Flash floods are getting to be a major pressing problem of the city. Only few nights ago, many of the streets of the city were inundated. We, the city residents were alarmed because while the rain was heavy, it did not last that long. In fact, the day's forecast by weather specialists did not warn us of any storm. The volume of water it poured could have been contained by existing drainage system, if…
In the late 80s, I had a privilege of being able to gather points of observation that could suggest how this city flooding evolved. My information brought me back to the era that followed the second world war.
Then, the city tried to rise from the ravages of the global conflict. To lead the way as a “modern cityâ€, it constructed a drainage system that somehow was efficient in handling heavy rainfall. The culverts used were, with two feet diameter, wide.
At that time too, the city was not thickly populated. There were few structures that dotted its landscape. It was only the downtown area where the buildings were erected either close to one another or on common property boundaries that they appeared connected and contiguous. Even then, such structures were constructed mostly along the streets. So, towards the rear portions of the buildings, there were vacant, necessarily open, spaces.
The areas located farther from the city's downtown were mostly residential. Even then, they were so sparsely inhabited that most houses had the luxury of having open spaces around them. I do recall that vacant spaces dominated both sides of the former Jones Avenue, now Osmeña Boulevard. Gen. Maxilom Avenue was called Mango Avenue precisely because a good number of mango trees lined it up. Only trees grew at the Nivel Hills and Maria Luisa Park was not yet a plush subdivision.
Those two factors, namely few structures and large open spaces prevented the occurrence of flash floods. When it rained hard, water just fell on mother earth and vegetation contained it for such a time to allow it to seep thru the soil. On its part, the drainage system the city had could adequately handle the volume that was thrown by the buildings to it.
It became a different story when the city got filled with structures. Open spaces vanished. Whether tall buildings or low residential homes, the roofs of these constructions would now accumulate rainwater and dump all of it, not on the soil, but on the drainage. Naturally, the culverts are no longer capable of handling such tremendous volume of water.
My point is obvious. It has become necessary to minimize the flow of rainwater from the buildings to the drainage system. The time to initiate this move is now. The city council should pound on its legislative anvil an ordinance that directs building owners to put up cisterns on their structures to impound the rain for a determinable period of time. In our observation, a heavy rain that is not a part of a weather disturbance lasts no longer than an hour. If the containment of the rain water is timed to this period, we therefore can be assured that when such kind of rain falls, no part of its water is thrown to the drainage and consequently, it does not have to spill to the city's streets and low lying areas.
Aside from flood prevention, there are other advantages that result from storing rainwater in cisterns. Washing cars, watering plants, flushing toilets and cleaning driveways are but a few practical uses of stored rainwater. There should be a lot more but with these liters saved, we do not put the pumps of MCWD on hard drive and help prevent brackish water from getting farther deep into the city. Well, I do not wish to say it but yes, we can spend the resultant savings in water and electricity bills for other necessities or even luxuries! How about it honorable city councilors?
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