Thermalito Forebay
Thermalito Forebay in Butte County, California is not rated for water quality — its monitoring record does not meet the evidence bar. Surface area: 576 acres.
- Area
- 576 acres
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Why Thermalito Forebay has no grade
We grade a lake only when the monitoring record supports a letter: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Thermalito Forebay, no water-quality sampling on record for this lake.
Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.
Sampling is run by your state environmental agency and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Thermalito Forebay is a 576-acre lake in Butte County, California.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled recent years. Grade methodology: LakeQuality methodology.
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Swimming Safety
Not ratedElevated nutrients
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Thermalito Forebay
These readings exist but are not enough for an A–F grade — see why.
No clarity data. Trophic State Index: undefined.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) |
Where to stay 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.
Top-rated places to stay near Thermalito Forebay
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Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 576 acres |
No bathymetric survey has been published for Thermalito Forebay, so its depth is not documented here.
Fishing Thermalito Forebay
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Frequently asked questions about Thermalito Forebay
Where is Thermalito Forebay?
- Thermalito Forebay is a lake in Butte County, California. LakeQuality has not rated this lake (UNRATED) — no water-quality sampling on record for this lake.
What is the water quality grade for Thermalito Forebay?
- Thermalito Forebay in Butte County, California is not rated for water quality — its monitoring record does not meet the evidence bar. Surface area: 576 acres.
Is Thermalito Forebay safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Thermalito Forebay is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
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Where this data comes from
Measurements for Thermalito Forebay come from the EPA Water Quality Portal. Per-sample source details are not recorded for this lake.