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s the rainy season approaches, residents are being urged to take part in efforts to minimize flooding.

Hydro-geologist Fatchy Muhammad of the Indonesian Water Society said many residents were still unaware that rainwater should be managed vertically, not horizontally.

'€œMost people think flooding occurs because the waterways are not wide enough. Hence, a majority of residents still wait for the city administration to widen the rivers and sewers to prevent flooding. This is a fatal mistake,'€ Fatchy told The Jakarta Post on Wednesday.

Instead, he said, rainwater should be stored for the dry season. To store rain water, Fatchy said, middle-upper class households could develop absorption wells, while lower-class households could provide biopore holes.

An absorption well is an underground chamber that collects rainwater and allows it to seep into the soil gradually and reduce runoff. By constructing an absorption well, rainwater could be saved as a water reserve to help fill the empty pores underground as a result of groundwater depletion.

Meanwhile, a biopore hole not only helps to absorb rainwater, but also functions as a waste management system for organic waste. A biopore can be made easily using a manual drill, a pipe and a manipulatable metal stick.

'€œIt'€™s time that we make use of rainwater. We need to change the mind-set that rainwater needs to be got rid off,'€ Fatchy said.

Architect Susiadi Wibowo said absorption wells could greatly help the cycle of hydrology, which had been disturbed due to a lack of soil surface. He added that existing sewers, canals and rivers could not accommodate the volume of water, causing overflow.

He said that every type of soil was different, therefore each warranted wells of different sizes.

'€œFor example, saturated soil only needs a small well or none at all. For conservation, one can use a bucket to store water. Meanwhile, soil of low water seepage quality needs a deep well,'€ Susiadi said.

Separately, Jakarta Water Management Agency head Tri Djoko Sri Margianto said that if developing absorption wells and biopore holes was too difficult or costly, residents could simply stop littering.

'€œAbsorption wells and biopore holes greatly help reduce water loads produced by the rain on our waterways. This will also reduce the possibility of overflowing waterways and can minimize flooding. These systems are affordable for the middle class,'€ Tri told the Post on Wednesday.

He pointed out that garbage often clogged up waterways and jammed pumps, which could result in flooding similar to that seen at Central Jakarta'€™s Dukuh Atas underpass last weekend.

'€œDisposing of waste in the right place is a small step that goes a long way,'€ Tri said.

He also revealed that the city administration starting next year would carry out a citywide zero-runoff program starting in public schools, especially in South Jakarta. Further, Tri said, all developers seeking to construct a building had to have a zero-runoff design starting next year.

Although building owners are mandated to develop absorption wells to equip all buildings as stipulated in Gubernatorial Regulation No. 68/2005, Tri acknowledged that many still did not comply with the regulation, while others provided such infrastructure as a formality, without ensuring it actually worked.
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