2024 review of maintenance dredging of Queensland ports
This review has been prepared by the Queensland Ports Association as part of reporting requirements under the Maintenance Dredging Strategy for Great Barrier Reef World Heritage Area Ports.
Queensland ports require routine maintenance dredging to remove sediments that have accumulated in channels, berths and swing basins due to siltation and sediment transport processes. Most ports cannot sustainably function without maintenance dredging. Maintenance dredging has occurred in Queensland since ports were first established.
Most of Queensland’s maintenance dredging is undertaken by the Trailing Suction Hopper Dredger Brisbane, a specialised dredger owned and operated by Port of Brisbane Pty Ltd. The Brisbane is uniquely designed for Queensland conditions and adheres to advanced environmental management practices. Its environmental safeguards align with the latest Trailing Suction Hopper Dredger technologies, ensuring minimal environmental impact during dredging activities.
In accordance with the Queensland Maintenance Dredging Strategy for Great Barrier Reef World Heritage Area Ports, a high-level schedule of maintenance dredging activities for 2024 was prepared and submitted to the Department of Transport and Main Roads (TMR). This schedule prioritised measures to reduce the scope and footprint of dredging activities wherever feasible, in alignment with government environmental objectives and strategic port management plans.
During 2024, maintenance dredging was undertaken at the following ports:
This maintenance dredging program for 2024 is now complete.
The sections below summarise the outcomes of the 2024 dredging program in relation to timing, volume, and outcomes of monitoring. Placement options for dredged material were thoroughly evaluated for all maintenance dredging campaigns, consistent with each port’s Long-term Maintenance Dredging Management Plan and in compliance with relevant state and federal regulatory frameworks.
The outcomes of the 2024 program highlight the commitment of Queensland ports to maintaining navigational efficiency while upholding the highest environmental standards. This sections below aim to support informed decision-making for future dredging activities and policy development, ensuring alignment with sustainable port operations and environmental stewardship objectives.
Amrun
Maintenance dredging
A total of 51,316m3 of material was dredged by the Trailing Suction Hopper Dredger Brisbane from 12 May 2024 to 14 May 2024. Dredging was undertaken at the Amrun approach and berth pocket.
All works were compliant with state and federal approvals and no environmental incidents or complaints were reported.
Environmental assessments
Seagrass
Seagrass populations around Amrun are located within Boyd Bay, outside the area of impact and no monitoring is required under the long-term maintenance dredging management plan.
Water
Visual observations and satellite imagery collected during dredging identified the plume was localised around the dredge vessel.
No vessel-based monitoring is required under the dredge management or environmental management plans based on the volume dredged.
Sediment
A Sediment Characterisation Study was completed in 2023 as per the 5-yearly requirement under the National Assessment Guidelines for Dredging 2009. The sampling confirmed compliance of maintenance dredged material to the National Assessment Guidelines for Dredging 2009 and continued suitability for ocean placement at the current approved Amrun Material Placement Area. A new Sediment Characterisation Study will be completed prior to the 2028 maintenance dredging campaign.
Turtles and dugongs
Visual observations were completed and recorded in dredge logs. No interactions or observations were recorded during dredging or placement operations.
Biosecurity
All vessels underwent a marine pest risk assessment prior to mobilising to site in which all vessels were assessed as low risk. No marine pests were identified during dredging activities.
Port of Brisbane
Maintenance dredging
A total of 369,484m3 of material was dredged by the Trailing Suction Hopper Dredger Brisbane from 1 January 2024 to 19 April 2024 and 15 December 2024 to 31 December 2024, and the Clam Dredger Ken Harvey throughout January to March, August and October 2024. Dredging was undertaken in the Brisbane River.
Activities were fully compliant with all state approvals (Environmental Authority, Marine Park Permit and Allocation of Quarry Material). No permit non-compliances, environmental incidents or complaints were reported regarding maintenance dredging operations or activities.
