Santa Margarita Lake
Santa Margarita Lake in San Luis Obispo County, California is not rated for water quality — its monitoring record does not meet the evidence bar. Surface area: 146 acres.
- Area
- 146 acres
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Why Santa Margarita Lake 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 Santa Margarita Lake, 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.
Santa Margarita Lake is a 146-acre lake in San Luis Obispo County, California. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled recent years. Grade methodology: LakeQuality methodology.
Watch Santa Margarita Lake water quality
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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 Santa Margarita Lake
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 Santa Margarita Lake
Compare lakeside cabins, hotels, and vacation rentals near Santa Margarita Lake in San Luis Obispo 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 Santa Margarita Lake
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Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 146 acres |
No bathymetric survey has been published for Santa Margarita Lake, so its depth is not documented here.
Recreation & Access
- Santa Margarita Lake Marina & StoreSemi-private
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fishing Santa Margarita Lake
Nearby Lakes in San Luis Obispo County
Frequently asked questions about Santa Margarita Lake
Where is Santa Margarita Lake?
- Santa Margarita Lake is a lake in San Luis Obispo 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 Santa Margarita Lake?
- Santa Margarita Lake in San Luis Obispo County, California is not rated for water quality — its monitoring record does not meet the evidence bar. Surface area: 146 acres.
Is Santa Margarita Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Santa Margarita Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
Are there boat ramps on Santa Margarita Lake?
- Santa Margarita Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Santa Margarita Lake Marina & Store.
Explore Santa Margarita Lake across LakeQuality
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Where this data comes from
Measurements for Santa Margarita Lake come from the EPA Water Quality Portal. Per-sample source details are not recorded for this lake.
Other records on this page
Named boat-access points from the USGS National Boat Ramps inventory