Geographic Information System (GIS) as a basis for the next generation of hydrogeological models to manage the geothermal area Waiwera (New Zealand)

The geothermal hot water reservoir below the small town of Waiwera in New Zealand has been known to the indigenous Māori for many centuries. Overproduction by European immigrants led to a water level decrease and consequently artesian flow from the wells and the seeps on the beach ceased. The Te Kaunihera o Tāmaki Makaurau Auckland Council established the Waiwera Thermal Groundwater Allocation and Management Plan to allow the geothermal system to recover. For a sustainable operation, the management regime can be informed by hydrogeological models based on monitoring data. The underlying geological model has been revised according to field observations and an existing numerical model transferred to the newly developed software package TRANSPORTSE. Monitoring and digitally derived data have been integrated in a geographic information system (GIS).