The summer flow season still has a good couple months left.
This calendar chart displays the history of discharge through the S-12s from 1970 to present. Black data points indicate times of high flows and where you see no dots indicates no flow. Although not unprecedented (i.e. the S-12s are usually flowing at this time of year), similar delays in the onset of flows through the gates also occurred in 1989, 2007 and 2011.
Late September is the furthest summer flows through S-12s have been sustained.
That happened during the epic drought year of 1989.
Typically the S-12s are releasing around 1,000 cfs into the Park.