February 09, 2015
Thousands of American lakes have power plants looming over them, and during February, portions of lakes near such facilities may be crowded with anglers. Cold-weather fish feed actively in warmer waters near power-plant discharges. Anglers who know this swarm to these areas to enjoy winter fishing opportunities without equal in cold climes.
How Power Plants Work
Water is a necessary part of coal and nuclear-energy facilities that produce electricity. Coal or uranium generates heat used to turn water into steam. The steam turns turbines, which results in electricity being generated. Water from an adjacent lake is run through condensers that cool the steam, and some water used in this process is returned to the reservoir in a warmer state, sometimes as much as 20 degrees higher than the lake water elsewhere. The presence of this warm water makes the winter bite good, but not for the reasons you may think.
Anatomy of the Power Plant Bite
Many anglers believe the warm water around a power plant draws fish from throughout a lake like moths to a flame, and the reason winter fishing is so good is because of the huge concentrations of fish thus attracted. In reality, this is not what happens. Fish living in areas of the lake far removed from the power plant have no way of detecting the warm discharges, so the only fish likely to be caught are those already living near the plant.
Why, then, is winter fishing so good in these waters? The answer relates to fish metabolism.
As the water temperature gets colder and winter progresses, many fish have a metabolic slowdown. They become less active and require less food. In “normal” lakes, this accounts for the lack of a good bite during the coldest periods of winter, at least for some species of fish. If the water temperature falls low enough, fish may not feed at all.
In a power-plant lake, we witness a different scenario. The presence of a warm discharge creates a zone of water where the temperature is closer to most fishes’ comfort range. Because the water temperature is higher, each fish’s metabolism runs at a more optimum pace, and the fish grows faster. Higher metabolic and growth speeds create a demand for a larger food intake, so the hungry fish feeds more and is more likely to be caught.
Evidence of this is found in growth rates of largemouth bass in some power reservoirs. Studies of some Texas and Louisiana power-plant lakes, for example, indicate a largemouth bass may gain an astounding 1-1/2 to 2 pounds annually. And because these well-fed bass stay healthier, spawns are typically better, and bass censuses reveal more fish per acre.
It’s no wonder power-plant lakes are popular with winter anglers. In colder waters, fish are sulking in the depths. In power-plant lakes, abundant fish are feeding ravenously to fuel their internal fires.
Deducing Where They’ll Be
To successfully fish a power-plant lake, one first must find the fish. Unfortunately, some anglers try to oversimplify the process. Find the warm water, they think, and you’ll find the fish. These anglers often go home disappointed because the lake didn’t live up to their expectations. With a little more on-the-water research, however, they could have been catching fish instead of just fishing.
The key to pinpointing fish concentrations is an understanding of each species’ “comfort range.” This is the temperature range at which the fish is likely to be most alert and active. Because the fish feels best within this temperature range, it always is seeking a place in the water where that range exists. For most warm-water game fish such as largemouths, crappie and stripers, this level will be somewhere in the low to upper 70s.
In some lakes at certain times of year, fish may be unable to find such a spot. But in the zone around a power-plant discharge, water temperatures are highly variable in different areas within the water, and from hour to hour as discharge rates change. Somewhere within the “mixing zone” where warm discharges and cold lake water intermix is that “feel good” zone, but fish may have to move frequently to stay within it. If an angler expects to catch these fish, he must move with them.
The simplest way to determine the best fishing areas is to use a thermometer of some type (electronic or otherwise) to determine temperature patterns within the power-plant discharge area, a zone that may cover hundreds of acres. When high volumes of water are being discharged, the zone of warmth may extend a mile or more into the lake. When flows are halted, this zone shrinks nearer to the discharge until warm water flow resumes.
In different lakes with different types of power-plant structures, the zone of warmth may be found at different areas vertically within the water column, too. For example, some power plants have surface discharges, so the warm zone will usually be at the water’s surface. Other power plants have subsurface discharges, which create an inshore zone of warmth near the bottom, and an offshore zone nearer the surface as warmer water rises to the top. The only sure way to determine these patterns at a given time in a given lake is by means of a temperature gauge that helps you zero in on the comfort zones. You could find some fish simply by casting and retrieving the proper lures near the right kind of cover and structure. But you’ll zero in on fish concentrations quicker if you first determine where water temperature is closest to ideal.
When you pinpoint an area with the proper temperature, look for other fish concentrators such as brush piles, submerged rocks, logs, depressions, humps or ledges. Fish seek ideal water temperature, but they’ll still remain near structure, cover and foods they prefer. If there have been no discharges from the power plant for several hours, the best structures may be in shallow waters near shore close to the discharge outlet. During high discharge periods, water near the discharge area may be too hot for comfort, thus fish will move to offshore structures within their comfort zone. The key to catching numbers of fish in power-plant lakes is knowing these movements occur, and knowing where each type of fish you seek is most likely to be under varying conditions.
What anglers should remember more than anything, perhaps, is power-plant lakes tend to be individualistic in terms of effective fishing patterns, and the patterns can change abruptly with variations in water discharge and weather conditions. To be successful, a fisherman must be versatile, willing to dip into his tackle box and try whatever lure or bait seems best for the areas where fish are holding. If you don’t get hits, try something different until you determine an effective pattern. If you’ve done some on-the-water scouting and pinpointed good areas of cover and structure within a zone of water at the right temperature, sooner or later you’ll entice some strikes. And when you do, get ready for action. Fish in power-plant lakes often form huge schools, and when you’ve figured out the pattern, you can have one on nearly every cast.