Byron shire councillor Cr Ibrahim’s ‘obsession’ with building a rock wall at Belongil shows through in his justification for the way in which the project was approved.
His suggestion that the environmental credentials of the project had been adequately scrutinised is not supported, mostly by his own arguments.
There was no Environmental Impact Statement (EIS) because the Review of Environmental Factors (REF) commissioned by Council said that one was not required.
Critically, the REF limited the possible impacts to the footprint of the wall only. As such many of the impacts beyond the site of the wall were ruled off limits before any assessment.
Clearly the process that Cr Ibrahim advocated for is severely limited and less than adequate.
While demanding that his critics produce ‘contrary scientific evidence’, he offers none at all for his spurious claim that ‘rocks result in less erosion’.
This appears to be his rationale for replacing ‘interim’ sandbags with a supposedly ‘interim’ rock wall. The idea being that the disturbance of the sandbags during storms is evidence that sandbags cause more erosion.
Keeping in mind that the sandbags are located between existing rock walls, one has to account for the impact of what is known as end effect.
This is where the wave energy that hits a rock wall is concentrated and transferred to the end of the hard surface leading to the possibility of greater erosion at the end of the wall.
In this case end effect energy from rock walls is having an impact on the sandbags, yet Councillor Ibrahim maintains it is the sandbags that are the problem.
Again the limitation of the REF is demonstrated. End effects are well known and understood and here we have an example of an existing rock wall transferring destructive wave energy beyond its physical footprint and a new rock wall to be built adjacent that will not examine impacts beyond its footprint.
Saying this is because the new wall will simply fill in between existing rock walls is murky thinking.
Logically the energy that is travelling along the existing walls and now being disseminated by the sandbags, will in future have to continue travelling along a much longer wall.
This raises the possibility that the energy may concentrate and cause erosion further north along the spit, closer to the sensitive rare bird breeding sites and mouth of the creek.
Of course these impacts are well away from the footprint of the proposed wall and therefore are not being assessed as part of the project.
Cr Basil Cameron, Goonengerry
Cr Cameron you know what the experts say?
2013 Council report:
“Re: Comparison of Coastal Engineering Aspects of Sandbag Seawalls with Rock Seawalls”
WRL2013012 LR20130213 3
6. Summary
More extensive advantages and disadvantages are listed above. A summary of the present Byron Bay situation and the main advantages and disadvantages of sandbag versus rock seawalls are:
None of the current Byron Bay coastal structures meet contemporary coastal engineering standards for long term works.
A structure of any material, engineered to contemporary standards, offers lower risk and maintenance than a non-engineered structure.
Differences in erosion “end effects” between sandbag and rock seawalls are not currently known. For a short seawall between two existing longer seawalls, there would be minimal incremental difference in alongshore erosion between the two. James Carley MHL
Thanks Basil for your informative letter. … What the responsible half on Council needs to do, now that they have been outvoted on this ‘tip of the iceberg’ issue, is to look hard and long at the costings, now and in the foreseeable future. I for one don’t want any of my rates to go towards funding the desecration of our beaches, and future maintenance costs for the whole spit, as well as sand pumping costs in future years, could well bankrupt Council. I hate to say this but I think it’s time the State government did merge Councils after all. A broader perspective on regional matters might then put a stop to self interest and damaging skulduggery.