Where is San Luis Reservoir?

San Luis Reservoir is a lake in Merced County, California. Its water-quality measurements are published by SWRCB and shown on this page as reported.

San Luis Reservoir

Merced County, California138 acresView map Directions

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

Area

138 acres

Surface area

Shoreline

4.5 mi

Measured length

Impaired · Mercury

See the measurements Directions Where to stay

San Luis Reservoir in Merced County, California has water-quality measurements published by SWRCB, shown here as reported. Surface area: 138 acres.

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San Luis Reservoir is a 138-acre lake in Merced 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. San Luis Reservoir is listed impaired under Clean Water Act §303(d) (IR 5) for mercury. Check local advisories before you swim.

Whether San Luis Reservoir 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 San Luis Reservoir

These are the measurements SWRCB publishes for San Luis Reservoir, 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.

Ask about San Luis Reservoir

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

Lake Details

Surface area

138 acres

Shoreline

4.5 mi

No bathymetric survey has been published for San Luis Reservoir, so its depth is not documented here.

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Stays near San Luis Reservoir

Compare lakeside cabins, hotels, and vacation rentals near San Luis Reservoir in Merced 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 San Luis Reservoir

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Fishing San Luis Reservoir

→ San Luis Reservoir fishing regulations (limits, seasons, special rules)

EPA Impairment Status

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

Causes of impairment

Mercury

Designated uses not supporting: Fish consumption, Other.

Source: EPA ATTAINS assessment unit CAL5423201020020430153652 · Official waterbody report

Nearby Lakes in Merced County

O'Neill Forebay5 miView →Los Banos Creek13.5 miView →San Luis Holding Reservoir12.8 miView →Los Banos Reservoir13.9 miView →Upper Ruth Lake17.7 miView →Mud Slough—View →

Frequently asked questions about San Luis Reservoir

Where is San Luis Reservoir?: San Luis Reservoir is a lake in Merced County, California. Its water-quality measurements are published by SWRCB and shown on this page as reported.
What is the water quality of San Luis Reservoir?: San Luis Reservoir in Merced County, California has water-quality measurements published by SWRCB, shown here as reported. Surface area: 138 acres.
Is San Luis Reservoir safe to swim in?: Nutrient and algae readings are not a swimming clearance. San Luis Reservoir is listed impaired under Clean Water Act §303(d) (IR 5) for mercury. Check local advisories before you swim.