Copan Lake
Washington County, Oklahoma4,850 acresView mapDirections
Oklahoma DEQ publishes the water-quality measurements for Copan Lake. Here is what has been measured.
- Eutrophic
- 62 ft max depth
- Public access
- Limited data
Copan Lake in Washington County, Oklahoma has water-quality measurements published by Oklahoma DEQ, shown here as reported. Water clarity: 1.6 ft visibility. Phosphorus: 79 µg/L. Surface area: 4850 acres.
Copan Lake is a 4,850-acre productive, nutrient-rich eutrophic lake in Washington County, Oklahoma with an estimated average depth of about 62 feet. Limited fish-species data available. Public access is available with 3 public boat landings.
Source: EPA Water Quality Portal sampling records, ODEQ, last sampled 2023-09-25. Methodology: how these readings are compared.
What Copan Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch3 documented ramps
- Camping1 public campground nearby
- Big water4,850 acres
Swimming conditions
Readings onlyLimited data
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Copan Lake is safe to swim in today is a call for the Oklahoma Department of Environmental Quality and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Copan Lake
These are the measurements Oklahoma DEQ publishes for Copan Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Very murky, less than 1.6 ft of visibility. Phosphorus 79 µg/L. TSI 69.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 1.6ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 79µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | No reading The green pigment in algae — a direct measure of how much algae is in the water. | |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 69 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Copan Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Max depth
~62 ft est.
Surface area
4,850 acres
Public access
Yes
Listed by Oklahoma DEQ
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Oklahoma has not published bathymetry for Copan Lake.
Lake Size & Watershed
Watershed (drainage) area
510 sq mi
HydroLAKES / HydroSHEDS
Shoreline
25.6 mi
HydroLAKES / HydroSHEDS
Elevation
712 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.
Recreation & Access
- Copan PointPublic
- Washington Cove ParkPublic
- Osage Plains ParkPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Public campgrounds near Copan Lake
- Washington Cove2.0 kmReserve
Nearest public campgrounds in the USGS National Map inventory, within about 3 miles. An empty list means USGS records no campground that close, which is not the same as camping being unavailable. Where the source gives an official reservation link, it is used; the cabin and hotel search does not cover campsites. More camping lakes
Stays via Stay22
Stays near Copan Lake
Compare lakeside cabins, hotels, and vacation rentals near Copan Lake in Washington County, Oklahoma — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water. The water-quality readings cover nutrients and algae, not lodging. Cabins and rentals around Copan Lake are listed below.
Top-rated places to stay near Copan Lake
Prices for Oct 30–Nov 1, 4 adults. Change dates on the map below.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a trip? Cabins and lodging at Copan Lake → · more Oklahoma lake trips
Follow Copan Lake’s readings
Email me when new measurements post for this lake. Updates stay free.
Or email
Fishing Copan Lake
Reservoir Info (USACE NID)
Copan Lake is a man-made reservoir impounded by the Copan Dam (completed 1983), built primarily for flood risk reduction on the Little Caney; earth-type dam, 73 ft tall and 7,730 ft long.
- Surface area
- 4,850 ac
- Normal storage
- 43,400 ac-ft
- Max storage
- 338,000 ac-ft
- Drainage area
- 505 sq mi
- Hazard class
- High
- Owner
- USACE - Tulsa District
All listed purposes: Flood Risk Reduction;Other;Recreation;Water Supply.
Source: USACE National Inventory of Dams, NID ID OK21489 · Operator website
Nearby Lakes in Washington County
Frequently asked questions about Copan Lake
Where is Copan Lake?
- Copan Lake is a lake in Washington County, Oklahoma. Its water-quality measurements are published by Oklahoma DEQ and shown on this page as reported.
What is the water quality of Copan Lake?
- Copan Lake in Washington County, Oklahoma has water-quality measurements published by Oklahoma DEQ, shown here as reported. Water clarity: 1.6 ft visibility. Phosphorus: 79 µg/L. Surface area: 4850 acres.
Is Copan Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
How deep is Copan Lake?
- No published bathymetric survey covers Copan Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 62 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate. The lake covers 4850 acres.
Are there boat ramps on Copan Lake?
- Copan Lake has 3 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Copan Point, Washington Cove Park, Osage Plains Park. Public access is listed as yes.
Can I fish at Copan Lake?
- Copan Lake has 3 documented boat landings in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Oklahoma's fish and wildlife agency, so check its current regulations before you go.
Are there campgrounds on Copan Lake?
- Copan Lake has 1 public campground from USGS The National Map within 5 km, including Washington Cove. This is a location join, not a booking. Cabins and hotels are listed separately; campsite reservations use the official link when the source provides one.
Explore Copan Lake across LakeQuality
More lakes in Oklahoma
Other Lakes in Oklahoma
Eutrophic Lakes in Oklahoma
Where this data comes from
53 measurements from 7 monitoring stations, 2017–2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- OWRB Lakes Monitoring
OKWRB-LAKES_WQX35 samples · 2017–2023 - Cherokee Nation (Tribal)
CHEROKEE_WQX18 samples · 2018
Analytical methods
- OWRB Lakes Field Data Collection
- Determination of Turbidity
- CN_QAPP
Monitoring station identifiers (7)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Lake size & watershed from HydroLAKES (HydroSHEDS)
Named boat-access points from the USGS National Boat Ramps inventory
Public campgrounds from USGS The National Map Structures, within about 3 miles