It seems that the difference between the 504 test sites identified in the UNSW Water Research Laboratory 211-page report on Clarence riverbank vulnerability and the 252 sites implied in the newspaper article raised some local eyebrows, but it was this paragraph which appeared to elevate the blood pressure of one particular reader who perhaps was remembering that the Clarence River is over 300 km long:
While the study found there were sections of the river in those areas where management of activities was warranted, the majority of the river was suitable for water skiing and wakeboarding for vessels making up to 150 passes of the river a day.
The irate reader himself also had trouble with the number of sections in the 37 km study area. Though to be fair it appears he may be using the locally recognised distinctions between stretches of the river between Rogan's Bridge and Ulmarra.
The study has a contentious history with Seelands residents - see here and here. The report
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The newspaper article
The controversial activity of wakeboarding is generally suitable for the Clarence River between Ulmarra and Seelands, says the draft of a university report released this month.
The University of NSW Water Research Laboratory study, Riverbank Vulnerability Assessment Using a Decision Support System: Rogans Bridge to Ulmarra, looks at the effect of water activities on the river on riverbank health.
While the study found there were sections of the river in those areas where management of activities was warranted, the majority of the river was suitable for water skiing and wakeboarding for vessels making up to 150 passes of the river a day.
Data collection for the report was concluded in May.
To study the effects of erosion on the banks and three river islands, the 37km stretch of river and Susan, Elizabeth and Peanut islands were divided into 84 sections and each section had six test points - three on each bank.
The erosive potential for each section was broken into five categories: highly resistant, moderately resistant, mildly resistant, moderately erosive and highly erosive.
These categories were used to come up with the decision support system (DSS) ratings: allow, monitor and manage.
The study also found riverbanks were generally more vulnerable to erosion at mid-low tide and high tide. It also looked at the effect of wind waves.
The Clarence Valley Council, the NSW North Coast Local Land Services (LLS) and NSW Roads and Maritime Services (RMS) funded the report.
The Maritime Management Centre (MMC) in Transport for NSW is now seeking feedback on the report, to help inform the development of a draft management plan for the area.
Confidence eroded
I refer to the DEX article "Report finds wakeboarding 'generally suitable' on Clarence" (30/12).
Your readers should be made aware that this article is factually incorrect and displays a level of irresponsible journalism that has negative effects beyond the continuing reduction of the credibility of this newspaper.
The riverbank erosion study did not find the "majority" of the river was suitable for wakeboarding.
The UNSW Water Research Laboratory study examined only three relatively small sections of the navigable river and therefore could not and did not draw any conclusions on suitability of wakeboarding for the "majority" of the river.
In the limited study areas, about one third of the riverbank studied was assessed as requiring "immediate enforceable no wash zones" (i.e. no slow-tow wakeboarding) to prevent further riverbank erosion; another third was assessed as requiring zoning to prevent wakeboarding within 100 metres of the riverbank; and for the rest there was a requirement to monitor riverbank erosion and conduct small areas of remedial protection works.
To report the study results as finding wakeboarding "generally suitable" on the Clarence is a nonsense and a significantly irresponsible action.
As a result of this misleading article, and the lack of effective action by CVC and RMS, the river between Rogan Bridge and Moleville Rock that was identified as particularly vulnerable to excessive wash is inundated by slow-tow wake boats and the significant (according to WRL) riverbank erosion and damage is continuing.
At the recent WRL study presentation Professor Glamore stated "blind Freddie" could see the riverbank from Rogan Bridge to Moleville Rock was extremely vulnerable to wash erosion.
However what the professor did not understand was that being blind to the legitimate concerns of the community (which have now been scientifically validated) is apparently part of the job descriptions for DEX, CVC and RMS personnel.
What DEX should be investigating is why CVC has not taken any effective action and why RMS refuses to implement immediate boat wash restrictions as recommended by the WRL study.
John Griffith,
Seelands
