Ngawha geothermal field

 

Key Statistics

 Resource Temperature   228°C
 Maximum Measured Temperature   301°C
 Number of Wells   3 Production
5 Reinjection
2 Other
 Typical Well Depth   1km
 Maximum Well Depth   2.3km

 

The Ngawha geothermal field is the only high temperature geothermal resource in New Zealand, outside the Taupo Volcanic Zone and is thought to be between 20 and 40km2 in area.

It has few natural surface features, apart from the springs adjacent to Ngawha Springs Village which, although modest in flow, are highly valued for their cultural and therapeutic properties. There are several lakes with geothermal inputs and also some soda springs.

The resource is characterised by very porous layers of rock beginning at about 600m below the surface, which are saturated with water and heated from below. This geothermal reservoir is sealed above by layers of solid cap rock, which allows considerable pressure and temperature to develop as the water is heated. Geothermal brine and gas move through fractures in the cap rock to reach the surface.