Lakes / California / Alameda County / San Antonio Reservoir
San Antonio Reservoir, California
770 acres
Surface Area
Where It Sits, and How Deep It Goes
Locator - California
37.58 degrees N, 121.83 degrees W - Alameda County. State and county outlines drawn from Census boundary data; the lake marker is placed by its USGS National Hydrography Dataset coordinates, not by eye. Schematic - not a survey map.
How San Antonio Reservoir Stacks Up
- Larger than 87% of the 1,147 lakes counted in California.
- The largest lake in Alameda County among those counted.
- About 35 miles from San Francisco, as the crow flies.
Lakes Nearby
| Lake | County | Distance | Surface Area |
|---|---|---|---|
| Lake del Valle | Alameda | 6.0 mi | 703 acres |
| Calaveras Reservoir | Santa Clara | 7.4 mi | 1,186 acres |
| Lake Elizabeth | Alameda | 7.6 mi | 78 acres |
| Halls Valley Lake | Santa Clara | 17 mi | 36 acres |
| Bethany Reservoir | Alameda | 18 mi | 164 acres |
| Lake Chabot | Alameda | 18 mi | 292 acres |
Straight-line distance between lake centers.
Facts and Figures
Questions About San Antonio Reservoir
How Big Is San Antonio Reservoir?
San Antonio Reservoir covers 770 acres in Alameda County, California.
What Is the Largest Lake in Alameda County?
San Antonio Reservoir is the largest lake in Alameda County, at 770 acres.
Largest Lakes in California
| # | Lake | County | Surface Area | Max Depth |
|---|---|---|---|---|
| 1 | Salton Sea | Imperial | 233,096 acres | - |
| 2 | Lake Tahoe | Placer | 122,975 acres | - |
| 3 | Goose Lake | Modoc | 93,048 acres | - |
| 4 | Honey Lake | Lassen | 59,917 acres | - |
| 5 | Mono Lake | Mono | 45,124 acres | - |
All 1,147 California lakes ranked by surface area
Sources: USGS NHD (The National Map NHD MapServer layer 12) named waterbodies FTYPE 390/436; counties via Census point-in-polygon lake data (ID 56642359). Verified October 30, 2026.