The Oroville Dam Failure

As I write the Oroville dam in California is eroding back toward a breach of the reservoir. I am a dam contractor. If you ever heard someone say “that dam contractor..” they may have been talking about me.

I have repaired hundreds of dams including ones like Oroville, which were in the process of failure. I know a lot about dams.

The spillway failure is a common type of failure, where phreatic, or surface water entered the spillway, migrating beneath the slabs. (A static element on a dynamic element, A hard element on a live element). The dam is hydrated and dehydrated as water levels rise and fall, moving, as soils swell from pressures and water mass. In times of high rain the phreatic surface (hydrated soils line) moves toward the surface, venting into the void so produced.

This creates a void. Moving water over the years has eroded soils from beneath the slab downstream and left a channel. Now, the spillway has been actuated in a high-flow event and the plates of the spillway have failed into the stream, scouring from beneath them. They will continue to fail as the water continues to flow. The hydraulic jump exacerbates this erosion.

If the flow continues for a long enough time, with sufficient velocity, the reservoir will be voided by the migration of the erosion to the pool (cut-back). I cannot tell if failure is imminent, from Ohio, but it is an unacceptable situation that has been allowed to develop. It is a case of pennies pinched producing dollars spent, perhaps tragedy.

What we can learn as a nation is the information that is being disseminated. Words chosen carefully, to not excite, to not scare. The issue, as it now stands is serious, life-threatening even. The officials, the owners reps, the media will tell us now, that there is nothing to be be frightened about – all under control (remember Katrina??).

We have, for so long, ignored the failing infrastructure of this great nation, Let us hope that a fatal failure is not necessary to get us to act. Past experience does not make me hopeful of that.

Oroville is 770′ high, 6,920′ long. It is one of the 20 largest dams in the world. If Oroville breaks, The city will be flooded.

Eight thousand three hundred and seventy five residents are at risk within the inundation zone. Two hundred thirty critical facilities in the city of Oroville are within the inundation zone, including; Eleven schools, twenty one day care and children service centers, fourteen elder care facilities, twenty six bridges will be lost, the airport, two fire stations, the government administration building, three law enforcement stations, the EMERGENCY OPERATIONS CENTER (brilliant) Two waste water treatment plants, the jail, and the Hospital. (from the City of Oroville local hazard mitigation plan update May, 2013)

We are not talking about a river rising, where people have time to evacuate. We are talking about a wall of debris, mud, and water taking out a city, buildings, roads, bridges, life, in a horrible instant.

When will we, at last mandate proper maintenance and inspection of these high hazard and medium hazard dams? Why are we willing to suffer a loss of hundreds of millions of dollars to save a couple of dollars on proper and responsible dam safety and repairs?

Whatever you may hear, this is a significant event which could be horrible in its scope and its magnitude. Let us pray that it does not breach, and let us hope that, at last people are sufficiently concerned to act.

Scott Cahill

Oroville – a failure of a once great nation

In considering the events at Oroville, it is easy to concentrate on the negative. There is so much negative to go around.

The Principal spillway, the normal method of shedding water from the reservoir, has failed from scour, the soils being discharged downstream by the high velocity water. The Principal spillway is a controlled spillway, with gates at the dam crest to “control” the flow of water down the concrete “sluiceway” to the stream below, in Oroville’s case the Feather River. In a normal discharge, the sluiceway would conduct the flow down the grade, discharging into a plunge pool. Concrete block-like elements may serve to break and confuse the flow, the plunge pool, then absorbing the remaining energy and the water moving downstream. Oroville’s principal spillway failed because the sluiceway was undermined by voids, which became “charged” by high-pressure water introduced from the discharge through the gates. The result was a failure of the components of the sluiceway, plate slabs, and training walls were washed into the stream below, impeding flow, and causing a backup of the pool below the dam.

The emergency spillway is an uncontrolled spillway. It will pass as much water as entered the reservoir across its weir and the water is then transmitted downstream. The emergency spillway at Oroville is unlined, composed of indigenous earth and rock. Abutting rock is assessed in construction of a dam to attempt to understand its erosion characteristics. Rock of abutments is often considered “weathered” Weathered rock is rock which has been exposed at the surface and has become fractured and less sound. Sound rock is called “High Recovery” rock. Soft and fractured rock is called “Low Recovery” rock. Low recovery rock is prone to erosion. As an example, granite which is not weathered (granite is resistive to weathering) is high recovery rock. If it has seams of sands, silts, or clays, even granite can be considered low recovery. Shale is a rock that weathers rapidly. Shale abutments are often subject to erosion with high flows across these soils (rock). It is acceptable for an emergency spillway to lose soils and to be damaged in a discharge. The emergency spillway is used in special cases where there are severe flows (flooding rains or a break of a reservoir upstream for instance). Oroville’s emergency spillway was an earthen spillway. It is a weathered bedrock outcropping. Upon actuation, because of the failure of the principal spillway, it became apparent that the emergency spillway’s underlying rock was erosive, causing severe cutback, which threatened the foundation of the ogee weir. Noting this rapid evolution of the cutback, the operators opened the gates again to the failing principal spillway.

