PAGASA made an earlier pronouncement that portions of the country will experience a return of the El Nino weather phenomenon which will reduce the amount of rainfall and affect water levels at the Angat Dam, Ipo and La Mesa Dams.

The National Water Resources (NWRB), the lead government agency in the water sector, conferred with policy-making, regulatory and quasi-judicial functions and responsible for the country's water resource, consistent with the principles of Integrated Water Resource Management will issue water allocations for domestic and irrigation. This is to maximize the full utilization of available raw water.

.Manila Water will closely monitor water levels at the major dams which are currently experiencing below normal levels because of the reduced rainfall.

As of January 22, 2010, water levels at Angat Dam, the primary source of raw water supply for Metro Manila's drinking water, is at 202.31 meters, 8 meters below the average elevation at 210 meters. Water inflow or the amount of water that helps refill the Angat Reservoir is now only at 12 percent on the average, the lowest on record for the past 30 years.

Manila Water is assuring its customers that despite El Nino, there water supply in the East Zone will be supplied 24-hours a day. Manila Water is preparing its El Nino mitigation measures as a proactive measure in case of a prolonged dry spell.

The mitigation plans include the following: intensifying leak repair and other system loss reduction programs, water quality monitoring, recovery of backwash water, deployment of portable water treatment plant, reactivation of standby wells and conducting a public information drive. The Company is also working closely with key government agencies like the MWSS, NWRB, PAGASA, NPC, NIA, DENR, DOH, DILG and stakeholder groups to mitigate possible effects in the event of an extended dry spell.