• Skip to primary navigation
  • Skip to main content
Featured Project: large, engineered log-jam structures to stabilise actively eroding streambank
catchment-solutions-logo
catchment-solutions-logo-white
Search
  • About
    • Vision, Capabilities & Values
    • Our board
    • Our team
    • Positions vacant
  • Work with us
  • Services
    • Water Quality Services
    • Agricultural Innovation and Support
    • Fisheries & Aquatic Ecosystems
    • Environmental Planning & Approvals
    • Ecosystem Rehabilitation & Repair
  • Projects
    • Featured Projects
    • Agricultural Innovation and Support
    • Ecosystem Rehabilitation & Repair Projects
    • Environmental Planning & Approvals
    • Fisheries & Aquatic Ecosystems
    • Water Quality Services
    • Archived Projects
  • News
  • Media
  • Contact
  • About
    • Vision, Capabilities & Values
    • Our board
    • Our team
    • Positions vacant
  • Work with us
  • Services
    • Water Quality Services
    • Agricultural Innovation and Support
    • Fisheries & Aquatic Ecosystems
    • Environmental Planning & Approvals
    • Ecosystem Rehabilitation & Repair
  • Projects
    • Featured Projects
    • Agricultural Innovation and Support
    • Ecosystem Rehabilitation & Repair Projects
    • Environmental Planning & Approvals
    • Fisheries & Aquatic Ecosystems
    • Water Quality Services
    • Archived Projects
  • News
  • Media
  • Contact
Project enquiry
Hide Search

Clyde Creek

150 tonnes of hardwood set to stop river erosion in Gladstone

diana · Jul 2, 2019 ·

Scientists have engineered 150 tonnes of salvaged hardwood into ‘log jam’ structures to halt heavy erosion in Clyde Creek, Gladstone.

It is the first time the novel environmental solution has been used in the area.

And while log jams have been used in freshwater rivers previously, this could be the first successful attempt to install them in a tidal estuary in Queensland.

Five of the structures – each made up of 17 hardwood logs and weighing 25 to 30 tonnes – were lowered into Clyde Creek 10 months ago.

Aquatic ecologist Matt Moore (environmental consultancy Catchment Solutions), said the Clyde Creek bank had been retreating at an alarming rate of 0.25 metres each year.

The log jams combat erosion, and are designed to deflect water away from the river bank back into the centre of the water course.

Habitat for fish species

In a triple-barrelled win, they also provide habitat for key recreational fish species like barramundi and mangrove jack; and give marine plants such as mangroves a chance to rehabilitate.

“The log jams give the creek bank a break. Previously, when fast water hit the bank in Clyde Creek, it was eroding badly, dropping sediment into the creek and out to sea. This solution benefits both the local waterway and ultimately the wider marine system. It means less pollutants washed out.”

Mr Moore said installing the log jams had been a stick-by-stick engineering feat in a tidal zone.

“We were racing against the tide to get the log jams in, with cranes and excavators on site.

“On a tidal flat, we can’t use machinery that is too heavy. The process is called stick building – we had a crane putting the logs into position one-by-one before the tide came back and washed us out!”

The log jams are five-storey engineered structures, about 3 metres high, with the logs arranged in a criss-cross pattern.

“We sourced salvaged native hardwood, that would otherwise have been wood-chipped or burnt,” Mr Moore said.

The natural ‘root ball’ ends of the logs were also kept attached as habitat structures for key fish species.

“Juvenile and adult fish can use the structures for protection from predators and currents and in turn this will be a real bonus for keen local fishers in the future!” Mr Moore said.

“The root balls provide ideal fish habitat where species like barramundi and mangrove jack can live and breed.

“It meant a lot more work was involved when extracting the salvaged trees, but we know fish love to take refuge in tree roots, and are attracted to them.

The log jams will also give marine plants such as mangroves a chance to recruit and re-establish. The local mangrove population will be monitored for improvements ahead.

Mr Moore said he was now keen to see the habitat structures replicated in other tidal estuaries and rivers across the state.

This project has been funded by the Queensland Government through the Department of Agriculture and Fisheries as part of offsets funding. The Engineered Log Jams were constructed by Catchment Solutions.

Clyde Creek Marine Fish Habitat Rehabilitation Project

diana · Nov 6, 2018 ·

Background and Objectives
In July 2018, Catchment Solutions conducted a marine fish habitat rehabilitation project in Clyde Creek, Gladstone. The project aimed to achieve a range of outcomes by undertaking a holistic suite of system repair works through utilising large, engineered log-jam structures to stabilise a section of actively eroding streambank, while improving fish habitat for economically important species.

Specifically, the objectives of the project were to;
• Restore fish habitat function on a severely eroded estuarine creek bank by reconnecting fragmented marine plant communities,
• Prevent further erosion processes from degrading marine plant and fish habitats,
• Incorporate innovative structures to increase the availability of structurally complex fish habitat,
• Increase fisheries productivity by providing habitat for economically important fish species, such as mangrove jack and barramundi, and
• Reduce sediment export to downstream receiving environments i.e. Calliope River and Great Barrier Reef Marine Park.

