Do Natural Thermal Features Recover from Field Testing?

Abstract

Production from a geothermal field may damage natural thermal features and some environmentalists object to the field even being tested, on the grounds this might permanently damage the features. Two examples are given where natural features have recovered after small-scale mass withdrawal has been stopped or curtailed. During a 4-year test of the Ohaaki Field (up to 27 the water level in Ohaaki Pool fell by 9.5 m, but recovered naturally over a period of about 10 years after testing stopped. In the 1960sand many natural features in Rotorua declined due to increased mass withdrawals (up to 31 from the shallow hot water aquifers. Since starting a programme of well closures in 1986 and increasing the amount of reinjection, the net mass withdrawal has decreased by about and some of the natural features have been rejuvenated.