There is no classic definition of a “flowage.” Most lakes called flowages arise in the North (most, in fact, are in Wisconsin, though some exist in Michigan, Minnesota, and other states). Some have all or most of the attributes of a lowland or flatland reservoir. But some occur in hilly country, employing relatively small dams that affect far less of the landscape than a hill-land reservoir. In Kentucky, this type of flowage is called a “river-run reservoir.” These are typically long and narrow with an easily distinguishable creek channel and lots of woodcover. Maximum depths at the dam may exceed 40 feet, but the deepest areas along the main river channel are in the 20- to 25-foot range. Flowages often harbor excellent crappie fisheries.

Somewhere between 1980 and 1995, most crappie anglers across North America’s flatlands gradually arrived at the same conclusion: Winter is usually the best time to pursue crappies in flatland reservoirs, because all the locational patterns merge into one. They coalesce into tighter groups during winter than at any other time of year. Because crappies everywhere seem to locate and suspend thickest in areas less than 50 feet deep, shallower flatland reservoirs offer the most habitat for them to spread out across. And their seasonal migrations in these types of impoundments tend to be longer than anywhere else.

In the latitudes of northeastern Kansas, winter fishing generally begins about three weeks prior to the winter solstice, which occurs 4 to 6 days before Christmas in most years. During late November in Kansas, crappies and their primary prey—gizzard shad—begin congregating in giant schools that gradually become even larger as winter progresses. By February, some schools of shad and crappies are 3 to 5 feet thick and 30 feet in diameter, suspended over submerged creek channels.

From such massive schools, anglers routinely extract 100 or more crappies per day. Perhaps crappies form such schools to increase predatory efficiency, just as the shad gather in tight schools for protection. Many Kansas anglers contend that such schools are more vulnerable to fishing pressure than they are during the spawn, and further contend that more restrictive creel limits need to be established for winter fishing.

Fishing can be so extraordinary in winter that a few crappie specialists shun big schools that suspend over creek channels, contending that suspended crappies are too easy to catch and rarely include the system’s biggest specimens. These anglers are looking for 2-pounders, which they believe assemble in smaller, looser groups. And bigger fish do tend to segregate themselves, spending more time near bottom, where a properly tuned depth finder is required to find them.

Schools of flatland-reservoir crappies can range from the dam to the upper reaches of feeder creeks and rivers. In lower Michigan, this behavior often ends during October, while it may continue until December in Kansas. As winter progresses, schools tighten and coalesce in the middle and upper third of the reservoir, leaving most of the waterway barren of crappies. During an unusual winter in Kansas, some schools of crappies and shad continue to hold less than a mile from the dam, suspended over depths of 30 to 35 feet. This typically occurs when crappie and shad populations are extremely high. In Michigan, lakes lack shad and may be iced over by early December. There it’s more typical for flatland crappies to remain in the lower third of the reservoir (closer to the dam) all winter. Latitude, climate, and forage all play a role in ultimately determining where crappies might spend the winter in flatland reservoirs, yet in all of these shallow lakes continent-wide, crappies group tighter during the cold months.