Cheaper solution to Malabon flooding: new floodgates

The Department of Public Works and Highways should not waste money raising General Luna Road and Governor Pascual Avenue and two or three bridges in Malabon City. They will not mitigate but instead worsen the flooding of our homes.

Stilling basins are the most effective defense against rain flood—and Malabon has no basin. But do not put up useless basins separated by a raised Governor Pascual Avenue from the rain flood coming from the La Mesa watershed.

Together with what we already have against tide flood, the DPWH should proceed to build the shelved floodgates (FG-o at Vitas and FG-3 at Bangkulasi) to turn the 43.75-hectare (water surface area) Tonsuya-Tinejeros-Tulyahan (TTT) rivers (a 100-percent direct flow collector) into the Malabon stilling basin, which should be complemented with three big pumps for FG-o and FG-3.

After one or two days of continuous heavy rain, our TTT basin, given the natural daily 2- to 3-hour transitions to lowest tide level, may overflow. The floodgates should be opened for two to three hours—also to save on pump fuel. At lowest tide level, the floodgates should be closed to stop the tide from flowing in and to make room for the still-coming rain water. All the time, the  pumps should be kept running. This can be done during the wet season (June to November).

During the dry season (December to May),  FG-o and FG-3 can be used to clean/dredge the entire TTT rivers—at no cost. The process is easy: close/open FG, high/low tide; the slow  inflow and fast outflow of the tides do it for free, every day, for six months—when there’s no rain, there’s no need for the TTT basin.

The DPWH should not insist on other solutions absent the FG-o and FG-3; they simply won’t work.

—ANGEL LAZARO JR.,

MSCE and architect,

technical adviser of Malabon Flood

Control Advisory Council,

160 Panay Ave., Quezon City