Environmental assessments
Seagrass
The annual survey was undertaken by BMT from 9 July 2024 to 7 August 2024. The results show a consistent broadscale recovery and recolonisation of seagrass meadows at all sites since the impacts of the 2022 floods. This pattern of sea grass recolonisation was noted following the 2011 and 2013 flooding events, and it appears the seagrass is nearing or has reached full recovery. The Port of Brisbane continues to work with various catchment management stakeholders to address the causes of excessive sediment generated in rain events in the Brisbane River catchment.
Water
Triennial dredging turbidity monitoring was last undertaken in February 2023. Reported results were consistent with previous investigations. The monitoring found that the dredging activity created larger plumes than the dredged material placement. Plumes remained within both dredging areas and the dredged material placement area and there were no impacts on sensitive receptor sites.
Sediment
The Sediment Sampling and Analysis Plan sampling was undertaken during September 2024. A total of 35 sites were sampled, comprising 26 sample locations within the proposed dredging area and nine reference locations. Results from 2024 were generally comparable to previous years. Sediments within the dredging zones were found to be suitable for ocean placement in accordance with the National Assessment Guidelines for Dredging 2009.
Turtles and dugongs
No interaction with dredging.
Biosecurity
In January 2020 the marine pest species White Colonial Sea Squirt (Didemnum perlucidum) was first detected at the Port of Brisbane. This species of marine pest has been detected in subsequent sampling campaigns. There has been no confirmed establishment of any new target invasive marine species at the Port of Brisbane.
View Port of Brisbane monitoring reports.
Port of Bundaberg
Maintenance dredging
A total of 99,981m3 of material was dredged by the Trailing Suction Hopper Dredger Brisbane from 20 April 2024 to 30 April 2024. Dredging was undertaken at the berths, swing basins, inner and outer channels.
No permit non-compliances, environmental incidents or complaints were reported.
Environmental assessments
Seagrass
The Port of Bundaberg Long-term Maintenance Dredging Management Plan monitoring for seagrass, benthic and particle size analysis assessment at the offshore Material Relocation Area is undertaken every 5 years with the last survey carried out in 2020. The study showed the presence of a large deep-water seagrass meadow within and outside the Material Relocation Area. No differences were found in seagrass biomass and sediment particle size distribution between inside and outside the Material Placement Area. Infauna communities were more diverse and abundant outside the Material Placement Area, however no relationship with increasing distance from the Material Placement Area was found. Therefore, the study showed no evidence of dredged material placement impacts on seagrass and benthic communities occurring outside the Material Placement Area.
Water
A water quality monitoring program has been designed and implemented prior, during and post maintenance dredging operations. This ensures water quality does not deteriorate as a result of maintenance dredging plumes, and sensitive receptors in the area are protected. Turbidity data is collected in the dredging phase and screened against developed turbidity triggers. The monitoring is paired with a tailored adaptive management framework, ensuring appropriate actions are taken when turbidity levels reach the above mentioned triggers.
No water quality impact was detected from the activity.
Sediment
Sediment quality assessment following the National Assessment Guidelines for Dredging 2009 was conducted in 2019, with sediments within the dredge footprint found to be suitable for sea placement.
Turtles and dugongs
Direct impacts are mitigated through controls documented in environmental management plans. These include fitting of turtle exclusion devices, visual observations, protocols on when to stop activities, wait, and re-commence activities, and guidance on reporting. Indirect impacts to these species are mitigated through the management of water quality during maintenance dredging activities.
Biosecurity
No marine pests identified during activity.
View Port of Bundaberg monitoring reports.
Port of Cairns
Maintenance dredging
A total of 357,171m3 of material was dredged by the Trailing Suction Hopper Dredger Brisbane from 3 May 2024 to 8 May 2024, 21 July 2024 to 31 July 2024, 21 August 2024 to 22 August 2024 and 17 October 2024 to 3 November 2024. Dredging was undertaken at the Port of Cairns channel.
