Environmental damage to the upstream area of the Citarum River, West Java's largest waterway, has been blamed for the worst ever flash floods in the hilly area below the Gunung Wayang region, South Bandung.
The flood hit 3,000 houses, washing away 55 in strong currents. The flash floods, which lasted two and a half hours, swept through six subdistricts in Majalaya district and one in Ibun district, located 70 kilometers south from Bandung city center, on Thursday night.
The six affected subdistricts in Majalaya are Majalaya, Majasetra, Bojong, Majakerta, Sukamaju and Biru. Tanggulun subdistrict in Ibun district was also hit.
Erosion in the river's upstream region left a layer of mud 20 to 30 centimeters thick, which local residents and 200 police and military officers helped to clear on Friday morning.
Asep Apendi from Ajirompe, Majalaya, said the flash floods occurred at 5 p.m. following an hour of heavy rainfall. Floodwaters reached 1.5 meters in the capital town of Majalaya district, forcing residents to flee their homes and seek higher ground.
Residents returned to their houses after floodwaters had subsided, but were later trapped by the mud.
"We really panicked. We took whatever we could carry and headed for shelter," Asep said.
Majalaya district administration head Yiyin Sodikin said 2,371 houses were lightly damaged by the flood in his area, while 55 other houses located on the banks of the Citarum River were washed away by the flood.
The flood, he added, also hit at least seven schools, three office buildings and 40 hectares of farmland, forcing 979 families to flee their homes. "This is the worst flooding we have experienced since the 1990s," Yiyin said.
The 1997 flood, which was previously referred to as the biggest, he said, only affected 1,726 houses.
A river restoration project along 7 kilometers of the Citarum River was underway along the border of Majalaya, Solokan Jeruk and Ibun districts.
Sedimentation and the narrowing of the river, which has decreased the river's width from 22 meters to between 1 and 9 meters, have been blamed for the annual flood in this region. "We had prioritized the project this year, but the flood was much bigger than we anticipated," Yiyin said.
Yiyin, however, said the river project had played a part in decreasing the flood's impact.
While similar floods would normally inundated the region for six hours, this flood only lasted two and a half hours.
The flood, according to Yiyin, also cut off all access to and from Majalaya region for about four hours because all roads to and from the district were under 30 to 50 centimeters of water.
Yiyin estimated financial losses from the flood at about Rp 700 million. He based this figure mainly from damage to houses, buildings and farmland.