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Latest On California’s Drought

October 12, 2016

By Paul Homewood 




Now that NOAA data for September has been published, we can look at Californian precipitation for the last hydrologic year, which runs Oct to Sep.

Total precipitation in the last 12 months ended up slightly above average. Prior to this, there was a run of four particularly dry years.

Maybe one reason why the recent dry spell has appeared to bee so pronounced is that the state had a number of unusually wet years in the 1980s and 90s.

But looking at the longer term trends, there have been similarly dry spells, notably in the 1920s and early 30s.





Reservoir levels across most of the state are either at or close to average.




New Melones is the one which is significantly down. Yet, during the 1976/7 drought, it was effectively empty.


ScreenHunter_4682 Oct. 12 13.22 image 



Statewide, reservoirs are 82% of the historical average, compared to 36% in 1977, based on September numbers.




California could certainly do with a couple of years of good rainfall, but things now appear to be manageable.

  1. Bloke down the pub permalink
    October 12, 2016 4:49 pm

    There are of course a number of ways of defining a drought and I suspect it will take a number of years of above average rainfall to turn all of them in to positive territory.

  2. October 12, 2016 5:32 pm

    Since 1970, California’s population has increased 84%. It reservoir capacity has increased 28% in a state that depends heavily on Sierra snowpack meltwater. Self inflicted wound. Since 1970 there have been 5 periods of multiyear below average precipitation, as shown on the first chart.

  3. John Ellyssen permalink
    October 12, 2016 8:20 pm

    While these stats are true, the fact still remains that the state is still in drought conditions.
    In my area, we recently upgraded from watering lawns from 2 mornings/nights a week to 3 days a week, but many reservoirs are still very low. We normally get 14 inches of rain per year, and this year while slightly better than the prior years was still only 6.5 inches. This is based on over 100 years of rain records.

    • John F. Hultquist permalink
      October 13, 2016 2:58 am

      Here in Central Washington State we get about 8 inches of precip per year. I water fruit trees, garden plants, and a few flowers. This year Dahlias and Gladiolus. These we take to people or places (Senior Center or such others) and they are much appreciated. I don’t water grass. It does not impress anyone.

  4. October 12, 2016 8:26 pm

    ‘California now imports 33% of its electricity supply from fast growing neighbors, with about 65% of that coming from the Southwest and 35% coming from the Northwest. These numbers increase most in summer months when air conditioning loads peak.’

    ‘Back-up from elsewhere’ is the model for most places that want to go mad on renewables, unless they have a very high percentage of hydroelectricity in their systems already e.g. Norway and parts of Canada.

  5. John F. Hultquist permalink
    October 13, 2016 2:50 am

    There is a massive Low system moving toward the middle part of the North American coast. Depending on just where it is centered someplace from B. C. to Oregon is going to be in a very sorry state by Sunday the 16th. CA is likely to have the tail of this storm pass across it and by this time next week the reservoirs will be higher.
    In case anyone wants to blame this on global warming — it has happened before, notably in 1880 (the Great Gale) and 1962 (Columbus Day storm).

  6. tom0mason permalink
    October 13, 2016 3:33 am

    Considering that California is a natural desert area, people should be not be that surprised that it goes into a drought condition every now and again. It amazes me that only through the ingenuity of man so much of California is habitable.

    Here’s a view from the people at Mono Lake

  7. October 13, 2016 3:39 pm

    Don’t get me started on our arcane water release policies. Folsom Lake would be substantially higher were they not releasing the quantity of water in Feb/March sufficient to raise Lake Tahoe by four inches each 24-26 hours–and it was simply running into the sea.

  8. TonyM permalink
    October 15, 2016 2:15 am

    Quite amazing. Computer models that have been 100% unsuccessful in predicting temperature can now predict the number of wildfires. Magical!

  9. AZ1971 permalink
    October 16, 2016 3:32 pm

    The reservoir level will be interesting at next week’s reading once the current storm plowing its way through the PNW is finished. I saw reports on the TV that 12-18″ of rain was expected along California’s northern coast, and all that water has to end up going somewhere.

  10. October 30, 2016 8:43 pm

    Reblogged this on Climate Collections.

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