The province will reopen an emergency channel to relieve pressure on a rising Lake St. Martin as early as July 2.
And provincial officials served notice Wednesday they may operate the Red River Floodway in the coming days to prevent basement flooding in Winnipeg if a major downpour is forecast.
Persistent rainfall -- twice the normal amounts in some areas of the province since April 1 -- has created problems throughout Manitoba.
The Red River Floodway may have to be operated to reduce the likelihood of basement flooding in Winnipeg.
The Portage Diversion may be reactivated for the same reason.
An emergency outlet to relieve pressure on Lake St. Martin could be reopened by July 2.
As many as one million acres of farmland in Manitoba may have gone unplanted this year. Flooding continues along the Assiniboine River south of the Shellmouth Dam.
Lake Winnipeg is currently higher than its regulated limit of 715 feet above sea level (715.34 feet on Wednesday).
-- source: Province of Manitoba
In Winnipeg, the Red River stood at 15.9 feet above normal winter ice levels at James Avenue on Wednesday and is expected to climb to 16.7 feet in the coming days.
"We can and will operate the floodway if necessary," Infrastructure and Transportation Minister Steve Ashton said Wednesday.
"If we're looking at a forecast of upwards of two inches of rain, we would activate the floodway," he told a news conference.
However, given the current forecast, the province may not have to take that step, he added.
In any case, the Red is expected to stay above 14 feet James until mid-July. The Forks walkway is visible at about eight to 8.5 feet.
Provincial officials said if the floodway were to be operated, the Red could be lowered by three feet in three days in Winnipeg.
Meanwhile, provincial officials said they may need to divert small amounts of water from the Assiniboine River into the Portage Diversion to protect farmland east of Portage la Prairie and minimize the possibility of basement flooding in Winnipeg.
Only about 1,000 cubic feet per second (cfs) would be sent along the channel, which the province said would increase levels on Lake Manitoba by "one-sixteenth of an inch after a month."
The Lake St. Martin outlet channel was built on an emergency basis during the devastating 2011 flood. The province recently received federal permission to reopen it once the lake reaches a sustained level of 803 feet above sea level. That is expected to occur by next Wednesday.
The initial discharge will be about 5,600 cfs and the operation will likely remain in place until the spring of 2015. With normal rainfall, provincial officials expect the lake to drop to 801 feet above sea level by Oct. 31.
Ashton also maintained the operation of the emergency channel, which eventually diverts water to Lake Winnipeg, will help draw down Lake Manitoba over the long term since it will allow for continued full-out flows through the Fairford channel (which drains Lake Manitoba into Lake St. Martin).
"(It) will provide immediate relief in and around Lake St. Martin. It would also provide long-term relief for Lake Manitoba," the minister said.
Ashton said using the channel should reduce the level of Lake Manitoba by about 15 centimetres.
"We need a break in the weather," Ashton said Wednesday.
"We could use hot, dry weather. After a long, cold winter, we've had a wet, wet spring and summer. We're not done yet by the looks of the forecast."
The emergency channel at Lake St. Martin was built for $100 million in 2011 to ease pressure on Lake Manitoba. It is only a temporary channel, which requires federal approval to operate. The province has received that approval as water nears what is considered to be flood stage.
Steve Topping, provincial executive director of hydrologic forecasting and water management, said the province has received 200 per cent more precipitation than normal this spring.
Lake Manitoba is high and can be whipped up even more by high winds, he said.
"We are putting out wind alerts on a daily basis," Topping said.
-- with files from The Canadian Press