Workers were on the job right up until the morning of the new concrete bridge's opening on August 27.

READ MORE: Goulburn's new Lansdowne Bridge opens to traffic

Now it's been revealed that the $800,000 project to improve the bridge approaches on Bungonia Road ran $280,000 over budget.

Mayor Bob Kirk said he was surprised by the blowout when it when he first saw the report, tendered to the most recent council meeting.

ALSO READ: .Back to the Arcade's new laser tag stalls over water and sewer costs

"I did say it was a little difficult to say no after the event. It would have been nice to have been told beforehand," he said.

"...I accept it was through necesssity and the work wasn't provided for in the original budget. Once those costs were apportioned it came in over budget. If it had come to us beforehand we would have said yes too and the outcome would have been no different. It's just the process."

A report to the September meeting stated that $754,478 had been spent from the $800,000 allocation, with a final two-coat seal programmed for March, 2020.

Business manager of works, Andrew Cartwright reported that two factors were to blame.

ALSO READ: NSW Police and Ambulance attending industrial accident in Goulburn

"Working in close proximity to the adjacent powerlines required additional site resources to act as spotters throughout the work," he said.

"This was necessary to ensure plant did not encroach into powerline offsets required by Essential Energy. Also, as required by Essential Energy, a physical barrier in the form of an earth mound was required along a section, thereby limiting available workspace throughout the project."

But sections of the road also required "significant rework" owing to slower drying over the winter months and "poor subgrade and material compaction."

ALSO READ: Einstein, eat your heart out: challenge brings out best of students

"Placement of the pavement along Bungonia Road was protracted due to difficulties in achieving the optimum moisture content and compaction," Mr Cartwright said.

But slow drying rates of the pavement over the winter months had also added to the cost. It meant that many sections had to be reworked to achieve the necessary compaction, also adding time to the project.

Meantime, the council remains in discussions with Essential Energy on who foots the estimated $150,000 bill to relocate a section of powerline. Mr Cartwight said the electricity provider was claiming the council was responsible because it had changed the road level in that area.

"This matter is yet to be resolved. Further, as an interim measure, a concrete barrier has been installed adjacent to a section of the existing powerlines to permit traffic to use the road. This barrier will be removed once a section of the powerlines has been relocated," he wrote.

The council will forgo the purchase of a CAT 12M grader and a tipper, expected to cost $430,000 in 2019/20, to cover the extra $280,000. The $150,000 balance will go into the heavy plant reserve.

In related news, an extra $150,000 will be allocated from Multiquip Quarry's section 94 reserve to to reseal its primary haulage route, taking in Jerrara Road, near Bungonia.

ALSO READ: Record crowd at first-cross ewe sale despite big dry

Mr Cartwright said $1 million was budgeted for the project but, which had been deferred from the cooler months. It will start once Gunlake Quarry's haul route is resealed.

That cost estimate was based on a standard bitumen reseal but Mr Cartwright said the variable nature and condition of the existing seal along the 18km route required a modified bitumen, which was more expensive.

"Also, annual cost increases permitted under the contract for (infaltion) and bitumen prices have come into effect since the initial estimate," he reported.

We care about what you think. Have your say in the form below and if you love local news don't forget to subscribe.