Sacramento basin streamflow

The Sacramento is California's largest river and the north half of the state's water supply. This page lines up its two mainstem index gages: Bend Bridge, above Red Bluff, which reads the upper river after Shasta and Keswick releases and the unregulated creeks below them, and Verona, which reads the river after the Feather and Yuba systems and the Sutter Bypass have joined it.

Reading them together is the point. The gap between the two is roughly what the Feather system and the valley's east-side tributaries contributed, so a wide gap means Oroville is releasing and a narrow one means it is holding. Both are storm-driven rather than snowmelt-driven, which is what separates the Sacramento's year from the Colorado's: peaks arrive with winter atmospheric rivers and pass within days, and the summer level is an irrigation and Delta-operations decision rather than a runoff curve.