MANILA, Philippines — The poor urban planning in Metro Manila, and not intense rainfall, could worsen the flooding situation in the capital, Science Undersecretary for disaster risk reduction Renato Solidum Jr. said.

In an interview with One News’ The Chiefs Tuesday night, Solidum said the drainage systems and rivers in Metro Manila could no longer accommodate the huge amount of rainfall. He blamed it on trash and siltation problems in the capital.

Solidum explained the rain dumped by the southwest monsoon over Metro Manila on Aug. 11 was only 270 millimeters or half of the rainfall brought by Tropical Storm Ondoy (international Ketsana) in September 2009.

“This amount of rain (which can be) accommodated by river and drainage systems are getting smaller and smaller either because of the trash, soil erosion, and (in the case of) Laguna Lake siltation because of overfeeding of the fish,” he said.

Solidum, who also heads the Philippine Institute of Volcanology and Seismology (Phivolcs), said Metro Manila is a floodplain.

“We know that there will be a problem but the exacerbation of how we built the environment, how we construct things around will make it worse through the years,” he said.

Non-stop heavy rains from the storm-enhanced southwest monsoon submerged many parts of Metro Manila last weekend, bringing back the memories of Ondoy, which killed hundreds of people.