Why CWA is challenging the “big lake” plan at Yallourn
On 18 August 2025, the Concerned Waterways Alliance lodged its submission on EnergyAustralia’s draft Yallourn Declared Mine Rehabilitation Plan. Our primary message is simple: the Latrobe system is already in water deficit, and the Gippsland Lakes are under stress. Rehabilitation should heal that reality rather than create a permanent new demand for scarce water.
The draft plan leans heavily on a large pit lake to achieve stability, with new surface-water access to speed up filling. On paper, it looks straight forward: fill the hole, tidy the edges, wait for nature to settle. In practice, it shifts water away from rivers and wetlands that need it for baseflows and ecological recovery, while locking in ongoing evaporative losses. It also leaves big questions about the Morwell River Diversion which is effectively an channel perched between two large mining pits. It is an aging piece of infrastructure with a track record of issues and whose failure could see the river ultimately cut from the La Trobe River and draining instead into a terminal pit..
CWA’s submission asks for a different sequence. Start by minimising water demand: use backfill where practicable, design stable, dry landforms, cap and revegetate intelligently, and treat a lake (if any) as staged and conditional rather than the default. If water is truly needed, exhaust manufactured sources first (recycled, stormwater, fit-for-purpose options), and only then consider limited, climate-contingent access to surface water with transparent pricing that recognises opportunity costs and protects environmental allocations.
We’re also asking for stronger guardrails. Model whole-of-system hydrology and water quality under median and dry futures, including implications for the Lakes. Set conservative operating levels and triggers to protect baseflows and connected ecosystems. Publish methods, data and uncertainty. Rebuild or reroute the Morwell River Diversion so it’s genuinely climate-robust, and with a future measure in centuries rather than potentially decades. And put independent oversight and durable financial assurance in place for the long term.
This isn’t about saying “no” to rehabilitation; it’s about saying “yes” to a pathway that doesn’t drain Country to fix a mine legacy. With a precautionary, staged approach—and genuine alignment to the Latrobe Valley Regional Rehabilitation Strategy and the Central & Gippsland SWS—we can stabilise the site without sacrificing the rivers and wetlands that define the region.
Bottom line: rehabilitation should return water to life, not lock it away.