McCoy Flat Reservoir
McCoy Flat Reservoir in Lassen County, California is not rated for water quality — its monitoring record does not meet the evidence bar. Surface area: 1408 acres.
- Area
- 1,408 acres
Next lake in Lassen County
Swipe left or right on this bar to open the next or previous lake.
Why McCoy Flat Reservoir 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 McCoy Flat Reservoir, 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.
McCoy Flat Reservoir is a 1,408-acre lake in Lassen County, California.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled recent years. Grade methodology: LakeQuality methodology.
Watch McCoy Flat Reservoir water quality
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
Swimming Safety
Not ratedElevated nutrients
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for McCoy Flat Reservoir
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 McCoy Flat Reservoir
Compare lakeside cabins, hotels, and vacation rentals near McCoy Flat Reservoir in Lassen 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 McCoy Flat Reservoir
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 1,408 acres |
No bathymetric survey has been published for McCoy Flat Reservoir, so its depth is not documented here.
Fishing McCoy Flat Reservoir
Nearby Lakes in Lassen County
Frequently asked questions about McCoy Flat Reservoir
Where is McCoy Flat Reservoir?
- McCoy Flat Reservoir is a lake in Lassen 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 McCoy Flat Reservoir?
- McCoy Flat Reservoir in Lassen County, California is not rated for water quality — its monitoring record does not meet the evidence bar. Surface area: 1408 acres.
Is McCoy Flat Reservoir safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. McCoy Flat Reservoir is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
Explore McCoy Flat Reservoir across LakeQuality
More California Lake Rankings
Other Lakes in California
Where this data comes from
Measurements for McCoy Flat Reservoir come from the EPA Water Quality Portal. Per-sample source details are not recorded for this lake.