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Rumsey Slough Mid Lake

Lake County, CaliforniaView mapDirections

SWRCB publishes the water-quality measurements for Rumsey Slough Mid Lake. Here is what has been measured.

Chlorophyll-a
4.6 µg/L
Typical for California
Measured by SWRCB
  • Limited data

Rumsey Slough Mid Lake in Lake County, California has water-quality measurements published by SWRCB, shown here as reported. Chlorophyll-a (algae): 4.6 µg/L.

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Rumsey Slough Mid Lake is a lake in Lake County, California.

Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2026-04-30. Methodology: how these readings are compared.

Swimming conditions

No reading

Limited data

Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.

Whether Rumsey Slough Mid Lake 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 Rumsey Slough Mid Lake

These are the measurements SWRCB publishes for Rumsey Slough Mid Lake, 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 4.6 µg/L. TSI 46.

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)4.6µg/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.46Mesotrophic
OligotrophicMesotrophicEutrophicHypereutrophic

Moderate nutrients, good water quality

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Frequently asked questions about Rumsey Slough Mid Lake

Where is Rumsey Slough Mid Lake?

Rumsey Slough Mid Lake 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 Rumsey Slough Mid Lake?

Rumsey Slough Mid Lake in Lake County, California has water-quality measurements published by SWRCB, shown here as reported. Chlorophyll-a (algae): 4.6 µg/L.

Measurements on this page ↑

Is Rumsey Slough Mid Lake safe to swim in?

Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.

Swimming on this page ↑

Where this data comes from

37 measurements from 1 monitoring station, 2020–2026. 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_BVR37 samples · 2020–2026

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.