The argument has been offered that the dam has not “failed” in comments on my other writings. The failure that I refer to is the failure of elements of the dam, and the principal and emergency spillways are clearly elements of the dam. A dam failure does not require the complete loss of pool. In fact, few dam failures result in a complete loss of pool. My title, perhaps sensational, is accurate in describing the failure of these elements. A dam without a method to remove the water safely is clearly in a failure mode. Oroville Dam, as of this writing, is in a precarious situation. The spillways are in the process of failure. The losses already suffered are horrible. If we see the weir of the emergency spillway fail, the losses will be incalculable.

The Oroville Dam will probably not breech. I hope with all of my heart that it does not. Don’t ever take my criticism as some desire for catastrophe. It is just the opposite. I find the failure to maintain our elements of our infrastructure as a societal failure of a magnitude heretofore unseen. If we continue unchanged with these failures, if we fail to rebuild and maintain, we will become a third-world country. If the great United States of America is to step into the next few decades as a world power, it will be with renewed infrastructure. Without it we will fail as a nation and as a government.

We have watched as our great steel mills moved to Japan. We have watched as our great manufacturing move to Japan, then China. We have watched as our assembly move to Mexico. Through it all, we have watched. The time has come to act, or to surrender all that we once were. As a nation we have a debt of nineteen trillion dollars with a further commitment of four trillion dollars. We have a backlog of infrastructure improvement of an additional two trillion dollars. These numbers are so large that the human mind cannot comprehend them. As a nation we must satisfy this debt. We cannot save our way out of this problem. It is too large.

To survive, as a nation, and a model to the free world, we must work our way out of our smothering debt. To do this, we must have the machine of our economy operating unencumbered. Our infrastructure is a systemic element of our health as a nation. The social and societal failures that we now see as a nation are symptoms of a failing nation, a failing way of life. They will be repaired by the improvement of the whole. The despair of many is real. Men must see an avenue to success. They must be able to sustain themselves and their families.

Let us consider what it would be like if we were unlucky. Certainly, we may yet be unlucky, but what would California, the United States be like if Oroville had failed completely?

Imagine a nation and a state stretched to a fiscal breaking point encumbered with the costs of the rebuilding of a huge area of homes, schools, businesses. Imagine the mud and the cleanup. Imagine the lives lost. Remember Katrina, if you think that the white knights would come to fix all that is wrong, we have allowed ourselves to become something less than we once were. I believe that such a failure would be the first loss in a digression of our standard of living, it would certainly be so for the areas in the inundation zone, crops lost from need of irrigation, drinking water rationed, water quality reduced.

Some choose to defend the operation of a near-failing dam. I weigh the hurt feelings of a few men who failed to maintain, against all of the death and destruction. I wish that all could be happy and nice. It can not. Perhaps, many people will have to die to change the minds of men. There are so many dams that are balanced, waiting on that one storm. Let it be a lesser dam, a lesser population, if some must die to get the nation to hear this cry. Let it be faces that I do not know, voices that I have never heard, so that my dreams are not haunted for the rest of my life.

Blame must be assigned when all is lost, as it certainly must be. When it happens, that tragedy, it will not be the fault of the operators of Oroville. It will not be the failure of the state or the nation. It will not be the failure of the men who refused to fund maintenance.

It will be the failure of one man only, one who did what he could, but failed. It will be the failure only of one who cared too deeply. When it happens, as it must, It shall be my failure, and my failure alone.

Scott Cahill

Oroville Dam, a Committee to Draft Culpable Deniability

For the moment, Oroville stands quietly on, and watches the workers, carrying out their work into the night to plug the holes in her magnificent structure. She is a bit of Mother Nature, constructed of her elements, manipulated by man, but still, elementally unchanged. Men pile rocks, and Mother Nature laughs, at the effort, as she levels mountains as a matter of course. She is a grand lady, yet a fickle one, She will bend, perhaps, but always, she shall have her way. To her, there are but two classes of man, those who respect, and those who do not.

