SAHARSA, India - At least a million Indian villagers whose homes, crops and cattle have been washed away by monsoon floods will be in dire need of aid for many months to come, aid workers say.

Experts say the flooding, caused by a river that burst defences upstream in Nepal and changed course to cut across a large swathe of land in northern India's Bihar state, has left the country facing a massive, long-term disaster.

Officials said work to fix the flood walls and divert the Kosi river back to its normal course cannot begin before the rainy season ends in October, and may not even be completed before early next year.

This means large areas of the already punishingly poor state will be underwater for months.

"A population of at least a million will be homeless and they may not get their homes back," said Mukesh Puri, emergency specialist with the United
Nations children's agency UNICEF.

"It will be a huge rehabilitation issue," he said.

UN agencies say three million people have been affected by the disaster. Half a million have fled to dry ground, while hundreds of thousands more are still awaiting rescue.

Evacuated villagers, some with buffaloes and cows they managed to rescue, are crowding into every available safe space on the perimeter of the vast flood plain -- schools, universities, temples and madrassas have all turned into shelters.

Even at the railway station in this ramshackle town, situated some 150 kilometres (95 miles) east of state capital Patna, at least a thousand sit or sleep on the few clothes and belongings they have saved.

For now, private citizens are pitching in.

In the town of Singeshwar, in the worst-hit Madhepura district, a Hindu temple has been providing meals for at least 5,000 flood victims a day, paid for by donations from town residents.

"As long as people come we will feed them," said Diwakar Singh, a temple trust official.

"No one will go away from here hungry.

"But once the goodwill runs out and fatigue sets in, the government will be on its own -- and facing challenges on every front."

Hundreds of thousands have lost their homes, lost their crops or lost their other means of income," said European Commission humanitarian aid representative Malini Morzaria.

"To get people back to the way they used to live, shelter is going to be key. That's always challenging -- to make sure people are maintained at a certain level of food and sanitation while they get back to their own lives."

In spite of an expected infusion of 200 million dollars from the Indian government, which has declared the floods a "national calamity," impoverished Bihar state is likely to find its resources strained.

Schools will take months to get back to normal as many are submerged, and those on dry land will be unable to cope with an influx of new children -- especially as many are being used as shelters.

And as the humanitarian crisis continues, the state will have to continue to make difficult choices -- such as whether health staff should be at the camps packed with flood victims or at regular village health centres.

For days, routine childhood vaccinations for measles and diphtheria have been curtailed in parts of the state as health workers are stationed in camps to watch for diarrhoea and outbreaks of other illnesses.

A few survivors who have the energy or the cash to do so are making their own plans.

"I hear there's work in Punjab," said farmer Pramod Kumar Paswan, 38, who was sitting in a railway carriage with his family, leaving for another city in the state, and then to wherever else in the country he could find work.

"If I have to drive a rickshaw I will. If I have to pull a cart, I will."

But tens of thousands more are in shock, and in desperate need of help.

"I didn't bring anything with me -- only my children," said Gita Paswan, who was sitting with her four children on the railway platform.

"What will we do now?"

Government officials acknowledge the task is enormous.

"One task is evacuating people. A greater task is putting up the ones whom we have evacuated in relief camps for another four, five, six months," said Bihar state's disasters minister, Nitish Mishra.

"2009 will be a very difficult year for all of us." - AFP/vm