Reading River Levels for Smallmouths
March 26, 2018
About 2,500 years ago, Heraclitus wrote, "It is not possible to step twice into the same river." Nothing could be more true, but it takes on special significance for fisherfolk.
Sandbars move. Trees, still anchored to the bank by a rootball, alter the flow. Ice floes gouge new troughs and grooves. Floods roll rocks and carve new channels. Logjams wash away to be deposited in new locations. Erosion eats at shorelines. Maybe that's why rivers can be lonely places to fish in summer.
Or maybe it's because low-water conditions typical in summer make every rock a potential outboard assassin. Jet boats are the answer, sometimes—but even those face barriers.
If stretches of river have shallow vegetation, stopping to clean the intake can eat up a significant portion of the day.
Most of the nation's smallmouth streams probably fall into the small to moderate size category—those that can only be accessed by canoe, kayak, or foot patrol. But, typically—the bigger the river, the bigger the bass. Even so, I'm often torn between boating big rivers and drifting down small ones in summer. All smallmouth streams have features in common, not the least of which is that you meet fewer people and less-educated bass.
In recent years, we've seen higher than normal water from June through August on the Upper Mississippi River. High water is one thing, but when we see tree-studded islands disappear under the flow, one common response for summer smallmouths is to leave. Destinations become connected lakes, backwaters, reservoirs, and smaller streams connected to the larger river.
High water in midsummer isn't the norm and we find smallmouths migrating instead of holding in key spots to feed. Bass hug the banks and tuck behind current breaks instead of posting up in front. In high water, structure and cover define location. But unlike migrating bass, fish in summer tend to congregate where the gradient of the land flattens and the river widens. These features slow current.
When rivers are higher than usual, look for smallmouths to use the inside of a bend instead of the deep water on the outside bend, which is where the main current is. Flow increases velocity in high water and smallmouths aren't built to function well in fast current. Immediately adjacent to fast water—yes. But not in it. They sidle up as close as comfort and physical strength allows, but won't tolerate fast water long without a current break nearby.
Look for bass to use the tip of an eddy. Current breaks—bridge abutments, shoreline points, rockbars, gravel bars, wing dams, boulder fields—create circling eddies behind them.
Active smallmouths hold at the tip of the structure closest to midstream, where the circulating water meets the powerful current rolling past. The tip of a key eddy can produce 10 to 20 bass at times. Structure concentrates bass in high water.
Many of the nation's streams experienced moderate flows in summer the past few years, too—more rain than usual, but not that much. Average flows concentrate bass around structure, but fish relate to it differently. In normal to moderately high flows, smallmouths typically hold on the upcurrent side of breaks—obstructions like a rockbar or the lip of a riffle. They create a current void or vertical eddy, sometimes marked by a bulge in the surface a few feet downstream. Smallies often sit in that void and wait for current to carry prey to them. They're aggressive fish with a second or two to decide, so they snap at things. Inactive fish sit in pools or in eddies behind current breaks.
Low rivers have less velocity. In low water, smallmouths spread out as they're no longer pushed against banks or behind breaks. Current voids may disappear. Smallmouths can be almost anywhere—even in spots almost devoid of structure or cover. Those swaying beds of river grass touching the surface become barriers to jet boats and home to smallmouths. Grass is rich with forage and bass know this. But in low water, think less about structure and more about covering everything, because at some point as the flow slows, current stops concentrating bass in predictable spots.
Think about that flow gradient when approaching smallmouth rivers in summer. Seek out the slower sections on flatter land during high water, and the faster sections when the water is low.
Thoughts on Tactics
In high water, I approach most spots by casting upstream or cross-current. High, fast water narrows effective casting angles. The lower the water gets, the wider the effective range of casting angles becomes.
In high water, you can approach a spot by moving upstream or down, either pushing against the current or slipping along and fighting current with the trolling motor. Using Spot-Lock or an anchor, you can hold on a key spot. In all these approaches, the most effective casts are upstream, bringing a lure or bait downstream with the current. The faster the current becomes, the less baitfish fight it, and the more bass focus on forage using current to move. At some point, depth control becomes almost impossible when pulling a lure upstream against the flow, and lures or rigs that get down quickly and stay down become important.
As rivers drop, casting angles widen. At a stream's lowest point, effective retrieves can be made in all directions, covering 360 degrees around your position. Consequently, as water level drops, lighter lures and topwaters become increasingly important. When rivers reach extremely low levels, poppers, prop baits, buzzbaits, and other topwaters should be first considerations over the entire river, followed by slow-falling options like tubes or grubs on light jigheads.
