Reservoir · Missouri · United States · USACE CWMS
Mark Twain Pool
27.1% full
Capacity
2,296.74 hm³
Volume stored
622 hm³
Coordinates
39.525°N, 91.644°W
Last updated
2026-07-30
Current fill
27.1%vs 7 days ago
0.0%stable
vs 1 year ago
-3.4%year-over-year
7-day trend
→stable
Data source: USACE CWMS — US Army Corps of Engineers — daily reservoir storage volume. Capacity is the design (normal full-pool) capacity from the US National Inventory of Dams (NID); fill % = current volume ÷ design capacity. Last reading: 2026-07-30.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 39.525, -91.644 · Open in Google Maps
About Mark Twain Pool
As of July 30, 2026, Mark Twain Pool is filled to 27.1% of its total capacity, holding roughly 622 hm³ of water out of a maximum 2,297 hm³. At this level the reservoir is low.
Over the most recent week on record the fill level has held broadly steady (+0.0 pts), and it is 3.4 points below its level on the same date a year earlier.
Across the readings we hold for Mark Twain Pool — 198 data points between July 31, 2021 and July 30, 2026 — the level has ranged from a low of 26.6% (October 1, 2021) to a high of 46.1% (July 31, 2021). On average the reservoir is fullest around August and at its lowest around October.
It is operated by USACE primarily for multiple purposes. It lies within the Missouri basin at 39.525°N, 91.644°W.
Key facts
- Current fill level
- 27.1%
- Water stored
- 622 hm³
- Total capacity
- 2,297 hm³
- 7-day change
- No change
- Year-on-year
- ▼ 3.4 pts
- Primary use
- Multipurpose
- River basin
- Missouri
- Operator
- USACE
- Coordinates
- 39.525°N, 91.644°W
- Last updated
- July 30, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 30 Jul 2026 | 27.1% | 622 |
| 29 Jul 2026 | 27.1% | 622 |
| 28 Jul 2026 | 27.3% | 627 |
| 27 Jul 2026 | 27.6% | 634 |
| 26 Jul 2026 | 27.9% | 640 |
| 25 Jul 2026 | 28.2% | 647 |
| 24 Jul 2026 | 28.4% | 652 |
| 23 Jul 2026 | 28.4% | 652 |
| 22 Jul 2026 | 28.4% | 653 |
| 21 Jul 2026 | 28.7% | 658 |
| 20 Jul 2026 | 29.0% | 666 |
| 19 Jul 2026 | 29.3% | 672 |
Frequently asked questions
What is the current water level of Mark Twain Pool?
As of July 30, 2026, Mark Twain Pool is at 27.1% of its capacity, holding approximately 622 hm³ of water, according to USACE CWMS (US Army Corps of Engineers) data.
Is Mark Twain Pool reservoir full?
No. As of July 30, 2026, Mark Twain Pool is low at 27.1% of its capacity, so it is not full.
Is the water level at Mark Twain Pool rising or falling?
The level at Mark Twain Pool has been broadly stable over the latest week on record (0.0 points).
How much water can Mark Twain Pool hold?
Mark Twain Pool has a total capacity of 2,297 hm³.
Where is Mark Twain Pool reservoir located?
Mark Twain Pool is located in Missouri, United States, within the Missouri basin (coordinates 39.525°N, 91.644°W).
What is Mark Twain Pool used for?
Mark Twain Pool is used primarily for multiple purposes, and is managed by USACE.