Mitigation Hierarchy

Decision making on managing habitats impacted by development is governed by the mitigation hierarchy - a structured framework used to manage and mitigate the environmental impacts of development projects, particularly on biodiversity and ecosystem services 1. In the context of land-scarce Singapore, only the first three (i.e., minimization, avoidance and restoration) out of the four sequential steps normally used are applicable:

The omitted step from the figure above is "offsetting" which requires compensating for any residual impacts that cannot be avoided, minimized, or restored. This often involves creating or enhancing biodiversity in other areas to achieve no net loss or a net positive impact. 

Land scarcity in Singapore presents a challenge for development, especially for public and private housing, and an even greater challenge if any offsetting for such development were to be considered. The total land area of Singapore is only approximately 735.7km² as at end December 2024. Within such constraints, Singapore’s Housing Development Board aims to build an additional 130,000 flats from 2021 to 2027. 

Given the land constraints in Singapore, offsetting as practised by other countries is a difficult proposition as it normally involves off-site land 2. Nevertheless, in the event that future scenarios which allow for off-site enhancement or creation emerge, these may be incorporated into the baseline calculation section of the SGBA, instead of being treated as a separate calculation. This simplifies the recording and assessment process for the practitioner in line with the intended more user-friendly and parsimonious approach of the SGBA. 

1: Pelucchi et al. (2020)

2: Singapore Youth Voices for Biodiversity, n.d.