Where does Auckland’s water come from?
Auckland’s water supply is obtained from three different types of sources; dams, rivers and from under the ground. The exact proportion of water supply from each source varies daily depending on the storage levels in the dams and the time of the year.
Dam water
Auckland’s dams are mainly located in two ranges: the Hunuas, and the Waitakeres which together supply around 80 percent of Auckland’s drinking water. The combined reservoir capacity of Auckland’s dams is over 100 billion litres.
River water
Auckland’s river water is sourced from three rivers: the Waikato River, Mahurangi River, and the Hoteo River. The Waikato River provided around eight percent of metropolitan Auckland’s drinking water needs in 2010/2011. The Mahurangi and Hoteo rivers supply Warkworth and Wellsford respectively.
Groundwater supply
Auckland’s groundwater supply comes from rain which percolates down through the soil or rock fractures, filling up the pores between sand grains or the fissures in rock. A small percentage of Auckland’s drinking water is sourced from groundwater supplies. There are a number of groundwater sources servicing the drinking water needs of local Auckland communities. These are located at Onehunga, Muriwai, Hamiltons Road (Algies Bay/Snells Beach), Pukekohe, Clarks Beach, Waiuku, Patumahoe, Puni, Bombay, Buckland, Glenbrook Beach, and Waiau Pa.