Sand erosion solutions complex for Sunshine Coast
Fri 19 June 2009
Stephanie Wall, Journalism
Crumbling beaches have become a devastating reality along the Sunshine Coast as solutions for the intensifying sand erosion are disputed.
University of the Sunshine Coast climate change, coasts and catchments senior lecturer Shireen Fahey said the sand erosion along the Sunshine Coast had become a dynamic problem, but could be addressed by education.
The devastating sand erosion developed into an environmental, engineering and social issue.
Dr Fahey said sand naturally drifted from south to north in a process known as migration along Australia’s east coast.
Sand built up at points and headlands, forming sand banks and then eventually deposited on to the shore.
Dr Fahey said that climate change was a contributor to the current problem, as natural sand migration patterns were disrupted and the rate at which sand could be replenished naturally was altered.
“In a basic sense, climate change can increases both the frequency and intensity of storms, so with storms occurring more often, sand doesn’t have enough time to replace itself along the beach,” Dr Fahey said.
“Climate change can also increase the global mean temperature which creates a rising sea level, which also causes sand erosion.
“It will affect the length of time La Nina weather patterns [periods where there is a higher frequency of storms] are in place and the rate at which they oscillate between El Nino.”
However, Dr Fahey said that human impact and development were also major factors contributing to the extent of sand erosion along the Sunshine Coast.
“While the process of sand erosion has been occurring naturally for thousands of years, it’s different now because of the impact of people,” Dr Fahey said.
“We need to start looking at the problem from a broad regional context.”
Dr Fahey explained that coast-long natural sand depositional flow was interrupted by man-made structures, like sand bags, trying to fix singular erosion problems.
“The design of structures need to be engineered in a fashion that won’t completely affect the entire beach both north and south of it’s position; it’s a science,” Dr Fahey said.
While the damage was extensive along the Sunshine Coast, Dr Fahey said the solution revolved around adaptation.
“We need to learn how to live with climate change by looking at ways to lessen the human impact along our coastlines,” Dr Fahey said.
“It all comes down to education because Mother Nature is always more powerful.”
University of the Sunshine Coast post-graduate student Christine Reeves completed a report in 2009 on the sand erosion at Noosa’s main beach.
Ms Reeves was enrolled in a Graduate Certificate in Environmental Change Management, and said she studied the vulnerability of Noosa’s main beach to climate change and the risk of further erosion.
“Basically my studies show that with more extreme storm events and sea-level rises due to climate change, beach erosion and beach retreat are also likely to occur, endangering coast properties,” Ms Reeves said.
“Due to construction…of the rock wall, the groyne and the retaining of the river mouth, the cycle of natural erosion and natural accretion have been interrupted.
“This has caused misaligned waves and resulted in the beach being denied its natural mechanism to recover.
“The solutions are hard…however suggestions of man-made structures only cause further problems as proven in Noosa and also at Cotton Tree where the river mouth constantly needs dredging because of the sand bagging…to protect the caravan park.”
Sunshine Coast Regional Council’s manager of parks and gardens Mark Presswell said the past year had been extremely bad for the coastline, but the council was in the process of developing and evaluating solutions.
“We need to work closer with the state government and the Environmental Protection Agency,” Mr Presswell said.
Mr Presswell said, in his opinion, that the notion of climate change affecting sand erosion was a “long bow”, and that infrastructure too close to the coastline was the main cause of sand erosion on the Sunshine Coast.
However, council’s solutions still only targeted specific points of sand erosion, and the main theme of solutions was man-made structures.
“Council is looking at several different areas along the coast that were gravely affected by the weather this year like Noosa, Bribie Island and Mooloolaba,” Mr Presswell said.
“Pumping sand around the river walls at Point Cartwright, transporting sand from Currimundi Lake and spitfire channels, geotextile sausages (geo-fabric bags filled with sand) and modular objects are all options to try and solve the extent of sand erosion.
“But obviously council will need to study the natural flow of those specific areas.”
The Sunshine Coast Regional Council was looking for more man-made structures to ease the erosion, while university specialists reaffirmed the need for education regarding climate change.
Regardless of the differing opinions, the solutions to sand erosion required a united approach that included a vision of the entire Sunshine Coast rather than specific areas of sand erosion.
Image(s) designed by Stephanie Wall
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Submitted Comments
The migration of sands and the effect of man is the result engineers of old building break wall faceing the wong direction to the sand migration by consultation and engineering sand can be controled.Rivers and inlets not used by plying trade have choked with sand leaving long running banks with no depth.this is another occurance with morton bay moving the south port entrance from natual to commercial.shall I continue this subject has a long term effect on the east coast of australia
Robert Richards