Australia’s record floods are causing catastrophic damage to infrastructure in the state of Queensland and have forced 75 percent of its coal mines, which fuel Asia’s steel mills, to grind to a halt, Queensland’s premier said on Wednesday.

The worst flooding in decades has affected an area the size of Germany and France, left towns virtual islands in a muddy inland sea, cut major rail and road links to coal ports, slashed exports and forced up world coal prices.

“Seventy-five per cent of our mines are currently not operating because of this flood, so that’s a massive impact on the international markets and the international manufacture of steel,” Premier Anna Bligh told local television.

Queensland state is the world’s biggest exporter of coal used in steel-making.