History

Like all sandy river mouths, the entrance to the Maroochy River has oscillated and changed over the years.

In pre white settlement and development times this didn’t matter, as the indigenous people of the area, the Kabi Kabi people simply adapted their usage to these natural changes.

In today’s world there is a need to protect foreshore areas from erosion.

About 20 years ago after the main river entrance to the sea had moved south, there was great concern that erosion caused by this at Cotton Tree would take away the camping area and other amenities just upstream from there.

To address this issue,  the council of the day set up a community consultative group, “The Maroochy River Entrance Working Party”, which consisted of people from all sectors of the community; business, tourism, environment and recreation, including council staff and councillors.

This working group was able to have meaningful input into the options put to the expert consultants, who then carried out physical modelling to come up with a solution which addressed all the values the community identified.

That solution was to place carefully positioned geotextile groynes (sand bags) on the beach at Cotton Tree, which would trap sand in the eroded area and build up the beach, at the same time allowing the natural northerly sand drift to fill in the southern entrance channel and encourage the river to enter the sea on the northern side of the river mouth around Pin Cushion.

Without a doubt, this has worked and the beach at Cotton Tree is stable and the deepest channel for the river to drain into the sea on the south side of Pin Cushion.

Deepest channel of river mouth south of Pin Cushion

When installed, the sand bags were considered to have a use by date of 15-20 years and although most of them are still in good condition, some have broken down or been damaged by people, sad to say mostly anglers, cutting them to remove hooks that have become stuck in them.

That time has come and the council now has to have a working plan to repair, maintain or replace the existing sand bags.

As part of this process, they are looking for a less expensive way of beach replenishment between Cotton Tree and Alexandra Headland than pumping sand from the Maroochy River onto the beach.

Long-time locals appreciate that after big swell events that stretch of beach would lose its sand and large areas of coffee rock would be exposed.

Although the beach naturally builds up again after these erosion events, we agree that today’s expectation of locals and visitors is, that except in the most extreme cases, there will always be beach for them to enjoy