COCKATOO Coal admitted the Baralaba Bridge project had taken longer than expected at a recent community meeting but assured residents the extra time was only to ensure the bridge was built without any future issues.
Baralaba residents had been left wondering when the bridge would be completed after first being told it would be completed by Christmas.
Department of Transport and Main Roads and Cockatoo Coal had jointly funded the work to upgrade the bridge that was cut due to the flooded Dawson River for more than 120 days last year.
A Cockatoo Coal spokeswoman this week explained the work.
"The first issue we had were the piers needed to go into the bedrock more because of mudstone banding at the original level, which put us back three weeks," she said.
"Due to the conditions that the bridge must withstand over its life, the DTRIS engineering standards are extremely stringent.
"As a result, the top 100mm of the head stocks of the pylons need to be remoulded.
"It is a relatively simple process to correct this survey issue."
Baralaba Mine general manager Tony Green said that extra precautions were all a matter of planning for the future.
"This isn't a major problem but for a bridge that we want to have for the next 50 - 100 years there would be nothing worse than if we had problems later on or have to pull it down and start again," Mr Green said.
"At the start to have the bridge completed in December was a very optimistic timetable."
Mr Green said the bridge work was hoped to be completed in eight - 12 weeks.
Residents have also asked why rock has been delivered at the site yet work has not commenced.
Cockatoo Coal responded stating the rock currently at the area was not related to the bridge project and was most probably a remedial fix to wash outs from last year's flood by Sunwater.
"We will be bringing suitable rock to the site for filling gabion baskets which will be installed on bridge approaches," a spokeswoman said.