Kitchener city staff say the aging Margaret Avenue bridge in Kitchener should be demolished "immediately," and replaced with a new one in a move that would cost an estimated $6 million.

In a report released Wednesday, staff said the bridge should be taken down "hopefully before the end of the year." Staff said the city should then immediately undertake an environmental assessment to replace the bridge outright.

That course of action "represents the best use of city capital dollars and the lowest risk to the city and railways."

The recommendation comes after an evaluation of the structure by engineering consultancy firm Morrison Hershfield, which concluded the need to replace the bridge is "crucial" and should not be delayed.

Staff had considered another option — conducting a short term emergency repair of the bridge by installing steel plates to reinforce the top and the bottom of the structure. The bridge would then be replaced outright in 2015.

Under that scenario, the bridge, which has been closed to traffic since June, would be open to some vehicular traffic in 2014.

Yet "there will still be a risk of failure, although it will be significantly reduced from existing (bridge unloaded) conditions," staff wrote. And there is no funding allocated to short term repairs, so those costs "will further compromise our ability to implement a long term solution."

Provincial regulations mandate all bridges in Ontario be inspected every two years. In 2012, the city's inspection identified the rail overpass between Victoria Street and Breithaupt Street as one that needed additional investigative work.

That led to the city calling in AECOM to investigate in January. The consultancy firm released its draft report Thursday.

The report stated that the structural issues were significant enough to warrant the closure of the bridge. That opinion was echoed by Morrison Hershfield in Wednesday's staff report.