Weirs, instead of dams, for our water problem

THE need for more dams , catchment basins, and other means to store water for use in our fast- growing cities has once again drawn national attention in the wake of the water shortage that hit Metro Manila’s east zone last week, prompting the House of Representatives to hold hearings on the problem.

Among the proposed water projects was the Kaliwa Dam at the foot of the Sierra Madre mountains , but opposition to the project has come from various quarters, and for many reasons. It would inundate the ancestral domain of the Dumagat Remontados who had lived in the Sierra Madre for centuries. The proposed dam was to be built over the Infanta Fault; should an earthquake damage the dam , a huge flood would sweep downstream along the Kaliwa River where some 100,000 people live.

The tribe and the river residents have found an ally in the Catholic Bishops Conference of the Philippines (CBCP) which said that the World Commission on Dams itself has noted that while dams have made important contributions to human development, “in too many cases, an unacceptable and often unnecessary price has been made to secure those benefits, especially in social and environmental terms, by people displaced, by communities downstream, by taxpayers, and by the natural environment.”

When Pantabangan Dam was built by President Ferdinand Marcos, an entire town had to be flooded after its population was relocated. To this day, it is said, when waters ebb in the dam, the tower of the submerged town church would stick out of the water, undoubtedly a painful sight to those who used to worship in the church.

In the wake of the opposition to Kaliwa Dam, an alternative project was proposed in 2009 by a Japanese company which presented an unsolicited proposal for a Kaliwa Intake Weir. A weir is a small barrier across a river, that alters the river’s flow and raises its level, but not to the extent that a big dam would.

The Global Utilities Development Co. (GUDC) of Osaka, Japan, presented the plan to the Metropolitan Waterworks and Sewerage System (MWSS) in 2009, when the two signed a memorandum of understanding. The GUDC resubmitted the proposal in 2017. The weir would be only seven meters high, with a 16-kilometer-long tunnel and a water treatment plant,

In the wake of rising opposition to dams in general because these tend to inundate established communities and pose danger to people downstream in case of damage to the dam from earthquakes or other natural causes, the idea of weirs instead of dams merits closer study and consideration by the government.

The Kaliwa dam has been held in abeyance for 30 years now. It still has no Environment Compliance Certificate as required by RA 7586. And the indigenous people have also not given their Free Prior and Informed Consent as required by RA 8371.

Metro Manila needs new sources of water to meet its ever rising demand which is now being met, rather inadequately by Angat Dam. The Kaliwa Dam has not been able to move forward all these many years because of fierce opposition from mountain communities which will lose their ancient tribal lands and from downstream communities who fear a catastrophe in case of damage to the dam. A weir, or a much smaller river barrier, as proposed by a Japanese company might be the answer to these concerns.