NIWA has mapped the Waiwhetu Aquifer, a crucial drinking water source under the Hutt Valley and Wellington Harbour, for the first time. The aquifer releases freshwater from the seabed through natural springs.
Dr Joshu Mountjoy, NIWA Marine Geoscientist, led the study. He highlighted that 70% of Wellington’s water comes from this aquifer. The study aimed to locate where freshwater was emerging from the seabed, essential for emergency planning, given Wellington’s earthquake risk.
Instead of expensive drilling, NIWA used various tools like acoustic measurements, seafloor samples, and seawater sampling to find and study these springs. They recorded freshwater flowing from many pockmarks in the Harbour, some over 100m wide.
This research will help in managing the aquifer for drinking and can be used to study other areas like Marlborough and Canterbury. Dr Mountjoy stressed the importance of understanding such aquifers globally, especially for countries facing water shortages.