Reservoir · Oklahoma · United States · BOR RISE
Foss Reservoir
Foss Reservoir and Dam
84.0% full
Capacity
208.13 hm³
Volume stored
175 hm³
Vs month average
94% of normal
Coordinates
35.550°N, 99.183°W
Last updated
2026-10-27
Current fill
84.0%vs 7 days ago
-0.2 pplosing
vs 1 year ago
-13.9 ppyear-over-year
7-day trend
→stable
Drought context
Storage vs October average
94%of normal
84.0% full on 2026-10-27, against an average of 89.7% for October across 6 years of readings (-5.7 points).
Drought Monitor at this site · 20 October 2026
D3extreme drought
The ground at Foss Reservoir's coordinates falls inside the D3 area of the weekly U.S. Drought Monitor map. That describes local conditions — rainfall, soil moisture, streamflow — not the reservoir's storage. Oklahoma 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: 2026-10-27.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 35.550°N, 99.183°W · Open in Google Maps
About Foss Reservoir
As of October 27, 2026, Foss Reservoir is filled to 84.0% of its total capacity, holding 174.77 hm³ of water out of a maximum 208.13 hm³. At this level the reservoir is high.
Over the most recent week on record the fill level has held broadly steady (-0.2 pp), and it is 13.9 points below its level on the same date a year earlier.
Across the readings we hold for Foss Reservoir — 1825 data points between October 29, 2021 and October 27, 2026 — the level has ranged from a low of 78.2% (April 24, 2023) to a high of 101.9% (June 18, 2025). 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 35.550°N, 99.183°W.
Key facts
- Current fill level
- 84.0% of total capacity
- Water stored
- 174.77 hm³
- Total capacity
- 208.13 hm³
- 7-day change
- ▼ 0.2 pp
- Year-on-year
- ▼ 13.9 pp
- Primary use
- Multipurpose
- Operator
- BOR
- Coordinates
- 35.550°N, 99.183°W
- Last updated
- October 27, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 27 Oct 2026 | 84.0% | 174.77 |
| 26 Oct 2026 | 84.0% | 174.84 |
| 25 Oct 2026 | 84.0% | 174.77 |
| 24 Oct 2026 | 84.0% | 174.84 |
| 23 Oct 2026 | 84.1% | 174.99 |
| 22 Oct 2026 | 84.1% | 175.13 |
| 21 Oct 2026 | 84.2% | 175.21 |
| 20 Oct 2026 | 84.2% | 175.28 |
| 19 Oct 2026 | 84.3% | 175.43 |
| 18 Oct 2026 | 84.4% | 175.57 |
| 17 Oct 2026 | 84.4% | 175.72 |
| 16 Oct 2026 | 84.6% | 176.01 |