Starting in August, motorists, cyclists and pedestrians who use Hog's Back Road near Mooney's Bay will find themselves taking detours for at least 16 months while two federally owned bridges over the Rideau Canal and Hog's Back Falls undergo repairs.

The National Capital Commission's swing bridge over the Rideau Canal will be the first to close, from August 2019 to May 2020, while the steel grating is replaced with a closed road surface, the structural steel is recoated and the bridge's electrical systems are replaced.

Coun. Riley Brockington says the bridge over Hog's Back Falls is in especially bad shape. The swing bridge over the Rideau Canal will also close for extensive repairs. 0:45

The NCC received $55 million in the 2018 federal budget for infrastructure projects including the swing bridge after the federal auditor general found 27 per cent of its assets to be in fair, poor or critical condition.

The Rideau Canal will remain open to boats and Colonel By Drive will stay open to vehicles, according to the NCC.

One of the locks over the canal will be modified to give cyclists and pedestrians a better way to cross the canal — many Carleton University students live in apartment towers at Meadowlands and Prince of Wales drives.

Pedestrians will be able to use a lock over the Rideau Canal while the Hog's Back swing bridge is repaired. Cyclists will have to get off their bikes to get them across. (NCC)

Once the swing bridge completed, Hog's Back Road will close slightly further east so Parks Canada can tackle its bridge and dam over the Rideau River. That section of road is anticipated to be closed from spring 2020 until December 2020.

"They can't be left much longer. They do need to be repaired, and I'm glad the necessary funds are going into it," said Coun. Riley Brockington, who held a public information session for his River ward residents on Monday night.

"The stationary bridge that spans the waterfall, you can see the deterioration — the concrete that's come off, rusted rods that are exposed, the railings are all corroded."

The first dam at the site was built in the late 1820s, but the current version dates back to 1977. The swing bridge was built in 1976.

The NCC says the Heron Road and Prince of Wales Drive intersection will be modified to take extra traffic due to vehicles having to avoid Hog's Back Road while the swing bridge is repaired. (NCC)

Sixteen or more months of closures in the area will have a major impact on traffic of all kinds, and could make busy Riverside Drive even more congested, Brockington said.

Any time the swing bridge is closed it also affects local businesses, he said. He visited them personally in recent weeks and found many were surprised to learn they face lengthy construction and detours.

"I don't think the timelines have sunk in yet," Brockington said.