Major Flash Flooding Event - On 15 January 2026, the Wye River estuary experienced a severe flash-flood event following an intense thunderstorm over the upper catchment. Heavy rainfall fell over a very short period, with approximately 170–180 mm recorded within several hours, causing the river to rise extremely rapidly. The most intense rainfall and flooding occurred from late morning through the early to mid-afternoon, with peak floodwaters moving through the township and estuary during the afternoon. Fast-moving water overtopped the riverbanks, carrying large volumes of sediment, vegetation and debris, with some material flushed through the estuary mouth into the ocean.

The flooding was driven by exceptional rainfall intensity over steep terrain, resulting in rapid runoff and minimal warning time. Hundreds of people, including residents and holiday-makers in caravan parks and low-lying areas, were affected, with emergency evacuations required to higher ground. Impacts relevant to the estuary included a sudden and major freshwater inflow, significant sediment and debris transport, likely short-term deterioration in water quality, and physical disturbance to the estuary channel and river mouth.

https://www.abc.net.au/news/2026-01-16/flooding-great-ocean-road-victoria-wye-river-lorne/106232918

https://www.abc.net.au/news/2026-01-16/vic-what-caused-great-ocean-road-flash-flooding/106235904

https://www.abc.net.au/news/2026-01-16/wye-river-flood-castlemaine-harcourt-fires/106236018

https://www.theguardian.com/australia-news/2026/jan/15/river-wye-flooding-victoria-great-ocean-road-cars-washed-away

https://www.reuters.com/sustainability/climate-energy/flash-flooding-hits-australias-victoria-state-cars-washed-out-sea-2026-01-15/

https://www.thenewdaily.com.au/news/state/vic/2026/01/15/storms-victoria

https://www.thenewdaily.com.au/news/state/vic/2026/01/16/flash-flood-carnage

https://www.9news.com.au/national/cars-swept-to-sea-as-flash-flooding-inundates-victorian-holiday-hotspot/385245a1-107c-408c-9da4-18063c853c91

https://www.pedestrian.tv/news/victoria-great-ocean-road-flash-flooding-cars-swept-out-to-sea/

https://www.afr.com/politics/federal/off-the-charts-flash-flood-sweeps-cars-out-to-sea-in-vic-20260115-p5nugb

https://www.heraldsun.com.au/news/take-shelter-flood-warning-issued-for-lorne-wye-river-as-severe-thunderstorm-hits/news-story/8af86fbae22601699cc63a46bc4dc6b1

https://www.heraldsun.com.au/news/victoria/wye-river-super-storm-sweeps-dozens-of-cars-and-caravans-out-to-sea/news-story/844ae754ebdb65fc8b6e812bb4964fc5

• Estuary mouth closed.  Water level at GOR bridge 1.5m AHD. 

Location:  north side of Coalmine Road monitoring site 5

Dark red colouration of suspended solids in water.  Seen flowing under Coalmine Road and detected when monitoring site 5. (pic 2) pH reading taken on this northern site of Coalmine Road = 3.1.  Regular Estuary watch reading for site 5 will be reported as usual in separate report.

This colouration also seen in shallow water near the middle of the estuary system as marked in the map. (pic 3)

Extra pH readings taken at water body known as the Duck Pond using Estuary Watch equipment.

Observed red residue on boardwalk where that part of the boardwalk had previously been submerged in water due to high water levels in the estuary. (Pic 1) Water colour different in both samples.  This water body is a distinctly different colour that the variations seen in the rest of the estuary system.  

Depth of water body estimated at 0.75m (water sampling stick used to reach bottom).

pH of top water sample 5.1 (pic 2)

pH of bottom water sample 3.3 (pic 3)

• Corangamite CMA staff visited the Anglesea River estuary seven days after an artificial estuary opening that took place on the 20th of August. 
• Water was still flowing steadily out to sea however the channel with flowing water was narrower than what had been seen earlier in the week. 
• Water level recorded from the  235278A ANGLESEA RIVER AT GREAT OCEAN ROAD BRIDGE monitoring station has dropped from 1.738 m at the time of the opening to 1.38 m at 8:00am. 
• Clumps of seaweed were seen in the channel that has been excavated.  This indicates that sea water is pushing up into the lower part of the estuary at high tide.
• Strong winds were blowing sand across the berm while the mouth condition data sheet was being completed.
• pacific and kelp gulls were seen feeding on dead fish at the river mouth. 
• a lot of the dead fish seem to have been removed by birds.  There was a small bodied fish that looked to have recently died.  It was identified as a Bridled Goby.   This is the first time during the acid flush event that this species has been found dead at the river mouth.  
• The water colour at the lower end of the estuary was milky in appearance and blue/green/yellow in colour (see photo of monitors at boat sheds)
• The water colour at the upstream extent of the estuary was a burnt orange iron colour (see photos taken at Coalmine Road).  The water was the same shade as the socks worn by one of the monitors. 

