From 2004 to 2012, Snowy Hydro Pty Limited conducted a cloud seeding trial in the Snowy Mountains to understand whether cloud seeding can increase snowfall in this area.
During this period, the Snowy Mountains Cloud Seeding Trial Act 2004 (the Act) required the Natural Resources Commission (NRC) to supervise authorised cloud seeding trial operations and report on the environmental impacts of those operations to the relevant Ministers. Details of the advice the NRC provided to the Government on the trial is set out below.
In September 2012, the Government announced that the trial would end and cloud seeding would become fully operational. It made legislative changes, including requirements for Snowy Hydro to carry out cloud seeding operations in accordance with an environmental management plan approved by the relevant Ministers, and review of cloud seeding operations by the Environment Protection Authority.
|Our advice on the cloud seeding trial
In 2012, we reviewed the Snowy Precipitation Enhancement Research Project (SPERP) Annual Report 2011 and provided advice to the Ministers.
Our review found that the trial continued to comply with the Act and there was no evidence of the trial having adverse environmental impacts or adverse impacts on rainfall in down-wind areas.
In response to one of our recommendations from the mid-term review, Snowy Hydro commenced a three-year research program in December 2012 to determine the fate of cloud seeding agents in the environment, specifically silver iodide and indium trioxide. The research program, and discussion and analysis of the study are scheduled for completion in 2014. We recommended vigilant monitoring of the research program to ensure it meets the research objectives.
2012 advice on cloud seeding trial (July 2012)
In 2010, we conducted a mid-term review of the trial that covered the first phase (2004 to 2009) of the trial.
Our review was based on 2009 SPERP Annual Report which included analysis of the results of its environmental monitoring program for the first phase.
Our review found that:
- the trial was being conducted in compliance with the Act and is of a high scientific standard
- there was no evidence of the trial having any adverse environmental impacts, including adverse impacts on rainfall in down-wind areas, over the first phase of the trial
- there was evidence that cloud seeding increased snowfall in the target area, under defined weather and operating conditions, over the first phase of the trial.
A key uncertainty identified by us was the transport and potential long-term accumulation and impacts of cloud seeding and tracer agents. We recommended that Snowy Hydro investigate the ultimate fate of these chemicals over the next phase of the trial. We also suggested that Snowy Hydro study the likely impact of climate change on the conditions for cloud seeding to be effective in the future.
Previous reports to Government