Lake J. B. Thomas water level — Texas
Lake J. B. Thomas in Texas was last measured at 2,227.09 ft (datum NGVD29), as of Aug 31, 2026, 2:45 AM (UTC-05:00) (USGS Water Services). Over its recent trend window the level has been falling (−1.3 ft). This reading is provisional and subject to revision.
- % of conservation pool full
- Not reported
- Storage
- 43,880 acre-ft
- Recent trend
- ↓Falling
−1.3 ft over the trend window
Recent trend
Readings this station published between Jun 2, 2026 and Aug 31, 2026 — a 89-day window — downsampled for display.
Data: USGS Water Services (waterservices.usgs.gov) and USACE CWMS Data (cwms-data.usace.army.mil), retrieved 2026-08-31. Both public domain (a work of the U.S. Government, 17 U.S.C. §105).
Source: USGS site 08118000, retrieved Aug 31, 2026, 8:24 AM (UTC+00:00). Official page for this lake →
About this gauge's record
This site's drainage basin covers approximately 3,389 sq mi of contributing watershed.
The dam behind Lake J. B. Thomas
Lake J. B. Thomas is held back by Lake Jb Thomas Dam (also recorded as Lake J B Thomas Dam) , an earthfill embankment, holding the pool back by sheer mass and an impervious core rather than by the strength of concrete , standing 105 ft high and running 9,200 ft along its crest , built across COLORADO RIVER in Scurry County , near COLORADO CITY . It was completed in 1952 and modified in 2007O , and is owned by COLORADO RIVER MUNICIPAL WATER DISTRICT (a local government owner) , to a design credited to FREESE AND NICHOLS;FREESE AND NICHOLS.
Its recorded primary purpose is water supply — delivering water to its customers comes first, so drawdown here follows demand as much as it follows rainfall . It also serves water supply;recreation.
It is founded on rock;soil, with a earth core. Its spillway is ungated: once the pool reaches the crest, water leaves on its own and the operator cannot hold it back. The spillway opening is 1,834 ft wide. Its outlet works use uncontrolled3;valve1.
NID classes it high hazard potential. That describes what a failure would cost downstream — loss of life would be expected — and says nothing about how likely a failure is, or what condition the dam is in. Its most recent condition assessment was fair: sound under normal loading, though a rare or extreme event could expose a deficiency. That assessment is dated 05/13/2024.
At its normal pool the reservoir covers about 7,820 acres. NID records a maximum storage of 430,600 acre-ft against a normal storage of 200,604 acre-ft. Its maximum discharge capacity is 161,002 cubic feet per second. It is regulated by TCEQ.
Dam facts: National Inventory of Dams record TX04138 , filed by Texas — U.S. Army Corps of Engineers, public domain. Water levels above come from USGS Water Services and are a separate source. (How this dam was matched to this gauge →)
How Lake J. B. Thomas compares nearby
5 of 6 nearby lakes with a current trend are also falling right now.
Nearby lakes
The six nearest published lakes by centroid distance (great-circle) — cross-state neighbors included.
| Lake | State | Level | Distance |
|---|---|---|---|
| Lake Colorado City | TX | 2,059.22 ft | 34 km |
| Moss Creek Lake | TX | 2,331.33 ft | 42 km |
| Champion Creek Reservoir | TX | 2,062.83 ft | 44 km |
| Lake Alan Henry Reservoir | TX | 2,209.36 ft | 53 km |
| White River Reservoir | TX | 2,349.61 ft | 96 km |
| E. V. Spence Reservoir | TX | 1,842.98 ft | 99 km |
Frequently asked questions
- What is the current water level of Lake J. B. Thomas?
- As of Aug 31, 2026, 2:45 AM (UTC-05:00), the pool elevation was 2,227.09 ft (datum NGVD29), provisional and subject to revision. See the trend chart above for the recent direction.
- Is Lake J. B. Thomas full right now?
- Its managing agency does not publish a %-of-conservation-pool-full figure for this lake, so we show the bare level rather than estimate one.
- Where does this data come from?
- From USGS site 08118000, retrieved Aug 31, 2026, 8:24 AM (UTC+00:00).
More in Texas
See every lake tracked in Texas, or read the methodology behind these figures.