The province hopes to convert a temporary emergency drainage channel on Lake St. Martin to a permanent one and build a second drainage outlet on Lake Manitoba, where one exists already.
The projects are among several recommended by a recent independent review into the disastrous flood of 2011, when many communities along the lakes were swamped.
"There are other recommendations that will be considered as we go forward, but our advice is that these ones will have the biggest positive impact in the shortest run for these communities," Premier Greg Selinger said.
Both projects need environmental approval and an exact location for the Lake Manitoba channel still has to be determined. The aim is to start construction in 2016 and finish both projects by 2021, Selinger said.
The price tag for both projects is expected to be $250 million, although the federal government may take on some of that. Selinger told reporters the projects are a key reason why his government plans to raise the provincial sales tax to eight per cent from seven per cent as of July 1.
"This is one of the most significant commitments we're making as a result of raising the PST ... and it will make a generational difference for people in that area."
Manitoba experiences some degree of flooding almost every year, due to its flat landscape and rivers that bring water from as far away as The Rockies and South Dakota. The province has a series of dams, channels and dikes all designed for one purpose — to keep the water away from communities and flowing through to Lake Winnipeg and eventually Hudson Bay.
The Red River Valley and Winnipeg already have the best protection in the province. The new projects are aimed at helping areas to the north and west including the Assiniboine River Valley, which was hard hit in 2011.
The two outlets will give the province more control over water levels in Lake Manitoba, which drains into Lake St. Martin, and Lake St. Martin, which drains into Lake Winnipeg.
The Opposition Progressive Conservatives said they don't believe the flood-fighting promises. NDP governments have long promised flood-fighting projects, such as work on the Shellmouth Dam, that have never come to fruition, Tory water stewardship critic Larry Maguire said in a statement.