High Quality Content by WIKIPEDIA articles! Waimangu Volcanic Rift Valley is the hydrothermal system created on 10 June 1886 by the volcanic eruption of Mount Tarawera, on the North Island of New Zealand. IT encompasses Lake Rotomahana, the former site of the Pink and White Terraces. IT was the location of the Waimangu Geyser, which was active from 1901 to 1904.WAimangu means 'black water' in M ori, the indigenous language of New Zealand. THis name comes from the water that was thrown up by the famous Waimangu Geyser, which was black with mud and rocks.THe valley is home to a population of wallaby and Black Swan, which according to local guides were introduced to the region from Western Australia by George Edward Grey in the 19th century.