Just an hour or less of rain yesterday, and voila, we find many places in the Cebu City and Mandaue City being flooded. Must we suffer from floods every time it rains?
It used to be that when there is flooding we point to loggers as the main culprit or the people who live in the mountains for cutting trees to give way for their upland farms or to earn a little from the sale of firewood to the people in the lowlands. Now we blame the indiscriminate throwing of garbage all over the city and the inability of the city government to build more drainage or clear them of debris which are mostly of plastic bags or bottles and what have you.
The truth is that much of the water flooding the city is the price we pay for our wanton disregard for the need of rainwater to sink underground when it falls by waterproofing our city with concrete. Look at the front, back and sides of your homes and commercial buildings near you. Most of them are now covered with concrete. Look at our parking spaces, including some of our public parks, they are covered with concrete. This is not to mention the hundreds of kilometers of concrete or asphalt roads all over the city.
Experiment this. Pour a pail of water in an open ground. In no time the water will sink and disappear. Do the same in a concrete court, parking area, or in your concrete front yard. You will find the water moving in the direction of low-lying points. When there is rain, that is also what happens and why there is flooding in low-lying areas of the city. Garbage thrown everywhere that clogs our drainage system only aggravates the situation. Too much run-off of rainwater is the problem.
Indeed, the water that drops from the sky will need some place to rest when not allowed to sink. When rainfalls on the mountains covered with trees, much of the water is held by their leaves and branches. Some may fall to the ground when the rain is excessive but then they are also absorbed by rotten leaves and woods below or by the soft soil underneath. Only when there is too much rain that water cascades downwards to the valleys where they are conveyed eventually to the sea or lakes by the meandering rivers, big and small. In the past, rarely would there be flooding in the city unless the rain continuous for hours or days that saturate the grounds and lead to greatly increased run-off.
Yet, only about 25 percent of the rain normally ends up as surface water runoff. Most of the rain would sink into the ground or return to the atmosphere by evaporation and transpiration. But not so when we denude our mountains that allows the rain to cascade fast downward in torrents as they fall in great amount and when we waterproof what remains of the city after we build our homes or construct our malls and other big structures for business, and other grand purposes.
Don’t we have a law which fixes how much of our individual home lots, subdivisions, commercial centers, industrial parks, and other lands uses be left open to allow nature to work its way in maintaining our water cycle? And what do we do with the rain that falls on our roof? Do we just let them flow down to the side of the streets and find their own rest elsewhere?