High and Dry: Reservoir Levels Tell Only Half the Story, Leaving California Dry as Drought Continues

, Former climate scientist | March 31, 2015, 8:43 am EDT
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You’ve probably heard about the California drought by now. If you live in California, it’s hard to hear about anything else. Unfortunately, the drought may be even worse than we realize, because the way we often measure water supply doesn’t consider future water availability. By relying on measurements of current reservoir levels, agencies in charge of water distribution are missing an important part of the water supply picture, leaving their customers vulnerable to longer and more severe droughts.


This blog is the third in a series on Climate-Water Disconnects, which profile key climate change planning failures related to water infrastructure.

Reservoir levels tell only half the story

One of the main ways that we measure our water supply is by tracking the state’s reservoir levels. As of today, reservoir levels are looking okay in a number of places. For instance, Lake Shasta, Lake Oroville, and Folsom Lake are more than half full. Lake Oroville and Folsom Lake are actually higher that they were at the end of March 2008 (which was also a dry year). But something is very different this year: the snowpack.

Snowpack is the largest water storage system in California, and as a water source we measure snowpack in terms of snow water content levels. As of today, these are looking very, very bad. Snow water content levels are well below the lowest levels ever recorded (in 1976-1977) and this holds true across the state. What this means is that, although the water levels in Lake Oroville and Folsom Lake are higher than during the last drought – there will be extremely little snow melt this spring and summer to refill them.

The problem with this is that many water providers use current reservoir levels to make decisions about water conservation. For instance, back in 2013 the Metropolitan Water District of Southern California announced that because reservoir levels were “high,” it would not reduce water supplies to local water agencies in Southern California or impose mandatory conservation measures. The District argued that it had more than two million acre-feet of water in storage at the end of 2013 (in addition to emergency reserves), should 2014 prove to be a dry year.


There will be extremely little snow melt this spring and summer to refill California’s reservoirs. Photo: Don Debold/Flickr

Climate change is intensifying drought

As we now know, 2014 was extremely dry and hot (the hottest year on record, in fact). And so far, 2015 isn’t any better.

Now, Metropolitan Water District is in dire straits, having drained its seemingly ample reserves. To make up for the shortfall, the water district is buying water from Sacramento Valley rice farmers—at such high rates that some can make more money selling water than growing rice.

While no one has a crystal ball, droughts are projected to intensify throughout the Western U.S. due to climate change and, according to NASA, we should expect “megadroughts” in the future. Hotter weather will continue to reduce snowpack, so that less snow melt is available in the spring and summer when it’s needed to refill reservoirs.

New tools are needed to forecast water supply

Clearly, new tools are needed to adapt to longer and more severe droughts. One of these tools should be a way to integrate data about snow levels into forecasts of reservoir storage. There is already information that integrates information about climate change impacts on snowpack, for instance the CalAdapt website has decadal projections of snowpack, but these are at a coarse-scale that makes it hard for water managers to downscale to their system. The U.S. Geologic Survey is currently developing modeling tools to characterize hydrologic processes relevant to changing snowpack and snow melt in five southern Sierra basins (Tuolumne, Merced, San Joaquin, King, and Kaweah basins), but more is needed and fast.

In the meantime, urban and agricultural water suppliers must take much more conservative approaches – it is no longer acceptable to plan as though next year will be wet. For instance, water suppliers should consider using only a fraction of available water supply this year in order to ensure some water is carried over to next year. If we don’t get better at forecasting our water supply beyond current reservoir levels, we might just be left high and dry.

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  • Todd Perry

    Yes we noticed you used NASA scam of climate change that was called global warming but they changed the name to try to continue that same old scam.
    Luckily most of the world knows it is a lie and will not fall for it.
    —Global warming / climate change is a lie and can and will never be proven as fact because all of the evidence has been falsified and can be disproven. This is why the power and oil companies, the politicians, writers and scientists in these companies back pockets would never ever agree to any kind of debate against the hundreds of scientists around the globe who have repeatedly proven it to be false. Some scientists has even tried to get these pro global warming / climate change scammers into a court of law debate with juriors and everything to prove that it is real but every one of them refused because they knew they could never prove it is a fact.
    —What is real and a fact is there is a climate shift which is a normal part of the planets life cycle that has been happening since the world was first created. For example Egypt used to be cooler, lush and green but over time it became hotter and drier and is now a desert and other parts of the world that used to be lush and green are covered in ice and snow.
    –Global warming changed to climate change to confuse the public is and always been a scam to pass carbon taxes and other taxes to make the corrupt oil and power companies, the politicians, writers and the scientists in their back pockets trillions of dollars at the expense of the public and is and has never had anything to do with saving the planet.
    —The real way to save the planet is for these scammers is to finally allow the proven alternate sources of green free energy out for the world to use and for these same people to stop cutting down every forrest to fill their wallets which is actaully destroying the planet.

