Reservoirs

Above normal

San Luis Reservoir water level

Live reservoir storage and water level in San Joaquin-Delta basin, California

Data through Oct 7, 2026 · source last checked Oct 8, 2026 · page revised Oct 8, 2026

Cite
acre-feet
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About this data
Source
US Bureau of Reclamation RISE; California reservoirs via CA DWR CDEC
Series
End-of-day reservoir storage
Geography
San Luis Reservoir water level
Unit
acre-feet
Calculation
Daily reading
Last observation
Oct 7, 2026
Update frequency
Daily

Now 1.49M af, 42% above the 5-yr median, 73% of capacity.

San Luis storage is 1.49M af, 42% above the 5-year median and 73% of capacity. Month over month the reservoir gained 11.3%, and year over year it is up 35.4%.

The numbers
PeriodCurrentPriorChange
Week over week1.49M af1.47M af+1.5%
Month over month1.49M af1.34M af+11.3%
Year over year1.49M af1.10M af+35.4%
vs 5-yr median1.49M af1.05M af+42.1%
Water surface elevation
MeasureValue
Latest reading, Oct 7, 2026498.51 ft above sea level
Change from a week earlier+1.94 ft
Change from a year earlier+35.83 ft
5-yr median for the date457.61 ft
Below full pool45.49 ft
Five-year low350.95 ft (Oct 23, 2021)
Five-year high543.04 ft (Apr 6, 2023)
Reservoir facts
MeasureValueSource
Full pool elevation544 ft above sea level (top of active conservation pool)USBR
Maximum depth at the dam303 ftUSBR
Surface area at full pool13,000 acresCDEC
Total capacity2,041,000 acre-feetCDEC

Previous weeks

Week of Sep 23, 2026

San Luis Reservoir entered water year 2027 at 1.47M af on October 1, 2026, up 3% on the week and 45% above its five-year median (Bureau of Reclamation). As California's primary south-of-Delta off-stream storage, the reservoir serves both CVP and SWP contractors. Storage is tracking well above the five-year seasonal norm heading into the new water year.

About San Luis Reservoir

San Luis Reservoir's water level is 498.51 feet above sea level as of Oct 7, 2026, 45.49 feet below full pool (544 feet), with 1.49 million acre-feet in storage (73% of capacity). That is 1.94 feet higher than a week earlier and 35.83 feet higher than a year earlier.

San Luis Reservoir is an off-stream basin behind B.F. Sisk Dam, filled by pumping rather than by a river of its own, and the largest off-stream reservoir in the country. Reclamation owns the dam and the California Department of Water Resources operates it, with the storage split about 55 percent state and 45 percent federal. In wet months, Delta water arriving down the California Aqueduct and the Delta-Mendota Canal is pumped up from O'Neill Forebay and held for release to farms and cities to the south later in the year.

Total capacity is 2.04M af, over the past five years storage has ranged from 192,050 af to 2.03M af.

San Luis Reservoir is one of the 21 major reservoirs this site totals each day. For the combined picture, western reservoir levels carries the storage of all 21 on one chart, which is the number to watch when the question is about the West as a whole rather than about this project.

Those figures describe the reservoir at full pool, not today. The chart at the top of this page tracks storage in acre-feet and the elevation table tracks the water surface in feet, so read storage against total capacity for how full the reservoir is, and the elevation against the full pool elevation and maximum depth for the size of the water column behind the dam. The two do not move together one for one: a reservoir narrows as it deepens, so one holding half its capacity still stands more than half as deep.

Sources: full pool elevation and maximum depth from the Bureau of Reclamation; surface area and total capacity from the California Data Exchange Center.

Because pumps fill it on the two projects' schedule, the level follows a yearly cycle rather than a river's: over 1991-2020 storage averaged highest in March and lowest in August, per the California Data Exchange Center. Why the San Luis Reservoir level swings walks through that cycle, the federal and state shares, and five years of readings.