We’re finally coming out of a seemingly endless winter. The drought appears to be over. But, have we learned any lessons when it comes to our fresh water demands?
As we’re all aware, Governor Brown and various Southern California water user groups are working diligently to modify how water is transported from Northern California to Southern California. That plus declaring “a water emergency” appear to be Sacramento’s solution to water shortages in Southern California. The two biggest political efforts underway are to raise the height of Shasta Dam as much as 18 feet, and to dig two 40-foot tall tunnels beneath the Sacramento River to transport large volumes of water south without the water ever entering the primary Delta ecosystem. There are a host of social, environmental, economic and engineering issues surrounding both plans. Note that neither of these engineering projects would actually produce more water. Building desalination plants would produce more water, so why the huge push to build the tunnels and raise the dam?
Literature reviews indicate there are at least three primary forces driving the plans to ship more Northern California water to SoCal. The first is, as they say, “follow the money trail”. The second is the claim that projects like desalination plants are a “knee-jerk reaction” to climate change but don’t really solve the problem. The third is simply a case of NIMBY (not in my back yard).
Let’s start with the first issue – “follow the money trail”. This past December marked the one-year anniversary for the Claude Lewis Carlsbad Desalination Plant, in Southern California. The plant was dedicated on December 14, 2015. Four months later it was honored with the Global Water Award as the Desalination Plant of the Year by Global Water Intelligence. They called it “the most impressive technical or ecologically sustainable achievement in the industry.” In June 2016 it was recognized by the San Diego County Taxpayers Association for stretching taxpayer dollars through cooperation between the public and private sectors. A month later it was recognized by San Diego Gas & Electric for its “commitment to sustainability, energy efficiency and conservation.” During its first year the Carlsbad plant produced 15 billion gallons of fresh water (45,000 acre feet) for local use in San Diego, before ramping up to 56,000 acre feet per year. Now, that’s actual new fresh water produced on-site, without messing with the ecological systems elsewhere in the State. The new facility is part of San Diego’s overall plan to improve water use efficiency, recycle more, and incorporate water from multiple sources. Construction costs were about $1 billion. The final product costs about ½ cent per gallon, somewhat higher than if they had simply shipped in more water from other watersheds. That translates into about $5/month for the typical San Diego household. In terms of actual water supply, the new desalination plant produces about 7% of San Diego’s fresh water. Obviously, if San Diego is to fully address projected population growth and associated water demands, more plants must be built, but the supply of ocean water is essentially unlimited and there is plenty of land available if the political will and financing sources can be harnessed. It would seem that in San Diego, at least, residents and local government officials are planning for the future, and those plans don’t simply amount to taking someone else’s water. There is already a possible second facility planned for Huntington Beach.
The builders of the Carlsbad plant saved some construction funds because of the location chosen. The Carlsbad facility was built to take advantage of some infrastructure already in place for the Encina Power Station. Other plants can be built, but they may have to be slightly further inland, and with a more extensive piping system, so future plants are likely to cost more. Or, they may have to buy out someone else’s location and remain on the coast, such as the Huntington Beach proposal. Still, with Governor Brown pushing to spend nearly $16 billion simply to move water from one place to another, desalination does seem to present a strong argument for actually increasing how much fresh water is available. The cost of the desalination plant is being paid for by the users of the water, those users are in relative proximity to the plant itself, and the end result is less dependence on water taken from a remote watershed.
But what about other users – such as subsidized farmers in places like Westlands Water District? Some of these water districts are affluent and influential in Sacramento. Obviously they would be unlikely to experience a benefit from coastal desalination plants. Given the quantities of water some of these agribusiness interests consume, they are far more interested in simply importing someone else’s water than producing it themselves. Ah, but then there’s more! Associated Press published a revised economic evaluation of the proposed tunnels by David Sunding of UC Berkeley, in September 2016. This analysis showed the tunnels wouldn’t help some of the water districts as much as Governor Brown has promised, unless the Feds pick up the tab for about 1/3 of the costs (italics mine). So here is another “follow the money” clue – actual desalination plants are ultimately entirely paid for by the local water users, but Brown’s tunnels might get to be subsidized! If enough voters and government officials are convinced that these water districts deserve more water from Northern California watersheds they may get someone else to pay for a hefty chunk of the bill. As for-profit enterprises that’s a substantial motivator for these water districts to push for more and bigger dams, plus the tunnels, rather than the more expensive solution to make more water.
