Banjir Ambarita, Jayapura – Thousands of people are at risk of starvation and disease after heavy flooding in Papua's Paniai district, an official said over the weekend.

District head Naftali Yogi said heavy rains over the past three months have led to Lake Paniai overflowing and flooding at least seven subdistricts in up to 4 meters of water, destroying homes and farmland and rendering thousands of families homeless.

There have been no reports of casualties as a direct result of the flooding. "The situation now is pretty grim because so much agricultural land and so many fish farms have been flooded and can't be harvested," he said.

"This means that around 10,000 people who are subsistence farmers and rely on prompt harvests are at risk of starvation." Naftali said the extent of the flooding also made outbreaks of diseases such as cholera, respiratory ailments and malaria more likely.

"We don't have enough medical supplies or health workers to respond to a potential outbreak," he said. "So we're calling on all residents not to drink water from the lake. Drink rainwater instead."

He added his administration was already distributing food supplies to residents, including uncooked rice and instant noodles – both of which need to be cooked in clean water. However, authorities have not distributed any potable water.

"We've been given Rp 1 billion [$115,000] in relief aid from the provincial administration and Rp 500 million from Jakarta, but that's only enough for a month," Naftali said. "We expect many residents won't be able to farm for another two years, so they'll need food aid until then."

Authorities have not set up shelters for the evacuees, who have been forced to stay with family and friends or out in the open. "We're still looking for sites where we can set up temporary shelters for those rendered homeless," Naftali said.

He blamed the flooding on the increased sedimentation in Lake Paniai, which he said was a result of the clearing of forests in areas adjacent to the lake.

"About 10 years ago the military scorched the forests because they suspected that separatists were hiding out there, and since then there hasn't been any effort to reforest the area," he said.

Besides the effects of deforestation and subsequent flooding, Naftali said the district was also at threat from illegal mining. He said illegal gold mines in Baya Biru subdistrict were responsible for large-scale pollution and environmental degradation.

"We've given the companies responsible until June to halt their activities, but obviously this is a tricky issue to handle," Naftali said. "There are an estimated 7,000 people working in the industry there."

He said previous calls by the district and Papuan administrations for a halt to the illegal mining had fallen on deaf ears because of the many interests involved in the industry.

"Those mines are so remote that you can only get there by helicopter," he said. "If those helicopter services could be stopped, there would be no more mining, but they continue to transport workers, supplies and ore in and out of there."