Contending With Water Shortages in the Pacific: Performance of Private Rainwater Tanks Versus Communal Rainwater Tanks in Rural Vanuatu

Abstract

Rainwater collection and storage is critical to water security in Vanuatu and the wider Pacific region. Across all Pacific Islands countries (PICs), more than one in six households-or around 2 million people-rely on rainwater collection as their main drinking water source (Table 1). Rainwater collection systems are especially important in Vanuatu, serving as the main source of drinking water for 36% of households (VNSO, 2017).Rainwater collection as a source of drinking water presents potential advantages and disadvantages, which in turn have important implications for efforts to achieve the Sustainable Development Goal (SDG) of safe water for all in Vanuatu and the wider Pacific region. The headline indicator linked to SDG target 6.1 requires safely managed water services to be improved source types, accessible on the premises, free of fecal and priority chemical contamination, and available in sufficient quantities when needed. Rainwater at the time of capture is typically of good quality and is defined as an inherently "improved" water source by the WHO/UNICEF Joint Monitoring Programme (WHO/UNICEF, 2018). However, there is clear evidence that rainwater collection systems in Vanuatu are still prone to fecal contamination , while others have noted concerns in regards to physical and chemical contaminants (Allibone et al., 2012;Kotra et al., 2017). Rainwater collection systems are often owned and managed by private households, and hence are commonly located on the premises of users. This reduces water collection times and minimizes the need for storing water in the household, which otherwise presents a contamination risk (Shields et al., 2015).Perhaps the most significant weakness of rainwater collection systems is their ability to ensure water is available in sufficient quantities when needed. These systems are highly vulnerable to climatic conditions,