Abstract:
The Waikite thermal valley is located in the centre of the Taupo Volcanic Zone (TVZ) of New Zealand about 25 km to the south-east of Rotorua city. Many natural thermal springs At Waikite discharge near-boiling water along the local NE-SW Paeroa Fault in what appears as a fault-dominated high-temperature two-phase geothermal system. Current hypotheses suggests that Waikite thermal futures are an extended outflow of the nearby Waiotapu geothermal system. However, more recent assessment indicates that Waikite is an isolated liquid dominated hot water (<220 °C) system or simply another smaller upflow from Waiotapu. In both settings the Paeroa Fault simply provides access to the outflowing geothermal fluids to reach the surface at near-boiling temperature. The natural thermal springs have a unique mineral deposition of lilypad-shaped formations that extend over the water surface. They consist of mainly calcite crystals, and are not found elsewhere in the high-temperature systems of the TVZ.
The Waikite thermal valley is known for its thermal bathing facility. Hot mineral water is channeled from one of the near-boiling discharging natural springs under gravity into a long man-made terrace to cool by evaporation. Additionally, fine temperature control is provided through controlled spraying some of the mineral water into the air using a small pump. At the end of the terrace, the mineral water flows into six hot pools and baths. It is also used in a heat exchanger for heating fresh water for the showers, bathrooms and kitchen. The used thermal water is discharged into the hot Otamakokore Stream, which it would naturally flow to. This eventually flows into the Waiotapu Stream, which is also naturally geothermally-influenced, and then to the Waikato River.