By Jay Lund
Wet. After five years of drought, most of California finally has become wet. The mountains are exceptionally wet and covered with snow. The state’s reservoirs are fuller than their long term average (with a few exceptions). Flood control structures are being employed, some for the first time since 2006.
We can now better understand the balance needed for California’s water system – which must operate for many sometimes-conflicting purposes in a climate with wild swings in water availability. Every year, California must operate for drought, flood, public and ecosystem health, and economic prosperity (or at least financial solvency).
Where is California’s Drought today?
Here are today’s numbers:
- Sacramento Valley precipitation – 201% of normal (for this time of year), 113% of average water year total
- San Joaquin Basin precipitation – 206% of normal, 110% of average water year total
- Tulare Basin precipitation – 205% of normal, 106% of average water year total
- Southern California – Mostly more than 150% of normal
- Statewide snowpack – 171% of normal, 110% of average April 1 accumulation
- Reservoir storage – 110% of normal, statewide
- Lake Cachuma (near Santa Barbara) – 16% of normal (the drought remains here)
2017 will not be a surface water drought for California. Precipitation and snowpack in much of the state already exceeds that for an entire average water year. And we still have two months to go in California’s wet season.
Despite these wet conditions, California has remnants of drought, some of which will persist for decades. Some Central Coast reservoirs remain very low. Groundwater in the southern part of the Central Valley remains more than 10 million acre-ft below pre-drought levels. Most of the groundwater deficit is in dry parts of the San Joaquin and Tulare basins, which could take decades to recover – with long-lasting effects on local wells. The millions of forest trees which died from the drought will need decades to recover, if the warmer climate allows. Native fish species, already suffering before the drought, are in even worse conditions today.
Drought indicator myths
Given the variety of drought impacts and conditions, many “drought indicators” seem Quixotic and distract policy and management discussions.
The US Drought Monitor is a common drought indicator, based mostly on soil moisture – designed mostly to indicate drought for rain-fed agriculture. This index is most useful for stress to forests and un-irrigated pasture and crops, which are not California’s biggest drought issues. California relies much more on large reservoirs and aquifers, which allow crops and cities to survive California’s otherwise beautiful and devastatingly dry summers. The US Drought Monitor, while a convenient general public service, is misleading for California’s most common drought issues. National statistics often have such regional problems.
Still less useful, in my mind, is the idea of a “snow deficit” accumulating over drought years. Snowpack in California physically resets to zero each summer as snow melts – Accumulating snow deficit over years has no physical meaning – and little management meaning. Real drought deficits do accumulate as aquifer overdraft, reservoir drawdown, dry soil, and cumulative impacts to forest and fish populations, which can take years or decades to recover. Less snow last year does not reduce water this year except for reduced storage in reservoirs or aquifers – where water deficits are managed and more properly measured or estimated.
Drought indicators should have physical and management meaning, or are more likely to mislead and confuse. Fortunately, California is more successful with managing droughts than developing drought indicators.
Although the drought is largely over, California remains a dry place. As a big dry place, some parts of California can be in drought while others are in flood (contrasting Santa Barbara and Sacramento today). Local and regional effectiveness and adaptability are vital for water management in California.
The end of drought does not solve California’s most important water problems. Groundwater sustainability (implementing SGMA), Sacramento-San Joaquin Delta sustainability, effective ecosystem management, and fixing rural drinking water systems remain major problems. Solving these issues involves difficult water accounting, integrated management, and finance issues at local and statewide levels.
Progress on these long-term issues is harder and requires more persistence than making progress during the urgency of a drought. But we should reserve “drought” management for unusually dry conditions, or risk losing the public confidence that democratic governments and effective water utility management require.
Leaving the drought, California has a clearer picture of the important work that remains to be accomplished. The next drought (and flood) could be coming soon.
Jay Lund is a professor of civil and environmental engineering and director of the Center for Watershed Sciences at UC Davis.
Some further reading
The banality of California’s ‘1,200-year’ drought
You Can’t Always Get What You Want – A Mick Jagger Theory of Drought Management
Is shorting fish of water during drought good for water users?
Lund, J., “After drought, California urgently needs to focus on big picture of water management,” Sacramento Bee, Op-Ed, 29 January 2017.
Great article… I agree Drought word should be reserved to when CA actually needs to be concerned.
