Seasonal Keys To Catching Walleyes On Flats

How often have you pointed across the lake and asked, “What’s over there?” And how often have you heard the reply, “Nothing. Just a big flat.” Flats are the Rodney Dangerfields of structures. Considered the antithesis of structure by the straight men of walleyedom, flats get no respect.

Not only are flats structure, but flats are where the food is. In fact, in most environments, walleyes spend more time on flats than anywhere else, because flats produce more food than any other type of structure.

Shiners, perch, suckers, sunfish, bullheads, and other baitfish spawn and live on flats most of the year. Pelagic baitfish like alewives, ciscoes, and shad forage over shallow or mid-depth flats at various times of the day, depending on the season. All these critters represent food to a walleye.

Insect hatches on shallow and mid-depth flats draw baitfish. Walleyes, too, gorge on nymphs and emergers, especially during major mayfly hatches. Then, as summer wears on, deeper flats in natural lakes attract ciscoes and perch; smelt in reservoirs; alewives in the Great Lakes. And in all cases, walleyes, walleyes, walleyes.

A variety of situations draw walleyes to flats throughout the year. Identify situations that draw them, and the game is in hand. To find concentrations of fish on flats, timing is everything.

Spring

Walleyes use flats all year, but opportune periods occur when most walleyes are on flats. Seasons and conditions determine which flats walleyes use when. Flats can be four feet deep, 64 feet deep, or anywhere in-between. Some flats are tabletops, while others slope 10 degrees or more. Walleyes use all of them in some environments.

Walleyes use predictable routes to and from spawning habitat. Leaving a river, creek, rock reef, or gravel shoreline where spawning occurs, they move to the nearest adjacent flats that harbor perch or shiners. They linger longest wherever they find food on shallow flats nearest their route.

In cloudy or muddy lakes, walleyes range close to shore to feed. In normal to slightly off-clear waters, they tend to penetrate no shallower than 4 or 5 feet during the day, but shallower at night. Levels of light penetration help pinpoint walleye location during daytime hours.

To find these flats on a contour map, look for broad shelves (where depth contours are farthest apart) in the critical depth range of about 5 to 12 feet. The best flats in spring have a fairly soft or sandy bottom. Weeds like chara, a low-growing plant that persists through winter (also called skunk weed or sandgrass) provide cover for perch, thereby attracting walleyes.

Nearby creeks or rivers entering the lake increase the odds that walleyes might use such a flat. Gravel shorelines and rock reefs in the vicinity have the same effect. The bigger the flat the better, but where two flats are precisely equal in size, cover, bottom type, forage, and depth, the flat nearest walleye spawning habitat receives a far bigger draw.

Flats don’t have to be like table tops, but anything more than a gradual slope seldom attracts as much activity. Some lakes lack extensive shallow flats, however. In that case, walleyes use available shallow shelves. Shallow flats on some lakes and reservoirs are bigger than Yankee Stadium. To find forage, walleyes must roam vast areas, requiring more effort to locate them.

The principles are constant for the Great Lakes, southern reservoirs, or Shield lakes of northern Canada. On Lake Erie, for example, some of the hottest action of the year is on flats near the mouth of the Maumee, the Huron, and other spawning tributaries, right after the spawn. Spawning creates an energy withdrawal that walleyes must replenish in the most efficient manner possible. They go where the forage is, and the most concentrated forage often is shallow, on flats adjacent to spawning habitat and exit routes.