What "Don't Rock The Maroochy" thinks of Council recommendations.

Regarding replacing the existing sand bag groynes with rock

  • The Maroochy River/Cotton Tree area is a world class natural recreational facility right in the heart of our city.  It is a jewel in the crown of what the Sunshine Coast has to offer locals and tourists alike and to destroy its natural beauty, would be akin to killing the goose that lays the golden egg.
  • The existing sand bag groynes have done the job they were designed to do and have increased the recreational value of Cotton Tree, by not only stopping erosion, but creating protected mini bays with mini swells providing an ideal nursery ground for kids learning to surf.

Sand building up around Geotextile bag groynes.

  • The young families who frequent the area clamber all over the sand bags without injury and to replace them with rocks would make that practice dangerous.

Cotton Tree sand bags a fun family playground

  • Broken glass, rubbish and unused bait would fall down between the rocks and attract rats and the brown snakes that feed on them, as has been witnessed in other coastal areas where rock walls have been built.
  • For these reasons and for the sake of preserving the natural beauty of the area as much as possible, we believe that council should continue to acknowledge the findings and action plan of the “The Maroochy River Entrance Working Party” and repair/maintain/replace the existing sand bag groynes and should not replace them with rock

Regarding building a 200m rock groyne from the Cotton Tree camping ground out to sea

  • History has shown that rock wall groynes built in other coastal areas in SE Qld have a bad down side of altering natural northerly sand flow, which causes sand loss on beaches north of the rock wall groynes.
  • Mitigating sand loss to the north of these rock groynes has usually required the building of more rock groynes to the north of the original one and in many cases installing expensive sand pumping by pass systems.
  • Building a 200m rock wall groyne out from Cotton Tree will train the river mouth to return to the south and will create a wide deep channel with increased tide flow, which will make the area unusable for the families who currently enjoy the area as it is.
  • If this wide deep channel is created, it will allow swells, particularly in cyclonic conditions or big swell events, to push up that channel without breaking on the existing sand banks on the south side of the river mouth and potentially cause surge and bad erosion to areas further up river. 
  • It should be noted when the entrance of the Nerang River was rock walled to create Southport Seaway, manmade Wave Break Island had to be created just inside the river mouth at huge expense to stop ocean swells pushing into the Broadwater and eroding the waterfront at Labrador.
  • For these reasons we believe that building a 200m rock groyne would be disastrous for the area and would eventually be many times more expensive than the cost of repairing/maintaining/replacing the existing sand bag groynes.

Regarding spending $3,000,000 on rock walling around the camping ground upstream to the sausage groynes at the Boatshed.

  • This recommendation appears to be linked to both replacing the geotextile groynes with rock and building the 200m rock wall groyne. 
  • If the 200m rock groyne isn’t built, we believe there should be no need to rock wall this section of the southern river bank.
  • If it is about replacing the existing geotextile sausage groynes with rock, for the reasons we have outlined against replacing the existing sand bag groynes, we believe it should not happen and a program of repair/maintain/replace the existing sand bags should be employed.

Regarding pumping 200,000 m3 of sand onto Alex/Maroochy Beach over the next 2 years at a cost of $1,000,000

  • As we have stated earlier, we believe that public expectation is that there will always be sand on this stretch of beach.
  • Having sand there is major part of the prosperity of the area and therefore sand replenishment will be needed after big swell events have eroded the beach.
  • We believe that when this has to happen, that based on hydrology reports, the sand should be pumped from areas in the river mouth that will assist the natural process of training the river mouth to the north near Pin Cushion and not from the banks naturally building up due to the geotextile bag groynes on the south side of the river mouth.

River running out just south of Pin Cushion