The Waikato River is the longest river in New Zealand. It runs for 425 kilometres from the eastern slopes of Mount Ruapehu, joining the Tongariro River system and emptying into Lake Taupo, New Zealand's largest lake. It then drains Taupo at the lake's north-eastern edge, creates the Huka Falls, then flows northwest, through the Waikato Plains. It empties into the Tasman Sea south of Auckland at Port Waikato. It gives its name to the Waikato region that surrounds the Waikato Plains.
The name "Waikato" comes from Māori and translates as "flowing water". (Full article...)