Going ‘around the grounds’ to end 2024: a bird’s-eye view of an assortment of NGT wetland restoration sites
Over recent months I have managed to drop in on a number of NGT’s longer-term wetland restoration sites from across SA, Victoria and Tasmania, to check current conditions. Given that a number of sites have experienced well below average rainfall in 2024, read on if you are interested to learn what I discovered…
Square Waterhole Swamp (Fleurieu Peninsula, SA)
One of the benefits of restoring peatlands, which includes some of the endangered Swamps of the Fleurieu Peninsula, is that the very nature of these communities offers some degree of in-built resilience during drier times. At previously drained sites, once drains have been backfilled and the peat profile has been successfully resaturated, the peat itself has the capacity to act as a sub-surface ‘reservoir’; effectively buffering the water needs of the ecological communities that grow in association with the restored peat.
Back in June, Ben shared this update about the restoration works completed in 2023 at Square Waterhole Swamp (near Mount Compass), and the rapid recovery that was being observed at ground level a year later. We didn’t share an equivalent oblique view at the time, so now I have the chance to do so!
Below you will see views before and after works, looking east across the southern portion of Square Waterhole Swamp, where it straddles Hesperilla Conservation Park (left half of image), a council reserve and private land (right half of image).
Some of the changes are obvious, like the backfilling of drains and the concurrent removal of weeds like pines, willows and blackberry that were growing on the spoil banks. You will also see the early spontaneous establishment of native plants within the temporarily re-disturbed footprint of the former drains, some of the supplementary revegetation completed by the Hills and Fleurieu Landscape Board (visible via the tree guards) and the bright green regeneration of wetland plants within the prescribed burn area in the Park.
In the final image shown above from 2024, if you look closely, you will also see the reflection of puddles of water in a number of places where the drains used to be, and the generally darker green tinge of the resaturated ground to the right of the image.
Mount Burr Swamp (Limestone Coast, SA)
NGT’s Mount Burr Swamp Restoration Reserve is sustained by a shallow perched groundwater aquifer that is seasonally recharged by rainfall.
Despite the dry winter in 2024, and levels being much lower than the same time last year, Mt Burr Swamp proper (which also happens to be a peat wetland) is still holding water and providing vital drought refuge habitat, as shown in the comparison below. You can also check out a nice short video flyover of the wetland that Bryan put together a few months back, by clicking here.
Again, this site has the benefit of restoration works causing some recovery of the local groundwater system around the swamp, which in turn then also repays the favour by helping to sustain the wetland during drier times. When I was out there in mid-December, there was also a Southern Bell Frog (aka Growling Grass Frog) chorus in full swing around the main wetland, meaning that breeding is underway at the site again this year.
Looking back in the opposite direction (to the east) over the more recently restored Stage 2 wetlands of the Reserve, and the drier year is much more apparent in these seasonal wetlands which are not as deep as Mt Burr Swamp proper. Compared to the same time last year, only a fraction of these wetlands (the deepest basins) are still holding water, and some of them didn’t get wet at all this year. Hopefully they will get a better drink again next year!
Hutt Bay Wetlands (Limestone Coast, SA)
Down on the coast south of Mount Gambier, it has also been a dry year for NGT’s Hutt Bay Wetlands Restoration Reserve, but since we backfilled the drains we have seen a major improvement in the condition of the wetland, especially up the eastern end of the Reserve. This is where a freshwater spring under a patch of rare alkaline peat fen tea-tree habitat seeps a slow trickle of groundwater into the wetland downstream, and this water is now retained (rather than drained away) since the artificial drains were backfilled two years ago. You can see the dark patches and lush green growth around the tea-tree patch in the foreground below – perfect habitat for nationally threatened species that have been recorded here like the Australasian Bittern, Swamp Antechinus and Swamp Skink.
In the background is an open terminal wetland in the deepest part of the wetland chain, known locally as Pascoe Swamp. This seasonal wetland naturally becomes quite saline as is dries down, and straddles the boundary of the NGT Reserve and adjacent private land. This part of the site is still holding a shallow sheet of water, but is drying fast.
To learn more and take a look at the works previously completed at this site, you can follow this link,
Long Swamp (Discovery Bay, Victoria)
Just around the coast and across the border into Victoria, and NGT’s long-running restoration project at Long Swamp, in Discovery Bay Coastal Park (also a Ramsar Site), is one of the few wetlands in the region that is bucking the trend, and showing no signs at all that it has been a dry year.
