PHIVOLCS Warns of Possible Lahar Flows from Pinatubo, Taal Amid Heavy Rains

The Philippine Institute of Volcanology and Seismology (PHIVOLCS) has warned of possible lahar and muddy streamflows from Mount Pinatubo and Taal Volcano as heavy rains brought by the southwest monsoon continue.
In an advisory issued Saturday, PHIVOLCS said prolonged and intense rainfall could trigger volcanic sediment flows, muddy runoff, and flooding in rivers and drainage areas surrounding the two volcanoes.
At Mount Pinatubo, significant deposits from the 1991 pyroclastic density currents remain in the watershed, which could be remobilized by heavy rains and generate non-eruption lahars.
PHIVOLCS said these flows may occur along the upper to middle reaches of the Sto. Tomas-Marella and Bucao River systems before transitioning into muddy streamflows and floods downstream. Communities in San Marcelino, San Narciso, San Felipe, and Botolan in Zambales could be affected.
Muddy streamflows may also develop along the O’Donnell and Pasig-Potrero river systems, potentially affecting downstream communities in Tarlac and Pampanga.

Meanwhile, heavy rainfall could trigger muddy streamflows, runoff, and volcanic debris flows around Taal Volcano, particularly along the western and northern slopes of Taal Lake.
PHIVOLCS said old and loose volcanic deposits that have become saturated from previous rains could be remobilized through streams, roads, and lakeward slopes.
Agoncillo, Laurel, and Talisay in Batangas are among the communities that could again be affected by muddy and debris flows.
PHIVOLCS urged communities and local government units in vulnerable areas to closely monitor weather conditions and undertake preemptive measures to ensure public safety.