The Jakarta Post
The mystery behind a large oval hole that formed on Sept. 6 in a rice field in Legoknyenang, Sukamaju subdistrict, Kadudampit district, Sukabumi, West Java, has finally been answered.
The hole measures 6.5 meters by 4 m, and locals were puzzled by how it formed, so officials came to check it.
Rustam of the Geological Agency’s Center of Groundwater and Environmental Geology (PATGL) said that the hole was the result of erosion of the natural water tunnel under it.
“The wall and the ceiling of the tunnel was eroded by the water, and eventually an underground cavity was formed,” said Rustam, who visited the site of the hole over the weekend.
He added that the cavity was growing to a size that was unable to support the ground above it. Rains in the region also made the ground looser.
He said the tunnel measured some 50 m in length with an outlet 3.2 m high and 2.5 m wide. It runs under the rice field from the northwest to the southeast, heading to Cigalunggung River.
Because of the collapse, water cannot run through the tunnel smoothly, creating stagnant water on the northwest side of the tunnel.
The tunnel’s walls and ceiling need to be strengthened to stabilize the ground above it, thus preventing it from collapsing.
He also called on people to be cautious against more possible collapses. He said police tape had been placed around the collapsed site as a safety measure. “A signboard also needs to be added to warn people not to get too close to the site.” (swa)