Reservoirs

Near normal

Folsom Lake level

Live reservoir storage and water level in American-Sacramento basin, California

Data through Aug 26, 2026 · source last checked Aug 27, 2026 · page revised Aug 27, 2026

Cite
acre-feet
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Free to republish with attribution. The chart updates automatically as new data lands.
About this data
Source
US Bureau of Reclamation RISE; California reservoirs via CA DWR CDEC
Series
End-of-day reservoir storage
Geography
Folsom Lake level
Unit
acre-feet
Calculation
Daily reading
Last observation
Aug 26, 2026
Update frequency
Daily

Now 474,332 af, 1% below the 5-yr median, 49% of capacity.

Folsom Lake storage fell to 474,332 af, down 6.5% from the prior week. The month-to-date decline totals 30.3%. Storage is 1% below the 5-year median and 49% of capacity.

The numbers
PeriodCurrentPriorChange
Week over week474,332 af507,513 af-6.5%
Month over month474,332 af680,677 af-30.3%
Year over year474,332 af481,433 af-1.5%
vs 5-yr median474,332 af481,433 af-1.5%
Reservoir facts
MeasureValueSource
Full pool elevation466 ft above sea levelUSBR
Maximum depth at the dam275.4 ftUSBR
Surface area at full pool11,180 acresUSACE NID
Total capacity977,000 acre-feetCDEC

Previous weeks

Week of Aug 19, 2026

Folsom Lake stands at 507,513 af, 3% above the 5-year median and 52% of capacity. Storage shed 8.9% on the week and 30.4% on the month amid summer drawdown. The lake is up 3.5% year-over-year.

An earlier week

Folsom storage fell to 556,962 af, down 28.4% over the past month and 8.6% week-to-week. Storage remains 6% above the 5-year median and 10.1% above year-ago levels at 57% of capacity.

Week of Aug 13, 2026

Folsom storage fell to 581,190 af, down 8.1% on the week and 27.2% over the month. The lake sits 7% above its 5-year median and is up 11.9% year over year.

About Folsom Lake

Folsom Dam holds back the American River just above Sacramento, a CVP reservoir built as much for flood control as for supply. A large share of its roughly one-million-acre-foot capacity stays empty through winter as flood space for the city below. Reclamation operates the water and power while California State Parks runs the shoreline recreation area.

Total capacity is 977,000 af, over the past five years storage has ranged from 214,225 af to 959,148 af.

Folsom Lake is one of the 20 major reservoirs this site totals each day, and one of several it tracks in the American-Sacramento basin. For the combined picture, western reservoir levels carries the storage of all 20 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 rather than water depth, so read the current figure against total capacity for how full the reservoir is, and 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 from the Army Corps' National Inventory of Dams; total capacity from the California Data Exchange Center.