2226.01 ft above mean sea level
20% full share of conservation capacity, as reported with the gauge reading
level 32.0 ft below full pool — typical for late September
Reading comes from Texas Water Development Board — Water Data for Texas (Water Data for Texas — j-b-thomas) by way of our own server, which asks the agency each time you load this page and passes on its figure in the agency's own datum, unchanged. Water Data for Texas publishes one figure a day for each reservoir, so the date beside the reading is the day that figure covers. For everything else the agency publishes about this reservoir, go to Lake J.B. Thomas at Water Data for Texas.
Is Lake J.B. Thomas full?
Not quite — 32.0 ft below full pool as of September 30, 2026
How full is Lake J.B. Thomas? Lake J.B. Thomas was holding 20% of its conservation capacity on September 30, 2026, per Water Data for Texas.
Lake J.B. Thomas through the year
The band is the lake's own normal: where the level has run on each calendar day, 1999–2026. The summer drawdown — and how this year sits in it — shows up without reading a single number.
This year vs the years that matter
This year's trace against last year and the driest and wettest years on record — the drought-context question every lake regular asks.
- 2026 (this year)
- 2025 (last year)
- 2016 (wettest on record)
- 2012 (driest on record)
Full pool, datum, and the gauge
"Full pool" here means the conservation pool — the level the lake is designed to hold for water supply and recreation, not the flood-control space above it. The full explainer covers flood pool and dead pool too.
| Full pool | 2258.00 ft above mean sea level · per Water Data for Texas — Lake J.B. Thomas |
|---|---|
| Conservation capacity | 199,931 acre-feet · per Water Data for Texas — Lake J.B. Thomas |
| Gauge | Water Data for Texas — j-b-thomas · Texas Water Development Board — Water Data for Texas |
| Datum | ft above mean sea level |
| Last verified | August 20, 2026 |
LakeDates reports lake level, not ramp status. Whether a given ramp or marina is usable at this level varies ramp by ramp — call the marina before you tow.
Quick answers
What is the lake level for Lake J.B. Thomas today?
Lake J.B. Thomas is at 2226.01 ft (above mean sea level) as of September 30, 2026 — 32.0 ft below full pool — typical for late September. The lake is holding 20% of its conservation capacity.
Is Lake J.B. Thomas full?
Not quite — at 2226.01 ft on September 30, 2026, Lake J.B. Thomas is 32.0 ft below its full pool of 2258.00 ft (above mean sea level). The lake is holding 20% of its conservation capacity.
How full is Lake J.B. Thomas?
Lake J.B. Thomas was holding 20% of its conservation capacity on September 30, 2026, per Water Data for Texas.
What is full pool for Lake J.B. Thomas?
Full pool (the conservation pool) for Lake J.B. Thomas is 2258.00 ft above mean sea level, per Water Data for Texas — Lake J.B. Thomas. Levels above it use flood storage; levels below it are drawdown.