After seven years of drought, elated cattle farmers in the Australian state of Queensland welcomed the rainstorms heading their way as a blessing.

Cattle that survived the flooding are seen here in Queensland, Australia.

But now, after one of the most devastating deluges in state history, a billion-dollar industry could be left in tatters.

Authorities estimate that nearly 500,000 cattle -- worth about $213 million (AU$300 million) -- have been killed by flooding in Queensland's north since the rain began falling late last month, CNN affiliate Seven News reported.

The downpours have ended but the cattle carcasses remain, baking in the record-breakingsummer heat. If not buried or burned, they will pose a health hazard. Video taken from overhead at one location shows scores of dead cattle huddled together amid the devastation.

"People have gone through drought, they have come out of years and years of drought, and they have now gone smack-bang into a natural disaster the likes of which no one out there has seen before," Queensland Premier Annastacia Palaszczuk said.

But cattle farmers and industry lobbyists say the worst could be yet to come.

Australia's beef industry is one of the country's biggest economic drivers, with exports in 2017 worth $5.3 billion (AU$7.4 billion). About $6.1 billion (AU$8.6 billion) worth of beef was consumed domestically from July 2017 until June 2018, according to trade group Meat & Livestock Australia.

The CEO of rural production advocate Agforce Queensland, Michael Guerin, described the flooding as a "humanitarian crisis" and "a disaster of unprecedented proportion."

"The speed and intensity of the unfolding tragedy makes it hard to believe that it's just a week since farmers' elation at receiving the first decent rains in five years turned to horror at the devastating and unprecedented flood that quickly followed," he said.

"Although we won't know the full extent of the livestock losses and infrastructure damage until the water fully recedes, it is certain that the industry will take decades to recover."

Many of the cattle that survived can't be reached since roads aren't passable yet. Authorities have resorted to air drops to provide feed, but the affected areas are so vast they may not be able to reach all the animals in need.

Georgie Somerset, the general president of Agforce Queensland, said on Tuesday that "we're literally ferrying one barrel of hay at a time to feed the stock that we can find."

Many cattle farmers are bracing for major losses. The Queensland government is providing emergency hardship assistance to those affected. Farmers are eligible for grants up to $53,000but may need more to rebuild herds.

Cattle farmer Jodi Keough told Seven News she expected to lose half her herd, adding that if authorities do nothing "we're talking about a possible collapse of a primary industry in Australia."

Meanwhile, one person has died from a soil-borne bacterial disease after the flood waters receded from the regional center of Townsville, Dr. Julie Mudd from the local health unit told reporters. Another seven have been hospitalized, she said.

Source: CNN