Cachuma is the next Owens Lake? Where Santa Barbra extracts water from the Santa Ynez River in 3 places which makes the last Reservoir Cachuma left with little to no water. The following view of the Santa Ynez and diversions is a great view:
Cachuma drought or better it’s water shortage is caused by bad water management and over drafting like LA did and continues to do at Owens (dry) Lake.
Now is the time to restore the Owens Dry Lake…
But wait!! We’re building a bullet train!! That will help right? Unsustainable building like what is going on in LA county is more of what we need….yeah that’s right, more homes to use more..uh water. The money spent on this stupid bullet train should be used to help get the water runoff that doesn’t go to reservoirs sent to the settling ponds to help the aquifers. Until it is proven that we can sustain more people a halt to building whole towns like LA county is planning in Santa Clarita. California is prone to droughts PERIOD…I’ve lived here for 62 years, my fathers grandfather moved here in 1889. There have been droughts every decade I’ve been alive and there droughts almost every decade since our family has lived in California. Stop trying to make it sound like it’s something out of the ordinary…..southern California is desert and Mediterranean climates…mostly desert.
Jay – I could not have said this better. It’s exactly the message that we have been giving the Governor and the State Water Board for more than two years now. You should have added to your paragraph about the ongoing water management issues the statement that none of them are addressed by the emergency conservation regulations. Groundwater depletion will require implementation of SGMA and more, ecosystem problems will need creative approaches such as the Nigiri project or all of the habitat restoration projects underway in the Sacramento Valley and localized drinking water shortage/pollution problems in rural communities in the San Joaquin Valley will require a collaborative approach among the State water Board, Counties and local agribusiness.
What about below surface ice like rock glaciers? Or single year ice?
Did you see James Kirchner’s talk at AGU 2016. H11D-02: The pulse of a montane ecosystem: coupled diurnal cycles in solar flux, snowmelt, evapotranspiration, groundwater, and streamflow at Sagehen Creek (Sierra Nevada, California) (Invited)
Total glacier volume in California is about 110 taf, compared with mean annual runoff of about 75 maf and surface reservoir storage capacity of 42 maf. Essentially no statewide overyear water storage in the solid phase.
“Accumulating snow deficit over years has no physical meaning – and little management meaning.”
Disagree. The physical meaning of snow is delayed runoff. If the Carbon believers are significantly correct (I am skeptical), the management implication is very clear and very difficult to resolve. If the runoff delay diminishes, the buffer between flood management and appropriate water storage diminishes as well.
So far so good this year. The banal 1200 year inevitable Carbon desertification is clearly quashed. Snow is staying in the Sierras as it should.
Rejoice! Get over the cabin fever. This is how groundwater accumulates in California. BETWEEN the droughts.
Better duck, as you just said something that will make the climate changers jump all over you. I was born and raised in California, since I was born in 55 there has been a drought every decade. The last one being the worst since I’ve been alive but not the worst by far.. oops, now we’ve just had one of the wettest winters, everything seems to even put in the end.
Thanks for the warning Kriss, but I am a not new to the fray. The important thing to my mind is to keep the dialogue going. In far too many venues dissent is silenced. I was banned from weather west recently when I took a notion to respond to the harpies you describe. Purely scientific rebuttals, no violation of policy; merely the temerity to point out that Daniel’s prediction of continued drought was off the mark.
Jay Lund is a true scientist, and I don’t want to venture off topic any more; the spirit of science is to preserve dissent and dialogue.
Well I’ve got good company then as I was banned from WW for something very similar.
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“The millions of forest trees which died from the drought will need decades to recover” …. hmm, this should prove interesting!
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Any chance of what this means for all the new water banks that have popped up beyond the old core Kern area since we last had a year like this? I’d be interested to see a post at some point about whether they are actually getting good access to some of the surplus surface water we have this year and what the magnitude in groundwater change is near water banks versus away in the San Joaquin valley. Anybody trying some sort of study on this at Davis? Obviously early in the year and water bank data is notoriously tough to get a hold of, but thought I’d ask.
Still under emergency drought rules…
For reference: Folsom has now released 2 MAF this water year (above what’s been stored, above normal releases); Shasta 1.3 MAF, and Millerton 0.5 MAF…Lots of water…No new storage…But plenty of evergreen regulation > THAT is why CA refuses to manage water. It gives authorities power, even in a deluge 225% of normal, even w snowpacks 110-140% of APRIL 1st, mudslides, broken dams, flooding…all CA gets is regulation. People should wise up and stop being naive.
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