NABUNTURAN, Compostela Valley (MindaNews/19 February)– New Bataan town in Compostela Valley lacks areas safe for the relocation of its residents as shown by simulated inundation maps, town Mayor Lorenzo Balbin Jr. said last week.
Citing the maps prepared by the Department of Science and Technology (DOST), Balbin said only 189.
19 hectares are safe for relocation or
0.27% of the 68,860 hectare total land area of New Bataan.
Areas covered by the debris flow, a mixture of mud, rocks and boulders, had a total of 2,472 hectares or “about the size of Makati City,” according to the DOST’s briefer.
The town had a population of 47,470 as of May 2010, including 7,550 who lived in Barangay Andap, which was covered with rocks and boulders when typhoon Pablo struck last Dec. 4, 2012 and caused floods that changed the course of nearby rivers.
Pablo’s death toll in New Bataan reached 128 aside from 450 missing persons.
Balbin aired the concerns to the Task Force Pablo (TFP) during its first briefing last Friday with key government officials at the provincial capitol here where DOST Secretary Mario Montejo presented simulated inundation maps of New Bataan, Monkayo and Compostela towns.
The DOST made the topographic maps using the Light Detection and Ranging or LiDAR technology as part of the relocation plan for typhoon victims.
The maps, which were outputs of the Disaster Risk and Exposure Assessment for Mitigation or DREAM Program under the DOST’s Nationwide Operational Assessment of Hazards, simulated floods in the next 100 years based on the new topography after Pablo.
Social Welfare Secretary Corazon Soliman said at the briefing the residents have to be relocated in safe areas as shown in the maps.
Montejo said that aside from the safe areas that were marked yellow on the maps, the areas marked orange, where flood levels would be from 0.1 to 1 meter, are still safe places for relocation.
He defined safe areas as those where flood levels would only be one meter or less.
He said the DOST and Mines and Geosciences Bureau will discuss the safe areas for relocation with the LGUs.
Engineering interventions
Worried that another heavy rainfall may cause flooding in the town, Balbin said engineering interventions such as de-silting and re-channeling of rivers, and construction of dikes, especially in Andap, were needed to protect communities while waiting for relocation.
Soliman said that while engineering interventions may reinforce protection, it is clear that it could not hold back hu
ge quantities of water, rocks and mud as shown by Pablo.
DOST’s briefer states that the volume of debris deposited mostly in New Bataan reached 25 to 30 million cubic meters or as many as the quantity of rocks that can be loaded in 2.5 to three million 10-wheel dump trucks.
The speed of the debris that hit Andap was 30 to 60 kilometer per hour and lasted five to 10 minutes, the DOST said.
Montejo said the simulated inundation maps were based on the changes in topography caused by Pablo.
Engineering interventions, he continued, might be more expensive and impractical considering such force of nature.
DPWH Assistant Secretary Dimas Soguilon said his department was waiting for DOST’s recommendations before doing any intervention in the three towns.
Rebuilding bridges and roads is so far the priority of the DPWH, he said.
In an interview after the meeting, Balbin said something should be done to protect the people since the relocation won’t happen immediately. He said he wasn’t sure if TFP would grant his request.
The mayor added he has yet to ask his constituents if they would agree to be relocated, as it was the first time for the LGUs to meet the task force.
The number of households to be transferred as well as the locations will be known after a meeting with local officials, he said. (Lorie Ann Cascaro/MindaNews)
