Managed Aquifer Recharge trial complete
Managed Aquifer Recharge (MAR) is Bunyip Water's strategy for balancing flows available in winter with demand in summer. Water will be temporarily stored in an existing underground aquifer which is a thick layer of water-bearing sandy material extending from about 40m to 90m below ground.
A well 60m deep was drilled and developed ready for MAR. Initially 60 ML of groundwater was pumped into the aquifer from a well 6km away to observe the increase in water level. After 30 days of carefully controlled injection to meet the stringent conditions of approval, the water level did not reach the surface. Most MAR wells in SA require high pressure to inject water into the aquifer, so the results were very pleasing and almost exactly as predicted by modelling.
After injection, some water was recovered using a submersible pump to test the drawdown effects. Data loggers were inserted in neighbouring wells as far as 4.6km away. The results will be analysed by hydrogeologists Australian Water Environments so they can update their models and predict the fate of the water with high certainty. This is part of the MAR approval process administered by EPA and DEW.