The Trevallyn dam - from where the Gunns Ltd pulp mill will draw 70 million litres of water every day.
Gunns Ltd: 'Despite being more expensive, Gunns Ltd has realised superior environmental and social outcomes from sourcing the water out of the South Esk catchment rather than the Pipers River'.
Proposal: 'The plant will use 26 billion litres a year.'
Comment: Gunns Ltd have now had to backtrack with the announcement that the Pipers River is unsuitable for use as a water source. The alternative proposal is to pipe the water from Trevallyn lake under the Tamar and up to Longreach next to the East Tamar Highway in a one metre diameter pipe. The route will follow an existing water supply pipeline with water being taken directly from Lake Trevallyn. The cost of the pipeline will be massive and its construction is bound to be disruptive to traffic at times.
Gunns Ltd:'The 26 gigalitres of water required for the mill currently generates 0.82 megawatts of power when put through the Trevallyn power station. Using the same amount of water, the pulp mill will generate 30 megawatts of power for the grid as well as sufficient power to run the mill.'
Comment: Let's think about this. The pulp mill will generate 30 megawatts of power whatever water source is used so to say it is a gain is false. Compared with building the mill at Hampshire, Tasmania will lose 0.82 megawatts. That is not very much on a day to day basic but, unfortunately, it is accumulative. Unless the Trevallyn dam is overflowing (a few days a year) or the Great Lake is 100% full (has not happened for years) the amount of water lost to the system will accumulate. The water lost will equal 1.5% of the flow through the power station. After 10 years it will equal 8 weeks of power generation at Trevallyn. Will that be critical in a future drought? Only time will tell. For the last eight years the storage levels have been falling. Will there be enough water to go round? The Tasmanian government ordered new generating capacity to cover the 2005/2006 summer. Another consideration is that the power station can just be shut down and alternative sources of power such as Basslink used. Shutting the pulp mill will be far more difficult and the suspicion is that farmers and households will have to bear the brunt of a future water shortage whilst the pulp mill continues to gobble up 70 million litres a day. The following link shows that storage levels in the Great Lake have dropped from 78% full in 1997 to only 15% full by July 2005. If that continues, it will be empty in another two years!
Storage levels of waterAlso of concern is the fact that quickly growing plantations use 10-50% more water than existing forests (according to hydrologist David Leaman) In an article in the Sunday Examiner on 19th February, farmers near plantations are complaining that their water sources are drying up.
They are not alone: Swedish survey by Anderson and Bartholdson: 'Peasants whose land is next to Veracel's plantations claim that the availability to water has diminished since the Eucalyptus plantations were established.
IIS: Construction of the water pipeline will take 9 months. Work will take place between 7am and 5pm. There will need to be a considerable amount of infrastructure built near the Trevallyn dam. The powerful and potentially noisy pumps will be totally enclosed in a concrete pump house. There will be six 375kw pumps, 5 working and one backup. The pipeline will cross the Tamar at Newnham and the pipe will be buried 5m. under the river by using jet trenching. The trenches will be left to fill in naturally. The expected disturbance to the river is expected to only last a couple of days. Highways such as the West and East Tamar Highways will be disrupted from time to time but hopefully traffic control measures and diversions will cut traffic disruption to a minimum. As the construction progresses, various properties will be affected by noise, dust, and access disruption (and there will be some blasting) but each property should only be affected for a short time. The pipeline will cost $1m. per km plus work at Trevallyn, Longreach, and river crossings. Gunns will pay $30 per mL. for the water (2005 prices). In his submission to the RPDC, hydrologist David Leaman draws attention to omissions in the IIS regarding water supply and other issues including:* No mention of disruption to agricultural communities when farms are turned into plantations * No mention of complaints about loss of reasonable water supply in various communities * No consideration of lower yields caused by water shortages and climate change * Many water catchments are already stressed and others heading that way * No mention of the risk of fires in plantations and the subsequent water losses as the areas regenerate * No proper State water policy or managementDavid Leaman's submission to the RPDC In the Examiner on 25/8/06 it was reported that Winter rainfall in 2006 was only about 20% to 40% (depending on location) of the long term average. If this continues it could have implications for water supply and rate of growth of plantations. In the Examiner on 23/11/2006, water restrictions were announced for the South Esk River which supplies the Trevallyn Dam because of the drought. So it begs the question: 'How is there going to be enough water to go round if the pulp mill is using up 70,000,000 litres a day?' This is an excerpt taken from a report on the pulpmill being built in Uruguay by Finnish company Botnia:
Report on mill being built in Uraguay
23/2/2007: BLUE-GREEN ALGAE IN WATER SUPPLY CAUSES CHOAS IN WATER EVENTSWater report on South Esk basin
VERDICT: Gunns have not dispelled fears about the Trevallyn dam option. We may not know for years or even decades whether there will be any impacts to other water consumers but there is a suspicion that the Meander Dam is being built at taxpayer expense to cover this eventuality.
Footnote: There's plenty of water at Hampshire.
