Provincial officials broke through a section of the Assiniboine River dike on Saturday morning as part of a bid to do a controlled release on the river in the midst of the flood battle.
"The controlled release of water through the Assiniboine River dikes at the Hoop and Holler bend began at 7 a.m. (Saturday) morning. It is expected to take a few hours before a significant amount of water begins to flow," said the province in a media release.
Premier Greg Selinger gave a public address Friday night on the flood situation.
The controlled release could affect an area of approximately 225 square kilometres and around 150 homes, said the province.
"I'm not worried but a lot of people are," an area resident told CTV News Saturday morning. The province said homes in the immediate area around the breach had been evacuated, with "significant efforts" put into place to flood-proof the houses.
In a public address Friday night on the flood situation, Premier Selinger said large parts of Manitoba are coping with some of the worst flooding the province has seen, a one-in-300-year flood.
"Unprecedented flood levels, fully saturated grounds and bad weather at the worst possible time have created a perfect storm. This is a natural disaster without precedent and it is affecting the lives of many Manitobans," said Selinger.
Provincial officials previously said the Hoop and Holler Bend was selected since it provided the least risk and best opportunity for managing water flows. The timing for a deliberate breach has been pushed back on multiple occasions this week.
Residents are being told to follow instructions from their local rural municipalities.
Selinger said the decision to go ahead with the controlled release was made after a unanimous recommendation from officials.
"It is intended that flows will disperse slowly across fields and then fill behind roads and spill at low points along roads and ultimately spill into the La Salle River," said the province Saturday morning.
The province said the deliberate breach and controlled release are aimed at relieving "pressure on the Assiniboine River dikes, which are under heavy pressure from river flows."
Earlier in the week, provincial officials said the controlled release would be carried out to guard against the possibility of uncontrolled breaches.
In an uncontrolled breach, about 850 homes would be at risk and it could affect an area of 500 square kilometres in communities including St. Eustache, Elie, St. Francois Xavier, Poplar Point and La Salle, among others, said the province.
The premier said provincial staff members have been told to create a special compensation program, in addition to disaster assistance.
"Families and producers affected by the controlled release will receive compensation to cover damages, income losses and the cost of recovering the land after the flood waters recede," said Selinger.
A road near Hoop and Holler Bend has been acting as a dike, holding back water from the Assiniboine River.
Crews have been working to surround it with large limestone boulders, or rip rap. To carry out the breach, crews were expected to make a cut less than a metre deep into the road, with water flowing through the boulders, absorbing the impact of the water. The province said the rocks will slow down the flow of water, making it a controlled release.
