Restoring Collinson’s Lagoon through partnership
A partnership between NQ Dry Tropics, Burdekin Shire Council and local landholders is helping restore the health of Collinson’s Lagoon, a coastal wetland that flows into the internationally-recognised Ramsar-listed Bowling Green Wetlands, south of Townsville.
Part of the Lower Burdekin irrigation network, used by Lower Burdekin Water and SunWater, the lagoon provides important habitat for native juvenile fish species like barramundi, sleepy cod and bony bream, as well as a diverse range of birds, reptiles and amphibians.
Naturally an ephemeral wetland, Collinsons Lagoon should dry out during winter. However, decades of altered water flows have left it permanently inundated, allowing invasive aquatic weeds such as water hyacinth, water lettuce and salvinia to flourish.
Woody weeds and exotic grasses along the banks have also increased the risk of intense bushfires, threatening remnant cloudy paperbark (Melaleuca dealbata) communities that provide vital wildlife habitat and help stabilise creek banks.
The Climate-Ready Coastlines project is tackling these threats with targeted weed control, fire management and habitat restoration to improve the lagoon’s ecological health and resilience.
The amphibious excavator in action at Collinsons Lagoon
Before: Looking upstream from the Collinson’s lagoon confluence before weed removal work began.
During: At the halfway mark, with open water now visible.
After: The amphibious excavator completed the work.
Restoring open water values
An amphibious excavator recently spent 10 days removing dense infestations of aleman grass and hymenachne, growing on thick mats of water hyacinth, water lettuce and salvinia, which had formed a floating blanket across the lagoon.
Senior Project Officer Georgia Robinson said the scale of the infestation required specialised machinery to safely remove the weeds to restore open water while minimising environmental impacts.
“Weed chokes strip oxygen from the water as they decompose, leading to potential fish kills, and reduced feeding opportunities for wader birds,” Georgia said.
“During floods they act as physical dams, causing trapped water to rise quickly and potentially damage bridges, culverts and farm infrastructure.
“The excavator did a great job restoring open water, which will enable Burdekin Shire Council’s Pest Management Team to undertake follow-up control measures on pockets of returning floating weeds, using its Weedoo weed removal boat.
“Complete eradication is impossible; however, with ongoing management, the objective is to prevent the weeds from covering more than 25 per cent of the lagoon at any time,” she said.
Senior Project Officer Georgia Robinson
Protecting riparian habitat with grazing
Restoration efforts also focus on protecting remnant cloudy paperbark (Melaleuca dealbata) communities, which stabilise creek banks, filter sediment, provide habitat for native wildlife and help suppress invasive weeds.
Wetlands Team Leader Scott Fry said decades of intense late dry season fires had reduced many of these important tree stands, making fuel reduction and a dedicated ‘no fire’ management plan essential.
“Exotic species like paragrass surround the paperbarks and increase the risk of devastating damage if a fire occurs,” Scott said.
One of the many benefits of riparian vegetation, particularly paperbark trees, is the habitat they provide for wildlife. The loose bark creates ideal shelter for hundreds of microbats.
“A single microbat can consume between 600 and 1200 mosquito-sized insects every hour, eating thousands of insects over the course of a night. This natural pest control can benefit growers of small crops, while the bats’ nutrient-rich guano also provides a natural source of fertiliser.
“This site has been a long-term cattle grazing site for more than 17 years, which seasonally grazes these exotic grasses, and demonstrates their effectiveness as a seasonal biological control tool for wetland management.
“Rather than using herbicide, carefully managed grazing is a preferable cost-effective solution, with a bonus of promoting weight gain for cattle.
“Unfortunately, three significant wet seasons have prevented cattle from grazing the area, however, we hope to reintroduce this practice to benefit the overall health of the system,” Scott said.
Wetlands Team Leader, Scott Fry
Building on decades of collaboration
The restoration program is guided by a System Management Plan developed in 2021, building on more than 20 years of collaboration between local organisations, landholders and water managers.
A key outcome has been the establishment of a Riparian Management Agreement (RMA), a cost-sharing model that funds ongoing weed management through contributions from landholders, Burdekin Shire Council, the local water utility and NQ Dry Tropics.
Wetlands Team Leader Scott Fry said the agreements supported on-ground works and encouraged shared responsibility for protecting local waterways.
“Collinsons Lagoon is one of eight creek systems whose ongoing management is supported by an RMA,” Scott said.
“We’d like to acknowledge and thank everyone involved for their contributions to the RMA, which provides vital funding to complement projects like Climate-Ready Coastlines.
“In the tropics, it doesn’t take long for weed populations to explode, but through strong partnerships we can stay ahead of the problem and restore Collinson’s Lagoon to a healthier, more natural state for future generations,” Scott said.
Actions at Collinsons Lagoon are guided by a comprehensive System Management Plan
The Climate-Ready Coastlines project is delivered by NQ Dry Tropics and funded through the Queensland Government’s Natural Resource Management Expansion Program.
This is the project attribution that needs to go at the bottom of the story in a shaded box (smaller point size).
