Snowy Precipitation Enhancement Research Project

NewsFlash

The outcomes of a major scientific research project, recently tabled with the NSW Government, has shown that cloud seeding can increase snowfalls by 14%.

To view the media release please click here

Background

Cloud seeding is a weather modification technique which involves the introduction of a seeding agent into suitable clouds to encourage the formation and growth of ice crystals or raindrops and, in turn, enhancing the precipitation falling from the cloud.

The terrain of the Snowy Mountains region of New South Wales and the prevailing meteorology during the winter months offers significant potential for cloud seeding.  This potential was recognised more than fifty years ago, with study undertaken by the CSIRO and the Snowy Mountains Hydro-electric Authority over the years 1955 to 1959.

This research reported a 19% increase in precipitation for those storms that were seeded.  The outcomes were challenged however because of issues relating to scientific conduct, and the evaluation and interpretation of the results.

Some limited studies on cloud seeding potential occurred during the 1970's and 1980's, however no cloud seeding was undertaken.  In 2003, an independent Expert Panel was commissioned to investigate any environmental issues associated with cloud seeding.  The Panel subsequently reported to the NSW government that cloud seeding "...would be unlikely to have a significant adverse impact on the environment".

The Snowy Precipitation Enhancement Research Project ("SPERP") commenced in 2004, following passage of the Snowy Mountains Cloud Seeding Trial Act 2004 (NSW) (the "Act")  This legislation authorised Snowy Hydro Limited to undertake a second cloud seeding trial over a target area of approximately 1000 km2, with a trial duration of six years.  It also mandated that cloud seeding experiments could only be "...carried out at a time when increased precipitation in the target area is likely to fall as snow" rather than rain. In 2008, the NSW Government approved an expansion of the program in area and duration.

The SPERP was designed specifically to answer the question "can cloud seeding be used to increase snowfalls in a cost effective way, and without any significant adverse environmental impacts".  Considerable effort went in to ensure the serious deficiencies associated with the 1950's trial were comprehensively addressed so that the results could be relied on, and accepted with confidence.

These measures included a formal experimental design and evaluation plan, setting out the methods for analysis and criteria for success - published and publicly available in advance of the evaluation of the trial.  At the operational level, procedures were developed to ensure that every cloud seeding experiment - without exception - was undertaken in accordance with the design.  Most importantly, the evaluation of the trial outcomes was to be undertaken independently of Snowy Hydro Limited.

There was also a comprehensive environmental management and monitoring plan developed in collaboration with experts from the NSW Department of Environment and Climate Change, with outcomes reported to the NSW government each year.

To view the "Cloud Seeding Program"  video click here

The SPERP 2009 Annual Report Executive Summary can be viewed at:

SPERP 2009 Annual Report Executive Summary | PDF File 1.2Mb