Reservoir · Utah · United States · BOR RISE
Upper Stillwater Reservoir
Upper Stillwater Reservoir and Dam
55.3% full
Capacity
40.86 hm³
Volume stored
23 hm³
Vs month average
99% of normal
Coordinates
40.566°N, 110.700°W
Last updated
2026-10-25
Current fill
55.3%vs 7 days ago
+8.2 ppgaining
vs 1 year ago
-1.2 ppyear-over-year
7-day trend
↑rising
Drought context
Storage vs October average
99%of normal
55.3% full on 2026-10-25, against an average of 56.1% for October across 6 years of readings (-0.8 points).
Drought Monitor at this site · 20 October 2026
D0abnormally dry
The ground at Upper Stillwater Reservoir's coordinates falls inside the D0 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: 2026-10-25.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 40.566°N, 110.700°W · Open in Google Maps
About Upper Stillwater Reservoir
As of October 25, 2026, Upper Stillwater Reservoir is filled to 55.3% of its total capacity, holding 22.61 hm³ of water out of a maximum 40.86 hm³. At this level the reservoir is within its normal operating range.
Over the most recent week on record the fill level has risen by 8.2 percentage points, and it is 1.2 points below its level on the same date a year earlier.
Across the readings we hold for Upper Stillwater Reservoir — 1823 data points between October 29, 2021 and October 25, 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 is at 40.566°N, 110.700°W.
Key facts
- Current fill level
- 55.3% of total capacity
- Water stored
- 22.61 hm³
- Total capacity
- 40.86 hm³
- 7-day change
- ▲ 8.2 pp
- Year-on-year
- ▼ 1.2 pp
- Primary use
- Multipurpose
- Operator
- BOR
- Coordinates
- 40.566°N, 110.700°W
- Last updated
- October 25, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 25 Oct 2026 | 55.3% | 22.61 |
| 24 Oct 2026 | 54.1% | 22.09 |
| 23 Oct 2026 | 52.7% | 21.53 |
| 22 Oct 2026 | 50.8% | 20.77 |
| 21 Oct 2026 | 49.8% | 20.35 |
| 20 Oct 2026 | 48.9% | 19.98 |
| 19 Oct 2026 | 48.0% | 19.61 |
| 18 Oct 2026 | 47.1% | 19.24 |
| 17 Oct 2026 | 46.1% | 18.85 |
| 16 Oct 2026 | 45.1% | 18.42 |
| 15 Oct 2026 | 44.0% | 17.96 |
| 14 Oct 2026 | 36.6% | 14.96 |