Reservoir · South Dakota · United States · USACE CWMS
Oahe Dam & Reservoir
80.3% full
Capacity
23,806.2 hm³
Volume stored
19108 hm³
Coordinates
44.450°N, 100.405°W
Last updated
2026-07-29
Current fill
80.3%vs 7 days ago
-0.1%losing
vs 1 year ago
-2.8%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: 2026-07-29.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 44.450, -100.405 · Open in Google Maps
About Oahe Dam & Reservoir
As of July 29, 2026, Oahe Dam & Reservoir is filled to 80.3% of its total capacity, holding roughly 19,108 hm³ of water out of a maximum 23,806 hm³. At this level the reservoir is high.
Over the most recent week on record the fill level has held broadly steady (-0.1 pts), and it is 2.8 points below its level on the same date a year earlier.
Across the readings we hold for Oahe Dam & Reservoir — 1821 data points between July 31, 2021 and July 29, 2026 — the level has ranged from a low of 70.6% (December 8, 2022) to a high of 93.5% (July 31, 2024). On average the reservoir is fullest around August and at its lowest around December.
It is operated by USACE primarily for multiple purposes. It lies within the South Dakota basin at 44.450°N, 100.405°W.
Key facts
- Current fill level
- 80.3%
- Water stored
- 19,108 hm³
- Total capacity
- 23,806 hm³
- 7-day change
- ▼ 0.1 pts
- Year-on-year
- ▼ 2.8 pts
- Primary use
- Multipurpose
- River basin
- South Dakota
- Operator
- USACE
- Coordinates
- 44.450°N, 100.405°W
- Last updated
- July 29, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 29 Jul 2026 | 80.3% | 19,108 |
| 28 Jul 2026 | 80.4% | 19,141 |
| 27 Jul 2026 | 80.6% | 19,177 |
| 26 Jul 2026 | 80.6% | 19,194 |
| 25 Jul 2026 | 80.7% | 19,220 |
| 24 Jul 2026 | 80.9% | 19,251 |
| 23 Jul 2026 | 81.0% | 19,285 |
| 22 Jul 2026 | 81.1% | 19,310 |
| 21 Jul 2026 | 81.2% | 19,329 |
| 20 Jul 2026 | 81.3% | 19,345 |
| 19 Jul 2026 | 81.3% | 19,347 |
| 18 Jul 2026 | 81.3% | 19,357 |
Frequently asked questions
What is the current water level of Oahe Dam & Reservoir?
As of July 29, 2026, Oahe Dam & Reservoir is at 80.3% of its capacity, holding approximately 19,108 hm³ of water, according to USACE CWMS (US Army Corps of Engineers) data.
Is Oahe Dam & Reservoir reservoir full?
No. As of July 29, 2026, Oahe Dam & Reservoir is high at 80.3% of its capacity, so it is not full.
Is the water level at Oahe Dam & Reservoir rising or falling?
The level at Oahe Dam & Reservoir has been broadly stable over the latest week on record (-0.1 points).
How much water can Oahe Dam & Reservoir hold?
Oahe Dam & Reservoir has a total capacity of 23,806 hm³.
Where is Oahe Dam & Reservoir reservoir located?
Oahe Dam & Reservoir is located in South Dakota, United States, within the South Dakota basin (coordinates 44.450°N, 100.405°W).
What is Oahe Dam & Reservoir used for?
Oahe Dam & Reservoir is used primarily for multiple purposes, and is managed by USACE.