Reservoirs

Below normal

Western reservoir levels, total storage

Reservoir levels for the 20 major western reservoirs The Waterline tracks, combined into one daily storage total in acre-feet

Data through Aug 11, 2026 · source last checked Aug 13, 2026 · page revised Aug 13, 2026

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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
Western reservoir levels, total
Unit
acre-feet
Calculation
Daily reading
Last observation
Aug 11, 2026
Update frequency
Daily

Now 35.45M af, 12% below the 5-yr median, 42% of combined capacity.

Combined storage at the 20 major western reservoirs fell to 35.63M af, down 1.6% on the week and 6.6% on the month. The pool sits 11% below its 5-year median, with year-over-year storage down 11.5% and current levels at 42% of combined capacity.

The numbers
PeriodCurrentPriorChange
Week over week35.45M af36.06M af-1.7%
Month over month35.45M af37.94M af-6.6%
Year over year35.45M af40.09M af-11.6%
vs 5-yr median35.45M af40.09M af-11.6%

About this total

This page adds up the reservoir levels The Waterline tracks, 20 of the West's major reservoirs including Lake Mead, Lake Powell, Hungry Horse Reservoir, Shasta Lake, into one combined daily storage total. It is the widest single read on how much water the tracked system is holding, compared to its own five-year median like every other page on the site. A day appears here only when every tracked reservoir reports it, so the total is always a true sum of the same set and a gap in one reservoir's feed never shows up as a system-wide swing. It is the total for this tracked set, not for every reservoir in the West: use it for the direction and scale of the system, and the per-reservoir and basin pages for the specific projects behind a move.