Reservoir Report

Diamond Valley reservoir

California, USA USBR
Today high
--
Tonight low
--
Current storage
744,663acre-ft
% of normal
18%
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Right now · current storage
Diamond Valley
USBR · DMV
744,663 acre-ft
As of 2026-05-11
Seasonal avg
629,191
Record max
809,458
24h change
0.1%
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Diamond Valley -- None reservoir
Diamond Valley None
About this reservoir

Diamond Valley

Diamond Valley Lake in California was created in 1999, and is the largest reservoir in Southern California. The lake is primarily used for municipal drinking water, but it also provides recreational opportunities, such as fishing and boating. The hydrology of the lake is largely dependent on surface flow and snowpack from the San Jacinto Mountains. The lake is managed by the Metropolitan Water District of Southern California, who also operate the Robert B. Diemer Water Treatment Plant. Surrounding the lake is the Diamond Valley Lake Marina, a recreational area that offers fishing, boating, and hiking. In addition, a portion of the surrounding land is used for agricultural purposes, with crops such as grapes and citrus being grown in the area. Overall, Diamond Valley Lake plays a significant role in providing water and recreational opportunities for Southern California.

StateNone
OperatorUSBR
Site IDDMV
Percent of normal18%
Last updated2026-05-11
Records since2003
Storage trends

Daily levels at Diamond Valley

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 Diamond Valley -- inflows here typically show up in storage 24-72 hours later.

Track Diamond Valley 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 Diamond Valley

Where does the data for Diamond Valley 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 Diamond Valley.

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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