  • Terry Holmes

    When I was a child campy movies like the Matt Helm and In Like Flint series, and TV shows like Batman featured science fiction themes, with lots of “mad scientist” types who threatened to control the weather. I now see presumed scientists who would deign to do the same. Not much distance between the old sci-fi and today’s climate alarmists.

  • Terry Spragg

    Our team has developed an easy, economic, verifiable waterbag transport technology that can deliver large volumes of water long distances through the ocean between any two coastal points on earth using large fabric waterbags connected into long trains with the world’s strongest zipper using solar or diesel powered drones guided by GPS. A YouTube video of a television news broadcast of a demonstration of waterbag technology can be seen at: http://www.youtube.com/watch?v=4TEJp6UZaDI. Additional information can be found in a Wikipedia article at: http://www.en.wikipedia.org/wiki/Flexible_barge or on our website at: http://www.waterbag.com. There is more than enough water on earth for all, but it is often in the wrong place and is difficult and expensive to transport. Our team has developed and demonstrated a solution that addresses these issues. I would like to make a friendly challenge to the members of the Union of Concerned Scientists to find a fatal flaw in our waterbag technology and/or our economics. We would be happy to respond to all serious inquiries. Additional information is available on request at: [email protected].

    • Much, much to small. that is only 2900 cubic meter, or tons of water per bag. A desalination plant can produce that much cheaper; which means with a smaller carbon footprint. Sorry.
      No, the solution has to improve the environment with use, there is such a way, we just don’t open our eyes to it.

      • Cliff_Goudey

        How much water do you need, PluviAL? Water transport by waterbag is a very scalable solution. Make them big, tow many, tow them often. Just decide how much water you need. You see, there is no shortage of fresh water on this planet, it is simply that it and our water use are not similarly distributed. Either move the water or move the people – your choice.

        The capital cost of a desalination plant is ridiculously expensive and can only be justified under a long-term contract for water production. But during years of rain do you continue to produce that expensive water or let the plant sit idle? In addition to the capital costs there are the energy costs associated with desalination, which, in the case of reverse osmosis, is equivalent to pumping that water to a height of 2,000 feet. We must pay for that energy and we must pay for the environmental costs the associated power plant. Those environmental costs circle around as additional climate change and more drought. Then there is the environmental costs on sea life of the intakes and discharges associated with a desalination plant. Why would anyone opt for that unless they are in the desalination business?

        The transport of water can be done for far less capital costs, far less energy costs, and far less environmental cost compared to desalination. Equally important, there are very few stranded assets to worry about if and when the rainfall returns.

      • How many gallons of fuel does it take to tow a bag to destination? If it is more than a thousand per bag, then your costs can not be better than RO, or FO. Still, you are talking about real available technology. My concepts are almost as simple, but the production rate is 7 bags a minute, maybe 14 or 21 bags per minute. Even Pluvinergy will produce 3 bags per minute. But then my concepts are just theories at this point, so all the best for your project. Wish me well too, we will need all the tools we can find.

      • Cliff_Goudey

        While the energy requirements vary with route distance, prevailing currents, towing configuration, and speed, let me assure you that in most instances fuel costs, even using conventional towing vessels, are a minor part of the equation.

        I looked at your website (http://www.pluvinergy.com/) and you’ve clearly put a lot of thought into the issue. I confess I was unable to follow, even at a high level, what you are proposing. That may be my failing, but I wonder what others here think. Based on what you said above, would not the removal of that water from the atmosphere mean less rainfall downwind, which is apparently one of the local manifestations of climate change in California.

        Regardless, good luck in your research endeavors and if successful, getting it permitted. In the meantime watch for a waterbag arriving at a port near you.

  • How about solutions, real solutions? Who is open to real solutions? As experts in science, we must accept the quest of seeking real solutions. But, the discipline of science requires us to limit the mind to the analytically supportable arena. Anyone who espouses intuition to find solutions is urgently ridiculed. However, it seems that the majority of the great breakthroughs are the product of combining analytical honesty with intuitive curiosity. Such intuitive exploration has its own discipline. Properly used it is a more powerful tool when challenged with intractable problems.
    The water, energy, and climate change issues are intertwined and so is the solution; solving one can solve the others. The challenge is to think on scale of the problems.
    For example: it is likely before 2050 we will understand that we have committed the earth to 40 mm sea level rise per year (4m/century). That is 2 Amazon rivers of water from the cryosphere into the oceans. Lifting 1200 kilometers of tropical air to precipitation each minute would produce this flow. Can it be done? Why not? The energy for the work is in that same air. If we did, what would we do with 2 extra Amazons? All soil moisture on the planet only requires 1.25 years of 2 extra amazons.
    What do we do with the extra 2 amazons for the next 99.75 years of a century? If we care to look, we can accommodate it. Doing so of course inverts the water problem, solves the CO2 issue, climate change, as well as the energy issue.
    As science experts, I say we can solve these problems if we set our minds to it.

