Does anybody know if any of the lakes in the DFW area are “constant level” lakes? Or where the nearest one is?
Thanks
JR
I don’t believe any of our DFW lakes are constant level. I know Lake Austin and LBJ are (supposed to be). Even they fluctuate.
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I hear Joe Pool is. But I never looked that far into it.
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It may supposed to be, but definitely is not. In a 2 month period it went to boat ramps closed because of low level at the end of summer to closed in spring because it and the picnic area were under water!
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With all area lakes being reservoirs whose functions are…
- Providing drinking water
- Usually flood control
- Recreation
… in about that order, constant level simply isn’t gonna happen.
Lakes without controlled spillways - such as White Rock - are more likely to maintain constant levels. In terms of Army Corps of Engineers lakes, this report shows lake levels; note that those without flood pools have more constant levels in my recollection … also note that the ‘release’ values are not absolute - i.e. Grapevine shows zero, but Denton Creek wasn’t a dry streambed when I passed it this morning.
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Lake Ray Hubbard (east on 30 near Rockwall) is a constant level lake (up to a point). It’s level has only fluctuated about 10 feet in the last six years (including deep drought and excessive rain. Since the drought broke in 2015, it’s only fluctuated a couple of feet.
In contrast, Lake Lavon (just upstream) is not a constant level lake, and dumps water into Ray Hubbard. During the same 6 years, it’s level has fluctuated more than 20 feet. It routinely fluctuates 15 feet within a given year, especially when water is taken from Lavon to fill Ray Hubbard.
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Love seeing data like that. Thank you so much for the analysis!
Is is true that Lavon is tapped to keep the Hubbard level up or is Lavon intentionally lowered to maintain its ability to handle a flood?
They are two sides of the same coin. Lowering Lavon to capture more flood water also helps provides reserve to keep the next lake from rising.
@Team_Civic_Hacking might be interested
White Rock Lake is indeed pretty constant. I don’t know that I’ve ever noticed it change in 5 years. Maybe during major flooding.
The net effect may usually appear to be the same, but the real effect can be very different.
The reason I ask is that the areas to the northeast of the Metroplex had been subject to extremely severe water use restrictions in the past years because the level of Lavon is so far below conservation pool.
There are two reasons the level of a lake may be intentionally lowered beyond conservation pool:
- In anticipation of a large volume of incoming floodwaters in the near future
- A law or agreement to release water to keep downstream reservoirs at some specified level
Not sure, but I would expect lavon to be managed similarly to Lewisville. Above full pool, the CoE determines release rate to minimize flood risk downstream. Below full pool, release rate is determined by the water utilities that pull from the stream downstream. And from on line reactions to people who were pissed last spring (or maybe the year before) when the lake was being drained down to full pool aggressively, they do manage it the same way.
About 100 miles east is Lake Cypress Springs near Mt Vernon TX in Franklin County. Spring feed as well as river fed. Used to have very little fluctuation.
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