Reservoir · Utah · United States · BOR RISE
Upper Stillwater Reservoir
Upper Stillwater Reservoir and Dam
36.6% full
Capacity
40.86 hm³
Volume stored
15 hm³
Vs month average
63% of normal
Coordinates
40.566°N, 110.700°W
Last updated
2026-10-13
Current fill
36.6%vs 7 days ago
-0.5%losing
vs 1 year ago
-18.5%year-over-year
7-day trend
→stable
Drought context
Storage vs October average
63%of normal
36.6% full on 2026-10-13, against an average of 58.2% for October across 6 years of readings (-21.6 points).
Drought Monitor at this site · 13 October 2026
D1moderate drought
The ground at Upper Stillwater 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. Utah 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: 2026-10-13.
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
As of October 13, 2026, Upper Stillwater Reservoir is filled to 36.6% of its total capacity, holding roughly 15 hm³ of water out of a maximum 41 hm³. At this level the reservoir is low.
Over the most recent week on record the fill level has held broadly steady (-0.5 pts), and it is 18.5 points below its level on the same date a year earlier.
Across the readings we hold for Upper Stillwater Reservoir — 1824 data points between October 16, 2021 and October 13, 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
- 36.6%
- Water stored
- 15 hm³
- Total capacity
- 41 hm³
- 7-day change
- ▼ 0.5 pts
- Year-on-year
- ▼ 18.5 pts
- Primary use
- Multipurpose
- River basin
- Utah
- Operator
- BOR
- Coordinates
- 40.566°N, 110.700°W
- Last updated
- October 13, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 13 Oct 2026 | 36.6% | 15 |
| 12 Oct 2026 | 36.6% | 15 |
| 11 Oct 2026 | 36.6% | 15 |
| 10 Oct 2026 | 36.6% | 15 |
| 9 Oct 2026 | 36.6% | 15 |
| 8 Oct 2026 | 36.6% | 15 |
| 7 Oct 2026 | 36.6% | 15 |
| 6 Oct 2026 | 37.1% | 15 |
| 5 Oct 2026 | 38.4% | 16 |
| 4 Oct 2026 | 39.7% | 16 |
| 3 Oct 2026 | 41.1% | 17 |
| 2 Oct 2026 | 42.5% | 17 |