A total of 26,404m3 of material was dredged by the Grab Dredger Willunga throughout the year at portions of the inner port wharves (1-12), Commercial Fisherman’s Base 1 and the Marlin Marina.
Works were completed under the 10-year Sea Dumping Permit and Marine Park Permit and utilised the dredged material placement area location.
Engagement with the Great Barrier Reef Marine Park Authority was required early in 2024 to access contingency provisions of the Permits in response to Tropical Cyclone Jasper and associated flooding in December 2023. A portion of the volume reported above (65,951m3) was removed during the first channel campaign in response to the extreme weather event. Due to the spilt campaigns and available days within the Trailing Suction Hopper Dredger Brisbane schedule, not all of the anticipated 320,000m3 of contingency volume was removed during the year with material remaining in the channel above design depth at end of the third campaign, however channel declaration was maintained.
All works compliant and consistent with Environmental Authority, Marine Park, and Sea Dumping Volume dredged was within annual permit limit. The Annual Fee for the Environmental Authority was submitted.
No permit non-compliances, environmental incidents or complaints were reported.
Environmental assessments
Seagrass
The Cairns Harbour and Trinity Inlet Long Term Seagrass Long Term Monitoring Program annual survey completed by James Cook University, TropWater, during September (helicopter) and November (vessel). Light data surveys continued.
Water
Water quality verification under the Long-term Maintenance Dredging Management Plan or Environmental Management Plan was not required during the period, with campaign specific sampling conducted to validate the hydrodynamic model and address in 2022. This will be next due in 2027 unless otherwise triggered.
Sediment
The Sediment Analysis Plan was implemented during March-April 2024 for the Channel, Inner Port, Marina areas. There was no detection of contaminants exceeding the National Assessment Guidelines for Dredging 2009 limits, and material was assessed as suitable for unconfined at sea placement under permit conditions.
Turtles and dugongs
No interactions or observations were recorded during dredging or placement operations of either the Trailing Suction Hopper Dredger Brisbane or Grab Dredger Willunga.
Biosecurity
Surveys of areas to be dredged as set out in the Sediment Analysis Plan, along with periodic checks of the monitoring devices within the inner port area were conducted. No detections of verified marine pests or samples requiring identification were reported during the year or via the Sediment Analysis Plan process. Within the port, the black scar oyster continues to be observed. A detection of Asian Green Mussel was reported from aboard a vessel arriving from Weipa that was lifted at one of the slipways during September. No subsequent observations were reported for the remainder of the year at Cairns either on vessels, infrastructure or sampling devices. Further detections were made at Weipa during surveillance operations by Biosecurity Queensland, requiring ongoing vigilance due to the potential risk posed by vessel movements between the locations. Implementation of Biosecurity Queensland’s Seaports eDNA Surveillance (Q-SEAS) program continues to be enacted for ongoing surveillance in response to the detections and Port North remain engaged with Biosecurity Queensland on surveillance outcomes to inform the management of risk to dredge equipment and vessel movements.
Port of Gladstone
Maintenance dredging
A total of 297,688m3 of material was dredged by the Trailing Suction Hopper Dredger Brisbane from 10 November 2024 to 13 December 2024, with 268,743m3 placed at the offshore material relocation area and 28,945m3 placed at the in-channel material relocation area adjacent to Tide Island. Dredging was undertaken at the berths, swing basins, inner and outer channels.
No permit non-compliances, environmental incidents or complaints were reported.
Environmental assessments
Seagrass
Light is monitored in real time at a seagrass meadow within the zone of influence before, during and after dredging. During the dredging phase, light values as a 14-day rolling average are screened against a light requirement threshold developed through field and laboratory studies. The light monitoring program is incorporated into an adaptive management plan which follows a multi staged approach for management responses to reduced light conditions as a result of dredging operations to occur before potential environmental harm to seagrass meadows and sensitive receptors occur.
This is supported by a comprehensive annual seagrass monitoring program that assesses the health of seagrass meadows through 3 key metrics: surface area, biomass and species composition.
