Fluctuating Water Levels / Learning to Fish Rivers & Streams

Fluctuating Water Levels in Rivers & Streams

Within just a few hours of a heavy rain, water levels in a stream can rise as much as 10 feet, the current speed may triple, and water that is normally clear can turn a nice, appetizing chocolate brown! Of course, this depends on the size of the stream, and some other factors – but the moral of the story is that water levels are going to fluctuate.

Flooded Bridge in Illinois
A few years back my local stream went way, way up after heavy rain, flooding roads and washing out nearby woodland areas.

Physical changes of this magnitude can make life difficult for fishermen – and fish. Fish will take up different positions during high water to avoid the fast, muddy water.

As water rises, fish tend to move shallower. The shallowest water available is usually near the advancing waterline, right against the bank. It can be a bit more clear, and baitfish and insects will be here as well – not midstream.

Fishing During High Water
Fishing During High Water

At the first sign of the water dropping back down, fish will move to steep banks and drop-offs, or deep holes. All kinds of fish – including baitfish – move out of the shallows. This is because fish possess an acute sense for changing water levels in their environment. If they did not, many would be trapped in small pools or puddles as the water recedes.

Good stream fishermen understand this behavior and pay close attention to water levels so they know where to look for fish. This can be done using water gauges on bridges or dams, by looking at in-stream objects like logs and boulders, or using a tool like the Deeper Pro+ Sonar, which is a castable depth finder we have talked about many times.

Water Gauge on a Bridge Piling
Even a drop as small as an inch or two can cause fish to move back out of the shallows.
Silt Left Behind After High Water
Freshly deposited silt by weeds, trees and rocks on the shoreline signal the water is falling and fish will move deeper as a result. When the water level is dropping streams will carry little floating debris.

Pay close attention to the clarity of the water following a heavy rain. Large clouds of mud rolling downstream usually mean bad fishing because the fish can’t see your presentation. Again, if you are going to try to fish these conditions, work close to the bank where the water can potentially be a bit clearer. You can also move upstream if muddy water is flowing into your fishing area from a tributary, as seen below.

Incoming Dirty Water
Chocolate milk? No thanks.

Some fishermen believe that rain washes all sorts of insects off the shoreline, temporarily changing the feeding behavior of the fish. Keep this in mind when you are selecting your presentation. A spinnerbait could be effective, or some sort of swim jig with a large trailer that brings with it a lot of thump and vibration to the table (I would opt for a darker color in muddy water, maybe with some chartreuse). If the water isn’t too fast and there is some visibility you could tie on a smaller crankbait to match anything that is getting washed off the shore, like the Rebel Tiny Crank Collection:

Rebel 4 Pack of Lures

When the water starts to clear up, fishing will improve because the fish will start to feed heavily. The speed at which these streams clear up depends greatly on the size of the drainage area. The larger the drainage area, the longer it takes. In fact, smaller streams fed primarily by springflow can cloud up much less and be a great choice when larger streams and rivers are too muddy to fish. The springflow can also maintain the water lever if there is a drought, making them more consistent throughout the entire year.

Moving Forward

Now that we know more about fluctuating water levels in streams and rivers, we can adjust out location and presentation accordingly. We mentioned early on that change in streams & rivers is constant which makes fishing challenging, even intimidating for many anglers – but if we’re going to explore these areas extensively this year – and yes, we are – then we need to absorb this knowledge and start off on the right foot.

Research is important but it’s time to put it into action!

2020 Fishing (Resized for Gallery)
Come on warm summer mornings…

It’s exciting and I can’t wait for the snow to melt… tight lines!

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