In his final State of the Nation Address last Monday, President Benigno Aquino III stated the following: “Para matugunan ang madalas na pagbaha sa Maynila, isinulong natin ang pagpapagawa ng catchment area, pero tumutol po dito ang isang malaking unibersidad. May lumang mga gusali daw kasi silang baka maapektuhan ng gagawing proyekto.”
As revealed in the past few days, P-Noy is actually referring to the University of Santo Tomas (UST). Of course, the UST community did not take the President’s remarks well.
Before anything else, here’s the back story: the Department of Public Works and Highways two years ago suggested the creation of a “retarding tank” underneath the university’s open grounds to serve as a temporary catch basin for rain fall and flood water (this will be pumped out to waterways later on) to mitigate the perpetual floods in Manila. The university rejected the proposal, citing “security concerns and the expected disturbance of the University’s regular activities.”
Politicians (mostly lawyers and celebrities), even if they are sincere, cannot solve nagging problems like floods, traffic congestion, and the like by themselves not only because they lack the necessary technical capabilities but also because a lot of them do not seem to have the vision needed for long-term planning (in other words, beyond the next election cycle).
At this point, I’d like to explain why UST’s decision not to cooperate with what the government wants actually makes sense:
1) Who in his or her right mind will allow others to bring things that may cause spread of bacteria, decease, infections, and other health or environmental hazard in your own backyard? Stated differently, why will UST allow its property to be a catchment area for flood water filled with trash, rats, muds, etc.?
2) For some reason, DPWH flood control projects are all crazy expensive and yet so damn inefficient. The taxpayers are getting almost no reprieve from flooding despite the high costs of these initiatives. In business speak, where’s the return-on-investment?
DPWH previously used the term CATCHMENT PIT (box type) or TUNNEL (long stretch). The new term they are using now is RETARDING TANK. For easy understanding, I will describe it simply as an expensive swimming pool without the ceramic tiles meant for flood water.
3) Here’s another thing worth thinking about: Will this catch basin be big enough to contain all flood water especially during extreme circumstances (aka the new norm) like a la Ondoy and habagat-induced volume of rainwater?
In addition to high cost, constructing these tanks takes too much time, which means disruption to vehicular traffic flow in the area. Apart from that, maintaining this closed catchment pit/tunnel or tank (including the pumping station) is also extremely difficult and expensive.
Closed catchment pits or tunnels or retarding tanks are appropriate for well planned cities like Singapore or in private areas and elevated properties or compounds like Rockwell. It is not recommended for cities and areas that are low lying and poorly planned like Manila, Mandaluyong, and Pasig.
(currently being applied in Quezon City by Mayor Herbert Bautista)
One proposal that may lead to flood prevention and mitigation is by reducing impervious surface in our cities (this is notably already being done in Quezon City thanks to Mayor Herbert Bautusta). Most of our cities are now covered with concrete, thus creating impervious or waterproof surfaces.
These include pavements, roads, sidewalks, driveways, and parking lots that are covered by impenetrable materials such as asphalt, concrete, brick, stone, and rooftops. Soils compacted by urban development are also highly impervious. Thus, it seals the soil surface, eliminating rainwater infiltration and natural groundwater recharge.