Taking a closer look at the remediation of saltmarsh at Yards Hole, Moulting Lagoon

Now that I have arrived back home in western Victoria after a stint based in Swansea last month on Tasmania’s east coast, I thought I’d share a few more images of the restoration works at Yards Hole, the wetland we spoke about in last month’s newsletter.

First up, let’s have a look at Yard’s Hole from the sky… please click through the pdf pages below to see the story of this wetland from 1948 up until last month.

If you take a good look a these images, a few things you will notice include that fact that:

• the water level in Yards Hole was very high in what were clearly wetter years in 1948 and 1978, noting that locals have told us that during dry phases before it was modified in the 1990s, it could completely dry out at times.
• there is a small section of bank on the northern margin of Yards Hole that was not remediated this year, to give us time to more closely assess a rarer species of saltmarsh growing on the artificial spoil bank in that area, before determining the best approach with the goal of continuing works in this area next summer (i.e. once we have an agreed plan in place with our project partners).
• due to the depth of water in the artificial channel that was backfilled, the remediated margin of Yards Hole could not be manually compacted effectively this year. With the passage of time, via gravity and the impact of rain and inundation events, we expect this bank zone to naturally settle and compact over time. We will also re-evaluate the progress of this process and the change in condition of this zone ahead of works next year.

This process of bank remediation is shown below.

As we discussed last month, you can see the black ground of the former surface which previously supported fringing sedgeland and saltmarsh habitat, which was hidden beneath the spoil bank, now re-exposed and ready to bounce back in the saturated ground.

Now let’s head across to the natural outlet area where Yards Hole interacts with Moulting Lagoon, and take a closer look at the full picture of works completed in March. Once again, please click through the pdf pages below.

As you’ll see in the 3rd image of the site before we started works this year, to put it bluntly, this area was a real mess! The series of ponds and channels constructed in the 1990s left a legacy of major changes to the saltmarsh land surface. However, now that the natural surface has been remediated, and given the regularity with which rainfall events and tides interact with this low-lying part of the site, we are expecting to see some very positive changes over the months and years ahead.

Finally, here is a before and after oblique image of this zone, to give you another useful perspective of what has been a very productive stint of autumn 2022 restoration works!

The restoration works at Yards Hole have been made possible thanks to the support of the owners of The Grange, as a result of the NRM South project at Moulting Lagoon, with funding provided via the Australian Government’s National Landcare Program.