People frequently ask "how high can the water go?" There are several answers to this question. To understand the "elevations" of the lake, we first need to talk about the dam.While the top of the dam is at 594 feet above sea level, the original 1914 design drawings called for the crest elevation (the highest water) to be 606.3. In 1997 the crest elevation of the dam's embankment was raised to 609.5 ft. so that the spillway could pass the probable maximum flood without the dam's embankments being overtopped.
The lake has never come anywhere near the 609.5 level. According to some records, the highest crest was in 1990 when the lake reached 598.7.
Here are the "official" lake levels:
594 - Normal Pool (full to the top of the dam)
597 - Minor Flood Stage
598 - Moderate Flood Stage
598.7 - Recorded high (1990)
Here are some historic high levels:
1990 598.7 - flood stage
2004 597.8 - flood stage
2007 596.1 - 11" under flood stage
At the 596 level, many docks are underwater and some of the homes on the lake are near to getting water in them.
If you live on the lake or are considering a purchase, you should understand the possible implications of high water. It's not a matter of "if" but "when."
(Photo by Angie Myrick Thomas 2015)
5 comments:
This is very helpful. Are the levels based on the 1929 or 1988 method of setting sea level? These two methods are abbreviated NGVD29 and NAVD88. The former is based on land-based measurements and the later is based on satellites. Depending on location, they can differ by 3 feet.
@Dave Brown - Hmmm. I have no idea. You will need to research that. As long as all the measurements are consistent, I doubt it matters how far above sea level that the lake actually sits.
Michael Dallas,
Thanks for the fast reply. I did more research and according to the website https://waterdatafortexas.org/reservoirs/individual/worth these elevations are based on NGVD29.
The reason it might matter is that I'm house hunting for lakefront property and want to avoid the risk of lake flooding. I'm using a cell phone application to get the Global Positioning Satellite elevation for the bottom floor of the house. Since the app. uses GPS it probably is closer to the NAVD88 method. The GPS app. is accurate to within 3-6 feet and the delta between 1929 and 1988 can on rare occasions be 3 feet. So unless I pay for a more accurate elevation survey, I need a "safety factor" of 9' to be sure the bottom floor of the house is above the top of the dam.
Sincerely,
Dave
Gotcha. You could set the phone just above the surface of the water for one reading then the floor level for the second reading. Just a thought.
... and compare those readings with the current water level.
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