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Hydrology Metering

Oroville Dam · Feather River · CA

Lake Oroville

The State Water Project's flagship and the tallest dam in the country — the 2017 spillway failure made this pool's level national news.

Water surface elevation

788.1 ft

California DWR (CDEC), daily · daily value, Aug 31

Water in storage

1.97 million acre-feet

California DWR (CDEC), daily · daily value, Aug 31

Share of capacity

55.8% full

against the DWR figure capacity figure (CA DWR (CDEC reservoir data))

Below full pool

111.9 ft

full pool at 900.0 ft

This month in the record

lower than 43% of the 40 Septembers on record

monthly mean storage; record low 645,775 acre-feet (1985), record high 3.18 million acre-feet (2011)

30-day trend

-17,375 af/day

storage, 2026-07-312026-08-30; over the year -956 af/day. Measured change, not a forecast.

Drought at the dam

D0 — Abnormally dry

US Drought Monitor at the dam's coordinates, released 2026-08-27; the feeding basin can differ.

full pool 900 ftcolumn continues below788

55.8% full

of capacity, by storage (DWR figure figure, CA DWR (CDEC reservoir data)). Sedimentation slowly shrinks real capacity.

The water line is elevation (CDEC datum); the percentage is storage ÷ capacity. They are different measures — a reservoir's volume is not linear in its depth, so the line's height in this column is not the percentage.

The last 120 days

Daily water-surface elevation in feet. The axis hugs the data — it does not start at zero. Source: committed snapshot (CA DWR CDEC, retrieved 2026-08-31).

776.9843.6910.3May 1Jul 1Aug 30789.8
See the numbers as a table
DateElevation (ft)
Aug 30789.81
Aug 29791.39
Aug 28793.07
Aug 27794.51
Aug 26795.43
Aug 25796.83
Aug 24798.35
Aug 23799.51
Aug 22800.82
Aug 21802.17
Aug 20803.63
Aug 19805.15
Aug 18806.64
Aug 17808.07
Aug 16809.72
Aug 15811.34
Aug 14813.09
Aug 13814.75
Aug 12816.51
Aug 11817.98
Aug 10819.37
Aug 9820.91
Aug 8822.61
Aug 7824.19
Aug 6825.73
Aug 5827.25
Aug 4828.80
Aug 3830.35
Aug 2831.81
Aug 1833.34

Most recent 30 days shown.

The whole record

Monthly mean elevation, Mar 1985 to Aug 2026. The axis spans the pools, not zero; elevations in CDEC datum. Months with fewer than 15 gaged days are dropped, and gaps in the record break the line. Source: CA DWR CDEC, retrieved 2026-08-31.

monthly mean elevationpool reference lines
613765916Mar 1985Sep 2006Aug 2026full pool811
See the numbers as a table
MonthMean elevation (ft)Days gaged
Aug 2026811.130
Jul 2026856.130
Jun 2026887.329
May 2026895.931
Apr 2026887.430
Mar 2026872.631
Feb 2026855.728
Jan 2026848.431
Dec 2025780.631
Nov 2025769.730
Oct 2025781.731
Sep 2025808.230
Aug 2025834.931
Jul 2025868.431
Jun 2025895.629
May 2025896.631
Apr 2025881.130
Mar 2025866.031
Feb 2025859.628
Jan 2025833.731
Dec 2024791.831
Nov 2024763.930
Oct 2024769.931
Sep 2024798.830

Most recent 24 months shown; the full monthly series is in the page's API response.

Storage against capacity

Monthly mean storage in acre-feet, zero baseline. The dashed line is the DWR figure capacity figure (CA DWR (CDEC reservoir data)) — sedimentation slowly shrinks real capacity. Storage can legitimately rise past a conservation-pool line when the flood pool is in use.

monthly mean storagecapacity
01.9M3.7MMar 1985Sep 2006Aug 2026capacity2.2M
See the numbers as a table
MonthMean storage (acre-feet)Days gaged
Aug 20262,231,25630
Jul 20262,789,46931
Jun 20263,229,87230
May 20263,362,11931
Apr 20263,233,14030
Mar 20263,018,31131
Feb 20262,784,16028
Jan 20262,688,32231
Dec 20251,903,95531
Nov 20251,785,46430
Oct 20251,906,87131
Sep 20252,195,39730
Aug 20252,515,58531
Jul 20252,961,55631
Jun 20253,353,51630
May 20253,372,54031
Apr 20253,140,90230
Mar 20252,925,02231
Feb 20252,837,74228
Jan 20252,499,70131
Dec 20242,014,54231
Nov 20241,729,56030
Oct 20241,786,95131
Sep 20242,091,56530

Most recent 24 months shown.

Where these numbers come from

Readings at Lake Oroville are the measuring agencies' own: each value above names its source (USGS gage, Bureau of Reclamation daily record, Army Corps project data, or this desk's committed copy) and its observation time in the reservoir's own time zone. The capacity figure is the DWR figure CA DWR (CDEC reservoir data) number; sedimentation slowly shrinks real capacity, so the vintage travels with the percent.