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NOAA & The Oroville Dam

February 15, 2017

By Paul Homewood


h/t Oldbrew




NOAA have a good account of what has been going on with the Oroville Dam:


As mentioned previously in the Event Tracker, California is going through one of its wettest water years (October – September) on record. In particular, precipitation so far in 2017 is on a record pace for northern and central California. While the water has been a godsend in reducing and relieving drought conditions, it also has been too much of a good thing as flooding has resulted. One case in particular is the ongoing emergency at the Oroville Dam north of Sacramento. Tremendous amounts of precipitation have led to the Lake Oroville reservoir—the second largest reservoir in the state—to fill past capacity.  The need to funnel water out of the reservoir and accompanying complications has led to flooding concerns and evacuations below the dam.


Oroville Dam, Flooding, rain

(top) Aerial view of the Oroville Dam on June 23, 2005. Photo Paul Hames, California Department of Water Resources. (bottom) Water gushing through a gully on river left of the primary spillway on February 11, 2017, following severe erosion on the paved portion of the ramp. Photo by William Croyle, California Department of Water Resources


The whole piece is worth a read as it is short and to the point. But the interesting bit is this graph:


Oroville Dam, reservoir, inflow, rain, flooding

Daily average inflow to Oroville Reservoir from January 1, 1995, through February 13, 2017. Recent inflows were the highest since 1997.


It shows that inflow to Oroville so far this year is far from unprecedented, with a much greater total in 1997.

And we can see from the state rainfall totals that January 2017 was nothing special:





But none of this stops NOAA from concluding:


Events like this are a reminder that in a warming world, in which heavy downpours are expected to increase (IPCC AR5) as greenhouse gases continue to rise, having resilient infrastructure will become even more important.


Oh well, we can’t win them all!

  1. Jack Broughton permalink
    February 15, 2017 11:14 am

    It was the “Fear of Climate Change” that made them over-fill the dam. The fear is costing trillions and many lives now and the situation is still deteriorating.

    The lives lost from the mass evacuations are of course hard to quantify, but it is becoming increasingly clear(California and S. Australia recently) that the “Fear of Climate Change” does not just cost vast sums of money, but lives too.

    • Gerry, England permalink
      February 15, 2017 1:54 pm

      Will they be worried by the loss of lives? Surely their plan is about population reduction by making life more difficult for everyone.

  2. Martin Brumby permalink
    February 15, 2017 11:21 am

    If, instead of spending trillions on ‘solutions’ (that may be buttock clenchingly expensive – but don’t really work) to problems that don’t really exist (or are at best insanely exaggerated); if a fraction of that money had been spent on “resilient infrastructure”, might we not be better off?
    Only asking…..

    • February 15, 2017 1:11 pm

      Yes. A job as a Donald Trump speechwriter awaits 😉

    • Gerry, England permalink
      February 15, 2017 1:55 pm

      Yes, adaption and mitigation are much better value and successful than trying to control something you can’t.

  3. Don B permalink
    February 15, 2017 12:12 pm

    For more evidence that the current situation is within the bounds of natural variability, look at the flood of 1861-62. Following twenty years of drought, California suffered through 6 weeks of torrential rain much more devastating than this years rain. That type of flooding has occurred every 100 to 200 years.

    “In 1861, farmers and ranchers were praying for rain after two exceptionally dry decades. In December their prayers were answered with a vengeance, as a series of monstrous Pacific storms slammed—one after another—into the West coast of North America, from Mexico to Canada. The storms produced the most violent flooding residents had ever seen, before or since.

    “Sixty-six inches of rain fell in Los Angeles that year, more than four times the normal annual amount, causing rivers to surge over their banks, spreading muddy water for miles across the arid landscape. Large brown lakes formed on the normally dry plains between Los Angeles and the Pacific Ocean, even covering vast areas of the Mojave Desert. In and around Anaheim, , flooding of the Santa Ana River created an inland sea four feet deep, stretching up to four miles from the river and lasting four weeks.”

