Drivers needing to cross the Bow River are being advised that one of the routes will be closed for a few weeks as crews work on a critical flood mitigation project.

Starting Friday, the lower deck of the Centre Street Bridge will be closed for the next little while to take care of one of the problems that was identified during the 2013 floods.

At that time, the city says the area was considered to be a ‘breach point’ and it would need to be reinforced ahead of another flood situation.

To do that, the crews will be installing cost-effective flood gates made out of aluminum logs on steel supports. Each gate will then be anchored to the deck of the bridge.

The lower deck isn’t the only spot where workers will be doing flood mitigation work. There will be some electrical work done on the upper deck and a small earth berm will be built on the southeast corner.

Deighen Blakely, one of the engineers on the project, says the lower deck of the bridge was identified when her team went through Calgary to identify problem areas because of flooding.

"The downtown core area is one of particular interest to us because it's so important to Calgary. The Centre Street Bridge deck is an area where we noticed in 2013 there was flooding through downtown and also to Memorial Drive."

She says that the work on the bridge will work in conjunction with the West Eau Claire Barrier as well as another downtown barrier that's still in the design process.

All of the work is being paid for through the city’s $150M flood mitigation program. Design and construction of the Centre Street Bridge portion is about $1.6M.

"This has been a pretty cost effective project. We are building some small earth barriers on either side of the project and the bridge itself will be blocked by aluminum stop logs that will be put in place in time of a flood."

While traffic will be shut down on the lower deck until September 11, drivers can still use the 4 and 5 Avenue flyovers and the 10 Street Bridge.

Blakely says there are other flood mitigation projects planned for Heritage Drive, Sunnyside, Bowness and Pearce Estate Park.