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What Is an Oxbow Lake?
By Joan Whetzel
There's nothing like a day at the lake. Fishing, Picnicking. Swimming, Catching some rays Maybe even a little boating. Well maybe not boating if it's an oxbow lake. These lakes are usually a bit too small for any serious boating and the shape doesn't usually lend itself to boating either. What is an oxbow lake, you say? Well, let me tell you about it.
Oxbow Lakes Defined
Oxbow lakes are u-shaped bodies of water that are formed from the bend in a river that was cut off from the river's flow at some point in time. The lake is formed into a thin, curved shape, like a horseshoe or part of a yoke used on oxen.
How Oxbow Lakes Are Formed
A river flows in a meander, meaning it curves back and forth, folding back on itself multiple times on its way to the ocean. The bending meanders become more prevalent (there's more of them) and pronounced (larger and more spread out) the closer they get to the ocean. This meander serves a purpose. As the river gets closer to the ocean, it enters a flood plain. It is also carrying more water because it is being fed by multiple smaller riverlets, bayous, and streams, as well as from rainfall, along the way. The meander allows the river to handle more water in less acreage, and feed all that water into the ocean without flooding the flood plains on non rainy days. The flood plains, though can handle the flood water from excessive rainfall in the area as well as heavy rains upstream.
Rivers pick up rocks along the way, which break down into smaller rocks and pebbles, and then silt, all of which get carried downstream. Rivers also pick up more silt from the river bed as the water makes its way from higher altitudes down to seal level. All of this debris, as you may well imagine, can clog the river way, especially when the water levels are low from lack of rain. If the river's curve is very thin, the silt can choke it off al together from the main flow, creating an oxbow lake that is no longer part of the river.
The Brazos River and Oxbow Lake Formation
The Brazos River, which flows through Texas, enters the Gulf of Mexico just to the South of Houston. It's floodplain is about 8 to 10 miles wide and spans an area to the west and south of Houston. It has a wonderful meander patter and, over the centuries, has formed some oxbow lakes within its territory.
There are a few located in Brazos Bend State Park as well as in the Richmond and Sugar Land areas near the river channel. Access to the oxbow lakes in Brazos Bend State Park has been made easy, thanks to the Texas Parks and Wildlife Department. The Brazos River near Sugar Land is accessible by underpasses at the U.S. Highway 59 Brazos River Turnarounds. From the parking area in the turnarounds, one can take any of the paths down to the river bank allowing hikers fine views of the river, its meander, and at least one nearby oxbow lake.
Wikipedia. Oxbow Lakes.
Encyclopedia Britannica. Oxbow Lakes.
Mahalo. Oxbow Lake.
The Brazos River. Fluvial sedimentation in a meandering river floodplain
TPWD. Brazos Bend State Park – Horseshoe Lakes.