No impact was detected from the activity with environmental factors such as ambient light levels and tidal state.
Water
Real time turbidity monitoring is undertaken at a compliance and support site. The location of these sites have been determined by maintenance dredging plumes modelling and impact assessment. During dredging, turbidity at the compliance site is screened against developed triggers. Adaptive management steps have been developed ensuring appropriate procedures and actions are undertaken when turbidity reaches such triggers. This ensures potential environmental harm from dredging related turbidity plumes is identified, assessed, prevented or minimised.
No water quality impact was detected from the activity with environmental factors such as tidal cycles and winds appearing to be the drivers behind turbidity patterns in line with historical data and maintenance dredging campaigns.
Sediment
In line with the Port of Gladstone Long-term Maintenance Dredging Management Plan long-term monitoring schedule and the National Assessment Guidelines for Dredging 2009, sediment quality in the main channels is assessed every 5 years. The sediment quality was assessed in 2022 following the National Assessment Guidelines for Dredging 2009 and found to be suitable for sea placement.
Turtles and dugongs
Direct impacts are mitigated through controls documented in Environmental Management Plans. These include fitting of turtle exclusion devices (where possible), visual observation, protocols on when to stop activities, wait, increase visual observations and commence or re-commence activity, and guidance on reporting. Indirect impacts to these species are mitigated through the management of water quality during maintenance dredging activities.
No impacts to marine megafauna were identified from the activity.
Biosecurity
As per the Port of Gladstone Long-term Maintenance Dredging Management Plan long-term monitoring schedule, a survey to identify any marine pests within the port is undertaken every 5 years. In 2021 and 2022, Gladstone Ports Corporation, in conjunction with the Queensland Department of Primary Industries, carried out monitoring within the harbour. Results from the monitoring and related samples collected detected 1 new invasive marine species since the previous sampling period, the White colonial sea squirt. It was recommended that visual surveillance should take place, and a tissue sample be collected and verified before this species is regarded as established in Gladstone. The National Consultative Committee on Introduced Marine Pest Emergencies provided advice that it is not technically feasible to eradicate this species in Queensland. Efforts to minimise further spread of this marine pest will be continued through marine pest surveillance which will assist with further understanding the distribution of this marine pest in Queensland. The latest report is scheduled for release in 2025.
View Port of Gladstone monitoring reports.
Port of Hay Point
Maintenance dredging
A total of 166,000m3 of material was dredged by the Trailing Suction Hopper Dredger Brisbane from 25 August 2024 to 14 September 2024. Dredging was undertaken at the Port of Hay Point apron and departure path, Half Tide Tug Harbour, and Dalrymple Bay Coal Terminal berths 3 and 4.
Works were compliant with state and federal approvals, with no environmental incidents recorded.
One environmental complaint was received from a member of the community regarding the plume from bed-levelling activities. North Queensland Bulk Ports monitors plumes generated by dredging and bed-levelling activities to ensure there are no impacts to sensitive receptors and confirmed there was no impact in this instance. The community member was offered an opportunity to meet and was also given information on the water quality monitoring dashboard and environmental approval conditions.
Environmental assessments
Seagrass
Annual seagrass monitoring was conducted in the Port of Hay Point during September-October 2024. The report will be made available on NQBP’s website once finalised.
Pre- and post-dredging monitoring of coral health was also carried out in August and October 2024. No impacts to coral communities were identified as a result of maintenance dredging.
Water
North Queensland Bulk Ports completed ambient marine water quality monitoring prior to, during and post the maintenance dredging program, and installed real time water quality loggers for the duration of the program. Data from the water quality monitoring as well as satellite-derived turbidity data was analysed.
Water quality thresholds for turbidity were not exceeded as a result of maintenance dredging activities, and no adaptive management action was required to minimise or reduce risk to the environment. Sediment plumes from dredging and placement activities were low concentration, localised and of short duration, and did not persist beyond the completion of dredging.
