Protecting Wilderness and National Parks

Briefing on Cloud Seeding on Kosciuszko National Park

Who is Snowy Hydro and what are they doing?

Snowy Hydro Ltd (SHL) is jointly owned by the Commonwealth (13%), NSW (58%) and Victorian (29%) governments.

In 2004 SHL secured legislation allowing a six year “trial” to increase snowfall by seeding winter storms with silver iodide from 12 pairs of ground based generators. The “target area” is 1,000 square kilometres surrounding the Main Range of Kosciuszko National Park. The trial area includes the Mt Kosciuszko, the catchments of Australia’s only mainland glacial lakes and the Western Fall Wilderness Area (west of the Mt Kosciuszko summit).

SHL claims that this trial will increase snowfall by 10%; produce 70 gigalitres of water per year; and generate an extra 130 gigawatt hours of electricity. In 2007 the Natural Resources Commission reported that despite $20 million of public money spent, the trail 'does not provide any evidence to support claims of increased snowfall caused by cloud seeding'. The Commission found that SHL's monitoring 'cannot scientifically prove whether or not cloud seeding causes environmental impacts'.

The Trail should be halted due to unknown impacts on the park and poor design. A trial over a larger area was proposed by SHL in 1993 and in 2007 SHL sought expansion into the Jagungal Wilderness. SHL is trying to talk up more cloud seeding achievements to secure contracts from water authorities desperate for rain.

Is the trial legitimate?

  • The current trial required special legislation as it does not comply with existing environmental laws. SHL bypassed the need for approvals from NSW Fisheries, Department of Environment and Conservation (DEC) or Department of Infrastructure, Planning and Natural Resources (DIPNR). No environmental impact or threatened species impact assessment has been carried out. The proposal still would have been an illegal activity within the national park and wilderness area, even if these approvals were granted.
  • The legislation sets a very dangerous precedent for undertaking proposals without environmental impact assessment in one of Australia's the most environmentally sensitive areas of national park.
  • The enabling legislation overturns the National Parks and Wildlife Act 1974; Wilderness Act 1987; Fisheries Management Act 1994; Threatened Species Act 1995; Local Government Act 1993; Protection of the Environment Operations Act 1997; and Environmental Planning and Assessment Act 1979.

Kosciuszko National Park – Internationally recognised

  • Fulfils the criteria for World Heritage listing
  • A UNESCO Biosphere Reserve (United Nations Educational, Scientific and Cultural Organisation)
  • A world centre of biodiversity (World Conservation Monitoring Centre)
  • Blue Lake is listed under the Ramsar Convention as a wetland of international importance.

Independent Scientific Committee on Kosciuszko National Park

  • An Independent Scientific Committee (ISC) provided a report to the NSW Government as part the Kosciuszko National Park (KNP) Plan of Management (PoM) process. All papers in the report were peer-reviewed maximise academic standards and objective assessment.
  • Despite the knowledge that the SHL cloud seeding proposal was imminent, the Government did not ask the ISC to comment.

ISC Findings: significance of Kosciuszko National Park

  • One of the few large protected areas remaining in temperate Australia where ecological processes can still occur without significant human intervention.
  • Has nine wilderness areas recognised under NSW wilderness legislation, which constitute 346,257 hectares (50.15%) of the park; and which are significant at national and international levels as part of the Australian Alps wilderness
  • Includes alpine areas that are of international significance
  • Protects 204 species of alpine flowering plants, including at least 21 species that are endemic and 33 that are rare
  • Includes subalpine ecosystems that provide habitat for a number of rare animal species (e.g. mountain pygmy-possum in Podocarpus heath and corroboree frog in sphagnum bogs)
  • Has probably the most outstanding development of subalpine treeless flats and valleys in the world
  • Includes populations of thirteen vertebrates that are listed as threatened or near threatened by the World Conservation Union (IUCN), including the endangered mountain pygmy-possum

ISC Findings: existing Pressures on the Alpine and Subalpine Areas of KNP

  • While all areas of the Park are under threat, the alpine and subalpine areas are the most vulnerable to increased pressures from tourism and recreation activities and facilities, mainly for commercial purposes.
  • A planned management response to climate change based on the conservation of the park’s values is needed.

