Where is Thermalito Forebay?

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

Thermalito Forebay

Butte County, California576 acresView map Directions

No nutrient or algae sampling on record from SWRCB for this lake.

Area

576 acres

Surface area

Shoreline

8.5 mi

Measured length

Impaired · PCBs

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Thermalito Forebay in Butte County, California has water-quality measurements published by SWRCB, shown here as reported. Surface area: 576 acres.

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Thermalito Forebay is a 576-acre lake in Butte County, California.

Source: EPA Water Quality Portal sampling records, your state environmental agency. Methodology: how these readings are compared.

Swimming conditions

No reading

Not rated

Nutrient and algae readings are not a swimming clearance. Thermalito Forebay is listed impaired under Clean Water Act §303(d) (IR 5) for pCBs. Check local advisories before you swim.

Whether Thermalito Forebay 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 Thermalito Forebay

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

No clarity data. TSI undefined.

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

Lake Details

Surface area

576 acres

Shoreline

8.5 mi

No bathymetric survey has been published for Thermalito Forebay, so its depth is not documented here.

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Stays near Thermalito Forebay

Compare lakeside cabins, hotels, and vacation rentals near Thermalito Forebay in Butte 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 Thermalito Forebay

→ Thermalito Forebay fishing regulations (limits, seasons, special rules)

EPA Impairment Status

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

Causes of impairment

PCBs

Designated uses not supporting: Fish consumption.

Source: EPA ATTAINS assessment unit CAL5154000020000209143205 · Official waterbody report

Nearby Lakes in Butte County

Thermalito Afterbay4.3 miView →Thermalito Diversion Pool5.2 miView →Miners Ranch Reservoir8.5 miView →Lake Wyandotte10.8 miView →Lake OrovilleOligotrophic10.8 miView →Concow Reservoir—View →

Frequently asked questions about Thermalito Forebay

Where is Thermalito Forebay?: Thermalito Forebay is a lake in Butte County, California. Its water-quality measurements are published by SWRCB and shown on this page as reported.
What is the water quality of Thermalito Forebay?: Thermalito Forebay in Butte County, California has water-quality measurements published by SWRCB, shown here as reported. Surface area: 576 acres.
Is Thermalito Forebay safe to swim in?: Nutrient and algae readings are not a swimming clearance. Thermalito Forebay is listed impaired under Clean Water Act §303(d) (IR 5) for pCBs. Check local advisories before you swim.