City officials say the emergency declaration comes as the result of flooding of the Hangingstone River and concern over the Clearwater River and its tributaries.
Mayor Melissa Blakes says it means evacuations that were voluntary are now considered mandatory, adding it's being done to "protect residents’ safety and ensure the swiftest possible response to the flood."
She says residents are encouraged to cooperate with local authorities and "stay upbeat during these trying circumstances.”
Late Tuesday, residents of 69 units at the Ptarmigan Court Trailer Park were ordered to leave their homes.
Residents of the Waterways and Draper areas were also placed under a boil water order by Alberta Health Services.
That means any water to be used for drinking, making ice, cooking, washing food or brushing teeth must be at a rolling boil for at least one minute before use.
The municipality says in a news release it is monitoring issues related to residents’ safety, including ensuring the safe operation of natural gas lines, telephone cables, water and sewer service.
Residents are also being encouraged to avoid rivers, valleys and low-lying areas.
Earlier Tuesday, 14 homes from a low-lying area called Grayling Terrace were also evacuated.
Keyano College advised students living in one of their residences to voluntarily evacuate to the city's emergency reception centre. Classes and exams have been cancelled for Tuesday and Wednesday.
The Syncrude Sport and Wellness will remain closed until Thursday.
Alberta Environment issued a flood warning for the Hangingstone River at Fort McMurray. A slow-moving, low pressure system over central Saskatchewan has brought between 80 to 180 millimetres of rain to the area since Friday.
"Right now everybody's been very co-operative, very receptive, they understand that the bank itself is starting to deteriorate and there is potential for flooding to occur, so yeah, they've been more than receptive to being displaced for hopefully a short period of time," said Brad Grainger, deputy chief of operations and technical services for the Regional Municipality of Fort McMurray.
City officials also asked residents in the Waterways and Draper areas to be ready to evacuate on short notice.
Annie Chatelain, who lives on high ground in Fort McMurray, said two major parks were completely flooded.
Chatelain has lived in Fort McMurray for decades and has never seen flooding like this.
She said several areas of the city were impassable because of flooded streets, adding even in her neighbourhood, water has been seeping into basements. Chatelain says everyone's sump pumps are working overtime.
Emergency officials were discouraging residents from trying to get close for photos or video of the overflowing river. The Fire Department said river banks are not stable and the water is moving extremely fast.
On Monday, flooding over a 30-kilometre section of Highway 63 resulted in the road being closed for several hours. A bridge on Highway 881 was damaged due to flooding and that road was also closed for most of Monday until repairs were done.
Blake said residents are at the mercy of the weather.
"The real risk is the weather. It's not just if it rains in Fort McMurray, if it rains a little further south and adds to the tributaries that go into the Clearwater (River), we still face the same risk."
Rain is in the forecast through Friday.
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