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Hydrology Metering

Shasta Dam · Sacramento River · CA

Shasta Lake

California's largest reservoir and the keystone of the Central Valley Project.

Water surface elevation

981.9 ft

Bureau of Reclamation, daily · daily value, Sep 29

Water in storage

2.45 million acre-feet

Bureau of Reclamation, daily · daily value, Sep 29

Share of capacity

53.9% full

against the project figure capacity figure (USBR Central Valley Project data)

Below full pool

85.1 ft

full pool at 1,067.0 ft

This month in the record

lower than 67% of the 83 Septembers on record

monthly mean storage; record low 582,654 acre-feet (1977), record high 3.72 million acre-feet (1974)

30-day trend

-9,322 af/day

storage, 2026-08-17 → 2026-09-16; over the year -623 af/day. Measured change, not a forecast.

Drought at the dam

D0 — Abnormally dry

US Drought Monitor at the dam's coordinates, released 2026-09-17; the feeding basin can differ.

full pool 1,067 ftcolumn continues below982

53.9% full

of capacity, by storage (project figure figure, USBR Central Valley Project data). Sedimentation slowly shrinks real capacity.

The water line is elevation (USBR project 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 (USBR RISE, retrieved 2026-09-17).

977.61017.71057.9May 19Jul 19Sep 16985.3
See the numbers as a table
DateElevation (ft)
Sep 16985.34
Sep 15985.51
Sep 14985.83
Sep 13985.95
Sep 12986.32
Sep 11986.65
Sep 10987.08
Sep 9987.42
Sep 8987.69
Sep 7987.97
Sep 6988.30
Sep 5988.73
Sep 4989.10
Sep 3989.52
Sep 2989.89
Sep 1990.22
Aug 31990.63
Aug 30991.06
Aug 29991.55
Aug 28992.11
Aug 27992.54
Aug 26993.10
Aug 25993.56
Aug 24995.19
Aug 23995.72
Aug 22996.24
Aug 21996.75
Aug 20997.29
Aug 19997.78
Aug 18998.22

Most recent 30 days shown.

The whole record

Monthly mean elevation, Jan 1944 to Sep 2026. The axis spans the pools, not zero; elevations in USBR project datum. Months with fewer than 15 gaged days are dropped, and gaps in the record break the line. Source: USBR RISE, retrieved 2026-09-17.

monthly mean elevationpool reference lines
6788841,089Jan 1944Jun 1985Sep 2026full pool988
See the numbers as a table
MonthMean elevation (ft)Days gaged
Sep 2026987.616
Aug 2026999.631
Jul 20261020.731
Jun 20261038.729
May 20261050.631
Apr 20261051.930
Mar 20261048.031
Feb 20261033.127
Jan 20261034.631
Dec 2025999.831
Nov 2025990.030
Oct 2025989.831
Sep 2025996.630
Aug 20251008.131
Jul 20251028.931
Jun 20251047.530
May 20251058.131
Apr 20251058.830
Mar 20251040.431
Feb 20251036.128
Jan 20251028.831
Dec 20241005.331
Nov 2024989.130
Oct 2024993.031

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 project figure capacity figure (USBR Central Valley Project 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
02.4M4.8MJan 1944May 1985Sep 2026capacity2.6M
See the numbers as a table
MonthMean storage (acre-feet)Days gaged
Sep 20262,567,51816
Aug 20262,821,55131
Jul 20263,306,51731
Jun 20263,760,07329
May 20264,079,02431
Apr 20264,116,12230
Mar 20264,009,47331
Feb 20263,613,12327
Jan 20263,651,27731
Dec 20252,828,80931
Nov 20252,617,22330
Oct 20252,612,06231
Sep 20252,754,63030
Aug 20253,008,80331
Jul 20253,508,72131
Jun 20253,996,76830
May 20254,293,48231
Apr 20254,312,75630
Mar 20253,805,49831
Feb 20253,694,19828
Jan 20253,502,53731
Dec 20242,950,39231
Nov 20242,598,69930
Oct 20242,679,16531

Most recent 24 months shown.

Where these numbers come from

Readings at Shasta Lake 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 project figure USBR Central Valley Project data number; sedimentation slowly shrinks real capacity, so the vintage travels with the percent.