Reservoir · Oklahoma · United States · BOR RISE
Foss Reservoir
Foss Reservoir and Dam
84.7% full
Capacity
208.13 hm³
Volume stored
176 hm³
Vs month average
94% of normal
Coordinates
35.550°N, 99.183°W
Last updated
2026-10-14
Current fill
84.7%vs 7 days ago
+0.7%gaining
vs 1 year ago
-13.7%year-over-year
7-day trend
→stable
Drought context
Storage vs October average
94%of normal
84.7% full on 2026-10-14, against an average of 90.2% for October across 6 years of readings (-5.5 points).
Drought Monitor at this site · 13 October 2026
D4exceptional drought
The ground at Foss Reservoir's coordinates falls inside the D4 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: 2026-10-14.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 35.550, -99.183 · Open in Google Maps
About Foss Reservoir
As of October 14, 2026, Foss Reservoir is filled to 84.7% of its total capacity, holding roughly 176 hm³ of water out of a maximum 208 hm³. At this level the reservoir is high.
Over the most recent week on record the fill level has held broadly steady (+0.7 pts), and it is 13.7 points below its level on the same date a year earlier.
Across the readings we hold for Foss Reservoir — 1825 data points between October 16, 2021 and October 14, 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 lies within the Oklahoma basin at 35.550°N, 99.183°W.
Key facts
- Current fill level
- 84.7%
- Water stored
- 176 hm³
- Total capacity
- 208 hm³
- 7-day change
- ▲ 0.7 pts
- Year-on-year
- ▼ 13.7 pts
- Primary use
- Multipurpose
- River basin
- Oklahoma
- Operator
- BOR
- Coordinates
- 35.550°N, 99.183°W
- Last updated
- October 14, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 14 Oct 2026 | 84.7% | 176 |
| 13 Oct 2026 | 83.5% | 174 |
| 12 Oct 2026 | 83.5% | 174 |
| 11 Oct 2026 | 83.6% | 174 |
| 10 Oct 2026 | 83.7% | 174 |
| 9 Oct 2026 | 83.9% | 175 |
| 8 Oct 2026 | 83.9% | 175 |
| 7 Oct 2026 | 84.0% | 175 |
| 6 Oct 2026 | 84.0% | 175 |
| 5 Oct 2026 | 84.1% | 175 |
| 4 Oct 2026 | 84.2% | 175 |
| 3 Oct 2026 | 84.3% | 175 |