Lake Merritt
Alameda County, CaliforniaView mapDirections
SWRCB publishes the water-quality measurements for Lake Merritt. Here is what has been measured.
- Impaired · Oxygen depletion (low DO)
- Public access
- Limited data
Lake Merritt in Alameda County, California has water-quality measurements published by SWRCB, shown here as reported. Water clarity: 5.2 ft visibility.
Lake Merritt is a lake in Alameda County, California. Limited fish-species data available. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2023-07-26. Methodology: how these readings are compared.
What Lake Merritt is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
Swimming conditions
No readingRecreation use not supported
Nutrient and algae readings are not a swimming clearance. Lake Merritt is listed impaired under Clean Water Act §303(d) (IR 5) for oxygen depletion (low DO), trash. Check local advisories before you swim.
Whether Lake Merritt 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 Merritt
These are the measurements SWRCB publishes for Lake Merritt, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Murky, only visible to about 5.2 ft. TSI 53.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 5.2ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | No reading The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. | |
| Chlorophyll-a (algae) | No reading The green pigment in algae — a direct measure of how much algae is in the water. | |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 53 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Lake Merritt
Answers come straight from the public measurements and survey records on this page.
Recreation & Access
- Lake Merritt Boating CenterPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Lake Merritt
Compare lakeside cabins, hotels, and vacation rentals near Lake Merritt in Alameda 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 Lake Merritt
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Fishing Lake Merritt
EPA Impairment Status
Lake Merritt 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, Recreation, Other.
Source: EPA ATTAINS assessment unit CAL2042004019990218150956 · Official waterbody report
Nearby Lakes in Alameda County
Frequently asked questions about Lake Merritt
Where is Lake Merritt?
- Lake Merritt is a lake in Alameda County, California. Its water-quality measurements are published by SWRCB and shown on this page as reported.
What is the water quality of Lake Merritt?
- Lake Merritt in Alameda County, California has water-quality measurements published by SWRCB, shown here as reported. Water clarity: 5.2 ft visibility.
Is Lake Merritt safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Lake Merritt is listed impaired under Clean Water Act §303(d) (IR 5) for oxygen depletion (low DO), trash. Check local advisories before you swim.
Are there boat ramps on Lake Merritt?
- Lake Merritt has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Lake Merritt Boating Center. Public access is listed as yes.
Can I fish at Lake Merritt?
- Lake Merritt has 1 documented boat landing in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by California's fish and wildlife agency, so check its current regulations before you go.
Explore Lake Merritt across LakeQuality
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Where this data comes from
12 measurements from 1 monitoring station, 2021–2023. Retrieved from the EPA Water Quality Portal on 2026-08-21.
Collected and reported by
- North American Lake Management Society
NALMS12 samples · 2021–2023
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database
Named boat-access points from the USGS National Boat Ramps inventory