Dude, where's my flood? 3 reasons why the deluge of 2019 still matters

There may not be much snow left in Manitoba, but U.S. water is still on the way. Here are three reasons why you should care.

Basement flooding, farm yields and transportation detours all spell potential trouble

Volunteers helped build this sandbag dike alongside Highway 75 just north of St. Adolphe, Man., in April 2009. In spite of favourable melt conditions, Manitoba could still see complications from flooding this year. (John Woods/Canadian Press)

Look around southern Manitoba and you'll see more mud, dust and exposed asphalt on the ground right now than patches of remaining snow.

Most of the winter's considerable snowpack has melted away without incident, thanks to three weeks of favourable weather that saw temperatures get just warm enough during the day to melt a little snow and cold enough at night to freeze the surface again.

The thaw has been so gentle, the snowpack has all but disappeared without filling rivers, streams and culverts. The Red River in Winnipeg only started rising significantly a few days ago and still remains below flood stage.

The ice on the Red has also thinned to the point where it should break up easily once the river does rise, significantly reducing the potential for ice jams.

All this good news does not, however, mean the significant flood predicted by the province is no longer happening.

A lot of water is still coming our way from the U.S. portion of the Red River drainage basin, especially northwestern Minnesota, which received much more snow this winter than did most parts of southern Manitoba.

Even with the favourable weather, the volume of water heading north is still expected to approximate the peak flow of the 2009 Red River flood, the second-most voluminous deluge of the past 50 years.

Here are three reasons why this is still a concern.

All about that basement

Winnipeg boasts some of the best flood protection on the planet, thanks to a floodway channel capable of diverting most of the Red River's flow around the city, the Brunkild Z-dike — which prevents the Red River from spilling into La Salle River — and a network of secondary dikes within the city itself.

These ditches and dikes protect the city from catastrophic flooding. But they don't prevent the Red from rising to the point where the city has to spring into action to prevent stormwater and sewage from backing up into thousands of basements.

Even with the use of the floodway, provincial  forecasters expect the Red in Winnipeg to rise as high as 20.5 feet above normal winter ice levels at James Avenue.

That's well above the level where combined sewers (which carry both land drainage and wastewater) and storm drains flow directly into the Red and other rivers within the city. When the outflow gates wind up below the surface of the rivers, the gates are either sealed off by water pressure or are shut down manually by city staff.

"Once the river is up to a certain level, gravity flow doesn't work any more. The river water's too high and the sewers can't drain," explained Chris Carroll, who manages wastewater for the City of Winnipeg.

If a major rainstorm hits the city while the rivers are running high, sewer or stormwater backups are possible. (Gary Graves/CBC)

In order to allow sewers and storm drains to function during a flood, the city relies on 39 permanent pumps called lift stations and several dozen portable, truck-mounted pumps to push meltwater into Winnipeg waterways.

"Basically, the land drainage sewers and the combined sewers that would go to the river cannot, for all intents and purposes" Carroll said.

"They're blocked by the gates and the river water, so when it rains or when we get a lot of snowmelt, the pumps turn on."

These pumps can only carry so much water, so if a major rainstorm hits the city while the rivers are running high, sewer or stormwater backups are possible.

This is why the city constantly reminds homeowners to install backup valves in their basements and check to ensure their sump pumps are working.

"They can get clogged up with debris and stuff from your home, so people should inspect them [and] make sure they're working properly," Carroll said.

The city has also put 123 property owners on notice they may need to build sandbag dikes. But the more widespread threat in a 2009-like flood involves the potential for basement flooding, which is difficult and expensive to clean up.

Farmers face a stressful spring

During the Red River flood of 2006, some kiteboarders took advantage of inundated farmland to spend a few hours hovering above the shallow water.

This justifiably angered agricultural producers. There's nothing quite like watching people play in flooded fields instead of preparing to seed the land for crops that may or may not arrive in time to yield a profitable harvest.

Spring flooding along the Red River, such as this deluge in 2009, mostly inundates agricultural land. (CBC)

While floods replenish the subsoil moisture below those fields, they can also prevent the surface from drying out in time for seeding. Farmers can harrow the fields to speed up the drying process, but run the risk of creating clumps in the soil if they're not careful.

"Once you are behind with your seeding and once things are delayed a bit it is very difficult to catch up," said Bill Campbell, president of Keystone Agricultural Producers.

"Your yield potential goes down and there has to be absolute ideal conditions from that point on.… So it just puts you behind the 8-ball at the start."

Some agricultural producers in the Red River Valley plant feed corn and soybeans, two crops that must be seeded early in order to develop properly in time for harvest. The usual alternative for these crops in soggy springs is canola, which may not be as viable this year because of the Chinese trade dispute.

"Canola can still be sown up until the first of June and still be a relatively high-yielding crop. But high-yielding does not mean profit, if we see trade distortion involved in the equation," Campbell said.

"That's the uncertainty causing the farm community all kinds of stress at this point in time."

Highway detours cost the economy

Every time Highway 75 is closed between Morris — about 60 kilometres south of Winnipeg, and connected to the city by the highway — and the U.S. border, the trucking industry spends more money on fuel and creates more greenhouse gas emissions.

The road is expected to close again this spring for the first time in eight years, if water levels approach 2006 or 2011 flood levels — or the even higher 2009 levels.

A resident of Morris, Man., pulls a boat across a bridge over the Morris River to his business, which was isolated by flood water, in April 2009. ( John Woods/Canadian Press)

This costs the transportation industry money and also hits the town of Morris hard, said Mayor Scott Crick.

"There is real measurable impact in terms of a Highway 75 closure," said Crick, explaining businesses in his town rely on revenue from highway visitors.

He's not convinced the flood will be as severe as forecasters predict.

"We can hold out hope it does not materialize the way it was thought," he said.

This also may be among the last seasons the highway is closed near Morris. The province has proposed a permanent flood-condition detour that could be in place by the end of 2020.


Bartley Kives

Senior reporter, CBC Manitoba

Bartley Kives joined CBC Manitoba in 2016. Prior to that, he spent three years at the Winnipeg Sun and 18 at the Winnipeg Free Press, writing about politics, music, food and outdoor recreation. He's the author of the Canadian bestseller A Daytripper's Guide to Manitoba: Exploring Canada's Undiscovered Province and co-author of both Stuck in the Middle: Dissenting Views of Winnipeg and Stuck In The Middle 2: Defining Views of Manitoba.