The major thermal areas of Tauhara field are situated around the town of Taupo, about 8 km from the Wairakei production borefield. Taupo, over 400 wells have been drilled to between 30 and 150 m depth, tapping the nearsurface hot water of Tauhara field for domestic heating. since the 1950's in both domestic wells and the hot springs of Tauhara field has failed to find evidence of a widespread decline in water level or near-2urface aquifer pressure. However, a significant increase in both temperature of the near-surface aquifer, and heat flow from thermal areas of Tauhara field has occurred since the mid-1960's. This has resulted in a spread of steaming ground and 3 hydrothermal eruptions on the outskirts of Taupo. A study of pressure changes in deep wells of Tauhara field suggests a decline of around 18 bars has occured at >400 m depth, due to exploitation at Wairakei. The deep reservoir pressure of Tauhara field is now about 7 bars higher than that of Wairakei field, and significant flow towards Wairakei production borefield is probably occurring. significant pressure drop in the surface aquifer of Tauhara field is due to the presence of low permeability lacustrine mudstone layers covering most of the field between 100 and 400 m depth. field has caused a steam zone to form beneath the mudstone layers, and this in turn has caused the increase in steam-heating or the surface aquifer.

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