Funding source: Snowy Hydro Limited

The Snowy Mountains Hydro-electric Scheme, built in the second half of the 20th century, was a visionary power generation and drought mitigation venture of a scale never before constructed in Australia. It remains one of the civil engineering wonders of the modern world.

Its complex infrastructure of integrated trans-mountain tunnels and power stations collects and stores rain and snow from Australia’s Southern Alps, then diverts the water to irrigate farms along the Murray and Murrumbidgee Rivers. It also supplies 4,500 gigawatt hours of electricity each year for eastern mainland Australia (32% of the grid’s renewable energy).

But what of the future? How will climate change impact on the Scheme’s capacity to continue playing a vital role in Australia’s national economy?

Snowy Hydro is benefiting from innovative UQ-based research which aims to understand how different climatic conditions affect the amount of water that flows into the Snowy Scheme. The knowledge gained could promote more efficient water management, particularly in extreme dry or wet years.

Professor Hamish McGowan and his team believe that improving the accuracy of river system inflow prediction will help agricultural and hydropower generation managers plan for more efficient water usage in both the short and the long term.

The researchers are collecting stable isotope signatures from precipitation events in the Snowy Mountains. These samples are compared and matched with stable isotopes of previous rain and snowfall events (preserved in stalagmites) to compile an extensive history of weather patterns for the region. Each signature reveals the type of weather that occurred at a particular time, as well as the air temperature changes which may have influenced evaporation and snow melt.

Reconstructing a high-resolution and long-term climate record from stalagmites will enhance understanding of long-term cyclic patterns, and help predict how future climate patterns might impact on the hydrology of the Snowy Mountains.

This research will help optimise the use of precious water from the iconic Snowy Mountains Scheme, and protect the region’s $3 billion annual agricultural output while continuing to power up south east Australia with renewable hydroelectric electricity.