From Watts Up With That?
News Analysis by Kip Hansen — 30 January 2023
There are claims that despite being flooded, washed away, landslided and buried in snow California is really still in drought. Cliff Mass says that The California Drought is Over. Definitively.
In Part 1 of this two-part series, I asked the question: “Is it possible that both claim and counter-claim are true?“ and answered, “Yes, very much so”. And I told readers how it could be so.
What is the drought situation in California now, as of this week?
If you’ve read Part 1 (and you really should), you will not be surprised that the answer to this question is:
It depends on who you ask
Mark Arax, who writes about California and water, penned an Guest Essay for the NY Times’ Opinion section with the title: “My State Is 1,000 Miles Long, and Not Everyone Living in It Hates the Rain”. The title gives his take on the rain and the whole piece, full of interesting history, is well worth reading.
The California Department of Water Resources just made the following announcement:
“Jan 26, 2023 — SACRAMENTO, Calif. –The Department of Water Resources (DWR) today announced that recent storms will allow the State Water Project (SWP) to boost deliveries to 29 public water agencies serving 27 million Californians. Based on the amount of water captured and stored in recent weeks, DWR now expects to deliver 30 percent of requested water supplies – or 1.27 million acre-feet — in 2023, up from the initial 5 percent announced on December 1.
The allocation increase is the direct result of extreme weather in late December and nine atmospheric rivers in early January that helped fill reservoirs and dramatically increase the Sierra Nevada snowpack. The SWP’s two largest reservoirs (Oroville and San Luis) have gained a combined 1.62 million acre-feet of water in storage — roughly enough to provide water to 5.6 million households for a year. While Water Year 2023 began with below average precipitation, conditions shifted to extreme above average conditions.”
Things to note: The water department has increased its expected water deliveries by a factor of 6 – they will deliver six times as much water. But even with that huge increase, it only comes to 30% of requested deliveries. (But that improves upon the miserable previous estimate of 5% of requested.) That represents the true condition of California’s water supply – demand is always far greater than supply.
As I explained in Part 1, drought is a very complex and complicated topic, and is not just “not enough rain recently”. There is no doubt that California’s drought situation has vastly improved – they got a lot of rain and a lot of snow in the mountains in the last two months. But we still cannot answer the question: “Is California still in drought?” because:
It depends on exactly what you ask and who you ask.
My solution to the conundrum of explaining California’s current drought situation is just to show images of various drought-related indicators from several sources. Readers are invited to arrive at their own conclusions. I am well aware that the physical reality on the ground in California will not change based on my or your opinions.
First, what is the long-term average precipitation in California?
This is the 30-year average, one climate period, showing the entire southwest U.S.A. I’ll pick out some features, as you need to be aware of this overall pattern to understand today’s California drought maps.
1) The Northwest-most corner of California, the purples, is a temperate rain-forest, receives over 100 inches of rain per year.
2) There are several regions, the blues, that receive over 50 inches of rain with darker blues being 60-70 inches per year.
3) The greens are moderately wet; southern Sierras, Big Sur region, the high mountains surrounding the LA Basin.
4) Guesstimating (everything browner-than-yellow) 80% of California is dry to very dry.
Today, if we ask the California Department of Water Resources, we get this answer:
Note: A 12-month SPEI version. About 50% of the state is in some sort of drought, still. The Colorado Desert, southeast-most corner, is still very dry – it got almost no rain in the recent storms.
The U.S. federal site, Drought.gov, gives us this most current view:
Note: This is current up to five days ago. Huge difference between this and the image just above from California Water Watch.
And again, Drought.gov, with its Multi-Indicator Drought Index (MIDI):
Still more disagreement – this shows even part of the Colorado Desert (lower right) as “W2” wet.
California’s stored water resources? Its major reservoirs:
After all that rain, why aren’t they all full? …or even up to historical averages (green lines) ? The first answer is exact location. Not all the rain fell evenly everywhere in California. Secondly, not every reservoir’s first priority is to retain as much water as possible – they double as flood control devices, and must not be full if-and-when more heavy rain comes. The general condition is that the reservoirs are in good shape. [ see the California Department of Water Resources statement far above ]
Remember, come April and May, the snowpack begins to melt, sometimes very rapidly. A very rapid snow melt causes the creeks, streams and rivers to flood — and the reservoirs must have room for all that extra water.
That leads to California Snowpack: (see link for larger image)
Statewide averages: 128% of normal for 1 April (end of the snow season – two months still to go in which to gain even more snow) and 214% of normal for this date. The Southern Sierra, which includes Mount Whitney, is at 255% for this date. This is water content, not just “feet of snow”. Skiers care about snow base depth, but the water department cares about water content.
If your interest is in skiing, see this report of snow depths at California ski resorts: almost all report snow depths of over 100% of normal 1 April averages – with two moths of snow season yet to go.
Now this one was a surprise even to me, the Palmer Drought Index for California. Take note of the explanation below the excerpted image (taken from the national map).
Groundwater is measured by vertical distance downward to the level to the top of the water column in a water well. Groundwater is very important to Californians, many of whom depend on wells for their home’s drinking water and for California’s farmers and ranchers, who pump water up from wells to irrigate crops or water animals.
Low in the image, just above and a bit to the left of Los Angeles county, is a concentration of pink dots indicating a water levels of greater than 500 feet down until water can be found. This is the southern San Joaquin Valley. In total, the valley produces about 13% of California’s agricultural output. Due to groundwater extraction over the last century, the valley floor has subsided by 20-30 feet (6 to 10 meters). (Note: After publication, I corrected the title of the image above.)
In speaking to a colleague recently, she presented Lake Mead water level as a “proof” of Global Warming/Climate Change. The Lake Mead watershed only includes a tiny bit of California.
That very small part of the Colorado Desert, within the Colorado River watershed, is below Lake Mead and does not feed into it.
As Cliff Mass clearly explained, and as is widely understood, Lake Mead’s low water levels are almost entirely down to the fact that water withdrawals keep increasing and always exceed water input to the lake. The two major reservoirs along the Colorado River, Lake Mead and Lake Powell, combined must supply water to over 40 million people. Phoenix, Arizona alone has added an additional 500,000 people since the turn of the century. Input into Lake Mead is highly variable and has been increasing ever so slightly.
I offer one last set of images: California Drought/Wetness since the turn to the 21st Century and the same for the last 2,000 years.
Using the eyeball test, we see that California has always been either very dry or pretty wet. A lot of extreme years, both dry and wet, and so many years in the +/- 20% range.
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It almost never suffices to grab some likely looking data set off the internet, bash it about until it is compliant, graph it up, and present it as the-truth-the-whole-truth….
Most of the subjects discussed on this blog just aren’t that way in the real physical world.
Like “drought in California”.
I’d like to read your opinions/conclusions, see any further data inputs you might suggest, and answer any of your questions if I can. Address your comment to “Kip” if speaking to me.
Thanks for reading,
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