Located in Mount Gambier, the Blue Lake is a volcanic crater made of porous limestone. It contains a considerable amount of groundwater – around 36 gigalitres – which seeps through the limestone from local aquifer systems.
Amanda Lewry, the general manager of sustainable infrastructure at SA Water, said that the bores will help determine how the lake interacts with the surrounding groundwater network.
“Water is fundamental to the economic and social prosperity of our regions, and we’re taking action to adapt to climate change by exploring how we can potentially augment Mount Gambier’s sources to secure ongoing reliability and support further growth in the regional centre,” she said.
“The Blue Lake is Mount Gambier’s main source of drinking water, and we’re currently using around 3.5 gigalitres each year to supply local homes and businesses.
“While its supply remains steady, we’re proactively looking at diversifying our sources for future generations.”
An eight-metre-high drilling rig has already been deployed to the lake, while will establish three observation bores . These bores will be 15 centimetres in diameter and 150 metres deep, and they will enable SA Water to collect data about the geology, chemistry and groundwater flow of the Blue Lake. This information will then be used to inform modelling of the aquifer system.
The drilling rig will also extract soil samples for evaluation, and install bore casing pipes to allow for long-term access to the groundwater samples.
“Once we’ve analysed the data, we’ll be able to build a comprehensive model of the groundwater network and explore potential options to supplement Mount Gambier’s water sources,” Lewry said.
As the lake is a popular tourist destination, Lewry has confirmed that the drilling will not take place during holiday periods, to minimise the impact on the local community.
For more information visit the SA Water website.