Gauge Description:

The gauge at Pohono is well above the defined reach. Flows in the reach can be highly dependent upon side creeks feeding water into the Merced, and there are many significant ones below Pohono and along the length of the reach. The most significant is the South Fork of the Merced, approx. 4.6 miles below Red Bud.

Two other flow point measurements exist.

Chris Shackelton's website, Dreamflows (click on Realtime Dreamflows) links all 3 sites/graphs.
The flow at Red Bud (aka the Foresta Bridge) is an estimate that mirrors the graph at Pohono, and seems very roughly accurate at "average" boatable flows.

The most useful gauge is one placed only a couple years ago (1999?) below Briceburg, as it includes inflow from the South Fork Merced at Savage's Trading Post, approx. 4.6 miles below Red Bud. It can be found at Gauge below Briceburg.

I've been told that the Briceburg gauge is solar powered and has a limited battery back-up power supply, resulting in the gauge dropping off line for hours during long periods of darkness or very bad weather. THESE ANOMOLOUS DROPS CAN SAFELY BE IGNORED! The Merced river in this reach is a natural flow without dam control, thus it doesn't "shut down" as might be inferred from the flow graph.

NOAA Flow predictions