Total streamflow across the South Umpqua River was last observed at 4,890 cfs, and is expected to yield approximately 9,699 acre-ft of water today; about 84% of normal. Average streamflow for this time of year is 5,801 cfs, with recent peaks last observed on 2025-03-17 when daily discharge volume was observed at 96,700 cfs.

Maximum discharge along the river is currently at the South Umpqua River Near Brockway reporting a streamflow rate of 3,490 cfs. This is also the highest stage along the South Umpqua River, with a gauge stage of 7.44 ft at this location. This river is monitored from 2 different streamgauging stations along the South Umpqua River, the highest being situated at an altitude of 991 ft, the South Umpqua River At Tiller.

The South Umpqua River is a 115-mile-long river in southwestern Oregon, United States. The river was named after the Umpqua tribe of Native Americans who inhabited the area. The headwaters of the river are located in the Cascade Range, and it flows into the Pacific Ocean near Reedsport. The river is a major tributary of the Umpqua River. The hydrology of the river is highly regulated by several dams and reservoirs, including the Galesville Reservoir, the Tiller Reservoir, and the South Umpqua Falls Reservoir. These reservoirs serve various purposes, including hydroelectric power generation, irrigation, and flood control. The South Umpqua River is also a popular destination for recreational activities such as fishing, camping, and boating. The river's waters are used for agricultural purposes, including the cultivation of berries and orchards.