How might we deploy coastal protection measures that better utilise land (when compared with conventional measures) and are adaptable to future requirements, like from rising sea levels?

Coastal Protection Department, Masterplanning & Regulatory Division

As a low-lying island, Singapore is particularly susceptible to the threat of rising sea levels. 

At present, about 70% of Singapore's coastline is protected from erosion by waves and storms, using structures such as concrete seawalls and stone revetments. The rest of the coast consists of natural areas such as beaches and mangroves. 

 The existing structures used for coastal protection measures typically take up premium waterfront land. For example, earth bunds are typically designed with slopes with 1:3 ratio for structural stability. In the event that taller bunds are required to protect against rising sea levels, it will not be sustainable to continue using 1:3 slopes, as it would take up premium waterfront land space to build coastal protection measures. 

The existing coastal protection structures also typically do not allow provisions for subsequent add-ons or modifications to adapt to rising sea levels. The structures are designed and built based on the expected loading conditions with limited allowance to cater for future uncertainties, to achieve optimal design. Hence, if there is a need to extend the height of coastal protection measures, a major re-construction of the coastal protection structure is typically required.

We are interested in solutions that can protect our coastlines from rising sea levels as well as erosion by waves and storms, and reduce the landtake for such measures without compromising on structural stability. 

We are keen to explore innovation in material science and construction engineering that allow for incremental enhancements of the coastal protection measures. 

We are also open to explore innovative techniques that incorporates nature or urban landscape features into our coastal protection measures. Nature-based solutions complementing traditional engineering structures could allow us to protect and improve the natural environment and biodiversity while urban landscape features could be functional for local residents and help justify the cost required.

To carry out a Proof-of-Con​cept (POC) study on the proposed coastal protection solution against future sea levels. The POC should already have been validated via numerical simulations and laboratory testing of prototype. 

The proposed coastal protection measure should have at least one of the following features:
●  Demonstrate provisions for incremental enhancement to adapt to the rising sea levels without major reconstruction of existing structure (applicable to existing coastal protection structure or new designs);
●  Demonstrate substantially less landtake. It is a bonus if solution is able to incorporate nature or urban landscape features as part of the solution to increase the coastal protection measure’s multi-functionality.
​●  Use of light-weight materials which are suitable for coastal environment;
●  Revolutionary construction methods that would reduce disruption and disturbances to existing measures.

There should be no significant increase in Operational & Maintenance (O&M) requirements to incorporate emphasis on Life Cycle Cost analysis. In your proposals, you should include an estimation of the life-cycle cost for constructing, operating and maintaining the solution over a time period of 50 years or more. Where proposed solutions require complete demolition and reconstruction, the estimated demolition and removal costs should also be included.

Conventional coastal protection structures currently:
●  Are designed to be practical and efficient in their functions of protecting the coast from sea waters.
●  Do not allow add-ons to support incremental improvement over time.
●  Require sand as a building material.
Materials used in coastal protection structures that have high porosity or permeability will typically have increased wave attenuation but lower their structural strength.

●  Press release about “Strengthening Singapore Coastal Defences”

Total project period : less than 18 months​

A POC study for an innovative coastal protection measure that meets at least one of above key considerations, which is validated by either numerical simulations and laboratory testing with small-scale prototype of the solution to demonstrate its feasibility. 

The numerical models and laboratory tests should include sensitivity analyses covering appropriate design parameters (e.g. sea level, environmental loading, design life, local soil conditions). In addition, laboratory tests should account for the various scaling effects where applicable.