An LA Times article (4/24/15) implied that desalination plants are a mistake because they are strictly a knee-jerk reaction to a drought, rather than a long-term water availability solution. That’s a curious position given newspapers generally hype anything that smacks of “global warming”, now recast as “climate change”. The article basically implies that “once the rains return” the higher-cost desalinated water will be excess, and the plants will be moth-balled. It fails to acknowledge that a functional desalination process would permit cities to permanently reduce their water import demands. There is some evidence to support their argument. Long Beach has an unused desalination plant built after a previous drought. Once the rains returned, it was shuttered because imported water was cheaper. They’re now in the process of spending $70 million to restart the facility and plan to spend $4.1 million per year to operate it going forward. The United Nations predicts that by 2025 2.4 billion people will live in regions of intense water scarcity. Maybe Long Beach residents will decide to keep the plant operating in spite of the costs, and rely less on imported water going forward. That might help keep them from participating in that 2.4 billion-person water shortage. Analyses of historic Central Valley rainfall patterns show this state has experienced droughts lasting as long as three decades, so we’re certainly not immune from a repeat of the last five years. If you truly believe that our climate is changing, and for the worse, then droughts such as what we’ve just experienced can reasonably be expected to become more common. That means we must prepare now, not wait till “knee-jerk reactions” become mandatory. Further, coastal city residents must accept desalination plants as a way to permanently ease the stress on those ecosystems where they currently take their water, not merely as short-term crisis solutions.
Critics of desalination plants often claim that they cause substantial environmental damage – it’s just conveniently out of sight under water. Certainly there are environmental effects, beginning with a large underwater intake for salt water. After extracting pure water, the extra-salty residue is mixed with more seawater and returned to the ocean. Certainly the intake sucks in some organisms, and the extra-salty return line will take some time and water volume to dilute. The weaknesses with this argument are two-fold. First, the location and screening of the intake can be made to minimize impacts to marine organisms, and I suspect that most people simply don’t have a real notion of just how vast the ocean is compared to the amount of water processed by one of these plants. Natural desalination (evaporation) removes so much more water from the ocean than any number of desalination plants ever could that in the big scheme it won’t be a huge issue. Second, the current scheme of bringing in water from the Sierras, the Colorado River and the Delta have all created their own ecological damage and somehow that damage doesn’t appear to matter to many SoCal water interests, perhaps because that ecological damage is in someone else’s back yard.
The NIMBY argument is at least more easily understood. After all, each of us generates trash but no one wants to live next door to the dump. We all want fuel for our boats but don’t relish the thought of offshore oil wells and tankers where we troll for salmon. As the LA Times put it in 2015, “as big industrial facilities, desalination plants can’t be plunked down just anywhere on the coast without destroying the qualities that attract people to the shorelines” (italics mine). Did you catch that? Basically the Times conceded that SoCal residents want a beachfront lifestyle, but don’t want to share said beachfront property with anything, even water-producing infrastructure that detracts from their lifestyle. So perhaps we’ve identified another truth on the issue – a classic case of Not In My Back Yard.
Ultimately it will be up to the citizens of California, and their political leaders, to spend our money on a long-term water-production solution. We’ve seen the damage to our salmon producing rivers that the current water distribution scheme has created. Minimizing water losses and water recycling are important, but by themselves will not resolve the problem. Moving more water from Northern California, Sierra watersheds or the Colorado River to SoCal cities and Central Valley farming districts would simply create more ecological stress to previously affected areas. As California prepares for the future, more cities will need to follow the lead of San Diego and invest in the necessary infrastructure to obtain water from the ocean. With the $16 billion Brown wants to spend on tunnels he could probably have a dozen desalination plants built and actually make a difference in the state’s water supply for generations to come.
How Modern Desalination Plants Work
Critics of extracting fresh water from the Ocean do have one thing correct. Desalination is a power-hungry process. Old-style desalination plants basically heated raw sea water to steam, then collected and cooled the steam back to pure water, recycling some of the energy in the process. That’s how ships produce water. Modern commercial desalination plants use a process called “reverse osmosis”. This process forces high-pressure seawater against a membrane with such fine molecular-sized holes that water molecules can squeeze through, but salt molecules can’t. By the time the process is completed, two gallons of sea water have been converted into one gallon of fresh water plus one gallon of doubly salty residue. The residue is then diluted with other raw seawater and pumped offshore to mix back into the ocean. The new fresh water then has chlorine added to keep critters from growing in it during storage and distribution.