Oneill Forebay reservoir
Oneill Forebay
O'Neill Forebay is a man-made reservoir located in California's Central Valley. Its construction was completed in 1967 and it serves as a part of the State Water Project, which supplies water to various regions of California. The reservoir's primary source of water is the San Luis Reservoir, which is fed by surface water flows from the Sacramento-San Joaquin Delta and snowmelt from the Sierra Nevada Mountains. The reservoir also receives additional water from the California Aqueduct. O'Neill Forebay is used for agricultural irrigation and provides water to nearby farms. It is also a popular destination for recreational activities such as boating, fishing, and camping. The reservoir holds a capacity of 93,000 acre-feet of water and is operated by the California Department of Water Resources.
Daily levels at Oneill Forebay
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
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.
Next 5 days, hour by hour
Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.
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.
| Time | Condition | Temp (°F) | Snow (in) | Rain (in) | Humidity (%) | Wind (mps) | Wind dir |
|---|---|---|---|---|---|---|---|
| Loading detailed forecast… | |||||||
15-day temperature & precipitation
Daily temperatures, snow, and rain projected over the next two weeks.
Nearby streamflow gauges
USGS streamgauges around Oneill Forebay -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Mud Slough Nr Gustine Ca | 43 cfs | → |
| Salt Slough A Hwy 165 Nr Stevinson Ca | 43 cfs | → |
| Orestimba C Nr Newman Ca | · | → |
| Pacheco C Nr Dunneville Ca | 4 cfs | → |
| San Joaquin R A Fremont Ford Bridge Ca | 389 cfs | → |
| San Joaquin R Ab Merced R Nr Newman Ca | 386 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Oneill Forebay.
Boat launches
Campgrounds
- San Luis Creek - San Luis Reservoir
- Medeiros State Rec Area - San Luis Reservoir
- Basalt State Rec Area - San Luis Reservoir
- Los Banos Creek - San Luis Reservoir
- Wilson Camp
- Coit Lake Horse Camp
Fishing spots
- Oneill Forebay
- O&Acute;Neill Forebay
- San Luis Reservoir
- Los Banos Reservoir
- Coyote Lake
- San Justo Reservoir
Track Oneill Forebay 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").
About Oneill Forebay
Where does the data for Oneill Forebay 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.
Other water bodies near here
Snoflo-tracked reservoirs and dams within driving distance of Oneill Forebay.