Horseshoe Lake
Alameda County, California330 acresView mapDirections
SWRCB publishes the water-quality measurements for Horseshoe Lake. Here is what has been measured.
- Public access
- Limited data
Horseshoe Lake in Alameda County, California has water-quality measurements published by SWRCB, shown here as reported. Water clarity: 12.7 ft visibility. Surface area: 330 acres.
Horseshoe Lake is a 330-acre lake in Alameda County, California. Limited fish-species data available. Public access is available.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2023-07-28. Methodology: how these readings are compared.
What Horseshoe Lake is good for
From access and monitoring records, not editorial picks.
- Clear water12.7 ft of visibility
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Horseshoe 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.
Water quality measurements for Horseshoe Lake
These are the measurements SWRCB publishes for Horseshoe Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Good clarity, visible to about 12.7 ft. TSI 40.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 12.7ft | 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. | 40 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Horseshoe Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Surface area
330 acres
Public access
Yes
Listed by SWRCB
No bathymetric survey has been published for Horseshoe Lake, so its depth is not documented here.
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Stays near Horseshoe Lake
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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. Its water-quality measurements are published by SWRCB and shown on this page as reported.
What is the water quality of Horseshoe Lake?
- Horseshoe Lake in Alameda County, California has water-quality measurements published by SWRCB, shown here as reported. Water clarity: 12.7 ft visibility. Surface area: 330 acres.
Is Horseshoe Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Can I fish at Horseshoe Lake?
- Public access to Horseshoe Lake is listed as yes on the lake record. 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.
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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)
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.