MANILA, Philippines?It will take four to five months before floodwater could be drained from areas at the fringes of Laguna Lake inundated three weeks ago by Tropical Storm ?Ondoy,? Laguna Lake Development Authority (LLDA) General Manager Edgardo Manda said Wednesday.

Testifying at a hearing of the Senate committee on climate change, Manda said that about 2.5 billion cubic meters of floodwater had to be taken out of Muntinlupa City, Taguig City and the towns of Pateros, Taytay and Sta. Cruz.

?It could take us four to five months before this volume of water can be taken out from the lake,? he said, adding that this could be done through the immediate dredging of the Napindan Channel.

Manda sought to explain the continued flooding in areas surrounding the Laguna Lake watershed that covers six provinces, 12 cities, 49 municipalities and 2,656 barangays, 187 of which are within the lakeshore. Around 12 million people live in the watershed.

Pasig River is the only outlet of Laguna Lake and that 100 streams drain into the lake, he said.

P10B needed to dredge river

During the rainy season, water in the lake usually increased by 0.8 meters every month, but for three months this year, lake water rose to some 2 meters or 0.67 per month.

With the onslaught of Ondoy (international codename: Ketsana), water level at the lake reached 1.2 meters.

As of Sept. 29 this year, the water level was at 13.82 meters elevation and if this trend continued, it may exceed the all-time record of 14.6 meters in 1919.

It would cost P10 billion to dredge Laguna Lake over five years and prevent its swelling, he said.

Illegal logging?

Manda presented pictures taken a day after Ondoy struck on Sept. 26 showing an aerial view of the heavily flooded San Mateo town in Rizal province from where the floodwater swept toward Metro Manila. One photograph shows mud and water rushing from the Sierra Madre mountain range.

Asked by Sen. Loren Legarda, the committee chair, whether the mud and water indicated illegal logging, Manda said this was possible.

The Manggahan floodway spilled 3,000 cubic meters per second of water coming from Marikina valley at the height of the storm and inundated Taytay, Cainta and certain parts of Pasig, Manda said.

He said the Pasig River was ?constricted? and a canal had been illegally built going to Manggahan floodway, thus making it impossible for water to come out in Cainta.

Manda showed a picture of several houses built on outlets for floodwaters of the Manggahan floodway.

Squatters warned

He said the LLDA had urged illegal settlers to relocate from places like Lupang Arenda in Taguig?a reclaimed landfill?three months before Ondoy struck.

Some 5,000 shanties were inundated and their residents subsequently fled. Some squatters had been renting out their shanties, Manda said, recounting that one overseas worker had told him he was paying a monthly rent of P800 for his space.

Around 400,000 squatters were estimated to be in the lake area.

Illegal fish pens demolished

Pictures of fishpens around the lake that were destroyed also were presented.

Manda said that he had been ordering the demolition of illegal fish pens and that under his watch, 600 hectares of these structures were destroyed.

He said he would ask the Coast Guard to see to it that these pens are not reconstructed.