Horseshoe Lake
Horseshoe Lake in Alameda County, California is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 12.7 ft visibility. Surface area: 330 acres.
- Clarity
- 12.7 ft
- Area
- 330 acres
- Public access
- Yes
Why Horseshoe Lake 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 Horseshoe Lake, no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years). 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.
Horseshoe Lake is a 330-acre lake in Alameda County, California. Limited fish-species data available. Public access is available with 2 public boat landings.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2023-07-28. Grade methodology: LakeGrade methodology.
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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 Horseshoe Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Good clarity, visible to about 12.7 ft. Trophic State Index: 40.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 12.7 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 40 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Horseshoe Lake
Compare lakeside cabins, hotels, and vacation rentals near Horseshoe Lake 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 Horseshoe Lake
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Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 330 acres |
| Public Access | Yes |
No bathymetric survey has been published for Horseshoe Lake, so its depth is not documented here.
Recreation & Access
- Central Park/Lake ElizabethPublic
- Quarry LakePublic
Named access points from the USGS National Boat Ramps inventory, snapped within 5 km. More lakes with boat ramps
Fishing Horseshoe Lake
Reservoir Info (USACE NID)
Horseshoe Lake is a man-made reservoir impounded by the Quarry Pits (completed 1997), built primarily for tailings on the Old Alameda Creek; earth-type dam, 26 ft tall and 9,150 ft long.
- Surface area
- 330 ac
- Max storage
- 3,360 ac-ft
- Drainage area
- 1.5 sq mi
- Hazard class
- High
- Owner
- Alameda County Water District
All listed purposes: Tailings;Recreation;Water Supply.
Source: USACE National Inventory of Dams, NID ID CA01422 · Operator website · Matched by proximity (0.79 km)
Nearby Lakes in Alameda County
Frequently asked questions about Horseshoe Lake
Where is Horseshoe Lake?
- Horseshoe Lake 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 Horseshoe Lake?
- Horseshoe Lake in Alameda County, California is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 12.7 ft visibility. Surface area: 330 acres.
Is Horseshoe Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Horseshoe Lake 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 Horseshoe Lake?
- Horseshoe Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Central Park/Lake Elizabeth, Quarry Lake. Public access is listed as yes.
Explore Horseshoe Lake across LakeGrade
More California Lake Rankings
Other Lakes in California
Mesotrophic Lakes in California
Where this data comes from
2 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
NALMS2 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
Named boat-access points from the USGS National Boat Ramps inventory