Australia's QR National estimates coal haulage will fall by as much as 20 million tonnes in the current quarter due to the recent flooding in Queensland state.

In the coal haulage business, volumes are estimated to be down by between 15 million tonnes and 20 million tonnes to the end of quarter three of financial year 2011, QR National said in a statement on Thursday.

The company said the estimate is based upon its assessment of currently available information and the final outcome will depend on the respective situation of each of our coal customers, their ultimate production for the balance of the financial year, and the specific terms of their coal haulage contracts as well as potential for further weather events during this period.

"This assessment also assumes that volumes will return to forecast levels in quarter four of Financial Year 2011," said QR National.

The company said it is working closely with all participants in the coal export supply chain to maximise throughput and will strive to reduce the financial impact of the Queensland flood crisis on its business wherever possible.

The company said further progress on reinstating operations has been made with the re-opening of the Blackwater line late yesterday, 24 hours ahead of the planned resumption of services.

All systems in the Central Queensland Coal Network are now open although speed restrictions continue to be applied in some areas.

Initial estimates of the impact on the Network Services business of the flood events in Queensland include immediate costs to repair damaged track to re-open all four coal systems amounts to approximately $10 million, excluding the Rolleston branch line which is still being assessed.