The possibility of ice jams and flooding prompted the province to issue a high water advisory for part of the Assiniboine River Saturday.
It's in place from St-Lazare to Portage la Prairie.
The province said water levels have risen by approximately seven feet overnight, or more than two metres, and water is on the road. Part of Highway 5 has been closed due to water.
Environment Canada has ended a snowfall warning for parts of southwestern Manitoba, but the province said snowfall amounts are still being monitored for their effect on water levels.
An ice jam has been reported on the Assiniboine River near Spruce Woods Provincial Park.
Another high water advisory is in place for small streams, drains and tributaries across southern Manitoba where the snowpack is melting.
The province said it may put the Portage Diversion into operation within the next 24 hours to manage the ice on the Assiniboine.
And its amphibexes are ready to be deployed to break up the ice if ice jams develop on major rivers.
The province is warning people to be careful around waterways, given how quickly flood conditions can develop.