Water in New Zealand and are of varying types and origins. Many of the lakes in the central North Island area are volcanic crater lakes, while the majority of the lakes near the Southern Alps were carved by glaciers. Hydroelectric reservoirs are common in South Canterbury, Central Otago and along the Waikato River. Over 180,000 kilometres of rivers has been mapped in New Zealand, the longest being the Waikato River with a length of 425 kilometres and the largest river by volume is the Clutha River with a mean discharge of 533 cubic metres per second. New Zealand has many notable waterfalls, some of
Ashley River (New Zealand) mountains in the west Lees Valley adjacent to Island Hills station and exits the hills at a gorge near Oxford township. It has tributaries of Duck Creek in this valley and is an accumulator of watershed between Lees Valley and Oxford township. Behind Waikuku Beach is one of the largest, least modified estuaries in New Zealand. It is abundant in bird life, including the wrybill ("Anarhynchus frontalis") and Black stilt ("Himantopus novaezelandiae"). Many migratory birds over-winter here. Ashley River (New Zealand) The Ashley River / Rakahuri is in Canterbury Region of New Zealand. It flows generally southeastwards for before entering