Most anglers stay home after heavy rain. The ones who go often have the best sessions of the year, because freshwater pushes bait and predators into a narrow band of the system.
The key is understanding that fresh water floats. The salt wedge underneath is where the fish still are.
Follow the salt
Fresh water sits on top of denser salt water. After a flood the entire fishery shifts downstream toward the mouth, where a saltwater layer still sits on the bottom.
Fish the deepest holes closest to the mouth and work the bottom third of the water column. Surface lures are usually a waste of time in this scenario.
Fish the dirty-clean line
Where muddy freshwater meets cleaner salt water, a visible colour line forms. Predators sit in the clean side and ambush anything that swims out of the murk.
Cast into the dirty water and retrieve into the clean. That direction matters — you are imitating disoriented bait leaving cover.
Drains and creek mouths
Every drain flushing floodplain water is a bait conveyor belt. Barramundi, jacks, jew and flathead park at the outflow and eat what comes past.
Fish the first two hours after the peak of the run-out, when the flow is strongest and the bait is being pushed hardest.
Safety and water quality
Floodwater carries debris, submerged logs and unpredictable current. Wear a lifejacket, avoid running at night, and stay off flooded bank edges that can collapse.
After major floods, check state health advice before eating fish from an affected system — sewage and runoff contamination is a real risk in urban catchments.
Key takeaways
- ▸Fish move downstream toward the mouth and hold deep after floods.
- ▸The dirty-clean colour line is the highest-percentage cast.
- ▸Drain mouths on the run-out concentrate bait and predators.
- ▸Treat floodwater as dangerous and check health advice before eating the catch.
This guide is general information only. Fishing regulations differ by state and change regularly — confirm current rules with your fisheries authority before you fish.