Uncertainties of cloud seeding methodology

  • While clouds across the globe have been seeded for 60 years to increase rainfall and reduce hail, there is no scientifically credible proof it works -“there is still no convincing scientific proof of the efficacy of intentional weather modification efforts.”3
  • Dakota Atmospheric Resource Board director Darin Langerud has stated "If you hold it to ... scientifically credible proof, it is true that a lot of aspects of cloud seeding have not met that standard.” 4
  • Precipitation augmentation through cloud seeding should not be viewed as a drought relief measure. Opportunities to increase precipitation are usually few, if any, during droughts; consequently the cost of mounting a cloud-seeding operation will far exceed the benefits that may be obtained. 5 Cloud seeding is not the answer to ending a drought because the clouds have to be there to seed. "You can't make it rain out of a clear, blue sky," Langerud said. 4
  • There are some indications that precipitation can either increase or decrease some distance beyond intended target areas (5) In the early 1990s, Montana farmers worried that cloud seeding over eastern Montana was stealing their rain. The Montana Legislature passed a law requiring an environmental study and a $10 million bond before any cloud seeding could take place, effectively putting a stop to cloud seeding in 1993. (SHL has admitted in a media release (011203): “The atmosphere is a dynamic system and does not behave in a simplistic manner”)6. There will be many people in the Park region that would have serious questions about what this trial will mean for them and their livelihood, particularly those in existing rainshadow areas.
  • It has been concluded in the US that careful attention should be paid to negative effects to the mountain and aquatic environment, long-term effects on the macroclimate, flooding and erosion. Some sensitive areas have required suspension of the activity 7.
  • Snow dependant animals, such as the Mountain Pygmy Possum, will suffer if increased precipitation falls are rain, not snow.


  • It is recognised that large protected areas such as KNP will become increasingly important as biological refugia 2.
  • For the Mountain Pigmy Possum, Burramys parvus, “the main threat in NSW is loss and fragmentation of habitat, mostly associated with the ski resort industry” e.g. winter snow grooming, building and road construction 8. More effective and more certain methods exist if we want to increase the chances that species such as Burramys survive. It is easier to reduce the impacts of the ski resorts. The ecological footprint of the ski resorts needs to be reduced.
  • Water that already exists in our dams should be treated as a scarce commodity. As such all components of its collection, transport and use should be analysed to minimise wastage and maximise reuse.
  • The efficiency of electricity use must be maximised and it’s wastage minimised.

Possible Impacts of elevated levels of silver due to cloud seeding

  • The silver iodide used in cloud seeding causes elevations in atmospheric silver concentrations.
  • Silver concentrations in precipitation resulting from seeding clouds with silver iodide were 10-4,500 nanograms per litre compared with concentrations of 0-20 nanograms per litre without cloud seeding (Cooper and Jolly 1970).
  • Human sources of atmospheric silver, such as cloud seeding, may be responsible for the enrichment of silver by factors of 326-355 over its average concentration in the earth's crust (Struempler 1975).
  • Silver is one of the most toxic heavy metals to freshwater micro-organisms, both plants and animals 9.
  • Silver becomes adsorbed onto humic complexes and suspended particulates; and incorporated into, or adsorbed onto, aquatic plants and animals. The most sensitive organisms are phytoplankton, and the embryos and larvae of animals, including the tadpole stage of the frog life cycle 9.
  • Any increased silver in the region is of serious concern for the endangered Southern Corroboree Frog because of frogs’ high sensitivity to toxins.
  • Silver is more bioavailable under conditions of low anion concentrations, low levels of reactive sulfide or sulfur containing ligands, low concentrations of organic ligands (humates), lower suspended sediment and lower pH. A number of these conditions apply to, at least, the Kosciuszko alpine lakes 2 and it is therefore of concern that silver will impact on plants and animals in the lakes.
  • Silver is a genotoxin i.e. capable of forming genetic mutations (It binds with DNA and can cause DNA strands to break and affect replication) 9.

Prepared by:
Colong Foundation for Wilderness
National Parks Association of NSW

2. Independent Scientific Committee, 2004, An assessment of the values of Kosciuszko
National Park
3. The National Academy of Sciences (US), 2003, Critical issues in Weather Modification
4. CNN 12 11 03
5. American Meteorological Society Policy Position,1998, Planned and Inadvertent Weather
6. Snowy Hydro Media Release 011203: Cloud seeding – robbing Peter to pay Paul” is a
common misconception
7. Colorado Water Conservation Board, 2003, Wintertime Weather Modification Report Fall
2002 - Spring 2003
8. NPWS Threatened Species online: KNP (
9. Ministry of Environment, Lands and Parks Province of British Columbia, Water Quality
Branch Environmental Protection Department Victoria, BC February, 1996, P. D.
Warrington, Ph.D, R. P. Bio, Ambient water quality criteria for silver,
10.Knight Ridder Newspapers, 171203 , Attempts to make it rain may not work, study says