FLOOD ZONE. Residential areas along flood-prone Recto, Manila, do not have an evacuation plan once a storm of Ondoy-like proportions inundates their community.

MANILA, Philippines – He lives near the flood-prone Claro M. Recto Avenue in Manila, but if another case of unprecedented flooding hits his area, community leader Lando dela Cruz couldn’t present an evacuation plan.

Like the recent tropical storm Sendong, Ondoy in 2009 flooded the most unexpected places like Barangay 310 in Sta. Cruz near Recto, Manila, where Dela Cruz resides.

A barangay tanod (community watchman) and vice president of his neighborhood association, Dela Cruz says floods of Ondoy-like proportions haven’t recurred in his community since then. In terms of floods, therefore, he says he and his neighbors have little reason to worry.

Dela Cruz says flooding – as well as evacuating – is something his community can deal with once it’s there.

“Siyempre ‘pagka ganon na, ‘pagka medyo tumaas na ‘yung tubig, (mag-uusap-usap) kami para maano namin kung saan kami dapat na pupunta para mas ligtas,” he says. (Of course, once the situation is such that water levels have risen, we will discuss among ourselves to determine where to evacuate to keep ourselves safe.

Recto is one of the areas that experienced waist-deep floods during Ondoy, says a user-generated report on Nababaha.com, a compilation of flood hazard maps developed by the Volcano Tectonics Laboratory Team based in the University of the Philippines-Diliman’s National Institute of Geological Sciences. 

To warn Filipinos about flood-prone areas, Nababaha.com merges reports from ordinary citizens with scientific flood simulation data based on the unprecedented rainfall dumped by Ondoy. (Read the site’s methodology here.)

The problem is that data from hazard maps often end up unused or untapped, says Nababaha.com webmaster Richard Ybañez in an e-mail to Rappler.com. “It’s not so much the mapping of hazards that is neglected, as it is the interpretation and implementation of data gathered from the maps,” Ybañez says.

Nababaha.com, for example, already uploaded the flood hazard map of Cagayan de Oro City last year, delineating the areas where flooding could potentially take place.

Cagayan de Oro City, along with other areas in southern Philippines, suffered floods induced by Sendong a week before Christmas, with a death toll having climbed to over 1,200.

“If this was taken into consideration by the local government or the people residing in CDO, and integrated (this) into an evacuation plan, more lives could have been saved,” Ybañez explains.

Scant information

Workers along Recto recognize the lack of information on what to do during floods.

Jonathan Empinado, who works at a tailoring shop along the Recto Underpass, says the last time a strong information campaign took place was after Ondoy, when barangay officials gathered community members to discuss typhoon-related safety information.

UNDERWATER. The Recto Underpass was filled with water when Ondoy struck.

The Recto Underpass, which houses other tailoring shops, was filled with water when Ondoy struck.

Jemuel Mutia, Empinado’s co-worker, says he doesn’t remember a repeat of post-Ondoy briefings when typhoon Pedring, for example, hit Metro Manila in September this year.

“Kailangan din nila ng mga paalala sa mga tao,” says Mutia, referring to barangay and city officials. “Kailangang sabihin nila na maghanda kayo dahil may bagyong darating.” (They also need to remind the people. They need to tell people to prepare for an impending typhoon.)

Mutia also cites the need for nearby establishments, such as Isetann Mall and Far Eastern University, to help by serving as temporary shelters for affected residents if needed. “Sa ganoong sitwasyon kailangan (na nilang) pumayag dahil buhay na ang nakataya,” he says. (In those situations, they need to give their consent because lives are at stake.)

Flood maps like those from Nababaha.com come in handy in these kinds of planning, Ybañez says.

“This website can serve as a guide to where these high-risk areas are and where to place their evacuation routes and evacuation centers. Since this is available to the public, ordinary citizens can formulate their own emergency plans based on the information presented here,” he explains.

Ybañez adds that geohazard mapping is of “utmost importance” especially in the Philippine setting because of its exposure to range of geohazards, from flooding to earthquakes to tsunamis.

“Our people are in constant danger from all these hazars and only updated, accurate, and well-done hazard maps can minimize and hopefully prevent (the) loss of (lives),” he says.

Updating maps

The challenge for Nababaha.com, as well as similar initiatives, involves updating data and disseminating information, says a write-up on the site.

Nababaha.com, for example, has yet to generate a flood map for Sendong-stricken Iligan. Meanwhile, most flood reports in Metro Manila go as far back as 2009.

“We are doing the best we can with our limited resources to generate as many maps as we can, as fast as we can,” the site says.

Ma. Antonia Yulo-Loyzaga, executive director of the Manila Observatory, vouches for the importance of hazard maps. She also suggests the development of “vulnerability” maps to show not only the natural hazards but also levels of human activity and exposure. (See related story.)

Flood hazard maps should help us learn from experience. Devastating floods – like history – repeat themselves after all. – Rappler.com