San Antonio Reservoir water level — California (USGS 11150100)
San Antonio Reservoir in California was last measured at 741.12 ft (datum NGVD29), as of Aug 31, 2026, 12:45 AM (UTC-07:00) (USGS Water Services). Over its recent trend window the level has been falling (−3.6 ft). This reading is provisional and subject to revision.
- % of conservation pool full
- Not reported
- Storage
- Not reported
- Recent trend
- ↓Falling
−3.6 ft over the trend window
Recent trend
Readings this station published between Jun 2, 2026 and Aug 31, 2026 — a 89-day window — downsampled for display.
Data: USGS Water Services (waterservices.usgs.gov) and USACE CWMS Data (cwms-data.usace.army.mil), retrieved 2026-08-31. Both public domain (a work of the U.S. Government, 17 U.S.C. §105).
Source: USGS site 11150100, retrieved Aug 31, 2026, 8:24 AM (UTC+00:00). Official page for this lake →
About this gauge's record
This site's drainage basin covers approximately 323 sq mi of contributing watershed.
The dam behind San Antonio Reservoir
San Antonio Reservoir is held back by San Antonio , an earthfill embankment, holding the pool back by sheer mass and an impervious core rather than by the strength of concrete , standing 202 ft high and running 1,433 ft along its crest , built across San Antonio River in Monterey County , near Bradley, San Ardo, Salinas . It was completed in 1965 , and is owned by Monterey County Water Resources Agency (a public utility owner) .
Its recorded primary purpose is flood risk reduction — the pool is drawn down between storms so there is empty space waiting for the next flood, which is why this level can fall in dry weather and climb sharply after rain . It also serves flood risk reduction;irrigation;water supply.
NID classes it high hazard potential. That describes what a failure would cost downstream — loss of life would be expected — and says nothing about how likely a failure is, or what condition the dam is in. Its most recent condition assessment was fair: sound under normal loading, though a rare or extreme event could expose a deficiency. That assessment is dated 04/12/2019.
At its normal pool the reservoir covers about 5,720 acres. NID records a maximum storage of 350,000 acre-ft. It is regulated by DWR, Division of Safety of Dams.
Dam facts: National Inventory of Dams record CA00813 , filed by California — U.S. Army Corps of Engineers, public domain. Water levels above come from USGS Water Services and are a separate source. (How this dam was matched to this gauge →)
Other gauges at this site
A second gauge reports at this same structure. Its readings are listed here rather than on a separate page, because it measures the same water.
| Gauge | Source | Elevation | Storage |
|---|---|---|---|
| San Antonio Reservoir | USGS site 11173990 | 455.56 ft (NGVD29) | — |
How San Antonio Reservoir compares nearby
4 of 6 nearby lakes with a current trend are also falling right now.
Nearby lakes
The six nearest published lakes by centroid distance (great-circle) — cross-state neighbors included.
| Lake | State | Level | Distance |
|---|---|---|---|
| Nacimiento Reservoir | CA | 750.91 ft | 4 km |
| Los Banos Reservoir | CA | 296.00 ft | 140 km |
| Alisal Reservoir | CA | 598.47 ft | 155 km |
| Big Dry Creek Dam | CA | 400.00 ft | 163 km |
| Hensley Lake-Pool | CA | 546.20 ft | 171 km |
| Friant Dam | CA | 508.83 ft | 171 km |
Frequently asked questions
- What is the current water level of San Antonio Reservoir?
- As of Aug 31, 2026, 12:45 AM (UTC-07:00), the pool elevation was 741.12 ft (datum NGVD29), provisional and subject to revision. See the trend chart above for the recent direction.
- Is San Antonio Reservoir full right now?
- Its managing agency does not publish a %-of-conservation-pool-full figure for this lake, so we show the bare level rather than estimate one.
- Where does this data come from?
- From USGS site 11150100, retrieved Aug 31, 2026, 8:24 AM (UTC+00:00).
More in California
See every lake tracked in California, or read the methodology behind these figures.