As you’ll see below, if anything, the site is slightly wetter than at the same time of year 2 years ago, meaning that it will provide incredibly important drought refuge habitat over the coming months. This wetland also interacts with shallow groundwater, which has been replenished through the restoration project, and this in turn improves its responsiveness of any larger rainfall events, like the inch or two that fell at the end of November and beginning of December.
Beyond the restoration site itself at Nobles Rocks, we’ve also recreated the natural flow-path throughout Long Swamp between Lake Momboeng and the Glenelg River mouth, enhancing the 11km of wetlands situated to the west, between Nobles Rocks and the estuary, through restoration of their hydrological regime.
Walker Swamp (Southern Grampians, Victoria)
The tough year for rainfall in 2024 has been more pronounced at Walker Swamp, where the deepest part of the wetland is now looking likely to dry down completely this summer for the first time since permanent restoration works were completed in 2019. The wetland will bounce back of course, but it does give us an indication of the tougher conditions that the site has experienced this year, with no inflows received at all over the winter or spring.
This trend is clearly visible in the view over Walker Swamp proper, which has a lower water level now than it did back in March (when it was already much reduced from full). As it dries, the salinity of Walker Swamp is also naturally increasing as the saltwater concentrates through evaporation. When Lachie measured this recently it was sitting at 14,000 EC (for comparison, seawater is about 50,000 EC).
It will be great to see this wetland explode back to life and freshen up when the water returns, and that certainly can’t come soon enough, with the Grampians experiencing major bushfires near Walker Swamp as I write this update.
Green Swamp (Southern Grampians, Victoria)
Being situated only a short distance from Walker Swamp, Green Swamp has experienced an identical trend of drying this year. The images below show how much the wetland has reduced in extent since the last time it filled in winter 2023.
Despite the reduction in size and a parallel increase in salinity (recently sitting at 18,000 EC), the importance of this wetland to the western Victorian landscape this summer is already being highlighted by the early arrival of vast numbers of flocking Brolga. The other day, Lachie counted 140 in the flock; numbers that we have come to associate with the autumn and early winter period, prior to the dispersal of pairs for breeding. After what we now assume has been a very poor year for breeding due to a lack of wetlands in the landscape, the flock are gathering here early this season – so hopefully the deepest part of the wetland persists for a while longer.
If it hadn’t been restored by NGT in 2014, it is worth remembering that Green Swamp would now be completely dry – highlighting the massive impact that artificial drainage is having on the landscape and the key role that wetland restoration now plays in helping to get our wildlife through the dry times.
Rowan Swamp (Goulburn Valley, Victoria)
Across to the north of Victoria to Rowan Swamp, near Benalla, and a couple of minor flows down Boosey Creek in 2024 have helped to give this restored wetland a minor drink. When I visited in November, the last of the water was drying up, but the recovering wetland vegetation across this shallow swamp was still looking lush!
While I was there, I thought I’d record a few observations about what I was seeing – so if you have 10 minutes to spare, have a look and listen to the video below. Not the most professional production, but this will help you understand the changes we have been seeing and the positive impacts of the restoration trial…
Finally, the view below (comparing 2021 to 2024, before and after the construction / influence of the trial structure) shows a couple of things worth noting. Not only has the erosion in this area upstream of the trial structure been halted, but the wetland vegetation recovery has been dramatic!
Apsley Marshes (East Coast, Tasmania)
The Apsley Marshes, on Tasmania’s east coast adjacent to Moulting Lagoon, have bucked the trend witnessed on the mainland, with a decent dump of rain recently in the Apsley River catchment upstream causing the marshes to flood – something that has been happening regularly since NGT started working at this site – but contrary to the drying trend of the preceding 10 years.
This means that things are still very wet out there, as this view over the lower marsh clearly shows!
The next step is to address the impact of the network of drains that are clearly visible in the image above. Ironically, progressing our plan for future restoration works at this site is going to require some drier conditions!
Burdens Marsh (Tasman Peninsula, Tasmania)
Last but not least, let’s check in at Burdens Marsh, an important saltmarsh area situated within the Tasmanian Land Conservancy’s Sloping Main Reserve. The photo below was taken on the 20th Dec 2024.
With the recent completion of our restoration plan for this area earlier in 2024, we’re now looking at commencing restoration works to reverse the impact of artificial drains and levees in autumn 2025, giving us a little extra time for things to dry out further.
At this site, and several others like it, we have plenty to look forward to over the year ahead!
