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Floods & Fishing


AUSTRALIA’S East Coast has experienced relentless rain and floods over the past two years, but there are still opportunities for exciting fishing in the dirty post-flood water.

Sydney is a big place. It can drizzle for days on the coast while the catchment area in the highlands remains bone dry. At other times, certain weather patterns see days of soaking rain fall across the entire system, the ground becomes sodden, drains are full and water has nowhere to go. The four major river systems within the Sydney basin become swollen and threaten to burst banks as they’re unable to effectively take sufficient water to sea.

A number of years ago, Sydneys’ major water supply, Warragamba Dam was down to around 40% of the 2.5 million mega-litre capacity. The threat of us running out of water became real enough for the government of the time to build a desalination plant to convert seawater to fresh, then pump it into the water supply network. That was done in quick time, with great expense and of course it seemed to trigger immediate rain!

Warragamba Dam today keeps relatively full and large rain events now make her overflow. While large amounts of water may be released, excess can still spill over the top, becoming uncontrollable. At its’ worst, residents on low ground may be forced to consider evacuation.

Those in Sydney’s north-west have now had this occur twice since early 2021, even more serious in 2022 thanks to an historically significant La Nina. Two weeks after the heaviest of the recent falls stopped, the estuary water began to clear. Given the amount of dead kelp and seagrass rotting in the shallows, overflown sewer systems, warnings of E.Coli and other dangerous bacteria remaining in the water, swimming or taking fish for the table from these areas was out of the question. I’d witnessed some of that untreated sewage pushing out into my local estuary of Port Hacking during the peak of the flood, so dared not immerse myself in that water, nor eat fish from it for some time.


That didn’t mean I didn’t want to fish. Itching to get back out amongst it, some mates and I had begun to try our luck again with some catch-and-release estuary action. Even during the height of that flood, pockets of water near the estuary mouths and out of the main current became holding areas for species such as flathead, whiting and Australian salmon.

Small schools of salmon were visible chasing skipping baitfish, gorging themselves crazily on the bait trapped between extreme freshwater and the dangers of the open sea. When the sun begins to shine again literally, it also shines for anglers figuratively. This period as the rain abates can advantage those who consider where certain species and their prey gather, whether by choice or by forces of flood and tide.

Having confidence when approaching this sort of dirty water doesn’t come naturally for most anglers, myself included. It was only a last-minute and reluctant invitation for a midday low-tide spin session between showers that opened my eyes and set me on a frantic few weeks of similar sessions, before those waters cleared properly and the action died off.

We have to remember even in times of flood that fish still need to feed. Here in Sydney, torrential rains make thoughts turn to how fish may be re-distributed in our local systems, along with how and where they would find food.



Back at Warragamba, these over-spills also take with them many freshwater creatures and relocate them downstream in the Nepean River. That includes rainbow trout that usually reside in the cool waters of the high country above the dam. They’re flushed down the Nepean River with the flood and once water levels begin to recede again, ultimately try to make their way back upstream. The first major barrier they come to is the Nepean Weir at Penrith. While it has a fish ladder, the weir becomes a likely holding point for trout returning upstream in the period following flood, particularly if it occurs during winter when they naturally run upstream to spawn.

Most of us down here closer to sea level rarely see trout in the metro area so this time is a bonanza to the locals (providing their houses were not in danger of course) who are usually restricted here in freshwater species to mullet, carp, bass and estuary perch. The trout are often hurt from coming over the wall at Warragamba and carry heavy scarring. To the locals, they are like a scratched up old trophy, which they’re excited and proud to catch despite their condition.

The Nepean River continues on to the Hawkesbury River, a very large estuary which runs to sea at Sydney’s northernmost outskirts. The muddiness of most of its’ tributaries see it turn chocolate brown after heavy rain, and with a powerful current. The Pittwater arm remains clearest and holds a lot of fish out of the main current, waiting to run back up river once the rains subside. Gosford Rail Bridge is historically a prime mulloway spinning spots in times of flood, using live large-bibbed or sinking hard-bodies to get down deep.

As with the Nepean, the Liverpool Weir in the Georges River becomes the first major obstacle for upstream migrating bass and estuary perch, or those returning upstream after being pushed down by the flood. It too has a fish ladder to allow fish through to naturally propagate. Climbing a fish ladder takes a fair amount of energy, making pools and deep-water pockets immediately beneath such structures ideal resting places in preparation for the run back upstream. Being brackish, there’s a decent cross-section of species available too. Bream and blackfish swim between bass and carp. Of course a flood quickly changes that dynamic, but as soon as a salty tide reaches that barrier again, there are fish of various species everywhere. Local social-media posts report such diverse and surprising species as silver perch, bull sharks and koi carp.


