There is a third lesson standing in the background
Now there is a third lesson standing in the background, that the Oroville flooding event is putting on the table for consideration. And this one is big. It is related to the now ongoing transition towards the Next Ice Age. And it is also related to economics. The spillway damage in the example shown here will be repaired, and the upgrade for the emergency spillway will likely be installed. The cost will likely add up to a quarter billion dollars. But what about the levees downstream on the Feather River?
The Feather River levee system for the outflow of the dam had been rebuilt at in 2015 at a cost of 300 million. It had been designed to serve 200 years. Its capacity of 170,000 cubic feet per second, carried the flood volume that was released with significant room to spare. The maximum that the Oroville spillway can release is, 150,000 cfs, and the turbines another 17,000 cfs. The actual release during the flood event didn't come anywhere close to full capacity for the dam and the State Levee system. Only some of the Non-State levees, that hadn't been rebuilt, had been filled dangerously to near the point of overflowing.
So it hadn't been the failure of the main spillway that hadn't been used for some time, that had driven the Oroville flooding to the point of disaster. The danger had been the weak link in the system, the levees that been sufficient during the past, and had not been upgraded. The dam's regulators were limited in their freedom to act, by this bottleneck. This time they succeeded. Disaster was avoided. But what about next year?