Reservoir · Wyoming · United States · BOR RISE
Big Sandy Reservoir and Dam
48.0% full
Capacity
48.97 hm³
Volume stored
24 hm³
Coordinates
42.268°N, 109.432°W
Last updated
2026-07-28
Current fill
48.0%vs 7 days ago
-0.7%losing
vs 1 year ago
-28.6%year-over-year
7-day trend
→stable
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: 2026-07-28.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 42.268, -109.432 · Open in Google Maps
About Big Sandy Reservoir and Dam
As of July 28, 2026, Big Sandy Reservoir and Dam is filled to 48.0% of its total capacity, holding roughly 24 hm³ of water out of a maximum 49 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 (-0.7 pts), and it is 28.6 points below its level on the same date a year earlier.
Across the readings we hold for Big Sandy Reservoir and Dam — 1824 data points between July 31, 2021 and July 28, 2026 — the level has ranged from a low of 0.2% (August 18, 2021) to a high of 105.0% (June 5, 2023). On average the reservoir is fullest around June and at its lowest around September.
It is operated by BOR primarily for multiple purposes. It lies within the Wyoming basin at 42.268°N, 109.432°W.
Key facts
- Current fill level
- 48.0%
- Water stored
- 24 hm³
- Total capacity
- 49 hm³
- 7-day change
- ▼ 0.7 pts
- Year-on-year
- ▼ 28.6 pts
- Primary use
- Multipurpose
- River basin
- Wyoming
- Operator
- BOR
- Coordinates
- 42.268°N, 109.432°W
- Last updated
- July 28, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 28 Jul 2026 | 48.0% | 23 |
| 27 Jul 2026 | 48.7% | 24 |
| 26 Jul 2026 | 49.4% | 24 |
| 25 Jul 2026 | 50.0% | 24 |
| 24 Jul 2026 | 50.4% | 25 |
| 23 Jul 2026 | 51.0% | 25 |
| 22 Jul 2026 | 51.8% | 25 |
| 21 Jul 2026 | 52.6% | 26 |
| 20 Jul 2026 | 53.5% | 26 |
| 19 Jul 2026 | 54.2% | 27 |
| 18 Jul 2026 | 55.0% | 27 |
| 17 Jul 2026 | 55.8% | 27 |
Frequently asked questions
What is the current water level of Big Sandy Reservoir and Dam?
As of July 28, 2026, Big Sandy Reservoir and Dam is at 48.0% of its capacity, holding approximately 24 hm³ of water, according to BOR RISE (US Bureau of Reclamation) data.
Is Big Sandy Reservoir and Dam reservoir full?
No. As of July 28, 2026, Big Sandy Reservoir and Dam is within its normal operating range at 48.0% of its capacity, so it is not full.
Is the water level at Big Sandy Reservoir and Dam rising or falling?
The level at Big Sandy Reservoir and Dam has been broadly stable over the latest week on record (-0.7 points).
How much water can Big Sandy Reservoir and Dam hold?
Big Sandy Reservoir and Dam has a total capacity of 49 hm³.
Where is Big Sandy Reservoir and Dam reservoir located?
Big Sandy Reservoir and Dam is located in Wyoming, United States, within the Wyoming basin (coordinates 42.268°N, 109.432°W).
What is Big Sandy Reservoir and Dam used for?
Big Sandy Reservoir and Dam is used primarily for multiple purposes, and is managed by BOR.