Reservoir · South Dakota · United States · USACE CWMS
Belle Fourche Reservoir
28.4% full
Capacity
236.92 hm³
Volume stored
67 hm³
Coordinates
44.737°N, 103.674°W
Last updated
2026-09-10
Current fill
28.4%vs 7 days ago
-5.4%losing
vs 1 year ago
-35.9%year-over-year
7-day trend
↓falling
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: 2026-09-10.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 44.737, -103.674 · Open in Google Maps
About Belle Fourche Reservoir
As of September 10, 2026, Belle Fourche Reservoir is filled to 28.4% of its total capacity, holding roughly 67 hm³ of water out of a maximum 237 hm³. At this level the reservoir is low.
Over the most recent week on record the fill level has fallen by 5.4 percentage points, and it is 35.9 points below its level on the same date a year earlier.
Across the readings we hold for Belle Fourche Reservoir — 1804 data points between September 12, 2021 and September 10, 2026 — the level has ranged from a low of 28.4% (September 10, 2026) to a high of 89.0% (June 25, 2023). On average the reservoir is fullest around May and at its lowest around September.
It is operated by USACE primarily for multiple purposes. It lies within the South Dakota basin at 44.737°N, 103.674°W.
Key facts
- Current fill level
- 28.4%
- Water stored
- 67 hm³
- Total capacity
- 237 hm³
- 7-day change
- ▼ 5.4 pts
- Year-on-year
- ▼ 35.9 pts
- Primary use
- Multipurpose
- River basin
- South Dakota
- Operator
- USACE
- Coordinates
- 44.737°N, 103.674°W
- Last updated
- September 10, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 10 Sep 2026 | 28.4% | 67 |
| 9 Sep 2026 | 28.7% | 68 |
| 8 Sep 2026 | 31.2% | 74 |
| 7 Sep 2026 | 31.7% | 75 |
| 6 Sep 2026 | 32.1% | 76 |
| 5 Sep 2026 | 32.7% | 78 |
| 4 Sep 2026 | 33.4% | 79 |
| 3 Sep 2026 | 33.8% | 80 |
| 2 Sep 2026 | 34.2% | 81 |
| 1 Sep 2026 | 34.7% | 82 |
| 31 Aug 2026 | 34.8% | 83 |
| 30 Aug 2026 | 34.2% | 81 |