The watershed provides 35,000 cubic meters of water daily to the Baguio City Water District.
Since last year, fires have destroyed some 10,000 hectares of forest and grass lands, authorities said.
Elsewhere, fire razed a factory of Dutch Boy Paint in Barangay Langkaan in Dasmariñas, Cavite yesterday.
The fire alarm was recorded at 4:10 p.m. At least 30 firetrucks from the province, Laguna and Metro Manila were still battling the blaze at press time.
Fire damage was initially placed at P10 million. Artemio Dumlao, Rene Alviar