THE report on June 17 said a planned underground drainage and reservoir system is likely to include tunnels to channel storm water, caverns for water storage, and a pumped storage hydro-power system which harnesses the power of flowing water to generate electricity ("Digging deep in Singapore for space solutions"; ST Online).

Deputy Prime Minister Tharman Shanmugaratnam said recently that Singapore does not have natural resources, not even a waterfall to generate hydroelectricity ("Safety net? More like a trampoline: DPM Tharman"; May 20).

We do have a man-made waterfall at the Jurong Bird Park, and there is hope that we can do more.

We have the technology to build 150m-deep lift wells to reach the caverns underground for gas storage.

Soon, it will be underground reservoirs.

The Government should conduct feasibility studies to build 150m-deep shafts and install magnetic-frictionless electric turbines at 30m intervals in each shaft, for the fast-flowing water to cascade down by gravity to spin the turbines.

There should be surplus electricity from the turbines in each 150m shaft to pump the water at the bottom of the shaft up to the surface and have perpetual fast-flowing water to generate electricity non-stop in all the shafts.

Singapore should set the pace to use this man-made new source of hydroelectric generation to reduce pollution caused by traditional sources of energy like oil and coal.

Tan Kok Tim