The recent prolonged dry spell and Hyflux saga have highlighted how difficult it is for Singapore to secure sufficient water.

We have long been reassured by Singapore's policy of having four national taps. But the Hyflux saga has highlighted the immense cost of building and running a desalination plant.

One alternative source of water is cloud seeding, which has been used fairly successfully in countries such as the United States, China and the United Arab Emirates.

Having rain at our command would have several advantages. It would help to cool our country, water our greenery and top up our reservoirs.

More research should be done on using cloud seeding. Now that drones can be used to replace manned aircraft, the process should become more predictable, efficient and cheap.

Seow Onn Choong (Dr)