Information on the Hyatt Powerplant located in the Oroville Dam.....
http://www.water.ca.gov/swp/facilities/Oroville/hyatt.cfm
According to the chart, 3 generators are able to pass 2800 cfs at full output, and the other 3 2850 cfs. So they are definitely not running them at full capacity.
I think they want to see the effects of each additional unit on river flows. They seem to be starting them in the evening and letting them run overnight before making a morning assessment.
More updated images. Refresh occasionally if needed...