Several years ago, outdoor writer Jeff Samsel, photographer Rick Hammer, and I went for a drift down the Mississippi River in extreme low-water conditions. The current was so lax we almost stalled if we stopped rowing. So two of us would cast while the other pushed us along. About halfway through the drift, we realized that few bass were stationed around rocks where we normally find them. The best spots were nondescript—where the bottom was a featureless dishpan of soft substrates. I had some success casting soft jerkbaits and stickworms to swaying beds of eelgrass, but it didn't take long for Samsel to discover how vulnerable river bass are to topwaters in low water. He's a popper fanatic, and began catching 5 or 6 bass to our 1 by walking the dog with a Rebel Pop-R, using a loop knot to help the lure pivot on every other snap.
Samsel used a fast-action, medium-power rod with 10-pound mono. I picked up a 7-foot medium-light St. Croix Avid with 10-pound Berkley FireLine. I think braid is a good choice for topwater fishing because it floats and it's thinner, making it easier to "mend" the line back upstream when current creates a bow in the line. I tied a 6-foot leader of 10-pound mono to the end of the braid, with a VMC CRS Crankbait Snap to give the lure more freedom of movement.
My usual tactic with a popper is to cast and let the rings settle as it drifts about 5 feet in the current. Keep the line tight, give it one bodacious "blurp," and let it drift for another 5 feet. Then twitch it. That's usually more then they can stand. But on that day, Samsel's walk-the-dog method was king until I tried a Heddon Baby Torpedo. When somebody is catching fish almost constantly, I always want to know if something else might work even better.
If bass want constant surface disturbance, a prop bait can be awesome. And on that day it "torpedoed" Samsel's popper. Seemed like bass were passing his popper to hit the prop bait on several occasions when I worked it with a rip-pause-rip cadence, leaving a bubble trail behind. At times it works even better with double-prop lure like the Rapala X-Rap Prop.
On the other end of the spectrum, when the water's high, think about cutting current. Braid is better at it than mono or fluorocarbon because it's thin and doesn't stretch. Spinnerbaits are great high-water tools, and single-willowleaf models get deeper and stay down better than Colorado, Indiana, or tandem blades. Or go with small tandem blades designed for fast retrieves, like Strike King's Baby Burner.
The spinnerbait is a search tool and the best second option in high water is a crankbait. As water levels rise, the best feeding stations narrow in number—the opposite of low water when feeding stations increase. The key is to quickly find feeding stations occupied by the most bass, then work them over with jigs and rigs that fall fast but comb the critical area methodically. Depending on the depth of the lip and the base of the structure, rip crankbaits like the Baker Lures RGD1 (2 to 4 feet), Rapala DT6 (6 feet), or Strike King KVD 1.5F (8 feet) quickly along the face or past the upstream tip of an eddy to find river bass fast.
In high water, one key ambush area can be occupied by dozens of smallmouths. After catching one or several on search lures, position the boat downstream or slightly down and across from the spot and switch to a hair jig or football jig with a craw trailer. If the layout of a bar, logjam, or other current break precludes casting upstream, position above or beside it and work it with a heavy drop-shot rig. I like to use action tails on high-water drop-shot rigs instead of finesse lures. Nose-hooked or Texas-rigged augertail worms, grubs, and soft swimbaits can "run in place," so to speak.
Spool 12- to 15-pound fluorocarbon and, using a 6.5- to 7-foot medium-heavy drop-shot rod, make short pitches with 1/2- to 1-ounce drop-shot weights, depending on current, several feet upstream of a push or the tip of an eddy. The current carries it to the strike zone where it settles. Keep the line tight, the rod tip still, and let the lure work. Periodically lift the weight off bottom and let it settle again. Cast at different angles to the spot, then move in closer and repeat until you're covered every aspect. If you hook a bass, keep working the spot. Another one often moves into the same key lie.
Short casts keep the lure up off bottom with an 18- to 20-inch dropper to a cylindrical or pencil-style drop-shot weight or in snaggy areas, a slinky. New drop-shot hooks from TroKar and VMC include swivels, reducing line twist, which can be bad in high water. You can even add a SPRO Power Swivel a foot or two above the hook.
My favorite tactic for mop-up duty is a jig-grub combo with a 5-inch grub and a head just heavy enough to swim along near bottom at a slow pace. Most of the time I use a 1/8- or 1/4-ounce jig on 6- to 10-pound mono and a fast-action, medium-power, 7-foot spinning rod. But the lower and clearer the water gets, the more effective the slow drop of a tube becomes. It's efficient, too, with the head inside the tube, as it snags less in slower current. And it can work better than a grub when bass hold tight to sharp breaks in faster water.
Rivers and bass force you to change every day. That's one reason for the solitude we often find there. No, you can't step twice into the same river. But you can catch twice as many bass by letting water levels indicate which river segments to fish and which tactics to use.
*In-Fisherman Field Editor Matt Straw, Brainerd, Minnesota, is an avid smallmouth angler who regularly fishes rivers far and near.