Thatcher Lock and Dam Upper water level — Arkansas
Thatcher Lock and Dam Upper in Arkansas was last measured at 77.30 ft (datum NGVD29), as of Aug 28, 2026, 12:00 PM (UTC+00:00) (USACE CWMS Data). Over its recent trend window the level has been falling (−0.2 ft).
- % of conservation pool full
- Not reported
- Storage
- Not reported
- Recent trend
- ↓Falling
−0.2 ft over the trend window
Recent trend
Readings this station published between Jun 2, 2026 and Aug 28, 2026 — a 87-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: USACE MVK/Thatcher L&D-Upper, retrieved Aug 31, 2026, 8:24 AM (UTC+00:00). Official page for this lake →
The dam behind Thatcher Lock and Dam Upper
Thatcher Lock and Dam Upper is held back by H.K. Thatcher Lock and Dam (also recorded as Calion Lock and Dam) , a concrete gravity structure, resisting the reservoir by its own weight alone , standing 80 ft high and running 698 ft along its crest , built across OUACHITA in Union County , near MORO BAY . It was completed in 1983 , and is owned by USACE - Vicksburg District (a federal owner) , to a design credited to CEMVK.
Its recorded primary purpose is navigation — the pool is held inside a narrow band to keep a navigable depth, so large swings are rare by design . It also serves navigation;recreation;water supply.
It is founded on soil, with a earth core. Its spillway is gated, so the operator can hold the pool above the spillway crest and meter what leaves. The spillway opening is 350 ft wide.
NID classes it significant hazard potential: a failure would be expected to damage property and infrastructure rather than cost lives. It is a consequence rating, not a condition rating.
At its normal pool the reservoir covers about 12,200 acres. NID records a maximum storage of 108,000 acre-ft against a normal storage of 79,900 acre-ft. Its maximum discharge capacity is 250,000 cubic feet per second.
Dam facts: National Inventory of Dams record AR01515 , filed by US Army Corps of Engineers — U.S. Army Corps of Engineers, public domain. Water levels above come from USACE CWMS Data and are a separate source. (How this dam was matched to this gauge →)
How Thatcher Lock and Dam Upper 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 |
|---|---|---|---|
| Felsenthal Lock and Dam Upper | AR | 65.27 ft | 43 km |
| Felsenthal Lock and Dam Lower | AR | 50.52 ft | 44 km |
| Bayou Darbonne Lake | LA | 79.71 ft | 67 km |
| Lake Claiborne | LA | 184.76 ft | 74 km |
| Garrett Bridge | AR | 149.71 ft | 99 km |
| Big Bayou | AR | 101.02 ft | 99 km |
Frequently asked questions
- What is the current water level of Thatcher Lock and Dam Upper?
- As of Aug 28, 2026, 12:00 PM (UTC+00:00), the pool elevation was 77.30 ft (datum NGVD29). See the trend chart above for the recent direction.
- Is Thatcher Lock and Dam Upper 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 USACE MVK/Thatcher L&D-Upper, retrieved Aug 31, 2026, 8:24 AM (UTC+00:00).
More in Arkansas
See every lake tracked in Arkansas, or read the methodology behind these figures.