SAN MANUEL–The water level at the San Roque Multi-purpose Dam Project (SRMDP) almost reached its critical level of 280 meters above sea level (masl) on August 26 but the rains slowed down soon enough not to require a water release from the dam.

Governor Amado Espino Jr., who also heads the Provincial Disaster Risk Reduction Management Council (PDRRMC), stressed that the flash floods last week resulted from overflowing rivers and not water spilled by the San Roque dam.

Meanwhile, Virgilio Garcia, chief hydrologist of the National Power Corporation (NPC) that owns the San Roque dam, showed a group of newsmen who visited the SRMDP on August 31 the closed spillway gates.

The water level did reach 275.94 masl on September 1, but the rains by then have weakened.

At that point, authorities of San Roque dam gave assurance that today’s protocol provides that even if the water of the dam reservoir reaches 280 (masl), they will no longer release water unless there was a typhoon expected within days.

The Ambuklao and Binga dams located further upstream, however, did release water but the volume was absorbed by the San Roque dam, constructed as the biggest rock-fill dam in southeast Asia and the second biggest in the whole of Asia.

The NPC official also explained that most of the water that flooded Pangasinan last week came from Mt. Ampocao, a fountain head in Tuba, Benguet, which drains into the Toboy River in San Manuel.

The Toboy River is connected to the Tagamusing River in Binalonan, which in turn flows into the Tulong River in Urdaneta City, then to the Sinocalan River in Sta. Barbara, Marusay River in Calasiao and finally the Pantal River in Dagupan City before exiting to the Lingayen Gulf.

Garcia said typhoon Mina dumped 522 millimeter per second of rain in and around Mt. Ampocao.

PROTOCOLS

Espino also assured that protocols are in place and being implemented to protect the people from possible flash floods in case San Roque dam releases water.

In 2008, water suddenly released from the San Roque dam at the height of Typhoon “Pepeng” caused a deluge in the plains of Pangasinan, drowning several people and destroying billions worth of properties and infrastructure.

Meanwhile, Tommy Valdez, vice president of the San Roque Power Corporation (SRPC), the company using the facility to generate power for the Luzon Grid, said the existing release protocol is when the water reaches 289 masl, a level which is now remote as the inflow from Ambuklao and Binga dams have been reduced.

Valdez pointed out that the dam needs to conserve all the available water in the reservoir to fulfill their commitment to generate power for the Luzon Grid and to irrigate farm in the lowlands of Pangasinan.

While the re-regulating pond below the dam has yet to be built, an irrigation weir of the National Irrigation Administration (NIA) catches the water released by the dam and distributes this to farmlands in Binalonan, Urdaneta, Villasis, Sta. Barbara, and Manaoag.

During peak hours when demand for electricity is at its highest, San Roque is generating 403 megawatts of power in its turbines, for which it coughs out 261 cubic meters of water per second, an volume that flows downstream of the Agno River from the dam.

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