Daily TribuneThe controlled impoundment successfully managed the discharge downstream to approximately 200 m3/s, significantly lessening the impact of the floods by a factor of 10
Aerial shots show flood water entering the Upper Wawa Dam reservoir and how the dam’s controlled impoundment reduced the impact of flooding caused by typhoon ‘Carina.’
Photograph courtesy of WawaJVCo.
Floods in most parts of Metro Manila could have been worse had it not been for the Wawa dam that controlled water flow, thus, indicating its huge potential to alleviate inundation of the capital city.
A water supply dam, like the one developed by Prime Infra-led Wawa JVCo Inc. in Rizal province, plays a vital role in mitigating downstream flooding and reducing severe flood damage caused by weather disturbances such as super typhoon “Carina.”
Originally intended to serve as a water supply dam, the project’s additional potential to alleviate flooding helped ease the impact of the recent typhoon to low-lying areas of Rizal province and the eastern district of Metro Manila.
The Upper Wawa Dam features a reservoir of about 450 hectares, approximately twice the size of Bonifacio Global City, and can store up to 120 million cubic meters of water. It is the largest dam to be built in over 50 years.
Based on measurements conducted throughout July 24, Wednesday, the floodwater entering the dam’s reservoir peaked at approximately 2,100 cubic meters per second (m3/s).
Water management works
During a situation briefing, Governor Nina Ynares informed President Ferdinand Marcos Jr. that without the Upper Wawa Dam, which is part of the Wawa Bulk Water Supply Project, flooding in certain areas of the province could have been significantly worse.
“Mr. President, sometime this month, we were together during the inauguration of (Upper) Wawa Dam. We saw it was empty and (they said) it would take six months for them to fill it up...Without it, I feel that, most likely, San Mateo and Montalban would be down; and definitely, Marikina and parts of Quezon City and even Pasig would be affected,” Ynares said.
Ynares noted that the Upper Wawa Dam’s reservoir needed six months to fully impound water.
However, due to the heavy rainfall from super typhoon “Carina,” the reservoir was nearly filled in just two days.
Eduardo Guillen, Administrator of the National Irrigation Administration (NIA), also emphasized the significance of the Upper Wawa Dam in mitigating the effects of flooding in Metro Manila.
“That’s the beauty of what our President Ferdinand Bongbong Marcos Jr. says, which is water management so that during the rainy season, floods can also be mitigated when we save water,” the local official said in an interview.
“Like in the case of Metro Manila, isn’t there an (Upper) Wawa Dam up there today? Our damage would have been worse without the (Upper) Wawa Dam because all the water it accumulated would have devastated Metro Manila,” she added.
