Maroochy Groyne Field Renewal Project
  • Last updated:
  • 29 Jan 2020


The entrance to the Maroochy River migrates due to coastal and estuarine processes. Its location has been both north and south of Pincushion Island since the 1940’s.

Southern migration in the 1990’s saw erosive pressure occur at the Cotton Tree Holiday Park. In 2003 council constructed groynes and a section of seawalls to protect the park assets.

Some of these coastal structures have now reached the end of their useful life.

An investigation into future coastal infrastructure upgrades was undertaken. This was part of council's endorsed Shoreline Erosion Management Plan (SEMP) 2014.

The SEMP provides a ten year plan of key coastal processes along the Sunshine Coast. It also recommends preferred management options. These options incorporate sound science, coastal engineering principles, community values and coastal dynamics.

A council report[1694KB] in January 2017 sought direction for future coastal infrastructure upgrades. This was part of the broader management of the Maroochy River mouth.

The report included an assessment by WBM consultancy. This assessment detailed a range of options for the renewal of the river mouth groyne field.

Option 1 (a) replace existing groynes - geobag to geobag

Option 1 (b) replace existing groynes - geobag to rock

Option 2 new 200m rock groyne at Cotton Tree

Option 3 northern channel with constructed beach

Option 4 northern channel with breakwater

Council resolved to:

  • undertake a further analysis of the economic, tourism, social and environmental impacts. Including retaining the geofabric bags at the Maroochy River entrance groyne.
  • undertake wide community engagement on the available options to inform any future recommendations.

As part of a competitive process, council engaged JB Pacific to undertake a further cost benefit analysis of the options. The results[9457KB] of the cost benefit analysis report are now available.

Community engagement

The first action was to establish the Maroochy River Estuary Consultation Group (MRECG). Council invited all regional residents and community interest groups to take part. Some positions were fixed and membership limited to ensure a fair regional representation.

As well as the MRECG, council also invited local residents to a series of community information sessions. Residents could also complete a survey or provide a submission to the MRECG.

Council appointed Professor John Martin as the independent chair for the MRECG. Professor Martin is an Emeritus Professor at La Trobe University.

Expression of interest applications closed on 22 May 2017.

Phase 2 - Consultation sessions and survey

Online Survey - submissions closed Friday 6 October 2017

Community Information Sessions - closed 29 August 2017

During August 2017, council hosted five community consultation sessions across the region. 350 people registered their attendance.

As part of the community consultation process council developed a set of frequently asked questions. These will continue to be updated as required.

The information sessions and feedback from the MRECG advised the community of each option available to council. This included a breakdown of the social, economic and environmental factors.

Members of the community made representations and submissions to the MRECG for consideration. Submissions closed on 31 October 2017.

All feedback received assisted council to make an informed decision on a suitable option for the required upgrades.

In December 2017, Sunshine Coast Council voted to replace the existing geobag groynes. The replacement option chosen was a like for like renewal.

Given the completion of this consultation process the MRECG has now been dissolved. Council is appreciative of the involvement of all members of this group.

Where to from here

After embarking on a 12-month contract to research and develop suitable options for the groyne renewal at Maroochy River, two preferred designs for the river mouth’s geotextile containers have been selected. This extensive research and design development follows the award-winning community engagement process to determine the most suitable upgrade option for the Maroochy Groyne Field Renewal Project, designed to protect the Cotton Tree precinct from erosion.

The two preferred design options will now be key components of the construction tender, which went to market on Saturday 23 November. The successful tender will be awarded late February 2020 after a detailed assessment process and it is expected construction will start late April 2020.

Construction works will be undertaken in two stages, with Stage 1 focusing on the two northern-most groynes and the seawall surrounding the Cotton Tree Holiday Park. This initial work is expected to last approximately six months, depending on weather and tidal conditions.

Stage 2 will start in 2021 on the two southern-most groynes as well as a ramp to facilitate emergency access to the north of the site.


For more information please contact the Project Officer via Customer Service.