Reservoir · Oklahoma · United States · USACE CWMS
Copan Lake
85.2% full
Capacity
53.53 hm³
Volume stored
46 hm³
Coordinates
36.886°N, 95.971°W
Last updated
2026-06-11
Current fill
85.2%vs 7 days ago
-1.0%losing
vs 1 year ago
-10.2%year-over-year
7-day trend
→stable
Data source: USACE CWMS — US Army Corps of Engineers — 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: 2026-06-11.
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 June 11, 2026, Copan Lake is filled to 85.2% of its total capacity, holding roughly 46 hm³ of water out of a maximum 54 hm³. At this level the reservoir is high.
Over the most recent week on record the fill level has held broadly steady (-1.0 pts), and it is 10.2 points below its level on the same date a year earlier.
Across the readings we hold for Copan Lake — 273 data points between February 6, 2024 and June 11, 2026 — the level has ranged from a low of 39.2% (February 6, 2024) to a high of 105.0% (June 3, 2024). On average the reservoir is fullest around April and at its lowest around February.
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
- 85.2%
- Water stored
- 46 hm³
- Total capacity
- 54 hm³
- 7-day change
- ▼ 1.0 pts
- Year-on-year
- ▼ 10.2 pts
- Primary use
- Multipurpose
- River basin
- Oklahoma
- Operator
- USACE
- Coordinates
- 36.886°N, 95.971°W
- Last updated
- June 11, 2026
Recent readings
| Date | Fill level | Volume (hm³) |
|---|---|---|
| 11 Jun 2026 | 85.2% | 46 |
| 10 Jun 2026 | 86.2% | 46 |
| 9 Jun 2026 | 87.5% | 47 |
| 8 Jun 2026 | 87.1% | 47 |
| 7 Jun 2026 | 84.8% | 45 |
| 6 Jun 2026 | 84.0% | 45 |
| 5 Jun 2026 | 82.7% | 44 |
| 4 Jun 2026 | 83.9% | 45 |
| 3 Jun 2026 | 85.9% | 46 |
| 2 Jun 2026 | 88.5% | 47 |
| 1 Jun 2026 | 89.3% | 48 |
| 31 May 2026 | 89.1% | 48 |
Frequently asked questions
What is the current water level of Copan Lake?
As of June 11, 2026, Copan Lake is at 85.2% of its capacity, holding approximately 46 hm³ of water, according to USACE CWMS (US Army Corps of Engineers) data.
Is Copan Lake reservoir full?
No. As of June 11, 2026, Copan Lake is high at 85.2% of its capacity, so it is not full.
Is the water level at Copan Lake rising or falling?
The level at Copan Lake has been broadly stable over the latest week on record (-1.0 points).
How much water can Copan Lake hold?
Copan Lake has a total capacity of 54 hm³.
Where is Copan Lake reservoir located?
Copan Lake is located in Oklahoma, United States, within the Oklahoma basin (coordinates 36.886°N, 95.971°W).
What is Copan Lake used for?
Copan Lake is used primarily for multiple purposes, and is managed by USACE.