Many of us now will be blaming climate change to a certain extent if there is a flood in your area. However, it may also have beeen caused by wrong or even worse, no planning at all.

Floods take place due to an increase in surface runoff water (water that flows on the surface) due to rain and the lack of drainage either natural or man-made. The lack of drainage can be due to shallow rivers, unplanned drainage for the urban and rural settlements, a lack of monitoring as well as maintenance of flood mitigation infrastructures.

The Fomca Environment Desk conducted a study at a flood prone area in Taman Garing, Rawang, Selangor. The residents’ plight started when a new construction was started uphill to their residential area in 2003.

There were mitigation measures, which we notice were only temporary measures. Fomca noticed a few similarities of the case to other cases as well.

Firstly, the maintenance of flood mitigation infrastructure was not done properly. There was high siltation (settlement of silt and soil) in retention ponds. There were also cases of water pumps that were not functioning during floods. Failure in this infrastructure or reduction in their capacity will cause floods to reoccur.

Secondly, blocking structures such as culverts designed below bridges may cause the same problem. Culverts are designed to give passage to water and allow traffic flow above.

However, old culvert designs are for old water discharge levels. Higher discharges need bigger openings for water to flow through. Any structure that blocks a high-velocity water flow will either be washed away or the water will find its way out and that may cause flooding.

Thirdly, development that reduces open soil area and increases surface runoff. More structures covering the open land will cause more surface runoff. This water needs to flow and be channeled out.
If the current drainage system was designed when there was few structures, it has to be redesigned or a new drainage system must be developed. Our rivers may not be able to carry this amount of water; the natural water cycle system was perfect until we altered it.

Lastly, highways like Lebuhraya Damansara Puchong which are sloped, have a huge tendency for water to flow down hill. The road separators designed can become ‘successful’ small dams during heavy downpours.

These are incidents which are not new but no action has been taken to prevent this to date.

Fomca would like to urge the relevant government agencies to revisit their flood mitigation plans and ensure there is good public participation in these plans.

We would also hope that forest destruction is not done with a free hand. Forests are the ‘temporary sponges’ to absorb surface runoff water. The more there is surface runoff water, the more will we be flooded by flood issues.

The writer is programme manager, Environment Desk, Federation of Malaysian Consumers Associations (Fomca).