DFDP-2 GEOTHERMAL DISCOVERY IN WESTLAND, NEW ZEALAND

Abstract

Boreholes drilled as part of the Deep Fault Drilling Project (DFDP) reveal a geothermal system in the hanging-wall of the Alpine Fault. The DFDP-2B discovery of 100°C water at 600 m depth beneath farmland adjacent to State Highway 6 near Whataroa has led to local interest in geothermal energy, and whether other Westland valleys also have resource potential. The hot temperatures are caused by a combination of fault slip, which moves rock and heat from depth, and topographically-driven fluid flow through fractured rocks that concentrates heat into valleys. Additional technical work is required to assess the size, quality and safety of the geothermal system, but the discovery provides an exciting opportunity for regional development based on clean sustainable energy that can directly leverage existing plant and people employed in a mining industry that is in long-term decline.