One lane of the busy highway was already closed due to the rising Red River prior to Monday's announcement.
Crews will use gravel to build up an existing dike around the town of Morris in order to at least maintain local access for residents.
Chuck Sanderson with the Manitoba Emergency Measures Organization called this year's flooding “unprecedented.”
The flooded area stretches from the Saskatchewan border to eastern Manitoba, and from The Pas south to the U.S. border.
As of Sunday, 70 provincial roads and 725 municipal roads were fully or partially closed due to flooding.
Meanwhile, crews are racing against time to build up dikes along the Assiniboine River, which being pushed to record flood levels by a persistent ice jam.
Both the Red and the Assiniboine could crest simultaneously, experts said on the weekend. That should occur sometime between April 27th and May 3rd.