PUB to explore underground space for drainage and water storage

SINGAPORE - National water agency PUB will be studying the technical and economic feasibility of developing an integrated underground drainage and reservoir system, according to a statement from the agency.

PUB will launch a 24-month study to look at the feasibility of the system to reduce the impact of climate change and enhance resilience against droughts.

This study will look into the design options for an Underground Drainage and Reservoir System (UDRS), which could integrate three key components - stormwater conveyance tunnels, underground reservoir caverns, and a pumped storage hydropower system.

One possible option is to have tunnels to convey excess stormwater to underground caverns for storage. The caverns can add to Singapore's reservoir water storage and enhance drought resilience. In addition, the study will explore the possibility of having a pumped storage hydropower system to recover energy from the flow of water from surface water bodies to the underground caverns.

"Besides allowing us to overcome land limitations for key drainage and water storage infrastructure, the UDRS study can potentially allow us to mitigate the impact of climate change and flood risks, and strengthen the overall drought resilience of Singapore's water supply," said Mr William Yeo, PUB's Director of Policy and Planning.

There are challenges involved in the construction of underground facilities and the knowledge of underground geological conditions is critical. The location and development of caverns and underground reservoir will require suitable rock material. The study will include geological surveys to obtain detailed information on soil and rock properties.

"In carrying out this study, we will work closely with key agencies and stakeholders to ensure that the geological surveys are conducted with care and sensitivity to the environment," added Mr Yeo.

The study is expected to be completed in end-2017, according to PUB.

candicec@sph.com.sg