Adaption planning for water security in Mauritius
Mauritius is a Small Island Developing State which is facing physical water scarcity. It is already classified as a water-stressed country (<1700 m3/capita/year) and is expected to be a water-scarce one (<1000 m3/capita/year) by 2025. Climate change and a growing population are further exacerbating this problem. With the UN Sustainable Development Goal (SDG) 6 linked to at least 62 out of 163 SDG targets, water security is deemed crucial to ensure the island’s societal and economic wellbeing. Contrary to traditional approaches used locally, robust and adaptive methods are now considered more suitable for decision-making in new water infrastructure due to uncertain prevailing and future conditions. This research’s aim is to assess how Mauritius can benefit from adaptation planning to inform such decision-making for long-term water security under deep uncertainty.
The Dynamic Adaptive Policy Pathways (DAPP) tool, coupled with a socio-economic scenario planning approach and a subsequent Multi-Criteria Decision Analysis, has been selected to explore this research question. The most pertinent result is that demand-side policies are key to Mauritius’ water security and relying solely on supply-side ones, as have always been prioritised locally, can have several unintended consequences. With regards to supply-side policies, non-conventional means, such as artificial aquifer recharge and wastewater reuse, can be highly effective, in terms of their tipping points, as compared to conventional ones such as dams and desalination. However, this requires a major overhaul of the current institutional, social and cultural policies, which are seen as the main change barriers, in order to adapt to the dynamic uncertainties in real time. Under all scenarios, artificial aquifer recharge has been ranked as the most sustainable investment component of the different adaptation pathways, principally because of its lower capital expenditure and multifunctional aspects. Conversely, despite similar benefits generated by wastewater reuse, the latter’s high costs made it less appealing. Hence, a participatory stakeholder engagement process is crucial to ensure that such strategies are prioritised. Overall, the adoption of an adaptive management strategy can be arguably justified by the results obtained. However, context-specific changes are required at all levels so that the resulting ‘just-in-time’ and low-regret infrastructure investment decisions can ensure the island’s long term water security.