|I think they got a bulk deal on signs. The cliff is maybe 20 feet high.|
I don't know the reasons for the increased flows, and now, a day later, they've already slowed the discharge to less than 1,000 cfs. The reservoir is currently 64% full, about 88% of what would be normal for this time of year.
PS: I'm told by the folks at the Tuolumne River Trust that it was a pulse flow to clear out hyacinth, and to assist salmon fingerlings to make the journey downstream.