Fishing Rivers Under Lakes

By Russ Bassdozer

Actually, many lakes we fish are not lakes. They're impoundments. Originally, river drainage systems that have been dammed by humanity.

A golden concept that applies to impoundments year-round but especially each spring is this: Fish impoundments as if they still are the original rivers. This means targeting the locations that were active flowing parts of the original river system before being dammed by man.

Even though their banks may have been overflowed and flooded over decades ago, the age-old creek channels and feeders can still be important to the bass. The creeks and gulches and washes and trickles were the oases of life before being flooded by the dam - and may still be the meccas of motherlodes of fish.

Although buried under water now, the riverine environment is still intact under the impoundment, and the bass still use the impoundment as if it still is a river system.

A river system (and hence an impoundment) is a mesh of countless connecting feeder veins and water flows of the following exemplary types which you should learn to recognize and target. Some of the larger constructs can be recognized from far away, and may extend down into the impoundment from far back on the adjacent land. Some of the smaller constructs often have an additional traipse of garnishy greenery on the way down to the shoreline, which is a surefire cue to a few water veins that fish like gold veins.

However, many original river features may be far offshore underwater now, and spottable only on a map (more on maps later).

Here are some of the key river constructs underneath an impoundment:

MAJOR CONFLUENCES. Where two rivers or streams that rarely dry meet (or would have met if they were not flooded under water by man). Confluences can be great summer and fall staging spots for bass.
PERENNIALS. These are more or less steady creeks that never completely dry up or only stop flowing during the very driest spells. These usually have silty flood plain deltas in the back, and may be marshland or flooded brush basins in the back.
NON-PERENNIALS. These are where an intermittent creek or wash, which may have been dry for most of the season, is now underwater. The confluences where non-perennial or lesser side creek would have met a stream or bigger creek - some of these MINOR CONFLUENCES can be great winter or summer deepwater holding areas for bass.
SEASONAL INFLOWS. Places that don't flow year-round but bring water in predominantly during the snow-melt season and/or only during the rainy or monsoon season. Snow-melt is more "systemic" and runs off from deeply-saturated grounds whereas rainy season inflows can often be but are not necessarily shallower surface ground run-offs. In other words, snow versus rain water may not necessarily journey across the same terrain nor enter the impoundment at the same places.
INCIDENTAL INFLOWS. Places that usually do not flow but only convey excess water as a result of heavy downpour or flash flood incidents. These can come from high ground, and may result in temporary waterfalls or spills. The area may be highly dangerous to approach on rainstorm forecast days or during the wet or flood season, but during dry and stable conditions, you may find a sand or sediment delta and washed-in debris deposits at the base. Sure spots for bass.
SEEPS AND SPRINGS. Water squeezed out of rocks or coming out of the ground. Actually, I don't think such water gets wrung right out of the rocks, but squeezed between the thin space between two layers of rocks. Nevertheless, even such innocuous "drip rocks" seem to have enhanced food chains on and about the drips - more terrestrials, insects, moss, algae - and right on up the food chain that ultimately attracts bass.
SHINING SAND OR WET SPOTS. I'd hardly call these any sort of serious water inflow, but still bass have an uncanny affinity for such areas, especially in the spring. Usually, they're a dimple or depression in the back of a bowl or a teacup-type sand flat. They may be the last spot of shoreline to dry after a rain, or the last spot to stay wet as lake water levels decline. A good way to notice them is simply sun reflection shining off wet sand rimming the shoreline - or a darker, damp tongue of dirt impressed on an otherwise drying shore. Upon closer inspection, the spot may reveal an old channel cut either coming out of or bending in close to the shoreline.

I may have lost many readers here with the drip rocks, shining sand and wet spots - but hopefully at least a few of you are nodding wisely about these heretofore undocumented bass hotspots in every impoundment.

Some of these spots, the smaller ones, are only recognizable from a certain angle, and you really do get better at spotting them with experience. Often times, on a steep shoreline, such spots can be more easily seen far up the land mass, and then traced down to where their journey descends into the impoundment

MORE ON MAPS

Maps can be extremely important and often are the only way to get a full picture of the rivers and creeks still flowing under and into an impoundment.

Impoundments can range from several hundred acres to several hundred miles long. On some of the smaller impoundments, map availability may be limited.

On the larger impoundments, new and different maps can be ferreted out readily - and each new map has a habit of showing different creeks, different inflows than the other maps. Not just fishing, boating and topo maps, but shoreline camping/hiking maps/books often note or describe water flows not documented elsewhere. I've come across snow melt maps, rainy season drainage maps, water rights usage maps, environmental impact statement maps, even forestation/vegetation density maps can give clues to creeks and water seeps. Bottom line, most every map I come across on a large impoundment may reveal yet another feeder creek clue or riverine perspective not previously marked on other maps.

Now, never go target any of these areas while they are still gushing or spewing water or even soggy rain-drenched - and most of the time, most places, they probably aren't like that. But I take great caution to avoid any such areas while they are gushing or active or rain-drenched or whenever inclement weather advisories are broadcast for an area, since the land around them (which may be above you) seems to have a higher chance to be unstable when wet - as in landslides, rock slides, cliff walls falling, and flash flood surges of uncontrollable dangerous water can enter an impoundment from rainstorms happening many miles away.

Always keep in mind, if your favorite lake was once a river, it probably still fishes like a river. Many anglers I've met never realize this about impoundments. Much of the rest of an impoundment (which was formerly dry ground) may be a poorer fishing prospect at times, although the original river and all its tributaries and veins still teem with life. In a very real sense, even though dammed by humanity, the original rivers remain the oases of life, and the connecting mesh of hidden underwater creek channels are often the premier places to be for bass.