Project overview
With increased rainfall intensity and land shortage in Singapore, PUB sought to explore the feasibility of underground stormwater conveyance and storage systems to mitigate the impact of rainfall-induced floods. The UDRS comprises three components: underground reservoir caverns (URC), an underground stormwater tunnel system (STS), and a pumped storage hydropower (PSH) system. The UDRS, when implemented, will be a huge undertaking by the Singapore government, holding enough water to supply Singapore’s population of five million for more than four months.
Key project stats
Our role
- Evaluate the feasibility and develop a conceptual design for a mega stormwater conveyance and storage system (UDRS) for PUB
- To identify and determine relevant information and potential changes in the following areas:
- Stormwater management
- Water supply
- Pumped storage hydropower
- To mitigate the impact of floods due to climate change and extreme rainfall events of up to a 100-year return period
- To provide a reservoir storage for significant water supply purposes by maximising space usage
- To provide electricity storage on a large-scale basis as a source of power generation
- Underground caverns located within the granite geology found in the central parts of Singapore
- Large underground cavern storage volume
- Diversion inlets, drop shafts and/or stormwater link tunnels for collection of excess stormwater from surface catchments
- Use of 1D-2D hydrodynamic modelling using MIKE FLOOD to identify flood areas and determine the ideal location and dimensions of proposed inlet weirs
- Use of yield modelling to investigate yield attainable from surface water catchments
Underground drainage and reservoir system design
Underground drainage and reservoir system design 2
Underground drainage and reservoir system computer design
Reservoir system ontop of water