Reservoir · South Dakota · United States · USACE CWMS
Angostura Reservoir
67.5% full
Capacity
106.28 hm³
Volume stored
72 hm³
Coordinates
43.307°N, 103.531°W
Last updated
2026-10-09
Current fill
67.5%vs 7 days ago
+0.5%gaining
vs 1 year ago
-4.1%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: 2026-10-09.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 43.307, -103.531 · Open in Google Maps
About Angostura Reservoir
As of October 9, 2026, Angostura Reservoir is filled to 67.5% of its total capacity, holding roughly 72 hm³ of water out of a maximum 106 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 (+0.5 pts), and it is 4.1 points below its level on the same date a year earlier.
Across the readings we hold for Angostura Reservoir — 1822 data points between October 10, 2021 and October 9, 2026 — the level has ranged from a low of 57.7% (September 5, 2026) to a high of 105.0% (March 25, 2022). On average the reservoir is fullest around June and at its lowest around September.
It is operated by USACE primarily for multiple purposes. It lies within the South Dakota basin at 43.307°N, 103.531°W.
Key facts
- Current fill level
- 67.5%
- Water stored
- 72 hm³
- Total capacity
- 106 hm³
- 7-day change
- ▲ 0.5 pts
- Year-on-year
- ▼ 4.1 pts
- Primary use
- Multipurpose
- River basin
- South Dakota
- Operator
- USACE
- Coordinates
- 43.307°N, 103.531°W
- Last updated
- October 9, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 9 Oct 2026 | 67.5% | 72 |
| 8 Oct 2026 | 67.5% | 72 |
| 7 Oct 2026 | 67.4% | 72 |
| 6 Oct 2026 | 67.3% | 72 |
| 5 Oct 2026 | 67.3% | 71 |
| 4 Oct 2026 | 67.2% | 71 |
| 3 Oct 2026 | 67.1% | 71 |
| 2 Oct 2026 | 67.0% | 71 |
| 1 Oct 2026 | 67.0% | 71 |
| 30 Sep 2026 | 66.9% | 71 |
| 29 Sep 2026 | 66.7% | 71 |
| 28 Sep 2026 | 66.3% | 70 |