people have been very co-operative about this," he said.

"It's no different than running a dike across their property -- they understand why it must be done."

Emergency preparedness co-ordinator Randy Hull said he does not know of an instance where a homeowner has outright refused to cap a drain. For now, it's merely a city recommendation.

If the city declares a state of emergency, however, basement drains could be capped by the city whether homeowners like it or not.

River levels are not expected to rise in Winnipeg until early April and the Red may not crest until late next month. The duration and severity of the flood will be determined by the weather in the coming weeks, provincial flood forecaster Phillip Mutulu said.

bartley.kives@freepress.mb.ca

Republished from the Winnipeg Free Press print edition March 28, 2011 B1