Three observation bores will be installed by an eight-metre-high drilling rig at the Blue Lake, Mount Gambier, to support the investigation into the South East’s drinking water.
Located outside the site’s reserve, the bores, which are 15cm in diameter and around 150m deep, will enable SA Water to collect vital data about the Blue Lake’s geology, water chemistry and groundwater flow, informing comprehensive modelling of the aquifer system.
The drilling rig, located on the southern side of the lake, will extract soil samples to help the utility analyse the different layers and geological material, with bore casing pipes installed for long-term access to sampling groundwater.
SA Water’s General Manager of Sustainable Infrastructure, Amanda Lewry, said the study is the final piece of the puzzle in understanding the interaction between the Blue Lake and 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,” Ms Lewry said.
“The Blue Lake is Mount Gambier’s main source of drinking water, and we’re currently using around 3.5GgL each year to supply local homes and businesses.
“While its supply remains steady, we’re proactively looking at diversifying our sources for future generations.
“Our observation bores provide a vital insight into the flow of groundwater out of the Blue Lake, the geology of the lake’s southern side and mineral composition of the water, expanding on our existing knowledge of the site while factoring in climate change and population growth scenarios.”
For around four weeks, the crews will be located near the southern rim of the lake collecting soil formation samples, observing and recording the changes in depth and geology of the site.
The crews will also be collecting groundwater samples over the next six weeks and taking them back to the laboratory in Adelaide for detailed analysis.
“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.
“Involving the local community in our planning will be essential to enhancing the region’s water security, and we look forward to progressing the conversation by sharing our concepts and ideas in the near future,” Ms Lewry said.
The Blue Lake is a volcanic crater that contains groundwater from local aquifer systems, which seeps into the crater through porous limestone to create a lake around 36GL in capacity.
Ms Lewry said the bore drilling was planned outside of the summer school holiday period to minimise any impact to the local community and tourists.
“We understand the Blue Lake is one of the region’s most iconic tourist destinations, and that’s why we worked together with the local council to plan this important work outside of peak tourism periods,” Ms Lewry said
“The size of the bores and specialised equipment we’re using will also ensure we maintain a light footprint and protect the surrounding environment while drilling.”