Guest Essay by Kip Hansen — 10 November 2023
If you read a newspaper or watch or listen to TV or radio news, you have heard that the drought in the State of California is one or more of the following: finally ended; maybe ended; only seemingly ended; not ended at all. Worse than the confusion these apparently conflicting statements represent is the fact they are all true.
I could write you a thousand words supporting each of the scenarios complete with references and images from the various drought monitoring agencies and departments.
I explained the reasons for this confusing situation earlier in the year in a post titled Doubts About Droughts . According to Drought.gov “in the early 1980s researchers found more than 150 published definitions of drought, reflecting differences in regions, needs, and approaches.” In short, there is no single referenceable metric by which to determine if an area, such as the State of California, is in a drought.
During the last water year, California received a great deal of precipitation.
The rain and snow came not only from the atmospheric rivers in the above graphic, but from a rare tropical storm that came up through the Gulf of California — Hurricane Hilary – which dropped inches of rain on the deserts of Southern California and Arizona/Nevada.
How much precipitation?
So, 141% of the historical average for rain, and 237% of the historical average for snowpack. That’s a great deal of extra water for a state that is generally dry. Generally dry, you ask?
The following image shows the Köppen climate types found in California. All of California consists of types described as dry, hot, desert, semi-arid, or Mediterranean, with the exception of the High Sierra, which are “dry-summer subarctic and tundra”. California’s very long-term climate is dry and warm-to-hot. It is natively dry.
On a personal note: I have recently returned from a trip to southern Italy, Greece, Crete, Rhodes, Cyprus, and Turkey – and they have Mediterranean climates and they are dry and dusty but with a two-month rainy season. Physically, they look very much like the rolling hills of Southern Californian deserts, complete with broad arroyos that flood when it rains. Scrub brush and cactus grow there.
The Köppen types tell us that California does not need a drought to be dry. It has been dry for a very longtime. And, it is expected, climatologically, to stay dry. If California suddenly switched to the climate of the U.S. corn belt, which is Köppen type Dfa — D (Continental) f (No dry season) a (Hot summer) – that would be climate change. But hot/warm and dry is normal and is not a change at all.
So why all the fuss when California is dry for a year or two or three? Why cry “endless drought in California”?
“Half of all fruits and vegetables grown in the U.S. come from California, and the state effectively produces all (at least 99 percent) of America’s almonds, pistachios, pomegranates, and walnuts. California is also the nation’s leading grower of lima beans, lemons, kumquats, raspberries, strawberries, and spinach…” [ source ]
California is the most populous state with over 39 million people making their home there. The Greater Los Angeles/San Diego Megalopolis, alternately the Southern California Megaregion, alone has 23.76 million residents.
Agriculture and people consume a lot of water.
On the Köppen map above you can see a horizontal line that goes right across the state, right up near the top of the image. That line is made up of three county northern borders but can be considered the line separating Southern California from the rest of the state (opinions vary…). What climate type prevails in Southern California with its approximately 24 million people? The red and pink areas ( BWh and BWk) are outright deserts. Brownish and tan areas are “arid” which means dry (BSh and BSk). The remaining two, yellow and greenish-yellow, Csa and Csb, are mediterranean climates which typically have dry summers and wet winters, with summer conditions ranging from warm to hot and winter conditions typically being mild to cool.
As seen from space:
The greenish coastal hills are brush covered and dry most of the year. There are pine forests in the higher elevations in the mountains around the Los Angeles Basin but these forests are hot and dry during the summer too. That encouraging looking great big lake, center bottom, is the Salton Sea – salt water like the Dead Sea in the Middle East. But the green areas extending to the north and south of the Salton Sea are the Imperial Valley, an important agricultural area for irrigated crops (using water from the Colorado River). The rest is, as it appears, a great big desert.
California has reservoirs for two reasons: 1) To store rainy season water for the rest of the year – for drinking and agriculture and 2) As flood control infrastructure. Here’s the current (as of 9 November 2023) conditions of the state’s major reservoirs:
The good news is that most reservoirs are above historical averages – which only means that they have not been drawn down by the demands of this past summer. Of course, they mustn’t be kept too full, as the rainy season is coming and an overfull and overflowing reservoir is worse than an almost empty reservoir. [see here and related Oroville Dam stories from Spring 2017 – and the disaster in Libya in September]
And finally, pay almost no attention to mass media and governmental sources showing images from Drought.gov:
Most of the mass media have been touting the one labelled “U.S. Drought monitor: California” (lower left) which shows no drought, just a little “abnormally dry”. But the Long-term Multi-Indicator Drought Index (top left) shows much of the state wet and maybe too wet. The Short-term Multi-Indicator Drought Index is a mixed bag. And the 1-week change map shows no change.
Take your pick.
One thing we can be sure of is that California is better off to have had the rain and the snow. But can we say that “The Drought” is over? Not exactly clear, is it?
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Author’s Comment:
I grew up in Los Angeles and am familiar with the climate there. My brothers and I sailed Tom Sawyer-style rafts on the lake where our local park was usually found — a lake that formed when the heavy winter rains came. When those rains came, sometimes houses would slide down the slopes into the canyons, arroyos would flood and wash out roads and highways, and the drainage ditches – designed to carry away the flood waters — would fill and the water would flow into the sea. Almost every year. One year a bunch of us “hippies” from UCSB went down to Carpenteria to fight the flooding.
The rest of the year was hot and dry – every year the brush on the hills somewhere above Hollywood and Malibu would burn and fill the air with smoke, adding to the smog.
If you are still curious, go to the WestSide Drought Tracker and use the selection list on the left to cycle through all the many maps showing differing views of various drought metrics.
That’s a mediterranean climate.
Thanks for reading.
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