Reservoir · Iowa · United States · USACE CWMS
Rathbun Dam & Reservoir
77.1% full
Capacity
379.3 hm³
Volume stored
292 hm³
Coordinates
40.826°N, 92.887°W
Last updated
2026-07-31
Current fill
77.1%vs 7 days ago
+0.1%gaining
vs 1 year ago
-3.5%year-over-year
7-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: 2026-07-31.
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 July 31, 2026, Rathbun Dam & Reservoir is filled to 77.1% of its total capacity, holding roughly 292 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 (+0.1 pts), and it is 3.5 points below its level on the same date a year earlier.
Across the readings we hold for Rathbun Dam & Reservoir — 328 data points between August 1, 2021 and July 31, 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
- 77.1%
- Water stored
- 292 hm³
- Total capacity
- 379 hm³
- 7-day change
- ▲ 0.1 pts
- Year-on-year
- ▼ 3.5 pts
- Primary use
- Multipurpose
- River basin
- Iowa
- Operator
- USACE
- Coordinates
- 40.826°N, 92.887°W
- Last updated
- July 31, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 31 Jul 2026 | 77.1% | 292 |
| 30 Jul 2026 | 77.0% | 292 |
| 29 Jul 2026 | 77.2% | 293 |
| 28 Jul 2026 | 77.3% | 293 |
| 27 Jul 2026 | 77.3% | 293 |
| 26 Jul 2026 | 77.3% | 293 |
| 25 Jul 2026 | 77.4% | 294 |
| 24 Jul 2026 | 77.4% | 294 |
| 23 Jul 2026 | 77.5% | 294 |
| 22 Jul 2026 | 77.6% | 294 |
| 21 Jul 2026 | 77.8% | 295 |
| 20 Jul 2026 | 77.3% | 293 |
Frequently asked questions
What is the current water level of Rathbun Dam & Reservoir?
As of July 31, 2026, Rathbun Dam & Reservoir is at 77.1% of its capacity, holding approximately 292 hm³ of water, according to USACE CWMS (US Army Corps of Engineers) data.
Is Rathbun Dam & Reservoir reservoir full?
No. As of July 31, 2026, Rathbun Dam & Reservoir is within its normal operating range at 77.1% of its capacity, so it is not full.
Is the water level at Rathbun Dam & Reservoir rising or falling?
The level at Rathbun Dam & Reservoir has been broadly stable over the latest week on record (+0.1 points).
How much water can Rathbun Dam & Reservoir hold?
Rathbun Dam & Reservoir has a total capacity of 379 hm³.
Where is Rathbun Dam & Reservoir reservoir located?
Rathbun Dam & Reservoir is located in Iowa, United States, within the Iowa basin (coordinates 40.826°N, 92.887°W).
What is Rathbun Dam & Reservoir used for?
Rathbun Dam & Reservoir is used primarily for multiple purposes, and is managed by USACE.