Reservoir · Iowa · United States · USACE CWMS
Rathbun Dam & Reservoir
77.9% full
Capacity
379.3 hm³
Volume stored
295 hm³
Coordinates
40.826°N, 92.887°W
Last updated
2026-09-14
Current fill
77.9%vs 7 days ago
0.0%stable
vs 1 year ago
N/A7-day trend
→stable
Data source: USACE CWMS — US Army Corps of Engineers — daily reservoir storage volume. Design capacity is unavailable for this site, so fill % is estimated against the 5-year maximum storage and may overstate fullness. Last reading: 2026-09-14.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 40.826, -92.887 · Open in Google Maps
About Rathbun Dam & Reservoir
As of September 14, 2026, Rathbun Dam & Reservoir is filled to 77.9% of its total capacity, holding roughly 295 hm³ of water out of a maximum 379 hm³. At this level the reservoir is within its normal operating range.
Over the most recent week on record the fill level has held broadly steady (+0.0 pts).
Across the readings we hold for Rathbun Dam & Reservoir — 328 data points between September 15, 2021 and September 14, 2026 — the level has ranged from a low of 72.3% (October 9, 2021) to a high of 100.0% (June 15, 2026). On average the reservoir is fullest around June and at its lowest around October.
It is operated by USACE primarily for multiple purposes. It lies within the Iowa basin at 40.826°N, 92.887°W.
Key facts
- Current fill level
- 77.9%
- Water stored
- 295 hm³
- Total capacity
- 379 hm³
- 7-day change
- No change
- Primary use
- Multipurpose
- River basin
- Iowa
- Operator
- USACE
- Coordinates
- 40.826°N, 92.887°W
- Last updated
- September 14, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 14 Sep 2026 | 77.9% | 295 |
| 13 Sep 2026 | 78.0% | 296 |
| 12 Sep 2026 | 78.1% | 296 |
| 11 Sep 2026 | 78.1% | 296 |
| 10 Sep 2026 | 78.2% | 297 |
| 9 Sep 2026 | 78.3% | 297 |
| 8 Sep 2026 | 77.9% | 295 |
| 7 Sep 2026 | 77.9% | 296 |
| 6 Sep 2026 | 78.1% | 296 |
| 5 Sep 2026 | 78.2% | 297 |
| 4 Sep 2026 | 78.3% | 297 |
| 3 Sep 2026 | 78.3% | 297 |