What is cloud seeding
Cloud seeding is a technique that increases rainfall in a target area. Hydro Tasmania has been involved in both experimental and operational cloud seeding over Tasmania and mainland Australia since 1964. In this time we have developed a great deal of knowledge and expertise in the area.
Our cloud seeding operations
Our cloud seeding operations are conducted from 1 May to 31 October when conditions are suitable. Find out what we describe as ‘suitable conditions’ and more useful information about cloud seeding in our frequently asked questions (PDF 700KB).
Tasmania was facing unprecedented dry conditions at the beginning of 2016. This is why this year's cloud seeding season began one month early on 1 April. Cloud seeding in the right conditions can increase the amount of rain that falls over targeted catchments. Cloud seeding only occurs when the Bureau of Meteorology forecasts rain, and even then only if conditions are favourable for cloud seeding to be successful.
Our cloud seeding program has been on hold since 6 June 2016. It remains on hold while we review it and consult and we will not undertake seeding again this year.
We will not resume the program until there has been:
- a full internal review of the program, and implemetation of any appropriate improvements;
- and extensive engagement with stakeholdes.
During the 2016 season a total of 31 seeding flights were undertaken by Hydro Tasmania, with conditions suitable for seeding on 12 occassions. Multiple catchments were targeted on some cloud seeding flights.
View the cloud seeding summary for 2015.
View the cloud seeding summary for 2014
View the cloud seeding summary for 2013
We also keep detailed flight maps of the most recent flights and an archive of previous flights. Find out more >
Environmental concerns - test results
In April and November 2014 soil samples were collected at two different locations in each of the townships of Queenstown, Rosebery and Zeehan. Water samples were also collected from waterbodies or creeks in or near these townships. The samples were tested for acetone and dichlorobenzene as these two chemicals make up more than 95% of the cloud seeding solution. Neither chemical was detected in any of the samples. The test results can be viewed here.
In a typical year the amount of silver iodide released as a result of cloud seeding is less than half of one teaspoon per square kilometre.
View a video about cloud seeding which was produced as part of the ABC's Catalyst television program.