Departing Goulburn Broken Catchment Management Authority chief Chris Norman has sounded an alarm over the way the Goulburn River is being managed to transfer large volumes of water during summer.
The CMA is a statutory authority reporting to the Victorian Government and the normally circumspect chief executive has taken the opportunity to warn about the environmental damage that could be caused by unseasonally high flows through the river systems in summer.
Mr Norman, who has resigned after 10 years leading the CMA, expressed “extreme frustration” in trying to get the problem recognised.
“I flagged with the department five years ago that this was the biggest risk we had under the basin plan.
“The risk was that the Goulburn River would become the sacrificial lamb for the basin plan, in that to get water down the system it would have to come down through the Goulburn or through the Barmah Choke.
“We can’t allow continued development down-stream in areas that are short term. We have to look at the whole system.
“It means we have bloody big flows coming down in summer to supply a system downstream. It’s not long term sustainable thinking. It’s for short term economic gains.”
The high summer flows have been caused by the transfer of water downstream to supply lower catchment developments.
A report to the CMA in 2007 raised a series of recommendations for managing the so-called inter-valley transfers (IVTs).
“At the time, we said: you free up the market, there is an environmental trade-off. We probably didn’t understand the implications of some of those decisions,’’ Mr Norman said.
Mr Norman said there were reasons for the transfers but the community should be considering the cost of he economic development.
“We have to think about the whole system when we make these sort of decisions. You have to think longer term, otherwise it will have an impact further down.
“The concern in Victoria was the thought that if we made it difficult for investors they would go to New South Wales.
“But in the long run is that a better outcome to have some economic loss but get a more sustainable environment?”
Rylah Institute principal research scientist Jarod Lyon has told Country News that high summer flows have a strong negative outcome for Murray cod.
He said their analysis, which used 15 to 20 years of monitoring data collected from several rivers in the region (including the Murray, Broken and Goulburn), indicated that the flows negatively impacted the Murray cod year class strength (the number of juvenile fish in the river), by impacting survival in their first year of life.
“For the Goulburn River our analysis indicated a 30 per cent reduction in year class strength when flows from December to March are elevated from the long term average, (of about 900 Ml/day), to 1800 Ml/day.
“This is what we’ve seen the past three years in the Goulburn system.
“Given Murray cod are a long-lived fish, this may not be an issue when it only happens occasionally, but when we get successive years of these conditions it is likely to impact populations. We’re currently looking at what these longer term impacts might be,’’ Mr Lyon said.
Mr Norman invoked the view of respected catchment advocate and farmer John Dainton, who said: “We should use water closest to its source”.