The water has never been measured this high in the board's history at those two locations, along with western Ottawa's Britannia area.
Water levels went up another four to six centimetres overnight in Gatineau, Que., according to the city, which has seen another approximately 200 people register as flood victims in the last 24 hours for a total of 1,593.
It's caused a westbound lane of Highway 50 to be closed around Lac Leamy, meaning severe headaches for people heading downtown.
Waters are expected to peak in Ottawa-Gatineau, Pembroke, Thurso, Que., and near the Ontario-Quebec border on Wednesday and Thursday.
Conditions could make things difficult for those working to shore up properties against the floodwaters on Wednesday.
Ottawa-Gatineau and areas to the west as far as Algonquin Park on the Ontario side of the river are expected to get two to five centimetres of snow mixed with ice pellets, then 15 to 25 millimetres of rain.
Areas along the St. Lawrence River and Lake Ontario, which are seeing some flooding but not at historic levels, could get 20 to 40 millimetres of rain.
Reinforcements for property owners across the region include volunteers, the military in some of the hardest-hit areas and, in a few cases, high school students in communities such as Cumberland in eastern Ottawa and, as of today, from West Carleton Secondary School in the west end.
A home in the flooded area of Constance Bay in western Ottawa caught fire late Monday night, according to Ottawa Fire Services.
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Despite escalating safety warnings around a bloated Ottawa River, some adrenaline seekers wont be stopped.
In video shared with CTV News Ottawa, a person is seen riding a jet-ski upstream through rapids. The footage was captured by viewer Craig Lutes, who said it was taken near Britannia, an area in the west end of Ottawa.
Minister of Transportation Marc Garneau has banned non-emergency boats from the Ottawa River between the capital city and the Carillon dam on the Ontario-Quebec border. Boaters could face a fine of up to $5,000.
Thousands of people across Quebec, Ontario and New Brunswick are facing widespread flooding. The City of Ottawa declared a state of emergency last week.