Solving the world’s problems, one wetland at a time

UNSW engineering researchers are using science from their award-winning wetlands projects to save large estuaries across Australia. With 80% of the population living near an estuary, their work can change the environment we live in.

Researchers from the Water Research Laboratory (WRL) at the UNSW School of Civil and Environmental Engineering are solving one of the world’s biggest ecological problems. By showing how wetlands damaged by acidic soils can be restored to their former glory, the group is setting the standard for other sites to follow.

Their work began in 1999 when Principal Research Fellow Dr William Glamore conducted research on how to restore small former wetland sites.  This foundational research helped develop techniques that allowed larger sites to be remediated and, by 2004, Will and his WRL research team were working on former wetlands in Tomago, in the NSW Hunter Valley.

The sightings of thousands of migratory shorebirds are the best demonstration the project has achieved what it set out to accomplish.

A site drained

The Tomago Wetlands site was historically an important area for migratory shorebirds travelling along the East Asian flyway. The birds, which flew from Siberia through Asia on their way to Australia, used the wetlands to rest and feed.

The water quality in modern-day wetlands across Australia is poor due to European settlements clearing vegetation and constructing drainage canals. In addition to standard farming, the Tomago site (which is near the RAAF base) was used for military purposes and the creation of rice paddies. By the late 1970s, the installation of tidal floodgates transformed the area into a series of paddocks with poor water quality. 

Dr William Glamore, Principle Research Fellow from the Water Research Laboratory“The site was drained and turned into farm paddocks in the 1960s and 1970s,” Will says. “Since then there has been a call to restore the site, despite many unsuccessful attempts to farm the land.” 

The challenge was to transform what looked like a grass paddock into over 400 hectares of beautiful tidal wetlands.  So the team started the task of recreating the ideal ecosystem from the ground up.

Making saltmarsh to attract birds

One of Will’s group, senior engineer Duncan Rayner, undertook crucial work for the restoration project. Using engineering, mathematical and science techniques, Duncan and the WRL researchers developed numerical models from computer software to design the daily volumes of tidal exchange that would be needed to reinstate the correct tidal depths.

They began small, looking at an area of a few hundred hectares. Innovative floodgates called “SmartGates” were designed and programmed to allow for the controlled restoration of Stage One and the creation of a saltmarsh habitat over 100 hectares.  In 2011, Stage Two was added, increasing the site size by another 200 hectares. In 2015, Stage Three completed the entire wetland restoration.

Big Swamp, which was initially an example of what not to do with wetlands, is now the 'posterboy' for how to go about restoring them.The results have been startling. The Tomago site is now listed as a Ramsar wetland, which means it is protected as an area of international importance for conserving biological diversity. Although researchers successfully made saltmarsh to attract migratory birds, no birds showed up for several years after the vegetation had re-grown. “Then literally one day, about three years ago, 2000 birds showed up out of the blue,” says Will.

Today nearly 5000 birds visit the site regularly, which is equivalent to about 5 per cent of the total population worldwide. The sightings of thousands of migratory shorebirds are the best demonstration the project has achieved what it set out to accomplish. 

Fixing a big problem

On the Manning River, near Taree, the WRL team is working on a project called ‘Big Swamp’. Taking lessons from Tomago, the team worked with Greater Taree Council to acquire about 800 hectares of land and redesign the landscape using fieldwork, computer modelling and on-ground scientific activities. 

Successfully completing the work without having an impact on nearby landowners was a major challenge. “It is a really large site – almost double the size of Tomago,” Will says. “It’s exciting to see such major changes to such a large landscape.”

The Big Swamp site produced major volumes of sulphuric acid from agricultural drains. “The drains lowered the ground water table exposing thousands of years of sulphur accumulated in the landscape to atmospheric oxygen,” says Will. “This filled the site with sulphuric acid, causing poor water quality. While this is common in every estuary, the lack of monitoring means we are largely unaware it is happening.”

Another research engineer working with Will, Jamie Ruprecht, had a personal interest in the success of the project, coming from a family with four generations of oyster farmers. Following floods in the catchment, Jamie and the WRL team monitored an acid plume for three weeks as it travelled down the river towards oyster fields,making front-page headlines in The Sydney Morning Herald. Will says the media interest helped draw attention to the problem.

Big Swamp, which was initially an example of what not to do with wetlands, is now the poster boy for how to restoration them. “The site has now completely changed,” says Will. “The tide comes in, flushes across the landscape and drains out. The wetland works, the water quality is much better and we have begun to fix a huge problem.”

Members of the Research team from the Water Research Laboratory (WRL) at the UNSW School of Civil and Environmental EngineeringThe group’s research has been recognised by governments at all levels. WRL has won several awards for sustainable solutions and innovative on-ground outcomes, allowing funding to continue its research and improve restoration techniques in Australian wetlands: 

Will’s work has been recognised with several personal awards, including a Winston Churchill Fellowship and a Peter Cullen Fellow.

Achieving state-wide wetland restoration

Using knowledge gained from their successful restoration works, the researchers are scoping, planning or monitoring many large sites on the NSW coast. “But that is a drop in the ocean for the number of sites we could work on,” says Will. “There are 5 million hectares of acid sulphate soils across Australia, and they all produce varying amounts of acid.” 

The WRL hopes to develop state-wide remediation strategies. “What makes the Tomago and Big Swamp projects different is that we are trying to evolve away from trial-and-error techniques,” says Will.  “We now have techniques for every stage of the restoration process and should be using these methods to do it properly in the future.” 

UNSW Water Research Laboratory: Tomago Wetlands Restoration Project

Acknowledgments

The team at WRL could not have accomplished its research without the support and funding from colleagues at the NSW Department of Primary Industries (NSW Fisheries), the NSW Department of Environment and Heritage, National Parks and Wildlife Service (NPWS) (“… it is their park, they are the ones making it all happen,” says Will), Hunter Region Local Land Services, Greater Taree City Council, Shoalhaven City Council, NSW Local Land Services, and Hunter Bird Observers Club.

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