Saltwater Intrusion in Southern Eyre Peninsula: Report developed through the Eyre Peninsula Groundwater, Allocation and Planning Project

The Eyre Peninsula (EP) in South Australia is home to some 55,000 people, with an economy supported significantly by agriculture and aquaculture exports. A network of mains pipelines covers much of the region with the majority of this water being used for domestic consumption and stock watering. EP sources approximately 85% of its mains water from unconfined aquifers within the Quaternary limestone (Bridgewater) formation, the most significant resource being the Uley South Basin near the southern tip of the peninsula. Regional groundwater levels are heavily influenced by seasonal recharge, however the aquifers typically exhibit low hydraulic gradients due to high hydraulic conductivities. Many of the aquifers on the southern EP are in direct hydraulic connection with the sea, and the low hydraulic heads suggest a potential seawater intrusion threat, particularly during periods of low recharge.