Where does the wai come from?

The spring water we know as Bullock Creek first makes its way down from Cardrona, filtered through the Wānaka-Cardrona aquifer, which is found in the Cardrona Valley between the Criffell and Cardrona ranges. This aquifer also regulates groundwater locally and affects some parts of the Ōrau Cardrona River during summer, and eventually flows into the Mata-au Clutha River and Lake Wānaka. This same aquifer also discharges (as it does at Bullock Creek Hatchery Springs) at springs around Albert Town, Lakeside Drive and Ripponlea, as well as numerous human-made bores and wells.

An aquifer is the body of water that has soaked through the ground, through the gravel, sand and rocks, and settled underground; also known as groundwater, aquifers take on water in areas known as recharge areas, as opposed to discharge areas, mentioned above.

Geologically, the river and glacial gravel and sedimentation associated with the Wānaka-Cardrona aquifer is a mix of the Pleistocene and Holocene rock, ageing them from the present day up to 2.5 million years old!

The quality of the water that we have at Bullock Creek is wholly dependent upon the types of rock contained within the aquifer but is also impacted directly by human activity. For example, leaching of chemicals and fertilisers used in farming can find their way into the aquifer as well as wastewater run off from urbans areas which can contain microbial pathogens, ultimately ending up in Bullock Creek and Lake Wānaka, for example.

Water quality studies and monitoring is important to understand the risks to water quality and to mitigate them. A number of local organisations and council departments provide this data, and also encourage members of the public to report water quality issues. WAI Wānaka and Otago Regional Council can be contacted for further information; to report water quality issues call ORC on 0800 800 033 or go to this website: https://www.orc.govt.nz/environment/report-pollution/