Major flooding possible on Manitoba’s Assiniboine River

The Manitoba government announced Tuesday the possibility of major flooding on several rivers including the Assiniboine, which runs through Brandon.

“An unfavourable weather scenario would result in major flooding of the Assiniboine Valley from Shellmouth to Brandon similar to those levels of 1974 but lower than those of major floods in 2011, 1995 and 1976,” the province’s infrastructure and transportation department stated on its website.  “Brandon flood protection works are higher than the predicted flows.”

The province’s Hydrologic Forecast Centre released its second 2013 flood outlook, which warns there is a risk of “moderate to major flooding” on the Assiniboine River “due to normal to above-normal average soil moisture in the upper portions of the watershed” and also due to higher than normal levels of snow and water.

“Provincial crews have inspected and made repairs at critical locations along the 160 km of Assiniboine River dikes which were heavily damaged in the 2011 flood,” the province stated.

“Provincial officials continue to work closely with the City of Brandon as work continues on the  $20 million flood-mitigation program.  Under the current outlook, one row of super sandbags may need to be positioned at 18th and First streets.  The recently completed eastern access roads will also provide alternatives when travelling in and around Brandon this spring in the event of significant flooding.”

According to published reports, about 1,000 homes were ordered evacuated in Brandon in 2011.

This week’s press release noted there was an above-average snow pack in many parts of the province, with low temperatures keeping frost in the ground longer than normal, suggesting more water could run off rather than be absorbed in the soil.

In addition to the Assiniboine River, the province warns of increased flooding potential on the Souris, Pembina, Saskatchewan and Qu’Appelle rivers, as well as the Red River, which runs through Winnipeg.

The Red River floodway, completed in 1968, was built due to flood damage in 1950.

The infrastructure and transportation department noted Tuesday the gates to the Red River Floodway have been refurbished “and are ready for operation once ice has cleared the inlet and control structure.”

However, the deparment added: “Unfavourable weather conditions would result in moderate to major flooding,” on the Red River.

“Levels in the main stem would be higher than 2011 but slightly less or the same as 2009 from Emerson to Winnipeg. Water levels north of the city of Winnipeg are likely to be close to those of 2009.”

The province is using three Amphibexex excavators to break ice and also has, among other things, two million sandbags and 43 km of Hesco Bastion barriers, which are wall systems made of steel wire mesh designed both for military use and flood protection.