    • 隖保罗

      The problem of deriving real solution is there are too many climate change deniers in position of influence and power. As long as there are those adherents professing “Climate Change” or rather the actual term “Global Warming” is voodoo science and doesn’t really exist nothing will ever change nor will real solutions come to fruition.

  • Richard Solomon

    The valley rice farmers are selling water they draw from wells. These wells are already severely overdrafted. So, MWD may be supplying its customers’ current needs but at a very big long term cost.

    The State Legislature recently approved a $1billion emergency intervention to try to lessen the impact of the drought. No long term efforts to develop alternative sources of water were part of that package. The State needs to admit that water resources developed in the mid 20th century are no longer adequate when our population has more than doubled since then and when, with global warming, we are probably facing permanent changes in our water supply. Things like desalinization for coastal regions of the state, greater reliance on recycled water, more treatment and use of sewage need to get developed pronto!

    • Si! Pronto! Pero: Those are disgusting, expensive, carbon intensive solutions, and wholly inadequate. We have got to think on scale of the problem. From my studies of advanced waste water treatment, and my work with QVEC, I can tell you this is really thinking small.
      I’m not suggesting this as a solution, but just to stretch the mind a little. There is sufficient moisture in the air in the lower coast of Mexico to produce two Amazon rivers. That is enough water to control sea level at 4 meters per century; if you had a place to put the water. (1200 km of coast, at 20 g absolute humidity, and 40 kph flow from Pacific.) That is looking at the problem on scale.
      We can’t place that much water on the American continent, but we can produce it. It’s no big deal. Its also a matter of thinking on scale. If you gave this task to NASA, they could solve it in 6 months. But we are not allowed, by the discipline of conventional, plotting, science to think that way. We would have to revive JFK, to get us to think so broadly.

      • Cliff_Goudey

        PluviAL, you make little sense. There are12,900 cubic kilometers of fresh water in Earth’s atmosphere. That’s less then 0.04% of the total amount of fresh water on the planet (the majority being locked up (we hope) as the Anartic ice sheet. And you want to somehow tamper with that atmospheric water to do what?

        By contrast, 107,000 cubic kilometers of rain falls on the continents each year and within 2 to 6 months most every drop returns by way of our rivers to the ocean to become salty and begin again the water cycle. So if you want to think big, then think about intercepting a portion of that fresh water before it hits the ocean and move it to where people, agriculture, and industry need it.

      • Yes, an that water in the atmosphere at any one moment will run the Amazon for 17,145 hours. And it is replenished constantly. This means the atmosphere has more fresh water than you will ever need. It also has all the energy, 2.5 million terawatts per km3. So, it also has all the energy we will ever need.
        We should plan on the assumption that we have already committed ourselves to cryosphere degradation, it is only prudent. If by some miracle we don’t get 1 to 4 meters of sea level rise per century we can be happy, if we do, as seems most likely, then we will be ready for it.
        I agree with you, it would also be wise to divert rivers that wash into the arctic to forestall or help to delay the slowing of the Gulf Stream, if Greenland melts catastrophically as is likely.
        We already broke the system, not accepting responsibility to fix is just different kind of myth-based denialism.

      • Cliff_Goudey

        Water is already being removed from the atmosphere – it’s called precipitation. Any human activity that removes that water upsets the natural water cycle and, like cloud seeding, happens at the expense of others. Less atmospheric moisture means less clouds. Less clouds means more global warming. I’m wondering if you’ve fully examined the consequences of your scheme.
        Otherwise, I agree that we are at a point where drastic thinking is needed to avoid the hugely expensive and disruptive consequences of our present day energy practices.

      • Yes, I have been considering this from all angles for the past 15 years. You are right that we have to think systematically about the operation of the global atmosphere if we are going to use it. Water is the largest global warming gas factor in the atmosphere, that’s sort of saying what you said. We can have both, in fact, we can cool the atmosphere or warm it with the water regime we select, when we have tools to work with the atmosphere at its scale.
        For example, we can remove moisture on the west coast of Mexico, with little or no effect to pacific precipitation. If we removed 10% of what is needed to control SLR, we will reduce cyclone activity in China and the Philippines, etc. The other 90% is reduced in other parts of the globe. But that is down the road, after we have studied the tools well, and can direct wasted cloud cover to the proper level, per your concern.
        The problem will become cooling the planet too much. It could be a puzzle if the gulf steam is interrupted, by SLR from Greenland. Then, we would have to target warming the planet around Europe, but cooling it elsewhere; in which case your concern is critically important.
        Although you are right, we have to proceed with such tools, we have no choice, and no time.