Newsletter

March 2026

Did platypus survive the flash flood?

Nature Notes by Mary Lush

On January 15, 2026, heavy rain in the hills behind Lorne resulted in flash flooding in the rivers between there and Kennett River. These rivers are short, steep and mostly confined by bedrock, which means that the runoff was channelled rapidly to the sea, sweeping away many things in its path including cars. If cars couldn’t withstand the power of water, what chance a platypus?

In the days following the flood, two dead platypus were reported on the North Lorne beach, presumably former inhabitants of the Erskine River.

We can shed a little light on what has happened to platypus populations because, starting five years ago, a small group of people has been participating in the monitoring program run by the Australian Platypus Conservancy (APC). Our two monitoring sites are both on Lorne’s St George River.

Immediately after the flood and before the St George River foot track was closed, a couple of us went to inspect the sites. The river was a different place.

Concerned about what might have happened to ‘our’ platypus, we asked Geoff Williams (APC) for his opinion. Here is part of his response:

“The timing of this flood is not good. Lactating females are typically in poor/weak condition at this time of the year and hence more likely to die of exhaustion/drowning in raging torrents. I suspect that this may have been the case with the dead one on the beach. In addition, juveniles in nursery burrows are probably still a few weeks short of the time when they could survive independently if their mother dies and/or the burrow becomes inundated for a lengthy period (hopefully the ‘flashy’ nature of this particular flood event means that the latter impact may not have been quite as lasting as a ‘slow’ event).

The exact impact of the flooding on the population is impossible to say at this point as it will depend on a wide range of factors, including the amount of loss of habitat, the extent of flooding within the catchment and length of the flood event etc.

The good news is that, in general terms, flooding does not seem to cause long-term threats to population viability.  

There will almost certainly be some loss of weaker individuals and the success of the current breeding season may be severely compromised (as described above). There will also inevitably some disruption of normal foraging habitats so that animals will probably be absent from areas where they are seen commonly. However, there is reason to believethat most animals are good at finding alternative places to occupy in the short- term (e.g. backwaters and billabongs opened up by the flood waters) or relatively undisturbed sections for temporary medium-term ‘refuge’.

While it is very difficult to prove with certainty what is going on, a lot of anecdotal information suggests that the ‘refugees’ start to return once conditions settle down again, typically after a few months. However, how quickly this will happen will vary from flood event-to-event and river-to-river. Thus, for example, rivers with plenty of woody debris will probably recover more quickly than those waterways with little to slow down the floodwaters and which therefore will suffer greater erosional/sedimentational impact.”

As the water receded, the river started to look familiar again, although it’s not quite the same. One difference is that the stripping of plants from the river banks has left the river more exposed to view. Could this result in easier access for predators, increasing the risk to platypus in the coming months? Geoff suggested that, at least in the immediate aftermath of the flood, predation was unlikely to be a problem because there would have been plenty of carrion.

Fortunately, we can monitor our oldest site even when the foot track is closed and we know that platypus are still present. The graph shows our post-flood data beside the corresponding period in previous years. To understand the vertical axis: a value of 0.5 N platypus/scan (2022) means we saw a platypus on about half our visits.

Following this year’s flash flood, the frequency of sightings was 0.81 platypus per scan, an increase compared to last year (0.45) and to the mean for the preceding four years (0.57). Geoff suggests this might possibly reflect an influx of ‘refugees’ who have drifted down from higher up the catchment. Unfortunately, all platypus look much the same so we can’t say anything about individual animals.

It is tempting to conclude that platypus survival in the St George was higher than in the Erskine, but perhaps dead animals from the St George simply went undetected. But there are differences between the Erskine and St George Rivers that might have affected survival rates.

For example, Lorne’s water supply reservoir might have mitigated flooding in the St George. A reasonable proposition in most years, but not in 2026. When the storm started the reservoir was already 98.9% full. According to Barwon Water, it would have filled and begun spilling within minutes.

A further difference, based more on my impressions as a bush- walker than on data, is that the Erskine is more confined by bedrock than the St George, which has more, albeit very small, flood plains. These plains may have had some moderating effect.

They may also have been the source of the sediment that was still being carried by the waters of the St George weeks after the flood, whereas the Erskine flowed clear within days.

The good news is that platypus have survived in the St George, and I expect they have in the Erskine too and in other rivers affected.

PS Acceptable plurals of platypus are platypus, platypuses and platypodes (the last reflecting the word’s Greek origin but never, to my knowledge, used).

—————-

Lorne Land Tax Trial Taking Shape

One wonderful thing about Lorne is that our community is made up of people with a variety of professional skills and knowledge. This means that last year when the Surf Coast Council asked Lorne for ways to address our need to find more housing for key and essential workers, the answers they got at their workshops were creative.

