Thursday 25 November 2010
Hansard of the Legislative Council



[11.05 a.m.]
Mr FINCH (Rosevears) - Madam President, if we did not know it already, the upper estuary of the Tamar River is in a mess, according to the latest report from Natural Resource Management North - NRM North. The report breaks down the Tamar estuary into five zones. Starting near the mouth, zone 5 is rated A minus; a little further upstream, zone 4 is B plus; zone 3 is rated B; zone 2 at B minus; and at Launceston zone 1 is rated at D. So we have a steady decline as we go upriver.

A D rating, according to NRM North, means a highly degraded ecosystem, poor water quality, with high levels of turbidity. That is no surprise. The problem has been going on for generations. Last year this House set up a select committee to investigate the management of the Tamar and Esk rivers. The evidence that the Tamar estuary's problems and its catchment were linked was overwhelming. The committee recommended the establishment of a single statutory authority to oversee the management of the Tamar and Esk rivers and their tributaries. Nothing has happened. However, there is strong evidence from elsewhere that single catchment authorities are the only way to remedy problems like the Tamar's.

Our committee, you might recall, looked at catchments in Victoria, at Bairnsdale and Corangamite, and Victoria, I might point out, has 11 catchment authorities working very successfully. But our most interesting visit was to Moreton Bay in Brisbane. Moreton Bay has a similar silt problem to the Tamar and I would like to detail what is being done there.

Members of this House might recall Brisbane Lord Mayor Campbell Newman's connection back to Launceston - father Kevin and mother Jocelyn Newman. The biggest threat to Moreton Bay used to be sewage and other pollutants, but now it is sediment brought down from small catchments way upstream of the Brisbane River.

The latest report card on Moreton Bay gave it a rating of C. That is marginally better than last year's D, so you can see the similarity of the problem. Brisbane's Lord Mayor has decided to finance the restoration of upstream catchments where the silt originates.

Over a 10-year period this could cost as much as $500 million - that is, $35 million to $50 million a year will be spent. Lord Mayor Newman says the big challenge is way upstream from Brisbane and not generally in the Brisbane local government area. The chairman of a study panel on the catchment problem, Paul Greenfield, says upstream areas of the catchment are the problem, with half of all streams degraded. He says that if you want to improve the estuary, you have to tackle that problem.

To handle heavy rain, catchment erosion has to be managed, creek channels stabilised, riverbanks improved and investments made in agricultural practices and water sensitive urban design.

Madam President, by applying a whole-of-catchment approach, practically each sample of silt in Moreton Bay can be scientifically traced back to its source. Radiation sampling and computer modelling are some of the tools being used, and all this information could help a management authority target the greatest problem areas and so concentrate the rehabilitation money where it is most needed.

So far the scientists have found that, typically, 80 per cent of the sediment load derives from less than 10 per cent of the catchment area. This information is helpful in targeting erosion controls.

We can learn a lot from what they are doing in Moreton Bay. I know the upper Tamar's problem is not just about new silt, it is also about the silt already in the basin being washed back by tidal movement. The silt that is already there may well be the major part of the problem but you also have to tackle eroded sources upstream, way back into the catchment. That requires a coordinated approach like Brisbane's. Evidence to last year's committee hearings acknowledged that NRM North and other groups were doing a fantastic job, but all this work needs coordinating, as in south-east Queensland and other mainland estuaries with problems.

That was the recommendation of our committee which featured the member for Windermere and the member for Launceston. A statutory management authority was the recommendation to manage the whole of the Tamar catchment. But, like a lot of good advice in Tasmania, nothing seems to be happening with it.