KASHMORE (Reuters) - It took farmer Ghulam Hussain almost a year to start re-building his house, destroyed last year in floods that left vast swathes of country underwater, and disrupted the lives of more than 18 million people. Now, his small, two-room mud and brick house - just a few hundred meters from the Indus River - is almost complete, but he is worried as to how long it will survive. It took me a long time to rebuild my house, as no one gave me any help, Hussain said as he along with five of his relatives put the final touches to his house in Sindh. I am praying to God that this year the waters be kind to us, he said. Pakistan remains woefully unprepared for floods this year which a UN official said could affect up to 5 million people in a worse-case scenario. While a repeat of last years epic deluge is unlikely, even smaller floods could cause millions in damages, set back reconstruction efforts and further unsettle the government, a stagnant economy, a deadly Taliban insurgency and tense relations with its neighbours. All along the Indus, dykes and embankments are incomplete, while international donations for preparedness have fallen short. Sindh, home to the commercial and industrial hub Karachi and one of last years most hard-hit provinces, is especially vulnerable to new flooding. A visit by a Reuters correspondent in rural Sindh revealed that most preparations the government says are complete still need weeks of work - and the rains have already started. I dont think the government has done enough, Hussain said. It is only up to God to save us. As he spoke, he glanced at the Tori bund (embankment), just a few hundred meters away in one of the worst-hit areas of last years floods. It was a poor defence against the rage of the swollen Indus last year. Last years floods began in late July after heavier-than-usual monsoon rains swelled the headwaters of the Indus River basin, sending flash floods through the northwest and inundating great swaths of the country. Some 2,000 people died, 11 million left homeless and another 7 million people were affected. The country suffered more than $10 billion in damages to infrastructure, irrigation systems, bridges, houses and roads. One-fifth of Pakistan was submerged. Aid organisations and the government were criticised for being too slow to respond while the military, widely seen as a far more efficient institution, took the lead in relief operations. But the United Nations says it working hard to stockpile food, water and tents in the event of more floods this year. Since the beginning of March, we have been in close contact with the government to make sure response is up and running and that we are better prepared this year, Manuel Bessler, head of the UN emergencies office (OCHA) in Pakistan, said in a recent interview with AlertNet, a free humanitarian news service run by Thomson Reuters Foundation. He said the most likely scenario is two million people affected, but it could reach five million if the monsoons are heavier than expected. The seasonal rains - expected to start July 1 have started four days early. At the Tori bund near Hussains house, labourers slowly stacked stones and mud in an attempt to strengthen the embankment.