La Mesa Dam: On red alert. INQUIRER FILE PHOTO
MANILA, Philippines—Authorities monitoring La Mesa Dam in Quezon City were on red alert for most of Monday to watch out for any water spillage from any of the dams at the Angat-Ipo-La Mesa Dam Raw Water System, the Manila Water Co. said.
“Yes, La Mesa is still on red alert. For alert to be downgraded to yellow, the level of La Mesa should be below 79.60 meters. LGUs [local government units] downstream of Tullahan (River) are still on alert,” Manila Water corporate communications chief Jeric T. Sevilla said in a text message.
Citing reports received by the water concessionaire as of 8 p.m., Sevilla said that compared to 4 p.m. levels, the water at La Mesa Dam was steady at 79.79 meters, Angat Dam increased by 1 centimeter to 189.19 meters, and Ipo Dam decreased by 11 cm. to 100.31 meters.
Still, given that rains have stopped, “we expect that the level (in Ipo) will gradually go down as well,” Sevilla said.
Authorities get concerned when water level at La Mesa Dam breaches 79.40 meters, Sevilla said.
“If levels go beyond 79.60, we declare red alert. Below 79.60, it is yellow alert,” Sevilla said.
Earlier in the day, water was released at Ipo Dam from 6 a.m. to 12 noon in anticipation of continuous rains, Sevilla said. One gate was opened by 30 centimeters, releasing an equivalent of 47 cubic meters per second.
La Mesa is a spill dam akin to a giant infinity pool. The spilling level, or the level at which water starts to overflow down the sides of La Mesa Dam, is 80.15 meters.
The excess water flows into the Tullahan River, which flows through the northern part of Quezon City, including the Fairview area, as well as the cities of Malabon, Valenzuela, and Caloocan. The river drains into Manila Bay.
Ipo Dam in Bulacan spills water at 101 meters.
Angat Dam, which is also in Bulacan, has a spilling level of 210 meters.
The Angat-Ipo-La Mesa Dam Raw Water System at present supplies most of Metro Manila’s domestic water needs. The resources extracted from this location get treated in two facilities: Manila Water’s Balara Treatment Plant and that of the other water services provider, Maynilad Water Services Inc.’s La Mesa Treatment Plant.