Province recommending evacuation of people and livestock from specific properties downstream of Rivers Dam

FILE: Little Saskatchewan River near its intersection with the Assiniboine River (Photo by Green slash at English Wikipedia, CC BY-SA 3.0)

Based on engineering assessments, and out of an abundance of caution, Manitoba Infrastructure is recommending an evacuation of people and livestock from approximately 30 to 40 properties along the Little Saskatchewan River downstream of the Rivers Dam in the rural municipalities of Riverdale and Whitehead.

The Manitoba government does not have confidence in the Rivers Dam. The dam is facing unprecedented flows on the Little Saskatchewan River following heavy rains over the past few days, and provincial and consulting engineers have indicated there is potential for a structural failure.

The municipalities of Riverdale, Whitehead and Cornwallis and the City of Brandon have been notified.

Municipal officials are working with the province to ensure residents downstream of the dam are aware of the situation and have destinations in mind if asked to evacuate as a precaution.

Manitoba Infrastructure is also recommending that all use of Lake Wahtopanah be suspended immediately.

The recommended evacuation comes as a weather system has brought significant precipitation in the past 72 hours in southwest and western Manitoba. Some areas have received record-high precipitation of more than 200 millimetres during this period. The precipitation has caused water levels to rise in rivers and creeks in these areas.

Overland flooding is being reported in areas across the Assiniboine River watershed. A number of rivers, including the Little Saskatchewan River, are above flood stage and low-lying land near the river is affected.

Flooding of low-lying areas is expected for most portions of the Assiniboine River and its tributaries. However, water is expected to remain below flood protection levels at most locations along the Assiniboine and Souris rivers.

A flood warning has been issued for the Whitemud River as the run-off from upstream watersheds is passing through the Arden and Gladstone areas. Water could rise above bank-full levels within a short period in the Whitemud River watershed.

A flood warning remains in place for the Little Saskatchewan River and Whitemud River watersheds.

As well, a high water advisory remains in place for the Spruce Woods Provincial Park area.

Operation of the Portage Diversion could begin within the next 48 hours to limit flows in the lower Assiniboine River to 10,000 cubic feet per second. The level of Lake Manitoba is currently 811.5 feet, which is in the middle of the desired water level range.

The operation of the Portage Diversion is not anticipated to have a significant impact on the level of Lake Manitoba. This operation is in accordance with Portage Diversion operating guidelines.

Manitoba Infrastructure crews are working in the flood-affected areas. Staff are monitoring water level conditions and inspecting infrastructure on an ongoing basis.

Property owners are advised to take precautions as water levels could rise significantly in a short time in these areas.