Where is Pilarcitos Lake?

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

Pilarcitos Lake

San Mateo County, California89 acresView map Directions

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

Area

89 acres

Surface area

Shoreline

4.8 mi

Measured length

Impaired · Mercury
Limited data

See the measurements Directions Where to stay

Pilarcitos Lake in San Mateo County, California has water-quality measurements published by SWRCB, shown here as reported. Surface area: 89 acres.

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Pilarcitos Lake is a 89-acre lake in San Mateo 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. Pilarcitos Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury. Check local advisories before you swim.

Whether Pilarcitos Lake 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 Pilarcitos Lake

These are the measurements SWRCB publishes for Pilarcitos Lake, 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 Pilarcitos Lake

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

Lake Details

Surface area

89 acres

Shoreline

4.8 mi

No bathymetric survey has been published for Pilarcitos Lake, so its depth is not documented here.

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Stays near Pilarcitos Lake

Compare lakeside cabins, hotels, and vacation rentals near Pilarcitos Lake in San Mateo 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 Pilarcitos Lake

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Fishing Pilarcitos Lake

→ Pilarcitos Lake fishing regulations (limits, seasons, special rules)

EPA Impairment Status

Pilarcitos Lake 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 CAL2022201020091208102331 · Official waterbody report

Nearby Lakes in San Mateo County

San Andreas Lake3.1 miView →Lower Crystal Springs Reservoir3.5 miView →Upper Crystal Springs Reservoir6.4 miView →Central Lake8.6 miView →Lake Lucerne—View →Arroyo de los Frijoles—View →

Frequently asked questions about Pilarcitos Lake

Where is Pilarcitos Lake?: Pilarcitos Lake is a lake in San Mateo County, California. Its water-quality measurements are published by SWRCB and shown on this page as reported.
What is the water quality of Pilarcitos Lake?: Pilarcitos Lake in San Mateo County, California has water-quality measurements published by SWRCB, shown here as reported. Surface area: 89 acres.
Is Pilarcitos Lake safe to swim in?: Nutrient and algae readings are not a swimming clearance. Pilarcitos Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury. Check local advisories before you swim.