  4. Tim Spence permalink
    February 15, 2017 12:16 pm

    Is it that they didn’t want to use the emergency spillway because it was broke? and so they took the chance that the outflow would ease off if it stopped raining.

    Or was there another reason why they allowed the dam to reach 100%, (something that they should not do, even in the noble cause of fighting man made climate drought)

    Whatever the reason, the inflow graph shows this occasion was badly managed.

    • February 15, 2017 1:57 pm

      The Oroville main spillway was significantly damaged forcing (?) the dam operators to reduce flow to prevent more (catastrophic?) damage. Why not? The emergency spillway is rated at 250,000 CFM, right?. When the e-spillway was used it received significant damage at much lower than rated flow.

      I can’t really call emergency evacuation of 188,000 people a good thing, however, if the dam survives the rains this week, the state and feds might be forced to upgrade the dam to handle rains that routinely (in geologic time scale) occur in that part of the country. A well timed disaster can sometimes prevent catastrophe.

    • Gerry, England permalink
      February 15, 2017 1:58 pm

      The emergency spillway is difficult to see. It just looks like earth and scrub. I have read something about it not being maintained either and is blocked with vegetation. Their fear for the emergency spillway is erosion. I presume the emergency one is just an overflow with no control in case somebody forgets to use the spillway to control the level.

      • February 15, 2017 3:05 pm

        If you look around for a video of the repairs being made, they are in the area to the left (looking at the dam) of the standard spillway, but the right of the emergency one. The flow over the emergency one was basically eroding UNDER the standard one, were this to happen for too long, there could be a scenario in which the standard spillway failed completely and water simply flowed straight out the lake, uncontrolled.
        Also on the left of the emergency spillway you can see an area where the water appears to be scouring a large trough directly in front of the concrete ledge. If this were to cause the collapse of the emergency spillway, then the lake would empty 30 feet or so in a very short space of time, I think it is this that caused the evacuation.

        Not putting links in because there are plenty of pics/videos out there,


        PS Have commented this article in the Scientific American article comments linked above.

  5. February 15, 2017 12:28 pm

    The incompetence of organizations like NOAA, coupled with the hysteria of AGW is the cause of the current Oroville crises. Had honest work been done on climate, instead of torturing data to support a conclusion, this could have been avoided by simply acknowledging ignorance and also preparing for when the rains returned.

    Obama had a term that was used instead of the word Terrorism. It was “man caused disasters”. This may not be terrorism, but it is a man caused disaster.

  6. February 15, 2017 12:45 pm

    Reblogged this on Tallbloke's Talkshop and commented:
    Over forty years ago ‘climate scientists understood that global cooling causes extreme weather, and global warming causes mild weather.’

    Nowadays many of them seem to have ‘forgotten’ about that.

  7. Athelstan permalink
    February 15, 2017 1:21 pm

    Quite informative actually, useful stuff from NOAA but why do they have to drift into politicized mythology and speculative extrapolation fantasies – what is it about these Marxist propagandists, they just cannot resist, leave it alone – can they

  8. February 15, 2017 2:11 pm

    There seems to be a universal mission creep into right-on areas in all organisations in the decadent West, possibly not unrelated to diminishing competence in core activities. I could go on also about the modern Cult of Management, at the expense of technical expertise.

    BBC Radio 5 Wake Up To Money this morning gave itself over to a long (several minute) wail from a feminist about a business conference having only 10% female speakers, nothing was reported about the conference itself. What a joy it is to be no longer paying the BBC tax.

    • RogerJC permalink
      February 15, 2017 2:41 pm

      The amusing thing about the “Wake up to money” item was that following the low number of women speakers at the equivalent event last year a special call was made for women and ethnic minority speakers at this years event. Result – fewer women and no ethnic minority speakers this year! Better luck next year.

  9. February 15, 2017 3:31 pm

    I’ve been following Roy Spencer’s daily update on the situation. He seems to be well on the ball.

