Saturday, August 28, 2010

Flash Floods

Intense rainfall occurring within a short period of time will overwhelm most drainage systems, even filling up waterways, thereby resulting in flash floods that often lead to traffic congestion, and in some cases, death and destruction. Flash floods are temporary by definition and should last under an hour or a couple of hours if the drainage system happen to be clogged once the rains relent.

Two weeks ago, the Clairvoyant and I were lucky enough to reach home after almost 3 hours. We navigated efficiently enough to reach our home via familiar routes that were not as congested if we used the conventional route from the university to our village. It only took about 40 minutes on typical nights that the Clairvoyant fetched me from work to reach our village. That night, however, took more time for travel because of a flash flood along Marcos Highway, no thanks to clogged drainage systems and silted waterways in the area. Late in the afternoon then, heavy rain fell over an area roughly covering Marikina, Cainta and Antipolo. Rip-raps along a section of waterway in one Cainta subdivision collapsed after it was unable to resist the sudden and strong rush of water. Parts of that subdivision were immediately flooded, reminding residents of the not so distant experiences from Typhoon Ondoy in 2009. The same waterway was part of a network that included a branch in Kingsville Subdivision along Marcos Highway that caused flooding in that major road. Various first hand reports from friends state that people coming from workplaces in Makati, Ortigas and Quezon City drove for 3 to 5 hours, with many reaching their homes by early morning the following day.

Two nights ago, there were more flash floods all around Metro Manila. Some were of the terrifying kind - "lampas tao" (deeper than the height of a person) or "hanggang leeg" (neck deep). Others alarming - "hanggang baywang" (waste deep) or "hanggang/lampas tuhod" (knee deep). And most others were of the inconvenient but "more acceptable" kind - "hanggang talampakan" (ankle deep). Still, any kind of flash flooding produced trouble, mostly of the traffic congestion kind. I got home quickly, deciding to leave the office while it was still raining and before nightfall. The Clairvoyant was not so lucky as she was unable to leave her office due to a deadline she was trying to beat. Yet, she was still lucky enough as I was able to persuade her not to drive home. The traffic that night was hell and the flood waters rose in many areas including our village where if it not for our service vehicle being a Pajero, I could not have reached home with dry feet. It made no sense to drive home with a car that will be unable to manage the flooded streets when most of our neighbors were already taking their vehicles to higher ground. I saw the signs and my 26-year first-hand experience on floods kicked-in. The clairvoyant should not attempt to drive home.

The waterways and the drainage systems in most areas in the Marikina, Pasig, Cainta and Antipolo (maybe including Taytay, too) have not been touched since Ondoy's onslaught in late September 2009. Many residents of areas affected by Ondoy perhaps chose to assume that the typhoon was one of a kind and that the flood we experienced was one of those that scientists categorize as 40- or 50-year floods. Acceptance of such assumptions tend to mislead and lull people into a false sense of security - one that is in denial of the possibility that we have another disaster waiting to happen in the next few weeks when La Nina takes over from El Nino.

Much of the responsibility for these waterways are with the local governments of those cities and municipalities. Yet, the leaders of these LGUs seem to have very short memories and instead spent the summer (that long very dry season from January to June) doing nothing with regards to flood control. The murky waters of Ondoy in 2009 brought in so much mud (from both clay and silt) that I am very sure that most drainage systems' capacities have been significantly reduced. Moreover, waterways that used to be dredged on a regular basis were untouched despite local elections in May where flooding happened to be one of the major issues. It is the ineptitude of our so-called leaders that will result in another disaster come September or October, when our weathermen predict that more heavy rains will fall and when the typhoons start arriving. We can only hope that there won't be more of the 50-, 40-, 30-, 20-, 10- or even 5-year floods occurring then. Flash floods are welcome as long as they remain "flash."

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