Fairfax Lake
Osage County, Oklahoma111 acresView mapDirections
Oklahoma DEQ publishes the water-quality measurements for Fairfax Lake. Here is what has been measured.
- Impaired · Algal growth
- 25 ft max depth
- Limited data
Ask about Fairfax Lake
Answers come straight from the public measurements and survey records on this page.
Fairfax Lake in Osage County, Oklahoma has water-quality measurements published by Oklahoma DEQ, shown here as reported. Water clarity: 2.6 ft visibility. Surface area: 111 acres.
Stays via Stay22
Stays near Fairfax Lake
Compare lakeside cabins, hotels, and vacation rentals near Fairfax Lake in Osage 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.
Top-rated places to stay near Fairfax Lake
Prices for Sep 18–20, 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 whole trip? See where to stay at Oklahoma’s top lakes →
Follow Fairfax Lake’s readings
Email me when new measurements post for this lake. Updates stay free.
Or email
Fairfax Lake is a 111-acre lake in Osage County, Oklahoma with an estimated average depth of about 25 feet. Overall water quality is declining over recent sampling years.
Source: EPA Water Quality Portal sampling records, ODEQ, last sampled 2024-07-29. Grade methodology: LakeQuality methodology.
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Fairfax Lake is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth. Check local advisories before you swim.
Whether Fairfax 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 Fairfax Lake
These are the measurements Oklahoma DEQ publishes for Fairfax 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 2.6 ft of visibility. TSI 64.
| Metric | Value | EPA condition class |
|---|---|---|
| Water Clarity (Secchi Depth) | 2.6 ft | Measured, not scored |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 64 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~25 ft est. |
| Average Depth | ~12 ft est. |
| Surface Area | 111 acres |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Oklahoma has not published bathymetry for Fairfax Lake.
Lake Size & Watershed
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.
Fishing Fairfax Lake
Water Quality Trend: ↓ Declining
Based on 4 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -2.914 m/yr | 4 |
Reservoir Info (USACE NID)
Fairfax Lake is a man-made reservoir impounded by the Fairfax (completed 1936), built primarily for water supply on the Wild Creek; earth-type dam, 55 ft tall and 1,300 ft long.
- Surface area
- 111 ac
- Normal storage
- 1,795 ac-ft
- Max storage
- 2,492 ac-ft
- Drainage area
- 8.81 sq mi
- Hazard class
- High
- Owner
- City of Fairfax
Source: USACE National Inventory of Dams, NID ID OK11020 · Operator website
EPA Impairment Status
Fairfax Lake is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit OK621200040040_00 · Official waterbody report
Nearby Lakes in Osage County
Frequently asked questions about Fairfax Lake
Where is Fairfax Lake?
- Fairfax Lake is a lake in Osage County, Oklahoma. Its water-quality measurements are published by Oklahoma DEQ and shown on this page as reported.
What is the water quality of Fairfax Lake?
- Fairfax Lake in Osage County, Oklahoma has water-quality measurements published by Oklahoma DEQ, shown here as reported. Water clarity: 2.6 ft visibility. Surface area: 111 acres.
Is Fairfax Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Fairfax Lake is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth. Check local advisories before you swim.
How deep is Fairfax Lake?
- No published bathymetric survey covers Fairfax Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 25 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 111 acres.
Explore Fairfax Lake across LakeQuality
More lakes in Oklahoma
Other Lakes in Oklahoma
Eutrophic Lakes in Oklahoma
Where this data comes from
37 measurements from 3 monitoring stations, 2016–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- OWRB Lakes Monitoring
OKWRB-LAKES_WQX37 samples · 2016–2024
Analytical methods
- OWRB Lakes Field Data Collection
- Determination of Turbidity
Monitoring station identifiers (3)
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
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)