Sediment
A Sediment Characterisation Study was completed in January 2024 as per the 5-yearly requirement under the National Assessment Guidelines for Dredging 2009. The sampling confirmed compliance of maintenance dredged material to the National Assessment Guidelines for Dredging 2009 and continued suitability for ocean placement at the approved Hay Point Dredged Material Placement Area.
Turtles and dugongs
No interactions or observations of turtles and dugongs were recorded during dredging and placement activities.
Biosecurity
No marine pests identified during activity.
Specific management measures were implemented during dredging activity at Port of Hay Point to minimise the incursion of marine pest species (Dredge Environmental Management Plan).
View North Queensland Bulk Ports monitoring reports.
Port of Karumba
Maintenance dredging
A total of 84,536m3 of material was dredged at the Port of Karumba from 9 June 2024 to 28 June 2024 (Trailing Suction Hopper Dredger Brisbane) and 12 June 2024 to 30 June 2024 (bed levelling vessel Pacific Titan). Dredging was undertaken at the channel including amended alignment for the established navigational area.
Activities were completed under the 10-year permit resolved with the Australian Government and an amended Environmental Authority with the Queensland Government. All works were compliant and consistent with the Environmental Authority and Sea Dumping Permit conditions. The volume dredged was within the annual permit limit. The annual fee for the Environmental Authority was submitted.
No permit non-compliances, environmental incidents or complaints were reported.
Environmental assessments
Seagrass
The Long Term Seagrass Long Term Monitoring Program annual survey was completed by James Cook University, TropWater. Continued productive meadows were observed in late 2023, with indications of some loss of biomass in some areas. The potential influence of the early 2024 wet season across the southern Gulf of Carpentaria on seagrass status was considered in preparation for the mid-year dredging campaign. Outcomes of the November 2024 annual seagrass monitoring indicated a further notable decline in seagrass condition as a result of flooding. This will be considered in the risk assessment and preparation for the 2025 campaign.
Water
Water quality verification monitoring under the Environmental Authority was required during the period, and campaign specific sampling was conducted between 7 June 2024 and 4 July 2024. Outcomes were satisfactory and no adaptive management of the campaign was required due to trigger levels not being reached.
Sediment
The 5 yearly Sediment Analysis Plan process was implemented in March 2020, along with specific sampling of the channel bend navigation area so as to inform application process.
No events recorded within intervening period or in advance of the 2024 campaign likely to have caused a change in contaminant status. Next Sediment Analysis Plan implementation is due in 2025.
Turtles and dugongs
No interactions or observations were recorded during dredging or placement operations of the Trailing Suction Hopper Dredger Brisbane activity.
Biosecurity
Benthic surveys were completed in 2020, with no detections within the areas to be dredged or at the dredged material placement area as set out in the Sediment Analysis Plan. There were no detections or reports of verified marine pests or samples requiring identification during the 2024 period.
Port of Townsville
Maintenance dredging
A total of 442,300m3 of material was dredged by the Trailing Suction Hopper Dredger Brisbane from 15 September 2024 to 16 October 2024 and 4 November 2024 to 8 November 2024. Dredging was undertaken at the Platypus Channel, outer harbours, inner harbour and authorised berth pockets.
A total of 6,154m3 of material was dredged by the PMG121 and PMG123 grab dredgers at various locations from 2 January 2024 to 18 January 2024 and 3 October 2024 to 24 October 2024.
Two on board permit compliance observations were undertaken for the Trailing Suction Hopper Dredger Brisbane. These observations were to verify controls are being implemented as per the Environmental Management Plan and permits. No issues were identified.
No environmental incidents or complaints were reported.
Environmental assessments
Seagrass
Seagrass monitoring within Cleveland Bay was undertaken in September and October 2024. The report will be made available on the Port’s website once finalised in early 2025.
View the 2023 Cleveland Bay monitoring report.
