High rainfall over the last two days of November caused localised flooding at the raw coal handling area of Isaac Plains’ preparation plant, hurting production.

“Steps to remedy these circumstances and to minimise their effect upon the performance of the mine are being taken and the company will provide an update once production resumes,” Aquila said on Friday.

The open cut metallurgical and thermal coal mine is aimed to ramp up to 2.8 million tonnes per annum of saleable production this financial year, up from the 2.48Mt it achieved in 2009-10.

Macarthur previously issued a profit guidance range of $115-125 million for this financial year based on 2.5-2.7Mt of saleable production.

But the rain over recent weeks has depleted stockpiles at its Coppabella and Moorvale mines and has affected mining operations.

“Bowen Basin coal miners have been impacted by unseasonal weather since the beginning of the financial year,” Macarthur chief executive Nicole Hollows said on Friday.

“Macarthur Coal was not unduly affected in the first quarter of FY 2011 and was managing any impacts on production by accessing run-of-mine stockpiles when required.

“However, coal mining and production has been hampered by heavy rainfall in recent weeks and Macarthur Coal is now declaring force majeure to its customers under existing contracts.

“It is not possible to predict the impact of continued unseasonal weather in the next half-year but once conditions improve, we have coal exposed that can be processed and transported.”

More wet weather hit over the weekend, also affecting the transportation of coal by Queensland Rail National.

With the official wet season underway, many mines in Queensland have already experienced setbacks from unseasonably high rainfall over the past few months.

The Queensland Mines Inspectorate warned coal mines to prepare for the “worst storm season in years” last week, on the back of longer term weather predictions.