Environment Canada has issued a special weather statement predicting up to 35 millimetres of rain by Saturday morning, and river authorities are now forecasting that in some areas, water levels could rise up to 11 centimetres above the peaks reached during the devastating floods in May 2017.
Watson said he's also asked for help from the Canadian Armed Forces, and has been told 400 troops will be deployed to key areas.
While levels on the Rideau River have stabilized, the Ottawa River is expected to rise about half a metre from Constance Bay to east of Cumberland by the weekend, according to South Nation Conservation.
CBC's Journalistic Standards and Practices|About CBC NewsReport Typo or Error|Send FeedbackRelated Stories Constance Bay residents brace for more flooding Mississippi rising: Lanark County residents scramble to save homes Spring melt means further flooding could come Woman who died in flood remembered for her compassion CommentsTo encourage thoughtful and respectful conversations, first and last names will appear with each submission to CBC/Radio-Canada's online communities (except in children and youth-oriented communities). Pseudonyms will no longer be permitted.
Saint-André-Avellin is flooded by the the Petite-Nation river on Wednesday. Residents rush back to their house after hearing that the sand bags didn't hold up and the basement just started flooding. Jean Levac / Postmedia News
At a 4 p.m. press conference Watson said the army is sending 400 troops and Premier Doug Ford has pledged provincial support.
At the press conference, city manager Steve Kanellakos said the city simply doesn’t have the capacity to handle what might happen in the weeks to come, which is why he went to the mayor to suggest declaring a state of emergency.
The city of Ottawa is opening three emergency community support as the 2019 flooding situation continues to worsen.
At each location, visitors will be able to speak to representatives from the city’s community and social services department and Ottawa Public Health.
In addition, representatives from the Canadian Red Cross and The Salvation Army will also help triage resident needs, answer resource questions, and follow up on resident inquiries or direct them to the appropriate service.
"If we reached the forecasted levels, it would be a new historic record for this region from Ottawa to Pembroke," said Michael Sarich, the Ottawa River Regulation Secretariat.
The West Carleton-March support centre is at the Constance and Buckham’s Bay Community Centre, 262 Len Purcell Lane. It is open from 1 p.m. to 7 p.m. Thursday and from 10 a.m. to 7 p.m. Friday through Sunday.
Grandbois, whose grandparents live on the Ottawa River in Britannia, has taken extreme measures to prepare this year, building a sandbag wall around the entire perimeter of their home.
The Bay community centre is at the Barbara Ann Scott Arena, 2250 Torquay Ave., while the Cumberland support centre is at the Cumberland Heritage Village Museum, 2940 Old Montreal Rd.
Meanwhile, across the river, the city of Gatineau saw 100 more people register as evacuees of flood stricken areas on Wednesday, as water levels in the Ottawa River continue to swell.
To date, 517 people have registered with the city, including 431 adults and 86 children, for a total of 242 households.
About 100 of the affected residences are around hard-hit Hurtubise Boulevard, anout another 100 from the Pointe Gatineau district. There have been no registrations from Aylmer district to date.