Gauge Description:

Flows between the fish barrier dam and Thermolito return are approximately 600 cfs year round.   This was established by an agreement between Fish & Game and Dept. of Water Resources in 1983.   Higher flows can occur during flood releases or to satisfy water temperature requirements or similar purposes.   

The main flows of the river are bypassed around this section through the Thermolito powerplant via Thermolito Forebay and Afterbay.  Four canals further divert water from the afterbay for irrigation or other purposes.  Some remaining portion of the water is returned to the river channel below Thermolito Afterbay.   Flow information is available  for the river below the afterbay.

Total Release to Feather River below Thermolito
Feather River at Gridley 

There does not seem to be an online gauge for flows in the bypassed reach.
USGS gauge #11407000 does provide historical information for this reach.  This gauge is located directly above the fish barrier dam. 

Thermolito Powerplant: historical flows are also available for some years.  The powerplant appears to be able to handle up to 14,000 cfs and perhaps more. Other sources indicate that up to 17,000 cfs can be diverted. 

Feather River at Lake Oroville USGS schematic shows gauges and diversion on the Feather in this area.