The Portage Diversion began operating Sunday to manage ice on the lower Assiniboine River, the province said.
A high-water advisory, which was issued Saturday, continues for the Assiniboine River from St-Lazare to Portage la Prairie due to ice jamming and the potential for ice jams and flooding.
The ice jam remains on the Assiniboine River in the vicinity of the Spruce Woods Provincial Park.
Since the jam formed, water levels have risen by approximately two metres and water is on the road.
A section of Highway 5 is closed.
Crews have posted signs in the area and continue to monitor the situation, said provincial officials.
The high-water advisory was issued for small streams, drains and tributaries across portions of southern Manitoba where snowmelt is occurring.
Overland flooding may be caused by spring runoff, with ice jams and blocked culverts resulting in a rapid rise in water levels on tributaries and drains, the province said.
It reminded people to be watchful of local waterways because flood conditions can develop quickly.
On Saturday, snow was falling in western Manitoba from Wawanesa to Brandon. Environment Canada issued snowfall warnings for most of the Parkland region of western Manitoba.
The province is reminding people to stay away from ice and water and not to drive or walk through fast-moving water.
Motorists are advised to call 511 to check road conditions before travelling.