Early start to cloud seeding season paying off

Hydro Tasmania’s decision to bring forward this year’s cloud seeding season is paying off.

The cloud seeding season usually runs from May to October inclusive. As part of the Energy Supply Plan, the decision was made to start the 2016 season one month early.

“Historical information shows that there is a good chance of being able to undertake some cloud seeding activity during April. One week into the early season and that is being borne out,” said Gerard Flack, Director Wholesale Energy Services.

“Since the early start of the season on 1 April, two cloud seeding flights have been undertaken (on 2 and 5 April). Two more flights are scheduled for today (Friday 8 April), one in the morning and one in the evening. These activities are contributing valuable inflows to hydro storages.”

Over the past week, Hydro Tasmania has seeded over the Gordon and Upper Derwent catchment areas, which include lakes Gordon, Pedder, St Clair and King William.

Cloud seeding only occurs when the conditions are suitable; we can’t make it rain if there are no clouds.

“A successful cloud seeding operation in Tasmania will make it rain a little harder for a little longer than would have occurred naturally,” Mr Flack said. 

“While the benefits of seeding are not precisely quantifiable, there’s no question that any additional inflows to our catchments are welcome, as we continue to manage this unprecedented and challenging situation.”

Research by Monash University found a consistent increase of at least five per cent in monthly rainfall over seeded catchment areas.

Tasmania has been experiencing unprecedented low rainfall since September 2015, which has affected inflows to hydro storages across the state.

The continued outage of the Basslink interconnector has also put pressure on hydro storages.

Measures being implemented under the Energy Supply Plan mean that we are able to access alternative energy sources, such as diesel and gas, to minimise the draw on hydro storages.

If we receive around half of average inflows, storages are projected to reach a low of 12 per cent by early May and hold at that level.

“While seeding over hydro-generation catchments will have the highest priority, Hydro Tasmania is also prepared to undertake cloud seeding over agricultural catchments and bear the cost of this extra activity.”

Hydro Tasmania has been cloud seeding since 1964. Hydro generation catchment areas to be seeded this year are Gordon (Lakes Gordon and Pedder), Great Lake, Upper Pieman (Lake Mackintosh) , Mersey-Forth (Lake Rowallan) and Upper Derwent (Lake St Clair and Lake King William).

As has been the case in recent years, there will be no seeding flights over the King River catchment area, close to Queenstown.

Hydro Tasmania is working with the West coast Council to determine the best approach to community engagement with people in that region. The details of each cloud seeding flight will be broadcast on West Coast Radio 7XS. Flight maps for all cloud seeding operations, plus more information on cloud seeding, can be found at: www.hydro.com.au/water/cloud-seeding

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Released by Ian Colvin