Where is San Pablo Reservoir?

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

San Pablo Reservoir

Contra Costa County, California785 acresView map Directions

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

Area

785 acres

Surface area

Shoreline

13.3 mi

Measured length

Impaired · Mercury
Limited data

See the measurements Directions Where to stay

San Pablo Reservoir in Contra Costa County, California has water-quality measurements published by SWRCB, shown here as reported. Surface area: 785 acres.

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San Pablo Reservoir is a 785-acre lake in Contra Costa County, California.

Source: EPA Water Quality Portal sampling records, your state environmental agency. Methodology: how these readings are compared.

Swimming conditions

No reading

Limited data

Nutrient and algae readings are not a swimming clearance. San Pablo Reservoir is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, pesticides, pCBs. Check local advisories before you swim.

Whether San Pablo 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 Pablo Reservoir

These are the measurements SWRCB publishes for San Pablo 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.

Ask about San Pablo Reservoir

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

Lake Details

Surface area

785 acres

Shoreline

13.3 mi

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

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Stays near San Pablo Reservoir

Compare lakeside cabins, hotels, and vacation rentals near San Pablo Reservoir in Contra Costa 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 Pablo Reservoir

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Fishing San Pablo Reservoir

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

EPA Impairment Status

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

Causes of impairment

MercuryPesticidesPCBs

Designated uses not supporting: Fish consumption, Other.

A Total Maximum Daily Load (TMDL) plan has been approved.

Source: EPA ATTAINS assessment unit CAL2066001220020129134014 · Official waterbody report

Nearby Lakes in Contra Costa County

Lake Anza12.3 ft clear2.1 miView →Briones Reservoir3.3 miView →Lafayette Reservoir6.4 miView →Mallard Reservoir—View →Contra Loma Reservoir4.1 ft clear—View →Antioch Municipal Reservoir—View →

Frequently asked questions about San Pablo Reservoir

Where is San Pablo Reservoir?: San Pablo Reservoir is a lake in Contra Costa County, California. Its water-quality measurements are published by SWRCB and shown on this page as reported.
What is the water quality of San Pablo Reservoir?: San Pablo Reservoir in Contra Costa County, California has water-quality measurements published by SWRCB, shown here as reported. Surface area: 785 acres.
Is San Pablo Reservoir safe to swim in?: Nutrient and algae readings are not a swimming clearance. San Pablo Reservoir is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, pesticides, pCBs. Check local advisories before you swim.