Oroville Dam

In the fall of 2005 the environmental groups, Friends of the River, the Sierra Club and the South Yuba Citizens League tried to convince the Federal Energy Regulatory Commission to fortify the earthen emergency spillway of Oroville Dam.* The California Department of Water Resources denied the risk, and the FERC denied the petitioners’ request for fortification.

The emergency spillway meets FERC’s engineering guidelines for an emergency spillway. The guidelines specify that during a rare flood event, it is acceptable for the emergency spillway to sustain significant damage.
John Onderdonk, FERC*

The petitioners were concerned that extensive rain could create an overflow beyond the concrete spillway, and  cause erosion that would endanger the local residents. There was a risk of failure, known as a “loss of crest control”*. The federal representatives felt assured that the system designed to handle flows of 350,000 cubic feet per second was quite safe. For 12 years, the FERC’s assertion remained untested.  In February, 2017, part of the main, concrete-lined spillway eroded.*  The Department of Water Resources decided to use the emergency spillway for the first time. On Sunday, February 12, 2017 the emergency spillway was working as designed, dumping water at a rate of 6,000 – 12,000 cubic feet per second.* A hole was then discovered in the spillway which had the potential to endanger the citizens of Oroville, California and nearby communities. This prompted the emergency evacuation of over 185,000 residents.

[The emergency is] of such severity and magnitude that continued effective response is beyond the capabilities of the state and affected local governments and supplemental federal assistance is necessary to save lives and to protect property, public health and safety, and to lessen the effects of this serious situation.
Governor Jerry Brown*

While this estimate may be standard script for obtaining emergency funding, the emergency described by Governor Brown is beyond the state’s capacity to handle. Had the warnings been heeded in 2005, this disaster may have been averted. The cost of the repair is now likely to exceed the cost of the requested fortification. So, what caused this crisis? Has something like this happened before?

In 1986, the space shuttle, Challenger exploded. The cause turned out to be eroded O-rings which failed to separate the sections of the rocket booster. The O-rings were known to have eroded. Over time, the extent of the damage caused by erosion continued to grow.* Because the shuttle was able to launch and return safety, the erosion ceased to cause concern. Ultimately, the erosion cost seven astronauts their lives.

When risk of the magnitude of these disasters is ignored, disasters occur. Though responding to risk may be costly, the cost of failure is greater. Though risk may occur in many areas where failure is not catastrophic, risks must be addressed. Attention must be paid and a mindful culture must be developed, especially around those risks that may cause catastrophic failure.

The events of February 2017 will be studied. Blame will be assigned. Damages will be repaired. The question that remains is whether or not we learn from these events. In this case, it appears that the evacuated residents are safe. How long will it be before the Oroville dam experiences another failure? How long until another dam endangers its local community? Hopefully the risks will be assessed, and personnel assigned to maintain vigilance. If not, another catastrophe is just a moment away.


References

Guerra, K. (2017). The stunning destruction of Oroville dam and the work ahead. The Washington Post. Retrieved February 16, 2017 from https://www.washingtonpost.com/news/post-nation/wp/2017/02/13/officials-were-warned-the-oroville-dam-emergency-spillway-wasnt-safe-they-didnt-listen/?tid=a_inl&utm_term=.67480fac603b

Rogers, P. (2017). Oroville dam: Feds and state officials ignored warnings 12 years ago. Mercury News. Retrieved, February 16, 2017 from http://www.mercurynews.com/2017/02/12/oroville-dam-feds-and-state-officials-ignored-warnings-12-years-ago

Weick, Karl E.; Sutcliffe, Kathleen M. (2007). Managing the unexpected (2nd ed). Hoboken, NJ: Jossey-Bass.