Recharge in Wairakei Geothermal Field for 1974-1983

Abstract

Repeat gravity measurements show that over the'whole field there has been net mass loss 100%recharge) for the period b yearly 1983 at i v e loss from the field was about 1450 x 10 and recharge about 1100 x kg. significant net mass loss of about 7 x occurred in an area west of the main production borefield and an approximately equal net mass gain occurred in the eastern part of the borefield. is the first time that a net mass gain has occurred anywhere in the field since began. The area in which this gain occurs roughly corresponds to an area in which shallow groundwater levels have dropped by up to 10 in this period, but is not centred on the area of greatest ground subsidence.