Grand Lake
Delaware County, OklahomaView mapDirections
Oklahoma DEQ publishes the water-quality measurements for Grand Lake. Here is what has been measured.
- Hypereutrophic
- 127 ft max depth
- Public access
Grand Lake in Delaware County, Oklahoma has water-quality measurements published by Oklahoma DEQ, shown here as reported. Water clarity: 1.6 ft visibility. Phosphorus: 720 µg/L.
Grand Lake is a highly nutrient-loaded hypereutrophic lake in Delaware County, Oklahoma with an estimated average depth of about 127 feet. Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available with 3 public boat landings. Compared to the 1 other monitored lakes in Delaware County, Grand Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, ODEQ, last sampled 2026-06-23. Methodology: how these readings are compared.
Grand Lake has 3 public boat landings, so a lakefront rental is not the only way to get a boat on the water. If you are planning to stay, you can search lake houses and cabins around Grand Lake on Vrbo, or look for a hotel room near the lake on Booking.com or Expedia.
What Grand Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch3 documented ramps
Swimming conditions
Readings onlyElevated nutrients
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 Grand 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 Grand Lake
These are the measurements Oklahoma DEQ publishes for Grand 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 720 µg/L. TSI 85.
| 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 | 720µg/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. | 85 | Hypereutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Very high nutrients, dense algae, poor clarity
Ask about Grand Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Max depth
~127 ft est.
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 Grand Lake.
Lake Size & Watershed
Watershed (drainage) area
10,294 sq mi
HydroLAKES / HydroSHEDS
Surface area
25,116 acres
HydroLAKES / HydroSHEDS
Shoreline
140.2 mi
HydroLAKES / HydroSHEDS
Elevation
751 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
- Honey Creek State ParkPublic
- Wolf Creek ParkPublic
- Bernice Area at Grand Lake State parkPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Grand Lake
Compare lakeside cabins, hotels, and vacation rentals near Grand Lake in Delaware 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 Grand Lake are listed below.
Top-rated places to stay near Grand 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 Grand Lake → · more Oklahoma lake trips
Follow Grand Lake’s readings
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Fishing Grand Lake
Water quality readings over time
3 seasons of samples on record (2013–2020). Calling a direction takes at least 4 years of the same measurement.
Water clarity
Improving3 years
Nearby Lakes in Delaware County
Frequently asked questions about Grand Lake
Where is Grand Lake?
- Grand Lake is a lake in Delaware County, Oklahoma. Its water-quality measurements are published by Oklahoma DEQ and shown on this page as reported.
What is the water quality of Grand Lake?
- Grand Lake in Delaware County, Oklahoma has water-quality measurements published by Oklahoma DEQ, shown here as reported. Water clarity: 1.6 ft visibility. Phosphorus: 720 µg/L.
Is Grand Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
How deep is Grand Lake?
- No published bathymetric survey covers Grand Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 127 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
Are there boat ramps on Grand Lake?
- Grand Lake has 3 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Honey Creek State Park, Wolf Creek Park, Bernice Area at Grand Lake State park. Public access is listed as yes.
Can I fish at Grand Lake?
- Grand 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.
Explore Grand Lake across LakeQuality
More lakes in Oklahoma
Other Lakes in Oklahoma
Hypereutrophic Lakes in Oklahoma
Where this data comes from
613 measurements from 16 monitoring stations, 2012–2026. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Seneca Cayuga Nation
SCEQ407 samples · 2013–2026 - OWRB Lakes Monitoring
OKWRB-LAKES_WQX206 samples · 2012–2024
Analytical methods
- OWRB Lakes Field Data Collection
- 10200 H ~ Chlorophyll a-b-c Determination
- Determination of Turbidity
- Phosphorus, Reactive (Orthophosphate) Ascorbic Acid Method
- Turbidity by Nephelometry
Monitoring station identifiers (16)
- OKWRB-LAKES_WQX-121600030030-08
- OKWRB-LAKES_WQX-121600030040-10
- OKWRB-LAKES_WQX-121600030030-04
- OKWRB-LAKES_WQX-121600030020-03
- OKWRB-LAKES_WQX-121600030040-12
- OKWRB-LAKES_WQX-121600030030-09
- OKWRB-LAKES_WQX-121600030030-05
- OKWRB-LAKES_WQX-121600030030-06
- OKWRB-LAKES_WQX-121600030040-11
- OKWRB-LAKES_WQX-121600030030-07
- OKWRB-LAKES_WQX-121600030040-13
- SCEQ-GL15
- SCEQ-GL13
- SCEQ-GL12
- OKWRB-LAKES_WQX-121600030020-02
- OKWRB-LAKES_WQX-121600030020-01
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