Groundwater levels in Australia's Limestone Coast, a rich agricultural region known as the Green Triangle, are rapidly declining due to decades of over-extraction and reduced rainfall. This long-term decline is impacting popular diving sites like Kilsby sinkhole and Little Blue Lake, which are experiencing significant water level drops and quality issues (algae blooms, waste). Ramsar-listed wetlands like Piccaninnie and Ewens ponds are also affected, with reduced flows and closures. The situation threatens agricultural output, wildlife, and local tourism, prompting calls for an independent review of water use data and a moratorium on new bores.
That sinking feeling: Australia’s Limestone Coast is drying up
South AustraliaAustraliaVictoriaEnvironmentWaterFarmingDivingSwimmingDroughtSouth Australian politicsRural AustraliaPollutionWasteTrees and forestsWetlandsConservationBirdsWildlifeIndigenous AustraliansAustralian politicsTourism (Australia)Climate crisis
AI Summary
TL;DR: Key points with love ❤️Groundwater levels in Australia's Limestone Coast, a rich agricultural region known as the Green Triangle, are rapidly declining due to decades of over-extraction and reduced rainfall. This long-term decline is impacting popular diving sites like Kilsby sinkhole and Little Blue Lake, which are experiencing significant water level drops and quality issues (algae blooms, waste). Ramsar-listed wetlands like Piccaninnie and Ewens ponds are also affected, with reduced flows and closures. The situation threatens agricultural output, wildlife, and local tourism, prompting calls for an independent review of water use data and a moratorium on new bores.
Trending- 1 1900s: South Australia experiences one of the driest years on record
- 2 1970s: Water flows at Piccaninnie and Ewens reduced (62% and 25% respectively)
- 3 1985: Bool and Hacks lagoons earned Ramsar status
- 4 1993: Consistent decline in groundwater wells observed
- 5 Mid-1990s: Groundwater levels in heavily irrigated areas decline
- 6 Late 1990s: Mosquito Creek began to dry up
- 7 1998: No official report to Ramsar on Bool and Hacks lagoons since this year
- 8 2004: Overall scheme of management for water allocation has not changed significantly since this year
- 9 2009: SA Department report found forests cut water recharge significantly
- 10 2012: No report on Piccaninnie Ponds to Ramsar since this year
- 11 2013: Plan to reduce water allocations in high-risk areas recommended
- 12 2018: Steven Marshall's Liberal state government blocked changes to water allocations
- 13 2019: Independent review published, confirming "catastrophic consequences" to lagoons and springs; Landscape Board set up
- 14 2020: Picanninie and Ewens listed as nationally endangered ecosystems; Conservation advice provided to federal government
- 15 2022: Piccaninnie Ponds closed
- 16 January 2025: Water levels at Kilsby sinkhole dropped 1.5 metres (between Jan-March); Little Blue Lake buzzing with swimmers; Portable toilet installed at Little Blue Lake; Dr Richard Harris conducted dive at Piccaninnie
- 17 February 2025: Snorkelling and diving at Ewens Ponds suspended
- 18 December 2027: Water allocation plan not due to be updated until this month
- Plunging groundwater levels
- Drying up of sinkholes and wetlands
- Compromised water quality (algae blooms)
- Closure of dive sites (Piccaninnie Ponds, Ewens Ponds)
- Risk to agricultural output (dairy businesses)
- Threat to wildlife (migratory birds)
- Increased risk for divers/swimmers due to lower water levels
- Endangered ecosystem listing for Picanninie and Ewens
- Slow regulatory response
What: Groundwater levels are plunging, causing sinkholes and wetlands to dry up and water quality to decline.
When: Long-term decline since 1993, worsened by one of the driest years on record since 1900. Water levels dropped 1.5 metres between January and March 2025 at Kilsby sinkhole. Piccaninnie Ponds closed since 2022. Snorkelling and diving at Ewens Ponds suspended in February 2025.
Where: Limestone Coast, Green Triangle region, straddling the border between South Australia and Victoria, Australia. Specific locations include Kilsby sinkhole (south of Mount Gambier), Little Blue Lake (south of Mount Gambier), Piccaninnie Ponds, Ewens Ponds, Bool and Hacks lagoons (north of Mount Gambier), and Mosquito Creek.
Why: Decades of over-extraction of groundwater, declining rainfalls, intensive irrigation, forestry developments (blue gum and radiata pine plantations), agricultural runoff, wastewater, and waste from visitors. Regulatory response has been slow.
How: Over-extraction and reduced rainfall directly lower groundwater. Forestry plantations and intensive irrigation consume large amounts of water. Agricultural runoff and visitor waste introduce excess nutrients, causing algae blooms and compromising water quality. Regulatory inaction (e.g., blocking water allocation cuts) exacerbates the problem.