Walnut Canyon Reservoir
Walnut Canyon Reservoir in Orange County, California is not rated for water quality — its monitoring record does not meet the evidence bar. Surface area: 41 acres.
- Area
- 41 acres
Next lake in Orange County
Swipe left or right on this bar to open the next or previous lake.
Why Walnut Canyon 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 Walnut Canyon 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.
Walnut Canyon Reservoir is a 41-acre lake in Orange County, California.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled recent years. Grade methodology: LakeQuality methodology.
Watch Walnut Canyon 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 Walnut Canyon 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 Walnut Canyon Reservoir
Compare lakeside cabins, hotels, and vacation rentals near Walnut Canyon Reservoir in Orange 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 Walnut Canyon 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 | 41 acres |
No bathymetric survey has been published for Walnut Canyon Reservoir, so its depth is not documented here.
Fishing Walnut Canyon Reservoir
Nearby Lakes in Orange County
Frequently asked questions about Walnut Canyon Reservoir
Where is Walnut Canyon Reservoir?
- Walnut Canyon Reservoir is a lake in Orange 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 Walnut Canyon Reservoir?
- Walnut Canyon Reservoir in Orange County, California is not rated for water quality — its monitoring record does not meet the evidence bar. Surface area: 41 acres.
Is Walnut Canyon Reservoir safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Walnut Canyon 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 Walnut Canyon Reservoir across LakeQuality
More California Lake Rankings
Other Lakes in California
Where this data comes from
Measurements for Walnut Canyon Reservoir come from the EPA Water Quality Portal. Per-sample source details are not recorded for this lake.