The Angat, San Roque, and Pantabangan dams in Luzon may still be struggling for water this November.
The prospect for the three dams’ full recovery from weeks of rainfall shortage remains dim as water level by the end of November would likely be still below the rule curves and spilling or normal high levels, according to the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA).
“Water level there has been low so those dams need a lot of water to recover,” PAGASA hydrologist Sheila Schneider said.
For next month, PAGASA expects rainfall in the basins where Angat, San Roque, and Pantabangan dams are to reach 454 mm, 153 mm, and 283 mm, respectively.
The bureau also expects the dams to have water allocations of 69 cubic meters per second (cms), 30 cms, and 26 cms, respectively.
Considering these parameters, PAGASA forecast end-November water levels to be at 197.52 m in Angat Dam, 243.76 m in San Roque Dam, and 203.52 m in Pantabangan Dam, well below the dams’ end-November rule curves of 205.70 m, 277.20 m, and 221 m, respectively.
The rule curve indicates a dam’s water level for it to ably serve its purpose.
Multi-purpose Angat, San Roque, and Pantabangan dams provide water for irrigation and power generation in Luzon.
Angat also supplies water for Metro Manila’s needs.
The forecast for the water levels of Angat, San Roque, and Pantabangan dams by the end of November are also lower than their normal high levels of 210 m, 280 m, and 218.5 m, respectively, PAGASA said.
Angat Dam’s basin needs about 563 mm of rainfall for its water to reach its normal high, while the basins of San Roque and Pantabangan dams need about 1,094 mm and 1,731 mm of rainfall, respectively.
These requirements are more than the rainfall PAGASA forecast for the basins this November. (PNA)