Dredged Material Management Facility, Ningi

City of Moreton Bay had been searching for a suitable site to manage dredged material from Pacific Harbour canals for many years. The site at 1077 Bribie Island Road, Ningi, was identified as suitable for use as a Dredged Material Management Facility (DMMF) as it is:

• close to the Pacific Harbour Canal Estate on Bribie Island
• large enough to manage dredged material, while maintaining buffers to adjacent residences
• a disturbed site that has existing disused prawn farm ponds, which are suitable for containing dredged material.

In 2019, we purchased this site as a strategic land acquisition for the future storage and treatment of dredged sediment.

Natural areas

The site has remnant bushland along the eastern boundary. This area includes eucalyptus woodlands and mangrove areas. As part of the site's development and management, Council monitors the area and treats weed species.  

The western part of the site was once a pine plantation. The previous owner legally harvested pine trees before Council purchased the land. 

Council is managing the native revegetation along the western sides of the site, including infill planting. As part of the revegetation works, we're incorporating fire and asset protection breaks into the plantings. As well as managing overland stormwater flows.

1. Yellow line: Property boundary, Purple line: Fire control line, Blue line: Swale drain
2. Orange line: Services corridor (power and sewerage)
3. Revegetation area
4. Dredged material placement area (repurposed aquaculture ponds)
5. Protected vegetation area (RE 12.5.3 Endangered and 12.2.5 Least Concern)

Cultural heritage

City of Moreton Bay and the Kabi Kabi indigenous traditional owners of the Ningi site completed a survey that identified areas and artefacts of cultural heritage significance.

Together with the Kabi Kabi people, we have implemented ongoing protection of the site’s cultural heritage and are working together on a strategic partnership for managing the site’s cultural and natural values.

Ponds

The disused aquaculture facility once used the 11 existing large ponds. 

As part of the planning and design for the Pacific Harbour dredging works, a detailed analysis took place. This was to determine the strength, stability and capacity of the ponds. 

Safety and security

The site is not open for public access or use at any time.

Council will continue to undertake vegetation management and assisted natural regeneration works. These works will continue to improve the natural vegetation values within the area. 

Use of the site for dredge spoil management commences in early 2025. During the dredging campaign, residents may notice minor or temporary impacts that managed on-site: 

Noise

There may be minor noise impacts from the Ningi site associated with the operation of vehicles. The site will be operational only during daylight hours, 7:00 AM to 5:00 PM, Monday to Saturday. The construction contractor monitors site noise to follow approval conditions.

Dust

Some dust may be generated within the Ningi site from vehicles using the unsealed roads or from the dried dredged material. Dust will be managed with dust suppression.

Odour

The marina muds and sands dredged may produce an odour when exposed to air, like the mangrove system in Ningi Creek at low tide. 

We will use odour suppressants and other techniques to limit the impacts on neighbouring properties. 

Water quality

The ponds on the site will dewater and dry the dredged material. 

The existing pond layout on the site meets State Government requirements. Council will take advantage of these existing ponds to treat water before discharge. Any water discharged from the site will meet the environmental thresholds set by the State Government. 

Mosquitoes 

Council has a comprehensive mosquito management program across the city, including the Ningi site. Read more information on Council's mosquito treatment program. 

Treatment process

Once placed into the existing ponds, the dredged material dries out by natural solar drying. Treatment of any residual acid sulfate soils at the ponds will occur if it's detected in the dredged material.

Once completed, dredging at Pacific Harbour will not need to take place for approximately 10 to 20 years.  

During this time, the material will have settled and dried significantly. This improves the geotechnical capacity of the material and creates additional capacity in the ponds. 

Rehabilitation of the native habitat will continue at the site. 

Council does not yet have any plans for the future use of the site or any potential beneficial reuse of the dredged sediments.