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Clear Lake Oaks

Lake County, CaliforniaView mapDirections

SWRCB publishes the water-quality measurements for Clear Lake Oaks. Here is what has been measured.

Chlorophyll-a
16.7 µg/L
Typical for California
Measured by SWRCB
  • Impaired · Biotoxins
  • Limited data

Clear Lake Oaks in Lake County, California has water-quality measurements published by SWRCB, shown here as reported. Chlorophyll-a (algae): 16.7 µg/L.

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Clear Lake Oaks is a lake in Lake County, California.

Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2026-06-24. Methodology: how these readings are compared.

Swimming conditions

No reading

Bacteria advisory

Nutrient and algae readings are not a swimming clearance. Clear Lake Oaks is listed impaired under Clean Water Act §303(d) (IR 5) for biotoxins, mercury, metals (other than mercury), oxygen depletion (low DO), pH / acidity. Check local advisories before you swim.

Whether Clear Lake Oaks is safe to swim in today is a call for the California State Water Resources Control Board and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.

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Water quality measurements for Clear Lake Oaks

These are the measurements SWRCB publishes for Clear Lake Oaks, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.

No clarity data. Chlorophyll-a 16.7 µg/L. TSI 58.

Water quality readings
MeasureReadingWhere it sits
Water clarity (Secchi depth)No reading

How deep a black-and-white disk stays visible from the surface. Higher is clearer.

Total phosphorusNo reading

The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential.

Chlorophyll-a (algae)16.7µg/LMeasured, not scored

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.58Eutrophic
OligotrophicMesotrophicEutrophicHypereutrophic

High nutrients, frequent algae, reduced clarity

Ask about Clear Lake Oaks

Answers come straight from the public measurements and survey records on this page.

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Stays near Clear Lake Oaks

Compare lakeside cabins, hotels, and vacation rentals near Clear Lake Oaks in Lake County, California — 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.

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Fishing Clear Lake Oaks

EPA Impairment Status

Clear Lake Oaks is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).

Causes of impairment

BiotoxinsMercuryMetals (other than mercury)Oxygen depletion (low DO)pH / acidity

Designated uses not supporting: Drinking water, Aquatic life, Fish consumption, Recreation.

A Total Maximum Daily Load (TMDL) plan has been approved.

Source: EPA ATTAINS assessment unit CAL5135200019980814115549 · Official waterbody report

Nearby Lakes in Lake County

Frequently asked questions about Clear Lake Oaks

Where is Clear Lake Oaks?

Clear Lake Oaks is a lake in Lake County, California. Its water-quality measurements are published by SWRCB and shown on this page as reported.

What is the water quality of Clear Lake Oaks?

Clear Lake Oaks in Lake County, California has water-quality measurements published by SWRCB, shown here as reported. Chlorophyll-a (algae): 16.7 µg/L.

Measurements on this page ↑

Is Clear Lake Oaks safe to swim in?

Nutrient and algae readings are not a swimming clearance. Clear Lake Oaks is listed impaired under Clean Water Act §303(d) (IR 5) for biotoxins, mercury, metals (other than mercury), oxygen depletion (low DO), pH / acidity. Check local advisories before you swim.

Swimming on this page ↑

Where this data comes from

132 measurements from 1 monitoring station, 2021–2026. Retrieved from the EPA Water Quality Portal on 2026-08-21.

Collected and reported by

  • Big Valley Band of Pomo Indians of the Big Valley Rancheria, California (Tribal)CA_BVR132 samples · 2021–2026

Analytical methods

  • Chlorophyll a
Monitoring station identifiers (1)

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