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You reported that Falls Lake is now full at 251.5ft. What is that a measure of? Certainly Falls Lake is not 251ft deep.

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By
Jim Holland

MIKE MOSS SAYS:    Jim,     You're certainly correct that the lake is not that deep. The lake levels are instead tracked according to the elevation of the lake surface above mean sea level. For Falls Lake, the Corps of Engineers designates 251.5 feet as the top of the conservation pool, meaning that at that level the lake is "full" in terms of the designed water storage for its purposes of water supply, wildlife management and release of water for maintaining streamflow and water quality downriver. Water that accumulates enough to push the lake surface above 251.5 feet is considered to be in the flood control pool, which extends up to 264.8 feet, and the lake is typically managed to keep the level fairly close to the "guide" or target level of 251.5. Water that rises above 264.8 feet tops the spillway and is considered to be in an uncontrolled flood storage range.

As far as the water depth, it varies greatly across the lake, but the "bottom" is listed as having an elevation of 200 feet above mean sea level, so when the lake is at its normal level of 251.5, the deepest part of the lake should be about 51.5 feet deep. You can find lots of other details about the lake at

http://epec.saw.usace.army.mil/falldesc.txt

and

http://epec.saw.usace.army.mil/fallpert.txt

 

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