A comprehensive city drainage masterplan has been considered as a solution to the perennial flooding problem plaguing lowland areas in Metro Manila.
On August 28, overnight rains caused by northwest monsoon or Habagat, flooded parts of Quezon City, Malabon City and portions of the National Capital, prompting local authorities to suspend classes.
“Yun kasing city Drainage Masterplan yan ay tulad sa ginagawa sa Netherlands, specifically sa City of Amsterdam, na tulad din ng Metro Manila na mababa at bahain,” Metro Manila Development Authority (MMDA) Chairman Atty. Romando Artes said while comparing both cities.
He further explained that Amsterdam implemented a masterplan that is being reviewed and adjusted every 30 to 60 years in consideration of weather patterns such as rainfall and other aspects.
Metro Manila’s drainage infrastructures, however, are already obsolete.
“Ang drainage system kasi ng Metro Manila ay antiquated. Maliit, silted at ang kailangan dito ay integrated. Kung gaano kalapad at kalalim ng drainage ay hindi pwedeng sa kabilang kalsada makipot at mababaw, para dire-diretso by force or gravity papunta sa mga waterways,” he pointed.
Artes also clarified that these infrastructures will transcend boundaries within cities in Metro Manila.
Engineering Intervention
Department of Public Works and Highways (DPWH) Secretary Manuel Bonoan said that the engineering intervention intended to address perennial flooding is only one component of solving the problem.
He emphasized that to come up with a solution, it has to be done holistically while taking into consideration other factors such as population increase, economic activity and solid waste management.
“This is what we want to address flood; that the flood management program should be done holistically and in an integrated manner. Kasi if we are doing the engineering part of it, we should be also addressing the environment and social issues,” Bonoan said.
However, the National Government still seemed to be unprepared to address perennial problems caused by the onset of the rainy season.
They admitted that the City Drainage Masterplan that they are considering as a solution to flooding is still an idea without a detailed design yet.
The MMDA said that together with the DPWH, they will propose it for budgeting.
“Ito ay pinag aaralan pa kung ano ang magiging scope, detailed engineering design. Kung ano ang magiging desinyo ng mismong kanal. Mag po-propose po tayo, together with DPWH,” Artes assured.
But aside from meteorological factors, the Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA) cited other causes of flooding, which included the accelerated rise in urbanization and development.
Urbanization causes unforeseen rise of flood water during heavy rains, particularly in Metro Manila, the agency said.
Weather Specialist Facilities II Adelaida Duran explained that 80 to 100 percent of flood or rainfall water seeps through the ground, while 20 percent passes through channels and water courses.
However, due to rapid urbanization, all rainwater now passes through the drainage system, which has “limited” capacity.
Our country has “inadequate” flood control structures since its capacity was only designed to deal with 60 to 80 percent of the flood water. And worst, if these drainage laterals and waterways are clogged, it triggers widespread flooding because it impedes the conveyance of water.
Both the MMDA and DPWH promise to recommend the Drainage Masterplan with high hopes that one day this will be approved to help address Metro Manila’s consistent flooding