Engineered log-jam structures were identified as the best remediation option to achieve the objectives at this site, with five structures, each containing 17 logs, constructed along the streambank. Log jams are permeable structures that extend into the stream for a short distance to deflect erosive stream flows away from the streambank into the main channel, thus preventing further erosion. This promotes the deposition of sediment on the downstream side of the structure, thus providing adequate substrate for growth of marine plants. It is the re-colonisation of marine plants at the site that will repair the streambank into perpetuity, and it is the role of the log jams to provide the correct hydraulic conditions (reduced bank velocity) and deposition areas for marine plants to colonise. Importantly, the log-jam structures have the advantage of providing critical, structurally-complex instream habitat for a range of socioeconomically important fish species.

Clyde Creek Erosion
Clyde Creek Erosion
Clyde Creek Erosion
Clyde Creek Erosion
Clyde Creek Erosion

Figure 1. Site images before remediation works, showing extent of erosion and degradation of the streambank and the lack of instream fish habitat and marine plant colonisation.

Log Jam Construction
A slew crane was utilised to lower each log, one at a time, into voids created in the streambank (Figure 2). Once all 17 logs of the structure had been positioned in place, 12 mm fibre core wire rope was used to secure all logs of the structure together. A lever block was utilised to provide maximum tension on the fibre core wire rope, ensuring no slip or movement of logs within the structures. 7 m pin logs were then driven into the substrate outside of the structures to provide further stabilisation (Figure 3 and Figure 4).

Figure 2. Slew crane lowering logs into position.

Figure 3. Structure near completion, showing first fibre core rope secured around the structure.

Figure 4. Structure with fibre core wire rope secured and 7 m pin logs driven into substrate for further stabilisation.
The final step in securing the structures in place was to back fill the voids structures were built within using rock. An excavator was used to fill the voids and compact the rock around the structures, to firmly lock the structure into position within the streambank (Figure 5 and Figure 6).

Figure 5. Side profile of completed structure with rock fill and armouring in place.

Figure 6. Image of completed structure, with rock fill and armouring in place.

Following completed construction of all five structures, when all construction machinery had vacated the site, a single excavator was used to batter the top section of slumping streambank back to a 1V: 3H gradient (Figure 7). This will minimise future erosion and provide suitable conditions for the re-colonisation of mangroves and other marine plants. Once established, the marine plant communities will further consolidate the reformed streambank and provide additional fish habitat into the future.

Figure 7. All five log-jam structures and the battering of the top metre of streambank to reduce future slumping and facilitate marine plant colonisation.

Figure 8. Structure 4 and structure 5 at downstream extent of site (left) and close up of rootballs of structure 4 (right).

Project Outcomes
The engineered log-jam structures will rehabilitate the actively eroding streambank by dissipating and deflecting stream flows away from the impacted streambank and back into the centre of the waterway. The structures also encourage the deposition of sediment transported from the upper catchment. This deposition will occur in areas of low velocity, on the downstream side of the structures. Future marine plant communities established due to the remediation works will eventually reconnect with remnant communities upstream and downstream of the works, stabilising and protecting the streambank from continued erosion. Additionally, the large rootballs present within the structures will provide critical habitat for a range of socioeconomically important fish species (Figure 9).

Clyde Creek Erosion
Clyde Creek Root ball structures to rehabilitate streambank erosion
Clyde Creek Root ball structures to rehabilitate streambank erosion
Clyde Creek Erosion, monitoring the sediment loss.
Clyde Creek Erosion, monitoring the sediment loss.

Figure 9. Before and after photos of remediation works (top; facing downstream and bottom; facing upstream)

Benefits to Fisheries Resources
The primary benefit of the project to fisheries resources, is through the provision of critical, structurally complex habitat, specifically, during low tide periods. Due to the previous years of active erosion at the site, available habitat is virtually non-existent at low tide. The structures now provide a number of locations where important commercial, recreational and indigenous fishery species such as barramundi, mangrove jack, threadfin salmon and bream, can seek refuge (Figure 10). These structures will also provide crucial refugia habitat on high tides for juvenile fish and baitfish species such as mullet, herring and glassfish for predator avoidance.

Clyde Creek Root Ball Structure

Figure 10. Image of structurally complex rootballs (left), three-dimensional habitat within the log-jams (right).

Future Monitoring
Future monitoring will continue to assist in determining project success and help convey results to stakeholders. Monitoring activities will include monitoring marine plant establishment to describe species composition, community structure and size class densities, sediment erosion/deposition on the streambank and fish community monitoring will also occur via underwater video analysis utilising baited and unbaited cameras (Figure 11).

Figure 11. Baited remote underwater video (BRUV) system utilised for monitoring at the site

Search

catchment-solutions-logo-white
  • Mackay Office

    PO Box 815
    Mackay QLD 4740

  • +61 (07) 4968 4216

  • info@catchmentsolutions.com.au

  • Melbourne Office

    Exhibition Street, Melbourne

  • 0408 139 289

  • info@catchmentsolutions.com.au

Tailored End-to-End Environmental Solutions

Helping clients Australia-wide to manage, design and execute projects to meet high standards of environmental excellence and corporate responsibility.

© 2025 Catchment Solutions · WordPress by The DMA
  • Legal
  • Privacy