Grand Lake is a lake in Delaware County, Oklahoma. LakeQuality grades it D for nutrients and algae. The letter is not a swimming clearance.

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.

Grand Lake

Delaware County, OklahomaView map Directions

Nutrient-rich

Nutrients and algae run above the regional average.

↑ up from F at the last regrade

Water temp

No gauge

Clarity

1.6 ft

Secchi · sampled 2026

Max depth

~127 ft est.

GLOBathy model

Level

No gauge

Trend

Improving

3 years of samples

Hypereutrophic
#1 of 2 in the county
127 ft max depth
Public access

See the measurements Directions Where to stay

Grand Lake in Delaware County, Oklahoma has a water quality grade of D (Nutrient-rich). Water clarity: 1.6 ft visibility. Phosphorus: 720 µg/L.

Clarity: 1.6 ft
Max depth: ~127 ft est.
Type: Hypereutrophic
Phosphorus: 720 µg/L
Trend: ↑ Improving
Public access: Yes

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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 grade measures nutrients and algae, not lodging — cabins and rentals around Grand Lake are listed below.

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Grand Lake is a highly nutrient-loaded hypereutrophic lake in Delaware County, Oklahoma with an estimated average depth of about 127 feet. Water quality is graded D based on 1 sampling years through 2026. 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. Grade methodology: LakeQuality methodology.

What Grand Lake is good for

From access and monitoring records, not editorial picks.

Boat launch3 documented ramps

Swimming Safety

Grade only

Elevated nutrients

Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.

The D is nutrients and algae, not a swimming clearance. Check local advisories before you swim.

Compare the safest swimming lakes near Springfield →

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Water Quality Grade: D (Nutrient-rich)

Very murky, less than 1.6 ft of visibility. Phosphorus 720 µg/L. TSI 85. The letter is not a swimming clearance.

Metric	Value	Grade
Water Clarity (Secchi Depth)	1.6 ft	Not graded
Phosphorus	720 µg/L	Poor
Chlorophyll-a (Algae)	No recent samples
Trophic State Index (TSI)	85	Hypereutrophic

Very high nutrients, dense algae, poor clarity

Lake Details

Characteristic	Value
Maximum Depth	~127 ft est.
Average Depth	~88 ft est.
Public Access	Yes

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

Surface area

25,116 acres

Shoreline

140.2 mi

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

Boat Landings

Yes

Public 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

Fishing Grand Lake

→ Grand Lake fishing regulations (limits, seasons, special rules)

Water Quality Trend: ↑ Improving

Based on 3 years of monitoring data (2020-2025).

Metric	Trend	Change/Year	Years
Water Clarity	↑ Improving	+7.308 m/yr	3

County Ranking

Ranked #1 of 2 lakes in Delaware County

Nearby Lakes in Delaware County

NRLake O the Cherokees—View →DEucha Lake3.1 ft clear · Eutrophic18.8 miView →NRLake Eucha—View →NRGrand Lake O' The Cherokees—View →NRBull Lake—View →DSpavinaw Lake3.3 ft clear · Eutrophic19.8 miView →

Frequently asked questions about Grand Lake

Where is Grand Lake?: Grand Lake is a lake in Delaware County, Oklahoma. LakeQuality grades it D for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Grand Lake?: Grand Lake in Delaware County, Oklahoma has a water quality grade of D (Nutrient-rich). Water clarity: 1.6 ft visibility. Phosphorus: 720 µg/L.
Is Grand Lake safe to swim in?: The D is nutrients and algae, 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.

Explore Grand Lake across LakeQuality

Lake Fishing Forecast

Species activity outlook by water temperature and season

Oklahoma Lake Trips

Where to stay at Oklahoma's top lakes, each with its grade

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Very high nutrients, dense algae, poor clarity

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Grade A/B + low algae filter

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Panfish-rich, public access

All Oklahoma lakes

Full state directory

Other Grade D Lakes in Oklahoma

Spavinaw Lake

Mayes County · 3.3 ft

Greenleaf Lake

Muskogee County · 2.5 ft

Copan Lake

Washington County · 1.6 ft

Washunga Bay Lake

Kay County · Nutrient-rich

Pioneer Cover Lake

Osage County · Nutrient-rich

Lake Sardis Clayton

Pushmataha County · Nutrient-rich

Hypereutrophic Lakes in Oklahoma

Claremore Lake Robert S Kerr Reservoir Hulah Lake Eufaula Lake

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 NationSCEQ407 samples · 2013–2026
OWRB Lakes MonitoringOKWRB-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)

Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated 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