• Corangamite CMA staff visited the Anglesea River estuary five days after an artificial estuary opening that took place on the 20th of August. 
• Water was still flowing steadily out to sea and had scoured sand to form a deeper channel than what was seen on the day of the opening. (markings on pole in images are every 10cm)
• Water level recorded from the  235278A ANGLESEA RIVER AT GREAT OCEAN ROAD BRIDGE monitoring station has dropped from 1.738 m at the time of the opening to 1.39m at 8:00am. 
• There was a similar amount of dead fish to what was seen the previous week along the water line of the river mouth.  Some had obviously been eaten by birds. 
• There was still signs of flocculant on the river bed.  The colour varied from milky white to orange. 
• A lone pelican was also seen at the river mouth

• Corangamite CMA staff visited the Anglesea River estuary two days after an artificial estuary opening that took place on the 20th of August. 
• Water was still flowing steadily out to sea and had scoured sand to form a deeper channel than what was seen on the day of the opening. (markings on pole in images are every 10cm)
• Water level recorded from the  235278A ANGLESEA RIVER AT GREAT OCEAN ROAD BRIDGE monitoring station has dropped from 1.738 m at the time of the opening to 1.44m at 9:00am. 
• There was a similar amount of dead fish to what was seen the previous day along the water line of the river mouth. 
•  There were two large dead Black Bream seen in the swash zone about 100m up the beach towards the Anglesea Surf Life Saving Club.  They looked like that had died recently. 
• We walked into the outcrop of rushes and sedges  upstream of where the river intercepts the sea.  There was a shallow channel alongside the rushes that had 20+ dead Yellow Eyed Mullet, 1 Black Bream and 1 Flounder.  The flocculant looked to be concentrated here too. 

• Corangamite CMA staff visited the Anglesea River estuary the day after an artificial estuary opening that took place on the 20th of August. 
• Water was still flowing steadily out to sea and had scoured sand to form a deeper channel than what was seen on the day of the opening. (markings on pole in images are every 10cm)
• Water level recorded from the  235278A ANGLESEA RIVER AT GREAT OCEAN ROAD BRIDGE monitoring station has dropped from 1.738 m at the time of the opening to 1.646m at 8:00am. 

• Anglesea River estuary was artificially opened by GORCAPA at the request of Corangamite CMA in an attempt to improve water quality. 
• The drainage channel was dug 20-30cm deep by an excavator. 
• Water level recorded by the  235278A ANGLESEA RIVER AT GREAT OCEAN ROAD BRIDGE monitoring station at the time of opening was 1.74m. 
   

• Flows from Marshy Creek reached the Anglesea River estuary on the 25/07/2025.  At the time, the pH of water recorded at the 235260A  ANGLESEA RIVER (MARSHY CREEK) @ ALCOA monitoring station was 3.8.
• Fish deaths were observed at Anglesea River estuary since Tuesday 5 August and continued throughout August. 
• On the 15th of August a Corangamite CMA staff member walked the water line at the river mouth and recorded 70 dead Yellow-eyed Mullet, 1 Australian Salmon and 8 Flounder and 2 Black Bream.  (to give you an idea of length, her shoe is 27cm in length. )
• By the 20th of August, there were more Black Bream found dead some of them were over 40cm in length.  (black lines on stick in images are 10cm apart)
• Fish death are likely to be cause by the acidity of the estuary and flocculation, which is a physical-chemical process of suspended particles clumping together, often resulting in altered clarity and colour (this can be observed as a milky blue appearance). 

• The 235260A  ANGLESEA RIVER (MARSHY CREEK) @ ALCOA monitoring station  indicated that the creek began to flow on the 06/07/2025. 
• Flows from Marshy Creek reached the Anglesea River estuary on the 25/07/2025.  At the time, the pH of water recorded at the 235260A  ANGLESEA RIVER (MARSHY CREEK) @ ALCOA monitoring station was 3.8.
• Photos taken on the 28/07/2025 looking upstream and downstream of Coalmine Road.  The milky blue coloured water upstream of Coalmine Road looks like Aluminium flocculant. 

After water levels had dropped 22.5cm, the entrance closed over again after sustained large swells and high tides.

The Powlett River estuary was artificially opened to the ocean whilst oxygen levels were still adequate. Given the low water levels and the length and height of the berm, it is expected that water levels will drop marginally, and the estuary will close over again sometime next week. 

Illegal estuary opening observed by EstuaryWatch volunteers.  Water level was 1.6m AHD at the  time. 

A Blue Green Algal bloom was confirmed after testing by SGW at Bourne Creek estuary. Birds seem to still be using the estuary upstream of Bass Highway and no dead fish have been spotted to date. First photo is from 11/02/25 and second photo is from 03/03/25.

Powlett River estuary entrance closed to the ocean after sustained low freshwater flows as well as moderate swells and tides.

With water levels reaching a maximum of 2.67mAHD and peak flows recorded at 556ML/day on September 21 at Powlett/Foster confluence (Wattlebank) the decision was made to artificially open the Powlett River Estuary. Water levels dropped by over 1.5m.

An artificial opening was approved to go ahead at Bourne Creek estuary after water levels reached 2.56mAHD which was enough to inundate the emergency lane of Bass Highway. The next morning water levels had dropped 10cm and water levels are expected to drop further during the week

The Powlett River estuary closed its entrance to the ocean after sustained large swells brought large amounts of sand into the estuary entrance.

Photos 1-3 flooding near Proudfoots By The River Restaurant

Photos 4-8 flooding at road from Warrnambool Ski club to boat ramp 

Photos  9&10 water height pole near boat ramp at Lyndoch

Photos 11-13 artificial opening photo taken from timber Hopkins river mouth viewing deck

After 77mm rain over April 2-3, Bourne Creek naturally opened to the ocean. 

Estuary closure reported by Breamlea resident.  Photos show estuary opened on the 18th of January 2024 and closed on the 19th of January. 

photo of the mouth, someone's unofficial opening attempt?

With over 20mm of rain, Bourne Creek naturally opened sometime over the weekend dropping water levels to 2.04mAHD.

high water level @ Site 2 - River Boat Cruise pontoon, unable to do observations, due to water inflow up stream and high tides @ estuary mouth