Domestic water supply vulnerability to climate change and the role of alternative water sources in Kingston, Jamaica

Globally, freshwater resources are threatened, resulting in challenges for urban water supply and management. Climate change, population growth, and urbanization have only exacerbated this crisis. For the Caribbean, climate change through the impact of increasing temperatures and rainfall variability has resulted in more frequent and intense episodes of disasters including droughts and floods which have impaired the quantity and quality of freshwater supplies. Using Caribbean-specific climate forecasting, it is shown that rainfall totals in Kingston, Jamaica, are expected to reduce by 2030 and 2050 under two RCPs. In addition, the timing of the primary rainy season is expected to shift, potentially impacting water supply security. Analysis of the potential of rainwater harvesting (RWH) to augment supply and enhance water supply resilience shows that in two communities studied in Kingston, it can contribute up to 7% of total water supply. Household storage requirements are about 1 m³ per household, which is feasible. RWH offers the potential to contribute to climate change adaptation and mitigation measures at a household level. Policy, incentives, and increased awareness about the potential of RWH to meet non-potable household demand in Kingston must be improved, as well as efforts to reduce the currently unreasonably high levels of non-revenue water in order to move towards an integrated, sustainable, and climate-resilient urban water supply strategy for the city.