Philippine Daily Inquirer
Water levels in dams still low despite rains
SAN MANUEL, PANGASINAN —Water levels in two major dams in northern and Central Luzon have continued to drop to critical levels as intermittent rains in recent weeks failed to supply their reservoirs, dam officials said.
In this town, the San Roque Dam’s water level on Friday dropped to 227 meters above sea level (masl), the second lowest since the facility opened in 2003.
“The current reservoir elevation is at 227 masl only when it is supposed to be at least 240 masl for July,” said Tommy Valdez, vice president for corporate social responsibility of San Roque Power Corp., which op- erates the power-generating facility of the dam.
Valdez said dam officials were expecting the water level to rise with the onset of the rainy season, but the reservoir level has remained low since May. The drop, he said, started in February.
The dam posted its lowest water level in July 2005, when it dropped to 225 masl, an SRPC report showed.
The situation this year was in stark contrast with the conditions in October 2009 when the dam released massive amount of excess water as Typhoon “Pepeng” dumped heavy rains in northern Luzon. The reservoir’s water level at that time almost reached its maximum 290 masl.
The water released from the dam last year flooded 36 towns and cities and left 63 dead and P6 billion worth of infrastructure and crops damaged and destroyed, reports from the Provincial Disaster Coordinating Council (PDCC) showed.
Valdez said the current reservoir level is lower than the normal operating level of 240-280 masl.
“These are the levels required to make the dam economically operational,” he said.
“There is no water for irrigation and not enough water for power generation,” said Valdez, who described the current status of the dam as “very abnormal.”
This does not bode well for farmers tilling 12,000 hectares of farmland in Pangasinan and who depend on irrigation water supply from the dam.
But Valdez said the dam could accommodate more water and act as safeguard to flooding in Pangasinan’s downstream should typhoons dump heavy rains in northern Luzon.
He said the dam reduces flooding in communities along the Agno River as it controls the river’s flow.
But he said the dam could not control other factors contributing to flooding in the area, such as the amount of water from other tributaries and the collapse of dikes that protect communities.
In Bulacan, water level at the Angat Dam also dropped to one of its lowest, at 158.64 masl, due to the absence of heavy rains in the dam’s watershed.
Rodolfo German, general manager of the Angat River hy- droelectric power plant (Arhepp), said the present elevation of the Angat reservoir, Metro Manila’s main water supplier, was more than 20 meters below the critical low level of 180masl reached in March. The dam has a normal operating level of 210 to 212 masl and a maximum capacity of 215 masl.
German said the low water level has forced the National Power Corp., which owns and manages the Arhepp, to shut down the power plant’s operation fromWednesday to Friday.
He said the shutdown will prevent damages to turbine blades.
But he assured that Metro Manila’s water supply will not be disrupted.