The secret to catching river walleyes is knowing how current and fluctuating water levels affect their behavior, and adjusting your tactics accordingly.
CURRENT. Walleyes will tolerate a slight current, but seldom will you find them in fast water, unless there is some type of cover to serve as a current break. You can find river walleyes in slack pools, in eddies or downstream from some type of current break like an island, a bridge pier or a large boulder. But many anglers make the mistake of fishing only the downstream side of obstructions. Current deflecting off the face of a wingdam or other current break creates a slack pocket on the upstream side (right), providing an ideal spot for a walleye to grab drifting food.
Current edges are to a river what structure is to a lake. Walleyes will hold along the margin between slack and moving water. This way, they can rest in the still water and occasionally dart into the current to get a meal.
FLUCTUATING WATER LEVELS. Most good river fishermen prefer low, stable water for walleye fishing. Under these conditions, the water is at its clearest, and the walleyes are concentrated in well-known spots.
Rising water causes walleyes to move shallower. They often feed near the base of flooded willows or brush, sometimes in water only a foot deep. If current in the main channel becomes too swift, the fish move into backwater lakes, oxbows, sloughs or cuts where there is practically no current. Or they may swim into the mouths of feeder creeks that are normally dry.
Walleyes continue to feed as long as the water level is rising or stable. But when it begins to fall, they immediately sense the change and move to deeper water to avoid getting trapped in a dead-water pool. Once they move deeper, feeding slows and fishing becomes much tougher.