  10. Broadlands permalink
    February 15, 2017 4:25 pm

    Not a lot of people know that the 1997 El-Nino began in April of 1997 and peaked at year end…coinciding with the peak inflow to the Oroville Dam. Any correlation with CO2?

  11. Nick Dekker permalink
    February 15, 2017 5:49 pm

    I have designed a major dam and spillway, and it is obvious from the comments that most commentators do not know what they are talking about.
    When designing such structures there is an overflow design cut-off point dictated by economics. Normally in the UK you design for the once in an X number of years flood. To design for a once in a 200 years flood will obviously cost more than a once in a 100 year flood. By the way these are statistical flood estimates that may occur ‘ somewhere’ in the UK,
    But it is quite possible for the occasional ‘ catastrophic ‘ flood to occur somewhere and overwhelm even the best designed spillway.

    In this case however there seems to have been a failure in the engineering quality of the lower part of the spillway possibly because the energy dissipation provision has not worked. In such an important structure a model spillway would have been tested, and from what I can see from the photos the energy dissipation provision at the bottom end of the spillway all seemed a bit ropey. As you can imagine there is an enormous amount of water energy from these high water flood flows as the water has gathered speed going down the step slope of the spillway channel.
    Also no-one would ever have an ’emergency’ overspill that discharged on to a hillside.

    The bottom line however is that this is simply an engineering and water management problem, so why it is being discussed as a climate change interest is beyond me.

    • Robert Christopher permalink
      February 15, 2017 6:20 pm

      “… so why it is being discussed as a climate change interest is beyond me.”

      About eleven years ago the advice to improve the emergency structure was dismissed, because ‘Climate Change Science’ predicted its unlikely use:
      “In 2005, three environmental organizations—the Friends of the River, the South Yuba Citizens League, and the Sierra Club—warned federal officials that the earthen emergency spillway wasn’t capable of handling extreme flooding.”
      The Oroville Dam Crisis Exposes the Flaws in Trump’s Infrastructure Plan

      Less than six months ago, a distinguished professor of geography and of ecology and evolutionary biology who was an international authority on drought and climate change forecast for the area, said ‘That aridity is the new normal‘ (See the link in my post at 5:55 pm.) There was therefore little need to prepare for any excess water. The prediction was that the area would be arid.

      The current emergency is due to not doing work because of poor forecasting based on Climate Change Science.

  12. Robert Christopher permalink
    February 15, 2017 5:55 pm

    Quotes, with my emphasis, from above:
    But none of this stops NOAA from concluding:
    “Events like this are a reminder that in a warming world, in which heavy downpours are expected to increase (IPCC AR5) as greenhouse gases continue to rise, having resilient infrastructure will become even more important.”


    “As long as warming forces like greenhouse gases are present, the resulting radiative forcing can extend drought-like conditions more or less indefinitely, said MacDonald, a distinguished professor of geography and of ecology and evolutionary biology [Department of Ecology and Evolutionary Biology, UCLA].
    Radiative forcing in the past appears to have had catastrophic effects in extending droughts,” said MacDonald, an international authority on drought and climate change. “When you have arid periods that persist for 60 years, as we did in the 12th century, or for millennia, as we did from 6,000 to 1,000 B.C., that’s not really a ‘drought.’ That aridity is the new normal.””
    Pacific Ocean’s response to greenhouse gases could extend California drought for centuries

    EQUALS a fight between:

    ” heavy downpours are expected to increase (IPCC AR5) as greenhouse gases continue to rise”


    “Radiative forcing in the past appears to have had catastrophic effects in extending droughts”

  13. BLACK PEARL permalink
    February 15, 2017 7:13 pm

    Every weather event related report always includes a nod to a warming world being the contributing issue / cause. Its like listening to a sermon from the pulpit.

  14. February 15, 2017 7:25 pm

    What they don’t need is another repeat of one of these.

