Reservoir Report

Lake San Antonio reservoir

California, USA USBR
Today high
--
Tonight low
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Current storage
270,863acre-ft
% of normal
49%
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Right now · current storage
Lake San Antonio
USBR · ATN
270,863 acre-ft
As of 2026-05-13
Seasonal avg
181,262
Record max
277,990
24h change
-0.1%
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Lake San Antonio -- None reservoir
Lake San Antonio None
About this reservoir

Lake San Antonio

Lake San Antonio is a reservoir located in Monterey County, California. The lake was created in 1965 by the construction of the San Antonio Dam on the San Antonio River. The dam was built primarily for water storage and flood control purposes. The lake's hydrology is primarily fed by the San Antonio River, which is sourced by the Nacimiento River and the San Antonio Creek. The lake's water levels are influenced by snowpack from the surrounding mountains, as well as surface flows from the river and creek. The lake is used for both agricultural purposes and recreation, including boating, fishing, and camping. The lake has also been used for water supply for nearby communities.

StateNone
OperatorUSBR
Site IDATN
Percent of normal49%
Last updated2026-05-13
Records since2021
Storage trends

Daily levels at Lake San Antonio

Storage volume, pool elevation, and total release plotted from the operating agency's daily observations.

Storage

acre-ft · code 2

Pool Elevation

ft · code 1

Detailed forecast

Plan around the weather

Same NOAA / yr.no feed Snoflo's iOS app uses. Watch the precipitation column on the meteogram -- rain on the basin upstream typically lifts inflow 24-72 hours later.

Hourly detail

Next 5 days, hour by hour

Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.

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Deep dive

5-day forecast table

Every 3 hours, broken out across temperature, snow, rain, humidity, and wind. Each cell is colour-coded relative to the column min/max.

TimeConditionTemp (°F)Snow (in)Rain (in)Humidity (%)Wind (mps)Wind dir
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Long-term outlook

15-day temperature & precipitation

Daily temperatures, snow, and rain projected over the next two weeks.

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Regional inflow

Nearby streamflow gauges

USGS streamgauges around Lake San Antonio -- inflows here typically show up in storage 24-72 hours later.

Track Lake San Antonio in the Snoflo app

Save this reservoir as a favorite and set push alerts when storage crosses a threshold (e.g. "alert me at 80% of normal").

FAQ

About Lake San Antonio

Where does the data for Lake San Antonio come from?

Daily storage, pool elevation, and release rates are sourced from USGS, USBR, and USACE monitoring stations. Weather forecast comes from NOAA / yr.no -- the same feed Snoflo's iOS app uses.

How often is the report updated?

Storage observations are updated daily by the operating agency. The 15-day weather forecast refreshes throughout the day. Snoflo caches and renders the most recent observation -- check the "as of" timestamp on the storage card.

What does the Hazard hazard rating mean?

The Corps of Engineers' hazard potential classification grades probable consequences if the dam fails: High = probable loss of human life; Significant = no probable loss of human life but possible economic loss / environmental damage; Low = no probable loss of human life, only minor economic / environmental losses. See the Dam Data Reference card above for the full definitions.

What's "% of normal"?

The current storage value compared to the historical average storage on this calendar day. 100% = right on average; values above 100% mean above-normal storage (wet year); values below mean below-normal (dry year or drought).

Can I get alerts when storage crosses a threshold?

Yes -- alerts are managed in the Snoflo iOS app. Favorite this reservoir, set a threshold, and you'll get a push the moment conditions cross.

More reservoirs

Other water bodies near here

Snoflo-tracked reservoirs and dams within driving distance of Lake San Antonio.

Premium feature

Favorites and alerts are part of Snoflo Premium. Save reservoirs, set storage thresholds, and get push notifications when conditions cross.

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Manage alerts in the Snoflo app

Custom alerts are configured in the iOS app -- favorite this reservoir, set a threshold, and you'll get a push the moment conditions cross.

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