Water
The Port of Townsville conducts quarterly marine water monitoring within the Port and the surrounding environments. The Port also deploys two real time water quality monitors in Cleveland Bay that measure temperature, turbidity and electrical conductivity. While the Port endeavours to provide data throughout the year, severe weather events and maintenance means that the equipment is unavailable occasionally. During the 2024 maintenance dredge campaign, one buoy experienced intermittent communication issues. During this time the Port provided a link to data from its underwater turbidity and light sensors located in Cleveland Bay while the buoy was being repaired. Regular analysis of the real time water quality and satellite imagery was undertaken before, during and post dredging.
View the Cleveland Bay buoys data.
Marine water data has also been provided for the Healthy Waters Partnership for Dry Tropics Annual Report Card. The 2024 Report Card is based on monitoring data from the previous year, collected from July 2022 to June 2023.
Sediment
A sediment characterisation study was completed in March 2021 as per the 5-yearly requirement under the National Assessment Guidelines for Dredging 2009. All material was assessed as suitable for unconfined sea placement, except that in Berths 3, 5, 8, and berths 6/7 (no longer in use), and Ross Creek. Should any material from these areas need dredging, the Port has sufficient land placement areas to cater for this material.
A supplementary sediment and analysis plan was undertaken in 2024 and approved by regulators in September 2024 for the maintenance dredging of widened channels which were completed in March 2024 as part of the Channel Upgrade Project. All maintenance material was assessed as suitable for unconfined sea placement.
The Port of Townsville conducts biannual marine sediment monitoring within the Port and the surrounding environments. This grab sampling aids in monitoring sediment between the 5 yearly sampling and analysis plan programs.
Turtles and dugongs
Marine fauna visual observations were undertaken during dredging and placement, as per the Port’s permit conditions, and the dredge Environmental Management Plan requirements.
Biosecurity
Port of Townsville partners with Biosecurity Queensland and other Queensland Port Authorities on the Queensland Seaports eDNA Surveillance (Q-SEAS) marine pest monitoring program. The White Colonial Sea Squirt continues to be sighted in Townsville waters and around port infrastructure. View further information on the White Colonial Sea Squirt in Queensland.
Port of Weipa
Maintenance dredging
A total of 717,400m3 of material was dredged by the Trailing Suction Hopper Dredger Brisbane from 12 May 2024 to 6 June 2024 and 30 June 2024 to 18 July 2024. Dredging was undertaken at the Port of Weipa South Channel, inner harbour and berths.
All works were compliant with state and federal approvals, with no reported complaints. There were 4 reported potential environmental incidents. The incidents were operational in nature and did not result in additional environmental risk or environmental harm. All were reported within required timeframes and appropriate controls implemented to prevent reoccurrence. Regulators determined no enforcement action was required.
Environmental assessments
Seagrass
Annual seagrass monitoring was conducted in the Port of Weipa during August and September 2024. The report will be made available on the North Queensland Bulk Ports website once finalised.
Water
North Queensland Bulk Ports completed ambient marine water quality monitoring prior to, during and post the maintenance dredging program. Data from the water quality monitoring as well as satellite-derived turbidity data was analysed.
The data showed that during the 2024 maintenance dredging program, the turbidity was generally driven by the natural conditions (tidal currents and wind/wave conditions). The Port of Weipa 2024 maintenance dredging program did not influence the regional turbidity of the area.
View a summary of the turbidity monitoring.
Sediment
A Sediment Characterisation Study was completed in January 2023 as per the 5-yearly requirement under the National Assessment Guidelines for Dredging 2009. The sampling confirmed compliance of maintenance dredge material to the National Assessment Guidelines for Dredging 2009 and continued suitability for ocean placement at the approved Albatross Bay Dredged Material Placement Area.
Turtles and dugongs
Visual observations were undertaken and recorded in dredge logs. No interactions or observations were recorded during dredging or placement operations.
Biosecurity
No marine pests identified during activity.
Specific management measures were implemented during dredging activity at Weipa to minimise the incursion of marine pest species (Dredge Environmental Management Plan).
- Last updated
- 17 June 2025