Manitoba Infrastructure’s Hydrologic Forecast Centre issued an updated flood warning and high water advisory for southwest and western Manitoba.
On July 1, based on engineering assessments and out of an abundance of caution, the Province of Manitoba lost confidence in the dam near Rivers. The province recommended the evacuation of people and livestock from approximately 30 to 40 properties along the Little Saskatchewan River, downstream of the dam, in the rural municipalities of Riverdale and Whitehead. Manitoba Infrastructure is recommending that all use of Lake Wahtopanah be suspended immediately.
The dam is facing unprecedented flows on the Little Saskatchewan River following heavy rains and Manitoba Infrastructure has indicated there is potential for a structural failure.
The recommended evacuation came as a weather system brought significant precipitation in the past week in southwest and western Manitoba. Some areas have received record-high precipitation of more than 200-millimetres during this period. The precipitation caused water levels to rise in rivers and creeks in these areas.
If required, evacuee reception centres will have social distancing measures in place.
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 levels within a short period in the Whitemud River watershed. Projected flows will be in excess of the peak flow during the 2011 flood event.
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 began early this morning 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.