Canada: Exceptional water deficits to persist in northern QC

17 February 2020

THE BIG PICTURE
The 12-month outlook for Canada through October indicates a forecast of deficits for nearly all of Quebec north of the Gouin Reservoir in the Mauricie region of the province including vast areas of exceptional deficit.

ISciences_Canada_Composite_Adjusted_201911-202010_12mo_panel.png

Elsewhere in the nation, exceptional deficits are forecast for western Labrador, a column along Ontario’s eastern border, the southwest corner of Hudson Bay, a belt across central Manitoba north of Lake Winnipeg reaching into Ontario, the Upper Assiniboine River region in southeastern Saskatchewan, central Alberta west of Edmonton and also the province’s northwest corner, and in British Columbia at the bend of the Fraser River east of Prince George.

A large block of extreme to exceptional surplus is forecast surrounding Churchill Lake in northern Saskatchewan leading north well past Lake Athabasca and west to Fort McMurray, Alberta. Surpluses of similar intensity are expected in the southern Columbia Mountains of British Columbia.

FORECAST BREAKDOWN
The 3-month maps (below) show the evolving conditions in more detail.

The forecast through April for Canada’s most populated areas indicates nearly normal water conditions for Québec City with deficits to the south, and normal conditions in Montreal, Saskatoon, Edmonton, and Vancouver. Moderate deficits are forecast near Ottawa, and moderate to extreme surpluses near Toronto. Deficits are expected around Regina and moderate surpluses near Calgary.

ISciences_Canada_Composite_Adjusted_201911-202010_3mo_panel.png

Exceptional deficits will persist in a vast area of northern Quebec (QC) reaching into western Labrador. Intense deficits are forecast in a wide path along Ontario’s (ON) eastern border, and severe to exceptional deficits in the province’s northwest quadrant. Surpluses will persist in a large block of north-central ON from Hudson Bay to the Albany River.

In the Prairie Provinces, exceptional deficits are forecast in a wide band north of Lake Winnipeg, Manitoba (MB) and in the northeast along Hudson Bay. Intense surpluses will persist in MB’s northwestern corner. In Saskatchewan (SK), moderate to extreme deficits are expected around Regina and exceptional deficits in the Upper Assiniboine River region. Intense surpluses will persist in a vast block of northwestern SK reaching across the border past Fort McMurray, Alberta (AB).

Exceptional deficits will persist in northwestern AB and severe to exceptional deficits in the Middle Reaches of the Athabasca River Watershed in the center of the province. Moderate surpluses will emerge on the South Saskatchewan River. Surpluses are also forecast in the Upper Peace River Region reaching across the border into British Columbia (BC) past Fort St. John and Williston Lake.

Elsewhere in BC, intense surpluses are expected in the southern Columbia Mountains; surpluses of lesser intensity in the southern Coast Mountains will increase. Deficits in central BC at the intersection of the Nechako and Fraser Rivers will remain intense though the extent of exceptional anomalies will shrink. A small pocket of exceptional deficit will persist around Prince Rupert on the coast and severe deficits will persist along BC’s border with Yukon.

From May through July, deficits will shrink in QC, but blocks of exceptional deficit will persist west of Lake Mistassini, surrounding the Caniapiscau Reservoir in the northeast leading well into Labrador past the Smallwood Reservoir, and near Sept-Îles in the east at the mouth of the St. Lawrence River. Intense deficits will persist along ON’s northeastern border and in the northwest quadrant of the province; surpluses in ON will nearly disappear. Similarly, deficits in MB north of Lake Winnipeg and around Hudson Bay will persist, but surpluses in the northwest quadrant will nearly disappear. Deficits around Regina, SK will downgrade, becoming merely mild. Widespread surpluses around Williston Lake in BC will retreat and surpluses in the southern Coast Mountains will shrink.

The forecast for the final three months – August through October – indicates that deficits will shrink, particularly in QC, as will surpluses in AB and BC.

(It should be noted that forecast skill declines with longer lead times.)

IMPACTS
It’s been nearly nine years since the Lake St. Martin First Nation community in Manitoba was forced to evacuate after major flooding on the Assiniboine River, yet hundreds remain unresettled as the extended cutoff date for evacuee benefits approaches. In the spring of 2011, officials diverted water from the Assiniboine River into Lake Manitoba to reduce the risk of flooding in Winnipeg, triggering a flood in the indigenous village. A $90 million settlement was reached in 2018 but the community is taking the federal government to court, petitioning for additional housing.

Portions of Toronto’s Don Valley Parkway were closed in mid-January due to flooding as heavy rains caused the Don River to overflow. Flooding was also reported in Orangeville, Vaughn, Brampton, Innisfil, the Kitchener-Waterloo area, and Clarinton. Roads were closed in Brampton, and Shelbourne experienced power outages as ice-burdened trees downed service lines.

Experts from British Columbia’s Forestry Practices Board say that logging contributes to spring flooding, particularly in regions afflicted by pine beetle outbreaks. Deforestation allows unobstructed flows of snowmelt, and infestation accelerates harvesting as logging companies race to salvage their investment before destruction by the beetles. The cleared area increases flood potential by removing protective canopy that prevents snowmelt and by creating a flood path.

Snowpack levels in southern BC’s Okanagan Valley measured 132 per cent above average at the end of January.

St. John’s, Newfoundland recorded its highest daily snowfall ever - 76.2 cm (30 inches) on January 17, prompting a state of emergency as snowdrifts rose to 15 feet on some highways. A video doorbell captured the time-lapse 24-hour accumulation that rose nearly to the porch roof and rendered a nearby parked car invisible. The Canadian Armed forces was tasked with snow removal, rescue operations, and emergency transportation.

NOTE ON ADMINISTRATIVE BOUNDARIES
There are numerous regions around the world where country borders are contested. ISciences depicts country boundaries on these maps solely to provide some geographic context. The boundaries are nominal, not legal, descriptions of each entity. The use of these boundaries does not imply any judgement on the legal status of any territory, or any endorsement or acceptance of disputed boundaries on the part of ISciences or our data providers.

Subscribe to our monthly Water Watch List

Search blog categories

Search blog tags