Floating an urban river in a raft, kayak, or paddleboard, I find interesting structures to target with a fly rod. Bridges spanning the river are one common and productive structure I target.
Bridge piers change the river flow by contracting the channel and increasing its velocity. This creates a funneling effect pushing aquatic insects and baitfish into concentrated areas, making them easy prey for trout, smallmouth bass, catfish, saugeye and other species.
Since most urban rivers have been heavily channelized reducing habitat complexity, any structure, like bridge piers, becomes a magnet for fish and other aquatic organisms. In fact, bridge piers can act like artificial reefs, providing shelter and feeding opportunities.
Bridge Fishing 101: Unlock the Secrets of Piers and Pilings
Bridge piers come in various designs. The most common include cylindrical, rectangular and solid wall piers that span the width of the bridge. The shape of the pier, combined with the riverโs flow characteristics, creates different patterns in the current, making it essential for anglers to read the water carefully. When I approach a bridge pier, I take a moment to observe the flow. This brief pause can help me better understand where fish are holding.
Around bridge piers, complex currents, eddies and wakes form. By watching the waterโs surface, you can gain insight into how the flow behaves upstream and downstream of the pier. Some vortices near the pier can be too strong for fish to hold; I look for calmer pockets of water nearby. Where turbulent waters meet calmer areas, I find large predatory fish waiting to ambush food swept in the current.
The vortices created by bridge piers also carve deep troughs, known as scour holes, in the riverbed. These holes are ideal when water levels drop and species like catfish seek out deeper pockets near the main river channel. In lower flows, I find bottom-feeding fish such as carp foraging in scour holes.
If the upstream side of the pier has a blunt design, such as a rectangular pier, it can create a buffer against the riverโs current. This buffer zone provides another location for fish to tuck into and pick off food as it drifts downstream. Debris, like tree branches caught on the upstream side of the pier, can also offer fish shelter from the current.
When Iโm fly fishing the water around a bridge pier, I use sinking fly lines with a three- to five-foot leader of 12- to 15-pound monofilament. Sink-tip and full-sinking lines in various sink rates carry my fly to the fish.
I typically start by using a streamer to cover the water efficiently. If thereโs no interest in the streamer, Iโll switch to a floating line with an indicator and nymph. A single heavy nymph below an indicator is effective for targeting seams between the turbulent and calm water.
If the river is low and clear, I might spot a common carp, freshwater drum or suckers tailing near the scour holes. When I find tailing fish, I use a floating line, 12-foot 2x leader and weighted fly line.
During summer, bottom-feeding fish often gather in the cooler, shaded water under the bridge. I anchor my raft or paddleboard, wade quietly into position, and make a careful cast.
By understanding how bridge piers affect the flow and structure of the water, and adjusting your fly fishing techniques accordingly, you can effectively target the fish that use these structures as their hunting and foragingย grounds.
Marc Fryt is a fly fishing instructor and writer currently finishing up a book titled The Urban Fly Fishing Guidebook. To learn more about this book and to receive updates, follow him on Instagram @marc_fryt.
Fish hide in artificial habitat. | Feature photo: Marc Fryt
