Peninsular Malaysia receives an average of 2,500mm of rain annually, although it varies from area to area. For instance, Kuala Lumpur gets around 2,400mm while some parts of Kelantan receive 4,000mm.

The total volume amounts to 990 cubic kilometers yearly, which is a huge amount of water. We also have about a 150 river basins in Peninsular Malaysia. We have flash floods and we have floods that inundate towns and villages for days on end.

With all this water pouring down from the sky, it will difficult to convince Malaysians to conserve water by installing rainwater harvesting systems. It would be like asking the Saudis to save on petrol by driving smaller cars.

Unless global warming were to drastically reduce rainfall, legislation is unnecessary to introduce rainwater harvesting. It should be done on a voluntary basis in areas where water shortages sometimes occur, like in parts of Selangor. Practical low cost designs should be made available inclined toward self-installation.

Legislating rainwater harvesting will only increase building costs, and worse still, the collected rainwater may not be utilised and result in a serious problem the breeding of the aedes mosquito. We should not try to solve one problem by creating a bigger one.

In the past, we gave priority to economic development over everything else including the environment. This resulted in water resources in many areas being destroyed or damaged, and rivers polluted.

We urgently need some powerful laws to protect water catchment areas and rivers. By eliminating pollution entirely from the upper reaches of rivers, we will have a lot of clean water available for the next 100 years.

Although year round rainfall in Malaysia makes rainwater harvesting unattractive as a way to reduce water usage, conservation of water is still very important to reduce sullage discharge. This plus the fact that we save money if we use less water.

The writer is attached to the Education and Research Association for Consumers Association.