DAGUPAN CITY — The San Roque Dam in San Manuel town will open one its spillway gates at 5 p.m. on Saturday, according to an official of the National Power Corp. (Napocor).
In a text message, Napocor spokesperson Odette Rivero said a sudden rise in the dam’s water elevation was observed due to the strong inflow of water upstream of the Agno River.
As of 2 p.m. Saturday, San Roque Dam had a water level of 278.31 meters above sea level (masl), which is about 1.69 meters below its normal high level of 280 masl. The dam can accommodate water up to 290 masl.
The inflow was recorded at 4,730 cubic meters per second (cms), while its turbine discharge was only 280 cms. A cubic meter of water is about five drums.
The dam, which is downstream of the Agno River, catches the water released by the Binga Dam, which in turn catches spillage from the Ambuklao Dam in the river’s upstream.
Ambuklao and Binga in Benguet province have been releasing water since Sept. 13.
Rivero said the spillway gate would be raised to a height of half a meter to spill water at 64 cms, in addition to the turbine discharge.
The gradual release of water would not cause Agno River to rise nor trigger flash floods, she said.
Residents living in villages along the river had been informed about the water release at 1 p.m.