Reservoir · Oklahoma · United States · USACE CWMS
Copan Lake
28.8% full
Capacity
134.74 hm³
Volume stored
39 hm³
Coordinates
36.886°N, 95.971°W
Last updated
2026-09-09
Current fill
28.8%vs 7 days ago
-0.6%losing
vs 1 year ago
N/A7-day trend
→stable
Data source: USACE CWMS — US Army Corps of Engineers — daily reservoir storage volume. Design capacity is unavailable for this site, so fill % is estimated against the 5-year maximum storage and may overstate fullness. Last reading: 2026-09-09.
Catchment Weather
Past 30 days + 14-day forecast · Open-Meteo
Satellite imagery: Esri, Maxar, Earthstar Geographics. Map: Esri, HERE, Garmin, © OpenStreetMap contributors. 36.886, -95.971 · Open in Google Maps
About Copan Lake
As of September 9, 2026, Copan Lake is filled to 28.8% of its total capacity, holding roughly 39 hm³ of water out of a maximum 135 hm³. At this level the reservoir is low.
Over the most recent week on record the fill level has held broadly steady (-0.6 pts).
Across the readings we hold for Copan Lake — 94 data points between June 6, 2026 and September 9, 2026 — the level has ranged from a low of 28.8% (September 9, 2026) to a high of 100.0% (June 29, 2026).
It is operated by USACE primarily for multiple purposes. It lies within the Oklahoma basin at 36.886°N, 95.971°W.
Key facts
- Current fill level
- 28.8%
- Water stored
- 39 hm³
- Total capacity
- 135 hm³
- 7-day change
- ▼ 0.6 pts
- Primary use
- Multipurpose
- River basin
- Oklahoma
- Operator
- USACE
- Coordinates
- 36.886°N, 95.971°W
- Last updated
- September 9, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 9 Sep 2026 | 28.8% | 39 |
| 8 Sep 2026 | 28.9% | 39 |
| 7 Sep 2026 | 29.0% | 39 |
| 6 Sep 2026 | 29.2% | 39 |
| 5 Sep 2026 | 29.2% | 39 |
| 4 Sep 2026 | 29.2% | 39 |
| 3 Sep 2026 | 29.2% | 39 |
| 2 Sep 2026 | 29.4% | 40 |
| 1 Sep 2026 | 29.5% | 40 |
| 31 Aug 2026 | 29.6% | 40 |
| 30 Aug 2026 | 29.7% | 40 |
| 29 Aug 2026 | 30.0% | 40 |