SPRING TO SUMMER

Rising water in a flatland reservoir sends crappies shallow. Conversely, drawdown forces them to secondary drop-offs. In either case, the mudflat pattern can dissipate, so it tends to follow a stable-condition model. “Still, the mudflat pattern in 14- to 20-foot depths always ends up being the most consistent for bigger crappies over the course of the season,” Kehde affirms. “But, if the reservoir is less than 15 years old, crappies can remain somewhat channel-bound, as if they don’t trust things not to revert back to the way they were before the dam was built. But the real reason crappies in newer reservoirs continue to relate to river and creek channels is the fact that fewer brushpiles have been planted on the flats. Also, as a reservoir ages, the less distinct its channels become.”

Most of the mudflat patterns Kehde talks about take place on the main lake away from the river channel. The most obvious summer patterns in flatland reservoirs involve crappies around brushpiles along the top lip of river and creek channels; but as Kehde insists, these are also the most commonly exploited patterns. Other patterns that persist through summer on flatland reservoirs include areas 10 to 20 feet deep, usually on brushpiles, logs, or submerged timber, in the backs of bays or the very back end of creek arms. These patterns hold until water temperatures at the surface drop below 60°F in fall.

Flowages: A type of reservoir similar to a flatland impoundment is the flowage, a riverine environment found mostly in Wisconsin, Minnesota, and some other upper midwestern states. A flowage is generally narrower than a flatland reservoir, with more current and created with a smaller dam. They’re often located in rolling country with hills and valleys. Flowages are often filled with cover in the form of flooded and fallen timber, cribs, and submerged brush. Flowages also can be ideal for the recruitment of riverine chubs and shiners. The combination of cover and an apparently limitless food source in a flowage can produce an excellent trophy crappie fishery.

Flowages can be tough to pattern during the Postspawn Period, because the fish scatter and have almost unlimited cover options. Crappies settle into summer patterns late, usually sometime in August. In the latitudes where flowages exist, the nights are already beginning to cool, and water temperatures are slowly backing down from summer highs. Crappies begin to school more tightly at this time, in and around the densest cover available on 10- to 15-foot flats adjacent to the river channel. As the nights begin to cool the water in late August, these schools begin to group even more tightly and start to move deeper.

The best spots in flowages from late August through September are often the deepest holes in the old river channel—the same places crappies frequently inhabit during winter. These holes occur in bend areas, and typically range from 18 to 28 feet in depth. When highly active during late summer, crappies may spread back up onto the flat during feeding forays, into the densest cover available in depths of 10 to 15 feet. They may group heavily where combinations of cover come together—for instance, logs mixed with brushpiles and boulders, with a few stumps thrown in for good measure.

It can be difficult to tell what the cover is composed of when using only sonar. An underwater camera can reduce the amount of time spent looking for key spots. It’s typical to fish 10 to 20 areas filled with dense cover before catching a single crappie, but the next spot could hide the mother lode concentrated in a small area of mixed cover. Once discovered, these spots ordinarily remain exemplary for the remainder of the season, and for many seasons to come during late summer and early fall.

Like their cousins in flatland reservoirs, crappies in flowages are most active during periods of stable weather with intermediate barometric pressure, and suspend in or near the tops of the branches of fallen timber and brushpiles. They may retreat into deeper holes and hug bottom after a cold front. But, as late summer gives way to fall, mild cold fronts may actually turn crappies on and precipitate a hot bite.