Reclamation project to help reduce flooding

MANILA, Philippines - An international research group has proposed the creation of a reclamation area along the coastal zones of Parañaque and Las Piñas cities to help reduce flooding in areas where water levels normally rise during severe weather disturbances due to storm surges and heavy rain.

In its proposal, Denmark-based DHI Water & Environment (S) Pte. Ltd. said their project will not cause flooding problems but at best it can improve the existing situation and help mitigate the effects of rising sea levels based on the proposed reclamation plan.

The proposal includes the following: extension of the Parannaque river to be dredged to increase the water depth by an average of 2-3 meters; dredging of the Las Piñas/Zapote river mouths to increase the water depth by an average of 1-2 meters; removal of the sand bar near the mouth of the Las Piñas river; and the provision of a 35-meter wide sluice gate and operation procedure for the causeway.

These measures will improve the drainage from the rivers during heavy rainfall events, and reduce the effects of storm surge in the Parañaque/Las Piñas/Zapote area.

DHI clarified that the reclamation project in general will not cause storm surge-related flooding, supporting an earlier assertion by the Philippine Reclamation Authority that well-designed reclamation projects actually help curb this type of flooding by providing sea barriers that provide protection from storm-driven waves.

“The proposed improvement of river mouth discharge conditions is expected to help reduce maximum water levels in the area,” the firm said.

There will be periodic dredging, construction of retention pond, and the creation of floating debris boom to reduce river passageway blockages.

“Part of the plan also calls for regular water quality monitoring and close cooperation with the local government units to ensure that drainages and culverts or tunnels are free of blockages,” it added.

The firm also assured that it would improve the “overall management” where migratory birds are staying.

DHI is an independent international consulting and research organization with head office in Denmark, and regional headquarters in Singapore. It is also a designated United Nations Environment Program (UNEP) collaboration center, providing international expertise in the fields of water and environment.