By 
National water agency, PUB has announced that it will be studying the technical and economic feasibility of developing an integrated underground drainage and reservoir system.
The water agency stated that Singapore with its limited land area of approximately 718 km2, faces a continuous challenge to come up with innovative solutions to create spaces for a range of uses, while keeping
the country highly liveable.
This study by PUB will look into the design options for an Underground Drainage and Reservoir System (UDRS), which could integrate 3 key components – stormwater conveyance tunnels, underground reservoir caverns, and a pumped storage hydropower system.
One possible option that PUB highlighted 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.
PUB added that there are challenges involved in the construction of underground facilities and the knowledge of underground geological conditions is critical. Suitable rock material is required for the location and development of caverns and underground reservoir and 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. The findings from the study will allow PUB to decide whether the UDRS can be pursued further.