Although there are no watercourses on Niue, a ‘lens’ of fresh water lies about 60 metres below the rim of the central plateau. This groundwater is tapped by a series of bores and is the island’s main source of water. Households have tanks in which they store the rain that falls on their roof.
Groundwater is replenished by rainwater. It seeps quickly through the thin layer of topsoil and down through the cracks and cavities in the underlying limestone rock. In so doing, it has sculpted huge caverns and caves, which define the island.
Caves in the centre of the island often contain pools of fresh water. Along the coast, springs of fresh brackish water leak out from the base of the cliffs. There are also many caves along the coast line and small coves, rather than the sandy beaches typical of Pacific islands.
Sources: Niue by Charles Cooper. Reed Children’s Books, 2000. ISBN 18694884 and National Biodiversity Strategy And Action Plan Of Niue, Government of Niue 2001