When It Rains . . .

Note: this is a long overdue post about the Oroville Dam crisis. Since I didn’t have time to write about events as they unfolded, this is a long post and one written in small chunks as I found time to write.

Thought I might follow-up on my hasty post a few weeks about the dangerous situation at the Oroville Dam. As my Facebook friends know, I’ve been obsessed with the failure of the spillway, the erosion caused when the emergency spillway was put to use for the first time in the dam’s history, and the subsequent problems as the water moved downstream. This obsession results from the fact that the possibility of the demise of the Oroville Dam was a major concern during my early years as a child growing up just south of the dam.

The Oroville Dam began operation in 1968. I was in kindergarten, and my Dad took me and some of the family to the opening ceremony. I don’t remember much about the ceremony itself, but I do remember it was hot and my ice cream cone melted so fast my scoop fell off before I had much of a chance to taste it. I also remember my Dad telling me about the construction of the dam and what could happen if it failed.

water_if_collpseThe potential for failure was a common topic of conversation for a while: “Wait until there’s a good size quake; then we’ll know if the thing is sound or not.”  In school they added what to do if the dam failed to the list of prepatory drills: fire drills, earthquake drills, nuclear bomb drills, and now dam failure drills. What I most remember about the dam drills was the directive “get to high ground” and “get up into the Buttes(the white area in this image) if possible.” It wasn’t a duck and cover drill because desks and tables weren’t going to stop the wall of water headed our way.

After a number of earthquakes and the passage of time, most of us stopped thinking about the threat of collapse and took advantage of the dam construction by visiting the salmon ladder to watch the tired, battered, and scared salmon make their way up and around the dam so they could reach their spawning grounds, visited the hatcheries and paid a nickel to feed the little fisheys, and fished, skied, boated and swam in the massive lake the dam created. In school I learned about the construction of the dam, it’s designation that I remember as “the largest earth-filled dam in the world,” and the floods that were common in the area before it’s construction.

All of these memories came rushing back on February 7th when the Department of Water Resources increased releases down the main spillway to prepare for incoming storms. 3D2C831600000578-4226368-The_problems_The_crisis_was_sparked_when_authorities_stopped_all-m-58_1487256590028When the water  reached about 60-thousand cubic feet per second, which is nearly 200-thousand less than the spillway should be able to handle, a hole formed in the concrete.

They stopped releasing the water so officials could examine the hole, but they had to resume releases again on Wednesday, February 8, because Lake Oroville was rising

emergency_spillway

Water flows over emergency spillway

too quickly.The goal was to release enough water to avoid using the emergency spillway. Then on the  morning of Saturday, February 11, water started spilling down the emergency spillway as the lake reached 901 feet. It’s important to note that this was the first time water flowed over the emergency spillway in the dam’s 49 yr history.

The water was rushing down the emergency spillway caused the hillside to erode, and the Department of Water Resources and federal and local officials feared it would collapse and send uncontrolled water out of the lake and down the river to homes and businesses.Late in the afternoon, the  Butte County Sheriff’s Office mandated an emergency evacuation of people in Oroville and Thermalito. Evacuations soon followed for those living near the Feather River from Oroville down Hwy 99 through Gridley, Live Oak, and Yuba City. Areas of Marysville, Linda and Olivehurst were also evacuated.

Keeping a close eye on the damage, the Department of Water Resources began releasing 100,000 cubic feet of water per second down the main spillway which was still damaged

la-ltimesheaviest_release

and would likely sustain even more damage as water was released. Down the Feather river folks patrolled the levees looking for seepage, boils, and threats of breaches. Although the the Feather river reached dangerous levels, damage was limited to localized flooding and a levee breach at Manteca. A week later, and as soon as a series of storms passed and Lake Oroville reached what the Department of Water Resources believed to be an acceptable level, they shut down the water being released from the dam to assess the damage.

spillway_perspective

See the people just above for perspective

As you can see, the damage is massive. Much of the spillway is gone, there is massive erosion, and rebuilding the spillway will take months and millions of dollars.

Both the massive amounts of water released and the sudden cut off the flow from the dam has also wrought damage down stream.On February 28th, California state biologists began working near the dam and discovered the release of water into the Feather River had been throttled back so quickly that there were dry sandbars, small puddles of water, and dead and dying fish wherever they turned. Although federal fisheries regulators had urged the Department of Water Resources to taper the spillway releases more gradually to prevent as many fish from

SECOND_RP_FISH_RESCUE_Sac_suckers

No salmon in this shot

getting stranded; DWR agreed to try but noted haste still had to be a priority because they needed to take advantage of the break in the wet weather to assess damage and bring in heavy equipment to repair what they could before another storm arrived. While that work proceeds, state biologists will probe every little pond along the river channel in the hope of recusing fish. In just one pond that formed in 3 inches of water, biologists rescued 23 baby Chinook salmon.

So here’s where things now stand: we have massive damage to the spillway and around the emergency spillway, levees that need to be strengthened and at least one breach that riverbanksneeds to be repaired. And today I learned riverbanks are collapsing along the Feather River. The possibility of more storms, of course remain, and we’ve yet to see what the melting of 180% of normal snowfall in the Sierra will bring.
Within a few months, the problem of five or more years of too little water in California has become a problem of too much water. Perhaps you saw some of the many photos of Lake Oroville reduced to a small stream like this one from August 2016. august_2016Something we might want to think about as SCROTUS undoes all the regulations President Obama put into place to slow down the ravages of climate change.
The rapid change from drought to deluge shouldn’t be a surprise according to Noah Diffenbaugh, a climate scientist at Stanford University. As a recent report on NPR notes, he says “California is likely to see more extreme flooding with climate change. And the reason is pretty simple. If it’s warmer, storms produce more rain instead of snow.” Among other problems, though, is the fact that California’s water system, designed a century ago,  was built, in large part, around the snowpack in the Sierra Nevada. The good news is that right now the state’s flood system can handle that slow melt; what it can’t handle, as the events in February made painfully clear, is a tremendous amount of rain all at once. Or, as Diffenbaugh puts it “Our water system was really built in an old climate [and that’s] a climate that is no longer the climate of California.” UCLA professor Alex Hall agrees. In a February lecture at Fowler Museum last, Hall shared his current research  which
predicts temperatures in the Sierra Nevada will rise up to 10 degrees by the end of the century if nothing is done to stem carbon emissions. More precipitation will fall as rain and snow will melt sooner—changes that California’s aging infrastructure is ill-prepared to handle.

Hall says, in fact that changes in “Sierra water resources may pose the most formidable—perhaps existential— threat” of all climate change effects in the state. It’s important to note, of course, some climate change effects are already being felt. Hall examined Sierra snowpack from 2012 to 2015—the peak of California’s recent severe drought, and found that without carbon emissions and a period of warming that stretches back to the start of the industrial revolution, there would have been more snow on the ground.

But Hall isn’t just worried about California. He argues that if we continue with business as usual, “Sierra Nevada and global climate will be unrecognizably different.”

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One Response to When It Rains . . .

  1. Pingback: Oroville Dam Crisis | Thinking it Through

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