Lake Merritt
Lake Merritt in Alameda County, California is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 5.2 ft visibility.
- Clarity
- 5.2 ft
- Public access
- Yes
Why Lake Merritt has no grade
We grade a lake only when its monitoring record clears the evidence bar: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Lake Merritt, the only measurement available is water clarity, which is not a water-quality indicator on its own — EPA's National Lakes Assessment does not grade clarity. Sampling here has recorded water clarity, but not phosphorus and algae (chlorophyll-a).
Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.
Sampling is run by your state environmental agency and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Lake Merritt is a lake in Alameda County, California. Limited fish-species data available. Public access is available with 28 public boat landings.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2023-07-26. Grade methodology: LakeGrade methodology.
Watch Lake Merritt water quality
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Lake Merritt
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Murky, only visible to about 5.2 ft. Trophic State Index: 53.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 5.2 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 53 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay 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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Recreation & Access
- Alameda BeachPublic
- Alameda EncinalPublic
- Alameda Fishing AccessPublic
- Ballena Isle Marina (An Almar Marina)Public
- Crown BeachPublic
- Central BasinPublic
Showing 6 of 28 documented landings from the USGS National Boat Ramps inventory.
Named access points from the USGS National Boat Ramps inventory, snapped within 5 km. More lakes with boat ramps
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
Source: EPA ATTAINS assessment unit CAL2042004019990218150956 · Official waterbody report
Graded lakes near Lake Merritt
Lake Merritt has no grade, but these lakes within a short drive do.
Nearby Lakes in Alameda County
Frequently asked questions about Lake Merritt
Where is Lake Merritt?
- Lake Merritt is a lake in Alameda County, California. LakeQuality has not rated this lake (UNRATED) — there is not enough recent sampling to assign a letter.
What is the water quality grade for Lake Merritt?
- Lake Merritt in Alameda County, California is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 5.2 ft visibility.
Is Lake Merritt safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Lake Merritt is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
Are there boat ramps on Lake Merritt?
- Lake Merritt has 28 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Alameda Beach, Alameda Encinal, Alameda Fishing Access, Ballena Isle Marina (An Almar Marina), among others. Public access is listed as yes.
Explore Lake Merritt across LakeGrade
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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)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated 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