Lake Merced
San Francisco County, California208 acresView mapDirections
No nutrient or algae sampling on record from SWRCB for this lake.
- Impaired · Oxygen depletion (low DO)
- 30 ft max depth
- Limited data
Lake Merced in San Francisco County, California has water-quality measurements published by SWRCB, shown here as reported. Maximum depth: 30 ft. Surface area: 208 acres.
Lake Merced is a 208-acre lake in San Francisco County, California with a maximum depth of 30 feet.
Source: EPA Water Quality Portal sampling records, your state environmental agency. Methodology: how these readings are compared.
What Lake Merced is good for
From access and monitoring records, not editorial picks.
- Deep water30 ft surveyed max depth
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Lake Merced is listed impaired under Clean Water Act §303(d) (IR 5) for oxygen depletion (low DO), pH / acidity. Check local advisories before you swim.
Whether Lake Merced 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.
Water quality measurements for Lake Merced
These are the measurements SWRCB publishes for Lake Merced, 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 Lake Merced
Answers come straight from the public measurements and survey records on this page.
Lake Details
Max depth
30 ft
Surface area
208 acres
Shoreline
3.5 mi
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Stays near Lake Merced
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Fishing Lake Merced
EPA Impairment Status
Lake Merced is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Designated uses not supporting: Aquatic life.
Source: EPA ATTAINS assessment unit CAL2021001020020315204138 · Official waterbody report
Nearby Lakes in San Francisco County
Frequently asked questions about Lake Merced
Where is Lake Merced?
- Lake Merced is a lake in San Francisco County, California. Its water-quality measurements are published by SWRCB and shown on this page as reported.
What is the water quality of Lake Merced?
- Lake Merced in San Francisco County, California has water-quality measurements published by SWRCB, shown here as reported. Maximum depth: 30 ft. Surface area: 208 acres.
Is Lake Merced safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Lake Merced is listed impaired under Clean Water Act §303(d) (IR 5) for oxygen depletion (low DO), pH / acidity. Check local advisories before you swim.
How deep is Lake Merced?
- Lake Merced has a maximum depth of 30 feet. The lake covers 208 acres.
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Where this data comes from
Measurements for Lake Merced come from the EPA Water Quality Portal. Per-sample source details are not recorded for this lake.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database