PUTRAJAYA, Nov 27 — Land use activities may have contributed to the debris flood incident in Bukit Tinggi in Bentong on Saturday, said Natural Resources, Environment and Climate Change Ministry (NRECC).

It said the activity to open land for agriculture and the use of unsuitable irrigation systems for crops led to the high erosion rate in the area.

It said checks by the Bentong District Forest Office using drones found a landslide along the banks of Sungai Tanglir in the Bukit Tinggi Forest Reserve, which had been encroached on for farming activities involving an area of 2.02 hectares.

"Enforcement action was imposed in March. The area has been replanted with trees and checks are being conducted to identify other areas that might have been encroached on near the site,” it said in a statement today.

On November 25, due to three hours of moderate-intensity rain ranging from 23.5 to 53.0 millimeters, a debris flood occurred, which inundated several houses and business premises in an average depth of 0.3 to 0.6 metres of floodwater.

NRECC said heavy rain also caused erosion and instability upstream, further contributing to a water surge incident, carrying stones and sediments, blocking the road crossing and causing Sungai Tanglir to overflow.

As an immediate mitigation measure, NRECC, through the Department of Irrigation and Drainage, is carrying out river maintenance, it said, adding that it would take about one month to clean up the area because it involves the removal of large boulders and sediment in the river.

The Department of Mineral and Geoscience (JMG) will identify and mark danger and control zones in the area to facilitate emergency responders and implementing agencies to conduct slope mitigation works and assess the threat of subsequent collapses, it said.

It said JMG would also carry out site mapping to mark the affected slopes and those at risk of collapsing.

After visiting the site on Sunday morning, Natural Resources, Environment and Climate Change Minister Nik Nazmi Nik Ahmad said long-term mitigation measures have also been proposed, including the implementation of the Bentong District Environmentally Friendly Drainage Master Plan (Pisma) that covers the disaster area. — Bernama