The rapid review confirms that Pacific Small Island Developing States (SIDS) are socially, culturally, and environmentally diverse, with some features in common, and which collectively make them unique to other regions of the world: Small island countries have uniquely fragile water resources due to their small size, lack of natural storage, competing land use, and vulnerability to natural and anthropogenic hazards, including drought, cyclones, and urban pollution (with between 0.5 percent to 6.6 percent of gross domestic product (GDP) being lost annually to disasters). Rurally dominated populations are widely dispersed geographically as many small communities, while most capital cities include significant informal settlement populations and are subject to rapid urbanization (a more than 3 percent yearly increase in urban population growth in most Melanesian countries is projected between 2015 and 2020) (Mycoo and Donovan 2017).