The water level of Laguna de Bay remains higher than that of Manila Bay following the rains brought by tropical storm “Ondoy” with channels out to sea  obstructed by silt and illegal structures.

This is the reason why many lakeshore towns remain flooded more than a week after the unusually high volume of rain brought by Ondoy flooded low areas in Metro Manila and nearby provinces, according to Taytay Mayor Joric Gacula.

During a meeting of the Regional Disaster Coordinating Council, Gacula said there is a need to clear the obstructions to the waterways from Laguna to the Manila Bay, including in the Napindan and Manggahan flood channels, so lakewater will flow out to the sea.

"A check on these waterways showed that water lilies and illegally parked barges have adversely affected the natural flow of the water," he said.

Meanwhile, as a short-term measure, local government units in flood-stricken lakeshore towns plan to pile sandbags around the lake and pump water out of flooded areas.

Gacula cited data from the Department of Public Works and Highways (DPWH), the water level of the Laguna de Bay appears so much higher than that of the Manila Bay.

The abnormally high water level of the lake caused Pasig City, Taytay, Cainta, Tagiug, Pateros, Muntinlupa and the remaining lakeshore municipalities in Rizal to remain under water.

Gacula said they have already sought the help of the DPWH in hastening the completion of the road dike, a multi-billion peso national government project dating back in 1998.

“With those dikes in place, there is very little chance of the Laguna de Bay water submerging our densely populated barangays, as what happened today," Gacula said.

He said lakeshore towns are putting up sandbags at the lakeshore after which water will be pumped out of the flooded communities with the help of the Metropolitan Manila Development Authority (MMDA).

This is already being done in Barangay Sta. Ana where some 30,000 families live.

Meanwhile, police have been called in to secure part of the dike to prevent residents of illegally built shanties from destroying parts of the dike in an apparent effort to lower the water level on the ground where they built their shanties.

Gacula said the sandbags and the clearing obstructions on the waterways are short-term solutions.

He said a long-term solution to the flooding problem in Metro Manila and outskirts is the desiltation of the Laguna de Bay and its tributaries.