Reservoir · Iowa · United States · USACE CWMS
Rathbun Dam & Reservoir
83.1% full
Capacity
379.3 hm³
Volume stored
315 hm³
Vs month average
106% of normal
Coordinates
40.826°N, 92.887°W
Last updated
2026-10-13
Current fill
83.1%vs 7 days ago
-3.0%losing
vs 1 year ago
N/A7-day trend
↓falling
Drought context
Storage vs October average
106%of normal
83.1% full on 2026-10-13, against an average of 78.4% for October across 3 years of readings (+4.7 points).
Drought Monitor at this site · 6 October 2026
Nonenot in a drought category
Rathbun Dam & Reservoir's coordinates fall outside every category on the weekly U.S. Drought Monitor map. That describes local conditions — rainfall, soil moisture, streamflow — not the reservoir's storage. Iowa drought figures →
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: 2026-10-13.
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 October 13, 2026, Rathbun Dam & Reservoir is filled to 83.1% of its total capacity, holding roughly 315 hm³ of water out of a maximum 379 hm³. At this level the reservoir is high.
Over the most recent week on record the fill level has fallen by 3.0 percentage points.
Across the readings we hold for Rathbun Dam & Reservoir — 330 data points between October 14, 2021 and October 13, 2026 — the level has ranged from a low of 72.4% (October 23, 2021) to a high of 100.0% (June 15, 2026). On average the reservoir is fullest around June and at its lowest around January.
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
- 83.1%
- Water stored
- 315 hm³
- Total capacity
- 379 hm³
- 7-day change
- ▼ 3.0 pts
- Primary use
- Multipurpose
- River basin
- Iowa
- Operator
- USACE
- Coordinates
- 40.826°N, 92.887°W
- Last updated
- October 13, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 13 Oct 2026 | 83.1% | 315 |
| 12 Oct 2026 | 83.3% | 316 |
| 11 Oct 2026 | 83.6% | 317 |
| 10 Oct 2026 | 84.0% | 319 |
| 9 Oct 2026 | 84.4% | 320 |
| 8 Oct 2026 | 84.9% | 322 |
| 7 Oct 2026 | 85.5% | 324 |
| 6 Oct 2026 | 86.1% | 326 |
| 5 Oct 2026 | 86.7% | 329 |
| 4 Oct 2026 | 86.8% | 329 |
| 3 Oct 2026 | 86.2% | 327 |
| 2 Oct 2026 | 85.4% | 324 |