Reservoir · Utah · United States · BOR RISE
Upper Stillwater Reservoir and Dam
79.8% full
Capacity
40.86 hm³
Volume stored
33 hm³
Coordinates
40.566°N, 110.700°W
Last updated
2026-06-09
Current fill
79.8%vs 7 days ago
-0.5%losing
vs 1 year ago
+36.5%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: 2026-06-09.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 40.566, -110.700 · Open in Google Maps
About Upper Stillwater Reservoir and Dam
As of June 9, 2026, Upper Stillwater Reservoir and Dam is filled to 79.8% of its total capacity, holding roughly 33 hm³ of water out of a maximum 41 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 36.5 points above its level on the same date a year earlier.
Across the readings we hold for Upper Stillwater Reservoir and Dam — 1823 data points between June 13, 2021 and June 9, 2026 — the level has ranged from a low of 4.6% (April 8, 2023) to a high of 95.3% (June 13, 2023). On average the reservoir is fullest around July and at its lowest around April.
It is operated by BOR primarily for multiple purposes. It lies within the Utah basin at 40.566°N, 110.700°W.
Key facts
- Current fill level
- 79.8%
- Water stored
- 33 hm³
- Total capacity
- 41 hm³
- 7-day change
- ▼ 0.5 pts
- Year-on-year
- ▲ 36.5 pts
- Primary use
- Multipurpose
- River basin
- Utah
- Operator
- BOR
- Coordinates
- 40.566°N, 110.700°W
- Last updated
- June 9, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 9 Jun 2026 | 79.8% | 33 |
| 8 Jun 2026 | 80.3% | 33 |
| 7 Jun 2026 | 80.7% | 33 |
| 6 Jun 2026 | 81.1% | 33 |
| 5 Jun 2026 | 81.3% | 33 |
| 4 Jun 2026 | 81.5% | 33 |
| 3 Jun 2026 | 81.8% | 33 |
| 2 Jun 2026 | 82.0% | 33 |
| 1 Jun 2026 | 82.0% | 33 |
| 31 May 2026 | 81.7% | 33 |
| 30 May 2026 | 81.4% | 33 |
| 29 May 2026 | 81.0% | 33 |
Frequently asked questions
What is the current water level of Upper Stillwater Reservoir and Dam?
As of June 9, 2026, Upper Stillwater Reservoir and Dam is at 79.8% of its capacity, holding approximately 33 hm³ of water, according to BOR RISE (US Bureau of Reclamation) data.
Is Upper Stillwater Reservoir and Dam reservoir full?
No. As of June 9, 2026, Upper Stillwater Reservoir and Dam is within its normal operating range at 79.8% of its capacity, so it is not full.
Is the water level at Upper Stillwater Reservoir and Dam rising or falling?
The level at Upper Stillwater Reservoir and Dam has been broadly stable over the latest week on record (-0.5 points).
How much water can Upper Stillwater Reservoir and Dam hold?
Upper Stillwater Reservoir and Dam has a total capacity of 41 hm³.
Where is Upper Stillwater Reservoir and Dam reservoir located?
Upper Stillwater Reservoir and Dam is located in Utah, United States, within the Utah basin (coordinates 40.566°N, 110.700°W).
What is Upper Stillwater Reservoir and Dam used for?
Upper Stillwater Reservoir and Dam is used primarily for multiple purposes, and is managed by BOR.