DENR warns flashfloods expose Negros upland risks

By Dolly Yasa

BACOLOD CITY — The Department of Environment and Natural Resources (DENR) has issued a warning following its consolidated assessment of the devastation caused by Typhoon Tino (Kalmaegi), saying the deadly flashfloods that struck Canlaon City, La Castellana, Moises Padilla and nearby towns must serve as a wake-up call for Negros Island.

According to a report released Nov. 14 and furnished to reporters Tuesday, ten straight hours of intense rainfall eroded loose volcanic debris on the slopes of Mount Kanlaon and sent torrents of mud, boulders and lahar rushing into densely populated areas.

Despite an increase in forest cover within the Mount Kanlaon Natural Park, DENR’s findings show that the mountain’s landscape remains highly vulnerable.

Much of the upland area is still dominated by annual crops, grasslands and open barren spaces that lack the capacity to absorb extreme rainfall.

In Negros Occidental alone, more than 6,200 hectares of MKNP land are planted to annual crops, making the terrain prone to erosion during prolonged rains.

The report said Canlaon City bore the brunt of the disaster.

Entire bridges and roads were destroyed as raging floodwaters—tightly packed with 2- to 3-meter boulders, mud and volcanic debris—crashed through the Malaiba and Nilothangan river channels.

The sudden surge was intensified by landslides near the river headwaters.

DENR said debris temporarily dammed the rivers, and when the blockage collapsed, a powerful wave of impounded water rushed downstream and overwhelmed barangays within minutes.

Numerous fatalities and missing residents have been reported.

Contrary to speculation, the assessment found no signs of illegal logging within MKNP.

The trees carried by the floodwaters were naturally uprooted from riverbanks and steep slopes because of the force of the water and the instability of the soil.

DENR also linked the impact of the flashflood to the city’s heavy reliance on upland vegetable farming.

These cultivated areas sit atop steep, highly weathered volcanic soil that becomes unstable during typhoons, contributing to landslides and debris flows.

“The very agricultural areas that support the city become the source of destructive floodwater, mud and lahar when intense rainfall strikes,” the report said.

The DENR stressed that Typhoon Tino’s aftermath must be viewed as a critical warning.

Negros Island remains dangerously vulnerable to extreme rainfall events, especially in areas surrounding Mount Kanlaon.

The report urged stricter enforcement of easements and buffer zones along rivers and creeks.

It also recommended the relocation of families living in flood- and landslide-prone zones.

It called for dredging and clearing of major waterways.

It encouraged updated land-use plans to reduce agricultural encroachment in the MKNP.

It also sought stronger monitoring of upland development activities and climate-resilient management strategies for MKNP and nearby communities.

DENR officials warned that without significant reforms, future typhoons could trigger equally destructive—if not worse—flooding events.

“This disaster shows how quickly extreme rainfall and volcanic terrain can combine to create deadly conditions,” the assessment concluded.

“Negros Island must act now,” it said.