Reservoir · Iowa · United States · USACE CWMS
Rathbun Dam & Reservoir
90.0% full
Capacity
329.19 hm³
Volume stored
296 hm³
Vs month average
96% of normal
Coordinates
40.826°N, 92.887°W
Last updated
2026-10-30
Current fill
90.0%vs 7 days ago
-0.3 pplosing
vs 1 year ago
N/A7-day trend
→stable
Drought context
Storage vs October average
96%of normal
90.0% full on 2026-10-30, against an average of 94.0% for October across 2 years of readings (-4.0 points).
Drought Monitor at this site · 27 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: 2026-10-30.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 40.826°N, 92.887°W · Open in Google Maps
About Rathbun Dam & Reservoir
As of October 30, 2026, Rathbun Dam & Reservoir is filled to 90.0% of its total capacity, holding 296.24 hm³ of water out of a maximum 329.19 hm³. At this level the reservoir is high.
Over the most recent week on record the fill level has held broadly steady (-0.3 pp).
Across the readings we hold for Rathbun Dam & Reservoir — 330 data points between October 31, 2021 and October 30, 2026 — the level has ranged from a low of 85.0% (January 12, 2022) to a high of 100.0% (October 4, 2026). On average the reservoir is fullest around October and at its lowest around January.
It is operated by USACE primarily for multiple purposes. It is at 40.826°N, 92.887°W.
Key facts
- Current fill level
- 90.0% of total capacity
- Water stored
- 296.24 hm³
- Total capacity
- 329.19 hm³
- 7-day change
- ▼ 0.3 pp
- Primary use
- Multipurpose
- Operator
- USACE
- Coordinates
- 40.826°N, 92.887°W
- Last updated
- October 30, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 30 Oct 2026 | 90.0% | 296.24 |
| 29 Oct 2026 | 90.0% | 296.24 |
| 28 Oct 2026 | 90.0% | 296.24 |
| 27 Oct 2026 | 90.1% | 296.55 |
| 26 Oct 2026 | 90.2% | 296.85 |
| 25 Oct 2026 | 90.2% | 297 |
| 24 Oct 2026 | 90.2% | 297 |
| 23 Oct 2026 | 90.3% | 297.15 |
| 22 Oct 2026 | 90.5% | 297.9 |
| 21 Oct 2026 | 90.9% | 299.1 |
| 20 Oct 2026 | 91.2% | 300.16 |
| 19 Oct 2026 | 91.5% | 301.36 |