Mooloolaba Boat Harbour entrance, long-term solution

We are planning for a long-term solution to improve safety and accessibility for all users.

The Mooloolaba harbour and entrance training walls were built in the late 1960's. Since that time, sand shoaling events have occurred periodically in the entrance channel causing marine safety and accessibility issues.

Maintaining a safe navigable entrance to the Mooloolaba Boat Harbour at all times is crucial for all boaties. We aim to maintain the boat harbour entrance clear to a design depth of at least -2.5m Lowest Astronomical Tide (LAT) at all times.

In the past, shoaling events were infrequent, occurring every few years, with intervals of 3-5 years or longer. In the last 10-15 years shoaling events have become more frequent. The most recent shoaling event, which took place from February 2022 to June 2022, required continuous dredging and had a significant impact on navigational access.

Due to unpredictable weather and swell conditions, dredging activities are not always immediately possible and a long-term solution is required to minimise the impact of shoaling events in the harbour entrance.


  • Improves safety
  • Contributes to economy
  • Reduces maintenance

Stakeholder Reference Group

We formed a Stakeholder Reference Group (SRG) in 2022 to help investigate a long-term solution for the Mooloolaba Boat Harbour entrance.

The Stakeholder Reference Group ensures the interests of key stakeholders – including local representatives from the Coast Guard, commercial and recreational fisherman, harbour business owners, and residents and community groups – are considered as part of our investigations.

This engagement operates in parallel alongside technical, environmental and cultural heritage investigations.

Our current works identified out of the reference group meetings include:

  • Commenced a western channel trial in 2022 to clear shoals west of the entrance.
  • Undertaking 'rock level mapping survey' across the headland to find any deeper rock areas where sand could be intercepted before moving to the entrance.
  • Progressing technical, environmental and cultural heritage investigations into the breakwater extension option.

Next steps

We will:

  • Continue our engagement with the Stakeholder Reference Group regarding the outcome of these initiatives.
  • Seek wider community feedback from the Stakeholder Reference Group investigations.

Investigations into a long-term solution

In 2014 an investigation into options to manage shoaling impacts in the entrance was undertaken by WBM Oceanics (now BMT). A 60m extension to the eastern breakwater, to intercept most of the sand before it enters the channel, was determined as the preferred engineering option to mitigate shoaling events.

Aerial view of proposed extension to the channel eastern breakwater

In February 2019, coastal engineering consultants Kellogg Brown & Root Pty Ltd undertook detailed design work of the 60m breakwater extension. The design was tested at the Queensland Government Hydraulic Laboratory through physical modelling using a 1 in 41 scale model. The design was modified and included analysis of concrete armour units for the construction of the breakwater.

Other options investigated to date include:

  • Permanent automatic sand bypassing system
  • Increased dredge channel depth with rock excavation
  • Excavated headland sand trap

Our investigations to date have focused on options providing a clear solution to shoaling events by stopping sand from entering the channel that impacts on navigation.

The current western channel trial provides less certainty with respect to effectiveness, given it still allows shoals into the navigational channel, but has the intention of attempting to maintain a channel to the west during these events. This was based on Stakeholder Reference Group's clear message to Maritime Safety Queensland (MSQ) that they want to completely exhaust potential alternatives before progressing with the breakwater extension option.


Physical model testing of the proposed lengthened breakwater

More information

To improve safety at the harbour entrance, dredging activities are undertaken regularly to maintain safe navigation.

For more information about dredging activities visit Mooloolaba Boat Harbour dredging.

Visit the Notice to Mariners for up-to-date marine safety information.