The snowpack waits, quiet in the mountains for the spring. The reservoirs, too wait. They wait for the onslaught of water running its course, inevitably to the great sea. Many are full, unable to help, to catch for a moment, the water which must come, in time.

Men wait, too. They are not the men who respect Mother Nature. They are men of words. They craft them, and they manipulate them. They even try to stop others from using them. Words can be grand, words can incite in men, actions that change the future of our world, These are not men of those words, their words are designed only for themselves. Their agenda is short term, to make it perhaps through the snow melt, to hide the lies, to make it to the dry season, when they can cover the wounds, and let the people forget. They think of retirement, and pay, coffee and donuts. They think themselves important because their failures elevated their persona, yet, still, their words do not reflect reality. Their words, still, only serve their insignificant agenda.

Great men use words, too. words are the tools of the greatest of men. They draft words, to convey, to insight, and to warn. Great men wish to change the world, to uncover truth and to address it. They wish for a world better than it is. They wish for honor.

Now, in the shadow of disaster, the men of the dam draft a “committee” assembled by those who so failed their charge, to investigate their actions, and to find them competent. They shall be found competent. It will be found that their actions and their lack of action were valid. It shall be said that “no one could have foreseen” such a storm (as they said of Katrina, a small storm). They shall be seen as heroes, who ran into the fray, and saved the day at the last moment. There will be articles and news conferences, where these “selected” engineers will explain what happened. Many will change their minds, convinced of the valor and the heroism of these great men who so poorly managed the dam. It will be said that the evacuation was a mistake. Perhaps the Sherriff will be blamed, for the unnecessary action. The men who failed so miserably, will have failed no more. They will be rewarded, they will be promoted. They will have proved themselves, in the eyes of a failed government, as worthy.

If the dam breaks, it will have been an act of God. “No one could have forseen such an event”, they will say. Perhaps they will write books, telling of their trials in the face of calamity with their faces on the covers and the dam, breeched in the background. They will site the report that they had written, explaining how the event was inevitable. They will repeat in the pages of their books, the absolutes that they told us all. They will speak of the bedrock. They will say that the spillway is not part of the dam. They will say that everything was done perfectly. They will reference the report to prove their point.

In the sunlight after the rain, some will have to rebuild this dam and the water resources that were destroyed, the whole of a way of life destroyed by negligence. These men will step forward, medals on their chests, and they will lead the way, backed by the “selected engineers” who were on the committee, they will reconstruct. Your heroes of the horrible flood will be your leaders of tomorrow. They will decide where the funds are spent, and they will be well paid, not for acting on the committee, but for the design and expertise that they offer after the failure.

History is written by the victors. History is being written today. It shall have no similarity to reality. It shall be it’s own truth, a secondary truth. When those who caused a massive problem investigate themselves there can be but one outcome. We all know it immoral. We all know it a lie, yet, it is happening beneath our noses.

Scott Cahill

Oroville Dam – Dishonor is dishonor. It has no bounds

I am an odd type. I am a builder who cares deeply about water quality. The Feather River will, of course never be the same. The ecological mess that took place as a result of the failures of the spillways are horrible in scope and intensity.

The men who manage the fish hatchery downstream, wisely moved the fish. Other men saved some fish from the river. That is wonderful, and I thank them.

A long time ago, my company drained a federal park dam in a national forest. It was in a mountainous area. We opened the valve and we had been directed to let the fish die. The fish in the reservoir were not indigenous species, and they were to be replaced with appropriate fish.

I was trying to sleep in my hotel room, finally getting dressed and going to the reservoir in the middle of the night to do what I could to save, perhaps, a few fish. When I arrived, I saw lights. My entire crew, also unable to sleep, were in the mud in the middle of the night with buckets and nets and tarps, saving and carrying fish to the next impoundment down the watershed. I helped, driving the fish down and releasing them. We stayed up all night. No single man who worked for me on that job stayed behind. They were not paid for their time. There only compensation was saving some little life.

I was very proud and tired when morning came. I bought the muddy lot breakfast, and with coffee, we toasted the fish and turtles. None of us felt good the next day, except in our hearts. We love fish and turtles and things that crawl in the mud.

Today a friend forwarded this to me. I do not know if it is real or not. Nothing could surprise me with this comedy of errors.

Let us all hope this a hoax. If we are hiding more and more, where does it end?

Scott Cahill