Around 2 million people in the Pacific depend on rainwater collection for their drinking water, however these systems often struggle to provide sufficient quantities of water year round. This study examined the performance of 1,878 rainwater tanks across 19 islands in Vanuatu to assess whether the likelihood of a sufficient year-round supply of drinking water differed between village-level rainwater tanks used communally and private rainwater tanks owned by individual households (i.e., self-supply). More than half of the tanks assessed failed to provide a sufficient supply of water year round. Compared with communal rainwater tanks, private rainwater tanks had significantly higher odds of a sufficient year-round supply of water (adjusted odds ratio 1.61, 95% confidence interval 1.24–2.09, p < 0.001). This relationship was evident when adjusting for village-level clustering, year of installation, presence of other improved water sources, tank volume, number of users, and a proxy indicator for rainfall. Private rainwater tanks outperformed communal rainwater tanks irrespective of whether communal tanks were managed by a community-based committee. The findings support the notion that in some circumstances private property rights can help avert resource depletion, and that household self-supply is capable of delivering a more reliable water supply than community-based management. However, the study design was unable to rule out differences in roof catchment area as a factor influencing the results. Further work is needed to confirm and elucidate the mechanisms by which private ownership facilitates a year-round supply and understand the wider advantages and disadvantages of self-supply.

中文翻译：

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应对太平洋缺水：瓦努阿图农村私人雨水箱与公共雨水箱的性能

太平洋地区约有 200 万人依靠雨水收集来获取饮用水，但这些系统通常难以全年提供足够的水量。本研究检查了瓦努阿图 19 个岛屿上 1,878 个雨水箱的性能，以评估在村级公共雨水箱和个体家庭（即自有家庭）拥有的私人雨水箱之间，全年供应充足饮用水的可能性是否存在差异。 -供应）。超过一半的评估水箱未能全年提供足够的水供应。与公共雨水箱相比，私人雨水箱全年供水充足的几率明显更高（调整后的几率比 1.61，95% 置信区间 1.24-2.09，p < 0.001)。在调整村级集群、安装年份、其他改进水源的存在、水箱容量、用户数量和降雨代理指标时，这种关系很明显。无论公用水箱是否由社区委员会管理，私人雨水箱的性能都优于公用雨水箱。调查结果支持这样一种观点，即在某些情况下，私有财产权可以帮助避免资源枯竭，并且家庭自给能够提供比社区管理更可靠的供水。然而，研究设计无法排除屋顶集水区的差异是影响结果的一个因素。