Whether it is building an underground substation or leveraging our waterbodies for stormwater management, there are many ways of maximising our resources to meet multiple needs. We learn more about two innovative solutions that contribute to Singapore’s resilience. 

Many creative solutions that maximise our land resources and infrastructure to serve multiple needs have been explored over the years. 

Some of the latest ideas include a new 230 kV large-scale underground electrical substation, a first in South-East Asia. To be completed by 2025, it can generate enough power to supply the Labrador area and will have a 34-storey commercial development above its underground substation¹. Over at Bidadari estate, Alkaff Lake in the new Bidadari Park that opened in 2024 is a first-of-its kind lake that also serves as a stormwater retention pond during heavy rainfall to protect the estate and surrounding areas from flash floods. 

Lee Bee Koon, Chief Engineer (Drainage Planning), Catchment and Waterways, PUB and Ryan Wong, General Manager (Special Projects), SP Group, shares more about these two creative solutions. 

Alkaff Lake

Tell us more about how Alkaff Lake was developed as a multi-functional drainage infrastructure for stormwater management.

Bee Koon: In land-scarce Singapore, it is not always feasible to widen and deepen our drains and canals to accommodate every extreme rainfall event. 

In the middle of the lake is a majestic Rain Tree that used to stand on an erosion control pond. This tree offers refuge to birds and hosts a variety of wildflowers, ferns and grasses. 

In creating a unique new Bidadari Park experience for residents, there was an opportunity to enlarge the Alkaff Lake to explore a different flood protection approach without the need to expand our existing drains. We worked closely with the Housing & Development Board and National Parks Board to design the lake to hold and moderate stormwater run-off while functioning as a regular lake with recreational and community spaces. In this way, we are not only harnessing the full potential of our waterbodies, but communities can also come closer to our waters too. 

How exactly does the lake moderate rainwater run-off? 

Bee Koon: Alkaff Lake is located at the lowest point in the estate, so during a heavy storm, stormwater run-off from half of the estate can flow into the lake by gravity. The stormwater in the lake is then released slowly into the downstream drain at Happy Avenue. This helps to mitigate flood risk in the areas downstream of the Bidadari estate.

Clear safety signs are put up at the lake to advise people to stay away from the waters when its levels are rising significantly.  

The 1.8-hectare lake can hold up to 40,000 cubic metres, or 16 Olympic-size swimming pools’ worth of water. It is designed to be transiently floodable, accommodating water depth of up to four metres during periods of heavy rainfall.

To prevent visitors from being on the footpaths when this happens, a robust warning system has been installed around the lake, which is tied to automatic sensors that monitor the water level. As the water level rises, beacon lights and audio broadcasts in four languages will be activated to inform the public to move away from the lake. There are also red safety markers and signages to let visitors know of the areas that they should avoid.

During dry weather, the lake’s water level remains between one and 1.5 metres, allowing people to safely enjoy the lake.

How do you ensure good water quality in the lake?

The scenic Alkaff Lake within the Bidadari estate is conveniently located just across from Woodleigh MRT station and mall. 

Labrador Underground Substation

Leveraging a waterbody and going underground – what led to the development of the underground substation in Labrador? What are the necessary factors that makes this a viable option?

Ryan: The opportunity to construct an underground substation arose when the equipment of an existing 230kV substation in Labrador was due for renewal. Comprehensive feasibility studies, including detailed engineering and topography assessment, ensured the project’s viability at this location. By building the substation underground, we can accommodate a five-storey Operations Support Centre and a 34-storey commercial tower within the same plot of land.

The viability of building an underground substation is dependent on several factors. These include the location’s importance to electricity demand, the existing network infrastructure’s renewal plans, and the overall topography of the site. Assuming that all these boxes are checked, building an underground facility will be typically more resource-intensive and will require specialised engineering capabilities to mitigate against major risks like adverse ground movement, flooding and fire.

Ryan Wong, General Manager (Special Projects), SP Group, played a key role in overseeing the development of the first large-scale underground substation in Southeast Asia. Image: SP Group. 

If commercial spaces are situated above the substation, just like Labrador, the site will tend to be in a more densely built-up area, with space being limited in many aspects. This poses an added challenge in the design to accommodate all the heavy and large power transmission equipment. For example, there must be careful planning of equipment delivery from the vehicular entrance of the facility to each equipment room, and laying power cables in and outside the substation, which is conventionally through public roads. We can rethink how these can be done more efficiently for future underground substations.

While underground construction works will always be more challenging, we expect that construction methodologies and equipment will continue to advance and mature over time for Singapore to take on more complex underground works.

This is the first time an underground substation is built with an integrated development. What are key elements that need to be in place for this combination to work well?

The 230kV underground electricity substation at Labrador is the first of its kind in Singapore, accommodating a five-storey Operations Support Centre and a 34-storey Commercial Tower within the same plot of land. Image: SP Group.

At its permanent state, we envisage our commercial/retail tenants and the public to enjoy and utilise the commercial and retail spaces freely without any compromise and interference with the daily operation and security treatment of the restricted spaces at the back-of-house. The stacking of above and underground structures required robust engineering expertise and techniques to ensure structural stability. 

Ryan: The Labrador Tower above the underground substation incorporates several pioneering sustainable features, including thermal energy storage and hybrid aircon distribution systems with conventional variable air volume boxes and Active Chilled Beams that improve cooling efficiency, a rooftop solar panel system contributing renewable energy, and infrastructure ready to support full-scale electric vehicle charging.

How does this build up Singapore’s energy resilience?

Ryan: The Labrador underground substation plays a vital role in strengthening Singapore’s energy resilience by enhancing the reliability of the electricity network and optimising infrastructure within a limited urban space. SP Group continues to innovate through solutions like microgrids, renewable energy integration, and advanced digital technologies, which will drive the nation’s energy transition goals. These efforts align with Singapore’s long-term energy sustainability goals while supporting urban development and climate change mitigation strategies.

¹ This is the first large-scale substation underground with a mixed-use development in Singapore and South-East Asia. There are already several underground 66 kV substations operating in Singapore.