One of the options generated is designed to see if we can coax some of the short-term rental houses in Lorne across to the long-term rental market for 2-3 years using the incentive of a land tax exemption. It’s an attractive option as it does not require more trees to be felled, land cleared or density increased. Of course, most people who have holiday homes in Lorne would not want to give up their house for long periods.  That is OK. Even if only 5% take the opportunity, that would still yield 20 or so houses, making a huge difference. It may be that even more financial incentive is needed to create enough available homes. That is what the trial could investigate. Our teachers, police, health workers, and others essential to everyday Lorne need to be able to live here.

The Surf Coast Shire Council (SCSC) has set aside $50k to work up a proposal to the state government.  

Meanwhile, here are some fun Lorne facts put together by the SCSC:

1,775: Dwellings in Lorne

1,093 or 62%: Unoccupied dwellings on census night (August 2021 ABS Census) 

172: Long-term rental properties (3-9% of total homes in Lorne)

465: Number of Airbnb listings – (25% of total homes in Lorne)

$3,720: Average annual land tax bill – some properties pay up to $15,000

$663: Median weekly rent ($34,476 annual)

$22,904: Average Airbnb annual earnings (one in four earned more than the median long-term rental annual income of $34,476).

A big thank you to our members helping the SCSC to design this work.

Visitor fees coming to the Twelve Apostles

The state government has recently announced the introduction of visitors’ fees and a booking system at the Twelve Apostles. It will be introduced when their new visitor centre at the Twelve Apostles is opened later this year.  The press release says this “will encourage a better and safer visitor experience with less congestion and guaranteed parking spaces even at peak times. It will spread people out, slow them down and help promote exploration of places across the region.” They explain that “fees generated will be used to operate the Twelve Apostles precinct and maintain its facilities. Revenue will also be reinvested in much needed visitor infrastructure and environmental conservation within the Great Ocean Road coast and parks.”

Over-tourism was one the topics of the five-part webinar series that was hosted by the Great Ocean Road Communities Network last year.  No one was in favour of over tourism, not surprisingly. Many saw a need to reduce day-only visitor numbers and distribute visitors out across the region, encouraging more exploration.

Locals will be exempt from payments. So too will be the area’s traditional custodians, the Eastern Maar.  Check out the FAQ on how a booking system might work; on how locals might be defined; and other practicalities GORCAPA is addressing during community consultations over coming months.

GORCAPA will monitor how the proposal affects visitors to the adjacent and transit communities. Note that the new development at Pt Grey will not be configured to accept big tourist buses.

Hoodie Update

The hoodie nest at Lorne failed for a second time this season. The expected chicks did not hatch in January. BirdLife Australia tested the eggs after they were long overdue, and a dissection showed no obvious embryo development.   This most likely meant that the eggs were infertile or that something happened very early on in the first day or so after laying which caused failure.   Meanwhile EV and his partner have been seen up at Moggs Creek. Their first nest in October was vandalised by a dog.  They are unlikely to nest again this season, but they are being watched.

The good news is that we recruited four new hoodie volunteers. This made a huge difference as the nest itself was in a perilous location on the beach. With the help of the new volunteers, the nest survived New Year’s Eve. The nest was directly in the path of the flash flood, but the flood occurred just a few days after GORCAPA had taken away the (seemingly non-viable) eggs, to encourage the hoodies to try again.  So the flood distress was avoided. The hoodie parents stayed close around the estuary for several days.

They were tremendous parents. Beach games, cabanas, and even an electric bike did not cause them to leave their eggs. They survived several intrusions of dogs. They saw off seagulls.

Friends of the Hooded Plover, Surf Coast is now trying to get more SCSC dog regulation compliance officers on patrol during hoodie season.

Once again, being on the beach was a chance to educate the public about hoodies. It was also a chance to learn from the public. A couple of science students introduced themselves. They had just rescued and returned an Argonaut octopus (paper nautilus) back into the ocean. It had become stranded in shallow waters. They knew that a shovel was needed to carefully lift and transport the creature at safe distance. Binoculars and a phone on the beach come in handy. We called 000 to report a fire. On another day a member of the public spotted what looked like an overturned jet ski with a rider drifting out to sea. Yes, our volunteer confirmed it was. Another rescue call. Good all-round citizenship we reckon!

—————-

Not a member?

We welcome your membership. We tap our members for opinions, expertise and information. Members tell us if we are off track or on track in what we do. We also send out regular email updates on Lorne planning and environment matters. Plus, joining us (for a mere $15) is a way to support our efforts.   And our Newsletters are terrific!