Reservoir · South Dakota · United States · USACE CWMS
Oahe Dam & Reservoir
74.7% full
Capacity
23,806.2 hm³
Volume stored
17776 hm³
Vs month average
92% of normal
Coordinates
44.450°N, 100.405°W
Last updated
2026-10-27
Current fill
74.7%vs 7 days ago
+0.2 ppgaining
vs 1 year ago
-11.2 ppyear-over-year
7-day trend
→stable
Drought context
Storage vs October average
92%of normal
74.7% full on 2026-10-27, against an average of 81.0% for October across 6 years of readings (-6.3 points).
Drought Monitor at this site · 20 October 2026
Nonenot in a drought category
Oahe 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. South Dakota drought figures →
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: 2026-10-27.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 44.450°N, 100.405°W · Open in Google Maps
About Oahe Dam & Reservoir
As of October 27, 2026, Oahe Dam & Reservoir is filled to 74.7% of its total capacity, holding 17,776 hm³ of water out of a maximum 23,806 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 (+0.2 pp), and it is 11.2 points below its level on the same date a year earlier.
Across the readings we hold for Oahe Dam & Reservoir — 1821 data points between October 29, 2021 and October 27, 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 July and at its lowest around December.
It is operated by USACE primarily for multiple purposes. It is at 44.450°N, 100.405°W.
Key facts
- Current fill level
- 74.7% of total capacity
- Water stored
- 17,776 hm³
- Total capacity
- 23,806 hm³
- 7-day change
- ▲ 0.2 pp
- Year-on-year
- ▼ 11.2 pp
- Primary use
- Multipurpose
- Operator
- USACE
- Coordinates
- 44.450°N, 100.405°W
- Last updated
- October 27, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 27 Oct 2026 | 74.7% | 17,776 |
| 26 Oct 2026 | 74.7% | 17,772 |
| 25 Oct 2026 | 74.6% | 17,765 |
| 24 Oct 2026 | 74.6% | 17,755 |
| 23 Oct 2026 | 74.5% | 17,746 |
| 22 Oct 2026 | 74.5% | 17,741 |
| 21 Oct 2026 | 74.5% | 17,736 |
| 20 Oct 2026 | 74.5% | 17,729 |
| 19 Oct 2026 | 74.5% | 17,728 |
| 18 Oct 2026 | 74.4% | 17,719 |
| 17 Oct 2026 | 74.4% | 17,713 |
| 16 Oct 2026 | 74.4% | 17,708 |