A POTENTIAL 10-year silt raking solution for the Tamar River has been bolstered by new survey results, the Launceston Flood Authority says.
The authority ran a raking trial last year which removed 22,000 cubic tonnes of mud from the river without any reported adverse environmental effects.
The new survey results reveal 17,000 metres of silt reaccumulated in the raked area over a four-month period.
Authority chairman Alan Birchmore said this demonstrated that raking did not accelerate the estuary's natural siltation rate.
On this basis, Mr Birchmore said a full-blown raking program could be expected to drastically improve the Tamar's appearance and usability if conducted annually.
The authority's board has just approved a $250,000 raking program for this year, which it wants to start in a few months.
Hydro Tasmania will be asked to deliver information forecasting the arrival of strong water flows so the authority can maximise the effect of raking.
The state government's annual dredging payments, now in excess of $250,000, will be enough to fund the raking.
``It's a maintenance program which increasingly will achieve what the people of Launceston want,'' Mr Birchmore said.
``In the short term our aim is to cover the mud at low tide and then we will assess as we go how much extra is needed.''
Mr Birchmore said the Tamar's rowing course had already been vastly improved by the trial and Launceston could look forward to regattas as the river's amenity improved.
Meanwhile, the authority may have found a solution to the costly silt pond dilemma.
The authority's Tamar dredging program has dried up in recent years due to the high costs involved and a $1 million government backflip on emergency funding.
A significant factor in the cost is the removal and treatment of silt, which is dumped in settling ponds in Riverside following the dredging process.
These ponds are now full.
In conjunction with the University of Tasmania and an obliging landowner about 1000 tonnes of silt will be taken from the ponds and spread over a hectare of farmland.
Tests will then be carried out to see if the silt can be used as a farm input.
Mr Birchmore said it had the potential to significantly reduce dredging costs.