DEPARTMENT of Environment and Natural Resources (DENR)-Western Visayas' Mines and Geosciences Bureau (MGB) has placed five mountainous barangays of San Remigio, Antique under closed monitoring.

The move came after the barangays show signs of mass movements like cracks and landslides.

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MGB Regional Director Van Juguan said the evaluation started through a request of San Remigio Mayor Elizabeth C. Coloso because of the observed artificial damming at the headwaters of Maninila River due to landslide.

The landslide-prone areas considered as danger zones are barangays Panpanan I, Panpanan II, Sumaray, Walker, and Insubuan.

MGB reported houses, families, schools and other structures, especially the elementary school in Barangay Panpanan I and Sitio Libudon in Barangay Insubuan and several houses at the proper area of Barangay Insubuan affected by the landslides, must be relocated to safer places preferably in flat to gently sloping areas and far from the bodies of water like creeks and rivers and from foot slopes of the mountain.

These residents and structures, if not relocated, are facing real danger of landslides.

It was also advised by the MGB geologists that communities along the rivers of Maninila, Sibalom, Tipulu-an and other large creeks must be totally informed of the situation and prepare themselves to evacuate the premises if there be heavy rains or storms.

The evaluation also showed that most of the San Remigio municipalities are underlaining with Antique Ophiolite Complex and late Oligocene and early Miocene composed of basalt with intercalated sandstone, siltstone, mudstone and conglomerate and other stone formation with crevices that could be penetrated by water, thereby making it soft and prone to erosion causing landslides.

At the headwaters of Maninila River, the main rock types consist of severely weathered and highly jointed basalt-sandstone, siltstone-mudstone conglomerate called Panpanan Formation that are also prone to erosion.

During heavy rains in these areas, the rainwater, in addition to the accumulated abundant groundwater, seeped through numerous joints and cracks of the severely weathered rocks.

These rocks are made up of broken fragments, cemented particles of sand, silt, mud and loose soil.

Landslides had occurred during the month of September to early October at the headwaters of Maninila River with a length of 70 meters and the debris about 7,000 cubic meters deposited at the narrow river channel below, creating an artificial dam.

The artificial dam upstream accumulated the rainwater and when the artificial dam broke up, the accumulated debris flowed downstream and although it did not cause flooding, water had subsided within the severely weathered rocks. This action had softened the rocks and caused a mass movement. (LCP)