Distribution of Atolls in Pacific Countries and Territories


Groundwater on atolls is often described as a lens of freshwater ‘floating’ on more dense brackish waters. This very thin and fragile freshwater resource relies on regular recharge from rainfall. The lens is subject to a set of impacts including natural variations in rainfall, anthropogenic impacts such as over abstraction from wells and bores which can cause salinization, as well as contamination from inappropriate sanitation or surface activities. In particular, the threat of climate change impacts on freshwater lenses in atoll environments is of great concern to the communities that inhabit these often remote locations. Small islands have unique hydrological features, including limited land area and catchment size, and the impact of the sea on the freshwater lens, and require unique hydrology and water resources characterisation methodologies. Similarly the ‘accepted’ concept and application of sustainable freshwater yield in a very dynamic hydrological environment needs to be considered.

Fresh Groundwater Lens in a homogenous strip island (Werner et al., 2013)


Assessing and quantifying what will be the likely impacts under different climate and abstraction pumping scenarios is not well known. Successful development of behavioural and technological adaptation options will rely on improved understanding of the unique freshwater lenses and quantifying the impacts on these lenses under a range of projected scenarios.

Over the last decade, throughout the Pacific governments and communities alike have embraced the principles of Integrated Water Resource Management (IWRM) where water is everybody’s business and where stakeholders are engaged in developing appropriate water management techniques. Stakeholders within the context of Small Island Developing States (SIDS) include government departments associated with water supply, environment, health, agriculture, the general community, as well as special focus groups and National Water and Sanitation Coordination Committees (NWSCC). The ultimate objective of IWRM in SIDS is to maximise the access to freshwater resources whilst ensuring adequate protection and sustainability of the water resource and environment. Successful water resource management, and changes to water use and conservation behaviour, are dependent on governments engaging with island communities to encourage increased responsibility by communities in the protection and management of their water resources, to occur through the sharing of relevant water resource information. This project will contribute to better groundwater protection and water resource management, with investigation techniques and modelling approaches aimed at quantifying the resource and identified impacts. The information on the extents and dynamics of the water resource as well as impacts from climate and anthropogenic influences will be made more accessible with the use of animations, graphics and physical models to encourage understanding across a wide audience.


Werner, A. D., Jacobsen, P. E., Morgan, L. K. 2013. Understanding seawater intrusion. [Poster]. Earth Sciences collection, Flinders Academic Commons, Adelaide, South Australia.