The Georges takes a long time to flush. The whole system is quite shallow and winds a long way for a tide to push to the upper reaches. Accordingly, the downstream push from a single day of heavy rain can close most of the river down to fishing for a whole week. Bream are normally thick through the river, but that surge of freshwater will make them retreat to holding areas such as Sylvania Waters and the many bays between Captain Cook and Como bridges. They respond well to baits with slow odour releases like chicken breast in these conditions, or lures with added rattle or tight action that send vibrations through the water.

The Hacking River in Sydney’s south can flood easily at the Audley Weir, preventing cars crossing and limiting access to the Royal National Park, Australia’s oldest National Park. The freshwater system above the weir is small and generally only home to eels and mullet. Below the weir, in a big fresh there are enough deep bays in the system that saltwater species can hang around where the heavier saline water underneath remains. Pan-sized snapper come alive here after a flood, surprisingly far up-river in those deeper bays or holes.

The fourth major system is the Parramatta River, flowing into Sydney Harbour. While the other three may be flooded, the harbour usually runs quite clear, particularly near the mouth. It takes a very heavy flood to turn the water under the Harbour Bridge brown. When we hear in morning traffic reports that ferries are cancelled due to Parramatta Weir flooding, it’s a sign that the lower parts of the harbour will be firing. Kingfish, tailor and salmon school-up east of the bridge, then eyes are out for feeding seagulls for us to follow with the spin gear. Rainy days in the harbour mean a lot less boat traffic too which makes fishing easier for boaties that otherwise have to deal with the washing-machine effect of such a busy waterway.


Freshwater species will be widespread until well after the flood has gone. For saltwater anglers who normally fish the tidal zones, it’s time to concentrate more on river mouths. More specifically, lees and bays away from the main freshwater-laden outgoing tide, close to that river mouth where the salinity remains fairly high. These periods actually concentrate river species into a smaller area, in bays just inside the river mouth, especially on a run-in tide. Like shooting fish in a barrel, as they say, opposing forces meeting will condense estuary fish populations into a smaller field. Then, as all that freshwater disperses into the ocean and saline tides push increasingly further upriver, that field slowly grows again.


The opportunity is brief for both anglers and predatory fish. After this recent flood, despite being right at the start of autumn and with very warm coastal waters still around, we saw plenty of salmon herding baitfish. Normally they’re known for being around Sydney when the water is cooler and while not in large schools, they were very active on the surface and made for a lot of fun casting surface stickbaits at crashing fish around us. Terns and seagulls would hover, eyeing the mobile salmon and casting underneath those birds, along with any surface disturbances worked well.

Flathead relished this area between the powerful brown flow and incoming tide pushing cleaner water back against it. Dusky flathead can be found along ocean beaches but don’t take to sea all that often. Being forced down to the mouth by so much freshwater, they were not only in good numbers, they were also ravenous! All sorts of lures seemed to work well, from fluoro green Berkley Shimma Shrimps and scented soft plastics, to dark-coloured shallow-divers such as the Daiwa Double Clutches. The only common trait of the lures that worked was their relatively large size; around 100mm.

The bream went surprisingly quiet and given their tolerance for fresh water, may have been widely dispersed or feeding more in the fresher, heavier flow a little higher up where fast water proves difficult to fish. This water comes with a large amount of debris making boating and wading unsafe, while also requiring constant attention to removing weed from lines. Another danger when wading proved to be the ”bay breaks”. After a large storm, wading in one of the bays just inside the estuary mouth in Port Hacking saw an occasional and very unexpected wave bend around and come right up into the bay, completely out of the blue.

While La Nina may continue for a while still, let’s hope there is more opportunity and less devastation. These systems will need time to rejuvenate after each event; from kelp beds to oysters, to juvenile fish and crustaceans that live in those environments.

Immediately prior to the early 2022 flood saw a large fish kill in the Parramatta River, with awful pictures of adult fish dead through the shoreline and mangroves in their hundreds. Here’s hoping the flush at least pushed out some of the dormant toxicity that some historic sections of that river hold.

Next time a big fresh has shut down your fishing, start thinking of the re-entry plan sooner rather than later. There is a window of time where fresh versus salt compact both bait and fish near the estuary mouth. The water may not look inviting, but opportunity hides amongst the murk.

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