Water School

Archive by category: Lake LevelsReturn

Why do lake levels fluctuate?

The level of water in all lakes fluctuates, raising during years of higher amounts of rainfall and snowmelt and falling during periods of drought. The Environmental Protection Agency has been measuring the fluctuations of the Great Lakes, the largest natural lakes in the United States, since the 1860s. Similarly, water levels in reservoirs, human-made lakes, fluctuate because of evaporation, a lack of rainfall, water supply use, and water flow requirements. Levels tend to be relatively lower in ...
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What is constant level?

Constant level is a term given to the practice of maintaining a body of water at a specific elevation.  No natural body of water has a constant level.  While some fluctuate more than others, all-natural bodies of water change on a daily basis, some rapidly during floods.Few man-made reservoirs have the ability to be maintained at a constant level as evaporation, drought, water use and/or flooding affect elevation levels. 
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What is a lake's elevation?

The height above mean sea level that water in a reservoir has reached. Brazos River Authority and U.S. Army Corps of Engineers lakes are actually reservoirs, or parts of the Brazos River basin impounded by dams. (A free-flowing river is measured in stages, that is, by depth from the river bed to the surface.)
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How deep is my lake?

Periodically, officials conduct surveys of reservoirs within the Brazos River basin to determine each lake’s volume. As part of that work, survey crews determine each lake’s depth (in feet). Do not confuse this measurement with lake level, however.A reservoir’s depth is the distance from the bottom to the top of the conservation pool, the point where the lake is considered full. The lake level is the number of feet the surface is above mean sea level.Surveys use a combinat...
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I’ve heard that reservoirs have a “lifetime.” What does that mean?

Texas streams and rivers are in constant motion and the waters they pour into our reservoirs carry with them a continuous but varying amount of sediment.When the water is slowed or stopped as it runs into a reservoir or by a dam, the sediment drops to the bottom. This sediment builds up year after year and at some point, fills the reservoir to a point it can no longer continue to serve its purpose in flood control or water supply. Without expensive dredging, this would be the end of the res...
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The information provided on this site is intended as background on water within the Brazos River basin. There should be no expectation that this information is all encompassing, complete or in any way examines every aspect of this very complex natural resource.

If you have questions about a post or would like additional information, please contact us or call 888-922-6272.

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