We directly experience higher tides and more frequent storms, which bring salt-water intrusion and coastal flooding. We have long periods of drought, an endangered supply of fresh water, and bleaching of the coral reefs that cradle our islands. The islands and atolls of Kiribati have limited ground water lenses. Potable ground water in wells has traditionally supplied water for the population but this supply has been failing as a direct result of climate changes that are being experienced. The coral limestone, which supports atolls, is porous and allows seawater to flow through it. The water table oscillates on a daily basis with the tides, and in the long term with the mean sea level. As sea levels have risen, many wells have become contaminated with salt water and can no longer be used. The ground water supply in South Tarawa is dependent on the size of the land area and as this diminishes as a result of rising sea levels and coastal erosion, so does the size of the water lens. Read this case study about drilling for water in Kiribati.
Traditionally there have been two seasons in Kiribati—“Aumaiaki”, the dry season from April to September, and “Aumeang”, the rainy season from October to March. But in recent years the country has experienced unusual and extreme drought-like conditions, even during what has traditionally been the rainy season. As a result rainwater catchment has been greatly reduced. The net result of these factors mean that the water supply in Kiribati falls short of the recommended WHO standard of 50 litres per person per day.