Cootamundra-Gundagai Council general manager Phil McMurray told The Daily Advertiser the weathered viaduct bridge required immediate action after a truck hit a weight-carrying beam.

"About three months ago, a truck hit the span over O I Bell Drive and structural engineers made an assessment that found [the bridge] was at risk of failure," Mr McMurray said.

"That section of the road was closed and a detour was put in place to take away that immediate risk."

The bridge was built in 1867 and has not been used by more than local traffic since the construction of the Sheahan Bridge in 1977.

It was built over the site where British explorer Charles Sturt first crossed the Murrumbidgee River.

"It was once the only bridge crossing the Murrumbidgee between Sydney and Melbourne and it's one of the longest timber bridges in the southern hemisphere," Mr Murray said.

Since 1896, the northern approach has fallen out of use due to safety concerns.

As a historic asset, the bridge comes under the jurisdiction of the Department of Planning, Industry, and Environment - Crown Lands.

A spokesperson for the department had "identified some deterioration caused by recent heavy rainfall and impact by a truck" while undergoing routine engineering assessments.

Over the last weekend, five spans were removed from two sections of the bridge.

"At the moment, it's still a connected unit but we're missing a few spans in the middle," Mr McMurray said.

The road underneath continues to remain closed and repair works are also expected to take place around the Landon Street overpass.

"The department has been liaising with Cootamundra-Gundagai Regional Council and safety fencing has been placed around the overpass until the community is consulted on the development of a management plan for the bridge," the spokesperson said.

Mr McMurray said it was expected the department would host consultations with the council and community before implementing a strategy to restore the historic structure.

"The bridge is obviously aged and decayed," Mr McMurray said.

"It's significant locally and nationally, that's why it's a shame to see it fall into disrepair."

Local residents have been advised of the work's commencement and further consultations are expected to take place soon.

"More community consultations will be held on the development of a management plan for the bridge prior to any further work," the spokesperson said.

Cootamundra-Gundagai Council mayor, Abb McAlister, said the department has indicated it will consult the community on future plans.

"The community has a lot of feeling about that bridge that people from outside may not have," Cr McAlister said.

Our journalists work hard to provide local, up-to-date news to the community. This is how you can continue to access our trusted content: