© Reuters/Fred GreensladeMembers of the Princess Patricia's Canadian Light Infantry (PPCLI) work at shoring up a dike along the Assiniboine River near Poplar Point, Manitoba, May 13, 2011.
Opening the dike will, over days, flood at least 225 square kilometres (55,600 acres) of land that includes 150 homes while taking the pressure off strained dikes.
After the deliberate dike breach, Manitoba Premier Greg Selinger said the gradual, controlled flood was going well and that he knew of no homes in its path that had been damaged.
Water was spreading rapidly across fields, however, swamping land when farmers are usually planting crops of wheat, canola and vegetables.
"This was a necessity because a catastrophic overflow would have taken all the people in this area, and around it they would have had up to five times more damage if the river opened up," Selinger told reporters near the breach site. "...The dikes are very stressed with the amount of water going through, which is why we had to do this opening here."
The controlled flood looked to continue for as long as a week with flows speeding up because the river was still rising, Selinger said.
