Large natural reserves of fresh water have been found on the island of Aitutaki.
The findings come after a group of eight researchers from the Pacific Community (SPC) and the government spent two weeks investigating previously untapped water sources. These sources could provide clean drinking water for the island in times of need, such as during a drought.
Aitutaki relies mostly on rainwater for its potable water supply, with households collecting rainwater and storing it in tanks. There are around 16 community water tanks in Aitutaki. The tanks vary in size and condition, with some having been repaired with assistance from donor agencies.
The non-potable water supply is sourced from seven groundwater infiltration water galleries - three at Vaipeka and one each at Vaipae, Tautu, Vaimaru, and Vaitekea.
Pumps shift water from the galleries to elevated reservoirs around the island, from which the water is distributed to homes via a piped reticulation network. All galleries are operated by the island council and the water is consistently brackish.
The work is being undertaken by the Pacific Community’s Disaster Community Resilience Programme, in partnership with the Aitutaki Island Council and Infrastructure Cook Islands (ICI).
The findings were presented to the local community and stakeholders last month. It is hoped a drilling schedule to install boreholes, as well as a resource management plan will now be developed for the newly discovered water source.
The work was part of SPC’s Atoll Water Security project, funded by the New Zealand Ministry of Foreign Affairs and Trade (MFAT).
SPC spokesperson Peter Sinclair says geophysical and electrical testing indicated these water sources would be able to provide high volumes of fresh water.
“We are able to identify…where the high-yield targets are likely to be,” says Sinclair.
“So from that, we think there’s potential for the water to provide a considerable amount of supplementary water to support the existing water supply system.”
The island relies on shallow groundwater and rainwater harvesting for most of its water needs however, drought conditions in 2013 and 2017 led to water rationing with most sources being impacted and insufficient water to meet demand.
Ongoing investigations into deeper and more reliant groundwater sources will help ensure water demands are met. Residents want to ensure these newly discovered sources are supplementing existing water sources if a drought should occur.
Aitutaki mayor Tekura Bishop says he is pleased to have had members of Infrastructure Cook Islands, the Aitutaki Island Council, and SPC “help to find a more reliable source of fresh water, especially during times of drought when our community struggles”.
Water Works Division supervisor Tukua Upokomanu says the results are promising.
“We will now need to drill these targets and carry out pumping tests to confirm the extent and usefulness of the freshwater for the community”.
ICI’s Secretary Ngametua Pokino says he is “keen to explore further opportunities for the same work to be extended, especially for those islands that require the drilling of groundwater boreholes as their main water source”.
Sinclair says the next step is sending a drilling rig to Aitutaki for further investigations. He says there are plans to conduct similar research in Mangaia, Atiu, and Mitiaro.