Around 50 million cubic meters of cold lava has been found on the slopes of the mountain and they may fall down if it rains, National Disaster Mitigation Agency (BNPB) spokesman Sutopo Purwo Nugroho stated on Tuesday evening.
Heavy rains around Mount Kelud since 3 p.m. on Tuesday, have led to the overflow of the rivers in Kediri and Malang districts, causing flooding around the areas along the rivers.
The floodwater contains volcanic materials such as sand and gravel that were so far, scattered only on the top and slopes of the mountain.
"Certainly the 50 million cubic materials will not fall all at once, but they will, in stages depending on the rain," Sutopo explained.
The BNPB records indicated that five houses and a mosque had been submerged by cold lava following floods that night; no casualties were reported in the incident in Kediri.
In Malang, a small bridge had been broken, while two houses had been carried away in the cold volcanic material floods. There has been no information on death due to the flooding in the district.
To manage larger flooding, in case it happens, BNPB has constructed a dam that can accommodate up to 14.5 million meter cubic of volcanic materials.
With the rivers in the region that can receive 14 million cubic materials, the total capacity will now reach 28 million meter cubic, he added.
"People have been ordered to stay alert and away from river banks," he pointed out.
(Reporting by Maria Rosari/H-YH/INE/KR-BSR/F001)