Power generation, drawdowns, spring runoff, wind--all produce currents, which vary in intensity. Fish respond to current by positioning around cover or along bottom contours. Generally, they face into the current because they expect forage to come from that direction. Regardless of the source of the current, then, the cardinal rule is to fish your bait, whether it's a natural bait or a lure, so that it moves naturally in the flow. Of course, there are exceptions to deal with, such as eddies or cross-current winds.