Saturday, January 24, 2015

Lateral Sort and Point Bars



This illustration shows a point bar on the inside of a bend in a typical stream. This constriction in the rivers channel makes the current speed up as it goes around the point. As you know a spot close to the center of a wheel is turning slower than a spot on the rim of a wheel. The water curving around the point also has to do the same so the faster swifter water on the outside of the bend digs out the bottom and far bank creating a hole off the end of the point. As the hole is eroded over time there is more pressure by the faster water on the outside side of any material dislodged. Also often a secondary current right on the bottom is often set up. These result in dislodged objects being moved slightly towards the point every time they are moved by high waters. In multiple high water events the bigger material is moved closer to the point while smaller material is swept away. Over the course of many many years this can sometimes result in a lateral sort of the rocky material off the point. With the biggest stuff that has stayed on the point after repeated events being right at the tip of the point and steadily smaller and smaller stuff laid down in strips as you go farther from the point. What's this got to do with fishing? Well crayfish and darters love rocks. Stuff the size of a grapefruit especially. So somewhere along the width of our point and pool of sorted rocks is a strip of bottom that is ideally suited for them creating a mini city of smallie food. (B in our diagram) While the outside side of the hole might be swept bare of bigger rocks and is just a layer of fine gravel deposited between big events. In other words NOT crayfish and darter cover. (C)  Now sometimes shiners will use this fast water pouring over bare gravel too so you do need to throw a cast or two there too.
But what happens is a guy comes along fishing beaches his yak or canoe and walks out to the end of the point. He then makes a nice average cast to the center of the hole and fishes his lure downstream thru the hole. He reels in repeats and does this a dozen times. If he doesn't catch a fish he moves on. Well he cast over top of the sweet spot and his lure was barely in in it. Sometimes we are reeling in and catch a fish seemingly right at our feet. When this happens make sure its not a lateral sort situation. Cover the holes off the ends of points laterally with each cast following a different path that the previous. Right along the steepest banks in bend pools if there is any cover is the ideal habitat for a shovelhead to make his home. (D) Below the bar (A), if the bottom is hard enough can be spawning habitat as well as a place for fish to move up shallow at night and feed.

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