Protection of Inland Elevated Slopes and Areas from Landslips and Weakening Soil Conditions

Ms Ng Ling Ling asked the Minister for National Development besides defending Singapore's shoreline against rising sea waters with a coastal defence plan, whether there will be similar efforts for the inland elevated slopes and areas with gradients to systematically identify areas where there can be risks of landslips and sinkholes and to fortify against weakening soil conditions.

Agencies that manage public land carry out regular inspections on slopes that may pose a risk to public safety and implement appropriate mitigation measures to stabilise the slopes if required. For example, NParks inspects slopes in parks and gardens on a quarterly basis during fair weather and on a weekly or monthly basis during periods of intense wet weather.

In addition, BCA requires all slopes that are formed as a result of building works to be assessed for risk of failure by a Qualified Person (QP) before construction commences. The QP is required to recommend slope protection measures to be put in place, such as earth retaining walls and stabilising structures, to ensure that the slope remains stable under adverse weather conditions, including extreme rainfall.

BCA also issues regular advisories to remind land and building owners to implement measures to manage the risk of landslips for their slopes. These include ensuring adequate drainage and proper maintenance of slope- and earth-retaining structures.

Sinkholes in Singapore are generally caused by larger scale excavation or underground works. For such works, BCA requires a QP to conduct a site investigation and recommend measures to prevent sinkholes from occurring. BCA also requires the builder and the QP supervising the works to monitor ground and building movements during construction, and to implement additional safety measures as necessary.