In Philippines, El Niño Means Drought


The water line of the Angat Reservoir in the Philippines falls well below the vegetation line during a 2004 drought. Droughts are not generally associated with the Philippines, but during El Niño cycles, much of the country experiences moderate-to-severe dry periods that can last for a season or more.

Photo courtesy of Manila Water Supply Service

Casey Brown arrived in Manila in early November on the heels of Typhoon Cimaron, a "super typhoon" that clocked 125-mile-per-hour winds. It was the second deadliest typhoon to hit the island nation since 1998.

But for Manila, home to more than 10 million people, it is drought — not typhoons — that has led to rising tensions between urban dwellers and farmers who work just outside the city.

Droughts are not generally associated with the Philippines, a country known for its steamy tropical marine climate. But during El Niño cycles, much of the country experiences moderate-to-severe dry periods that can last for a season or more. For areas already water strapped, such periods can spell disaster for hundreds of thousands of households as well as individuals whose livelihoods depend on regular precipitation.

"Water scarcity is a contentious issue that arises every year in Manila, but the tensions become more extreme during El Niño," said Brown, an associate research scientist at the International Research Institute for Climate and Society (IRI). According to the IRI, during El Niño, the water inflows into the Angat reservoir are often significantly decreased, placing substantial duress on the domestic water supply and irrigation needs of farmers. To help water resource managers and other stakeholders better plan for climate events, the IRI has been working in Manila for the past three years, applying their expertise to mitigate drought impacts.

In early November, Brown, along with Esther Ebrahimian, Bradford Lyon, and Shiv Someshwar, traveled to Manila to share forecasts of reservoir inflows and ways to manage reservoirs before and during times of drought.

"El Nino conditions may be affecting the country right now," said Brown. "Everyone asks, 'Is this El Niño going to cause the droughts it often causes in the Philippines? If so, how soon and for how long?'" The new question that the IRI team is helping stakeholders in Manila ask is: How can we better manage our reservoirs to adapt to climate variability?

This visit to Manila was hosted by the National Water Resources Board, a government agency established to help mediate tensions resulting from competition over water. Representatives from the urban water supply agency, the irrigation agency that represents farmers, the national power agency and PAGASA, the national meteorological agency, also participated.

Manila has a small reservoir that serves many needs. Using climate data to forecast reservoir inflows over the several months can help water resource managers conserve water in times of drought. If managers have a better sense of what the future holds in terms of climate, they can potentially use this information as an incentive to work together to share the dwindling resource.

"Our goal is to build the decision making process among water stakeholders and to improve communication flows among the groups," said Brown. "It's important that these processes are participatory and sustainable, and continued long after we've gone."

Brown also stressed that it is critical for all stakeholders to understand that forecasts are probabilistic — that is, no climate forecast can, with 100 percent accuracy, predict what weather events lie ahead. This uncertainty should play an integral role in the planning processes of water resource managers.

"We can't tell people what will happen, we can only tell them what is more likely to happen. This is the essence of climate risk management: how to lessen the impact of climate events like water shortage while also incorporating the knowledge that no climate event is certain."

In spring of 2007, the IRI team will head back to Manila, this time to host a workshop that will aim to build a consensus on decision making processes based on probabilistic forecasts and climate risk management.