Reservoir · South Dakota · United States · BOR RISE
Angostura Reservoir
Angostura Reservoir and Dam
68.3% full
Capacity
106.28 hm³
Volume stored
73 hm³
Vs month average
89% of normal
Coordinates
43.343°N, 103.438°W
Last updated
2026-10-29
Current fill
68.3%vs 7 days ago
+0.3 ppgaining
vs 1 year ago
-6.1 ppyear-over-year
7-day trend
→stable
Drought context
Storage vs October average
89%of normal
68.3% full on 2026-10-29, against an average of 76.7% for October across 5 years of readings (-8.4 points).
Drought Monitor at this site · 27 October 2026
D1moderate drought
The ground at Angostura Reservoir's coordinates falls inside the D1 area of 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: BOR RISE — US Bureau of Reclamation — 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: 2026-10-29.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 43.343°N, 103.438°W · Open in Google Maps
About Angostura Reservoir
As of October 29, 2026, Angostura Reservoir is filled to 68.3% of its total capacity, holding 72.6 hm³ of water out of a maximum 106.28 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 (+0.3 pp), and it is 6.1 points below its level on the same date a year earlier.
Across the readings we hold for Angostura Reservoir — 1320 data points between October 31, 2021 and October 29, 2026 — the level has ranged from a low of 57.7% (September 4, 2026) to a high of 105.0% (March 24, 2022). On average the reservoir is fullest around May and at its lowest around September.
It is operated by BOR primarily for multiple purposes. It is at 43.343°N, 103.438°W.
Key facts
- Current fill level
- 68.3% of total capacity
- Water stored
- 72.6 hm³
- Total capacity
- 106.28 hm³
- 7-day change
- ▲ 0.3 pp
- Year-on-year
- ▼ 6.1 pp
- Primary use
- Multipurpose
- Operator
- BOR
- Coordinates
- 43.343°N, 103.438°W
- Last updated
- October 29, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 29 Oct 2026 | 68.3% | 72.6 |
| 28 Oct 2026 | 68.3% | 72.57 |
| 27 Oct 2026 | 68.2% | 72.53 |
| 26 Oct 2026 | 68.2% | 72.47 |
| 25 Oct 2026 | 68.1% | 72.37 |
| 24 Oct 2026 | 68.1% | 72.33 |
| 23 Oct 2026 | 68.1% | 72.33 |
| 22 Oct 2026 | 68.0% | 72.3 |
| 21 Oct 2026 | 68.0% | 72.23 |
| 20 Oct 2026 | 67.9% | 72.16 |
| 19 Oct 2026 | 67.8% | 72.1 |
| 18 Oct 2026 | 67.8% | 72.06 |