Rail operator Aurizon faces multi-million dollars worth of costs from disruptions caused by the Queensland floods.
The group gave the warning on Wednesday as it reported a 10.3 per cent drop in first half profit.
Ex-tropical cyclone Oswald and subsequent flooding caused significant damage to Aurizon's Blackwater and Moura rail systems in January.
Aurizon said the Moura system was re-opened on Tuesday night after a 26-day outage, while the Blackwater system had re-opened earlier in February.
The company estimates the below-rail repair costs will be between $10 million and $15 million, which the company plans to recover through regulatory processes in 2014.
It also estimates that it will lose four million tonnes in coal volumes as a result of the floods, which will cause a $22 million hit to its earnings.
"The financial impact of the derailment is expected to be approximately $5 million in EBIT (earnings before interest and tax)," Aurizon said in a statement.
Chief executive Lance Hockridge said he expected the company's coal volumes this financial year to be in the range of 192-195 million tonnes.
"We will continue to work with our customers with the objective of all parties recovering lost tonnages, noting the average weekly coal railings in the 13 weeks prior to the floods was 3.94mt," Mr Hockridge said.
Aurizon's net profit fell to $175.7 million in the six months to December 31, from $196 million in the previous corresponding period.
Revenue for the company, which changed its name late last year from QR National, rose to $1.9 billion from $1.7 billion.
The group's net profit result was dragged down by $88 million in redundancy payments.
Underlying net profit rose to $222 million from $175 million.
Mr Hockridge said Aurizon's financial results for the first half were achieved despite flat coal railings of 97 million tonnes.
Volumes dropped three per cent in Queensland, but rose 15 per cent in NSW.
Iron ore volumes in Western Australia also rose, by 89 per cent, lifting haulage revenue by $99 million.
Mr Hockridge said new contracts with miners including Whitehaven, Rio Tinto and Cockatoo Coal had been negotiated under more favourable commercial terms and provided significant growth for Aurizon well into the next decade.
Aurizon lifted its partly franked interim dividend to 4.1 cents a share from 3.7 cents.