Dozens of Canadian Armed Forces reservists had to be redeployed from a training session in Chatham this weekend to help residents in Ottawa dealing with the flood waters.

Coincidentally, they were supposed to be in Chatham to train for just that situation.

The exercise was called “Arrowhead Response” with the goal to practice the planning and execution of domestic support operations during a crisis like a natural disaster or an industrial accident.

Little did officials know a call for help from flood-ravaged communities diverted many of the soldiers from taking part in the training exercise to do the real thing.

Still, there were several Army reserve soldiers who spent the weekend training in Chatham as well as Hanover and Woodstock.

But about 100 reservists were rerouted to the Nation's capital region to help fill sand bags and help residents escape record high water levels.

There are dozens of properties threatened by flooding along the bloated Ottawa River, which is at or above record levels set in the last flood in 2017.

The river's peak is expected to arrive by Tuesday or Wednesday, depending on the location -- and then remain stable depending on the weather.

Canadian Armed Forces personnel are also packing and stacking sandbags in central Ontario's cottage country, where flooding has prompted the declaration of states of emergency in the communities of Bracebridge, Muskoka Lakes, Huntsville and Minden Hills.

And more rain is forecast for the region later this week.

The Canadian Armed Forces says it goes to show why this type of training is imperative.

Officials say one of the hardest parts of training is getting boots on the grounds because many reservists are students or have other jobs. But because of this weekend's scheduled training, it was easy to get people sent to different Ontario communities.