    Quote: An ARkStorm (for Atmospheric River 1000 Storm) is a hypothetical but scientifically realistic “megastorm” scenario developed and published by the United States Geological Survey, Multi Hazards Demonstration Project (MHDP). It describes an extreme storm that might impact much of California causing up to $725 billion in losses (most caused by flooding), and affect a quarter of California’s homes. The event would be similar to exceptionally intense California storms which occurred between December 1861 and January 1862.[1] The name “ARkStorm” means “Atmospheric River (AR) 1000 (k).”

  15. Bitter&twisted permalink
    February 15, 2017 8:00 pm

    NOAA- Never Obviously Admit Anything.

    Why tell the truth about climate?

  16. manicbeancounter permalink
    February 15, 2017 8:26 pm

    Extreme precipitation events are so common in California as a whole that there is a organisation for it, called the California Extreme Precipitation Symposium, with annual lectures on the topic. The 2012 lecture “The 1861-1862 Floods: Informing Decisions 150 Years Later” was probably the source of the Scientific American article. The 2015 lecture “California’s 1,000-Year Storms Since 1906” was given by someone from the California Dept of Water Resources who manage Oroville Lake.

    • Broadlands permalink
      February 16, 2017 6:16 pm

      What about organizing a California extreme drought symposium?

      California…1898 was the third driest year on record (1895-2015)…

      “The drought of 1898 was, if possible, more devastating in its effects than previous droughts except that of 1862-1864. The southern half of the state was most severely affected, grasses drying as early as March so that cattlemen were in search of northern ranges early in the year. Lacking grazing facilities or the ability to transfer their herds long distances to better pastures, cattle producers found their stock dying in droves before the end of the summer. Even in the usually humid Pajaro Valley in Monterey County cattlemen resorted to the felling of trees in order to obtain the moss and browse from their branches, Tulare Lake, which had been the succor of thousands of cattle during the drought of 1862-1865, went dry during the summer of 1898.”


  17. manicbeancounter permalink
    February 15, 2017 9:18 pm

    I actually think that the operators of reservoirs and dams have an extremely difficult job in terms of strategy. Most of the time you can use the artificial lake to control river levels downstream to both prevent flooding after heavy rainfall and to conserve water supplies. These two can go together. In arid areas there can be flash floods. The reservoir can prevent the floods, whilst capturing the waters to ensure water supplies. The problem is when there is extreme rainfall at the end of a drought. How fast do you let the flow rate increase against increasing the water levels? Let minor flooding occur when the lake is well below capacity and the authorities could be sued, or at least become the subject of political investigations if (as if usually the case) it turns out the controlled flooding was unnecessary. Go the other way, and maybe just one in a hundred times you will end up with the Oroville crisis or the Cockermouth Floods of 2009.
    Add “climate change” into to the equation and these decisions could be biased even further. This could have happened at the Wivenhoe Dam above Brisbane in 2012. Built to prevent serious flooding of Brisbane under extreme rainfall conditions, during a severe drought, which many alarmists thought would might be the signal a permanent change, the Dam was allowed to fill. So when the rains came this flood prevention measure was practically useless.

  18. Sheri permalink
    February 15, 2017 10:43 pm

    Interesting link I ran across:

  19. Cassio21 permalink
    February 16, 2017 8:52 am

    Plenty of useful information here:

    To make sense of the fast-developing situation at California’s Oroville Dam, Chris spoke today with Scott Cahill, an expert with 40 years of experience on large construction and development projects on hundreds of dams, many of them earthen embankment ones like the dam at Oroville. Scott has authored numerous white papers on dam management, he’s a FEMA trainer for dam safety, and is the current owner of Watershed Services of Ohio which specializes in dam projects across the eastern US. Suffice it to say, he knows his “dam” stuff.

  20. Gerry, England permalink
    February 16, 2017 1:50 pm

    And there looks like a lot more fun to come as weather modeling is showing an atmospheric river heading straight for them during the next 10 days. An estimate is that the rainfall delivered to the catchment area will raise the water level by 120ft. That’s a lot of water.

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