is desalination the answer to the california drought?
the small farmhouses and vast fields of california’s central valley evoke a romanticized idea of the simple life in rural america. grapes, almonds, asparagus and others grow in rows running perpendicular to quiet freeway lanes. stripes of color extend across the lowland plains until the valley’s mountains force them to an end.
about once a year i drive through part of this 450-mile stretch from my home in san diego to yosemite national park to go camping. i fell in love with the wilderness at a young age. i feed off the challenge of climbing mountains, and i thrive off the view from the top. neither words nor pictures capture the awe those lands bring a person. mountains and lakes stretch across the landscape, inspiring a natural appreciation that is often suppressed in an urban lifestyle.
as i gaze over these lands, however, i cannot ignore the haunting idea that this sort of beauty is not permanent. yosemite is a protected land, but it does not have a monopoly on natural beauty. many of california’s similar sights are at risk of ruin, with fresh bodies of water suffering enormously as california plunges further and further into drought. water levels in lakes and rivers drop daily to quench the population’s constant thirst for more. the natural beauty of our state, food and water security for our people, and job security for our farmers, are subsiding as quickly as the water line.
as i drive north, much of the landscape feels familiar and comfortable. however, a new air of panic permeates the peaceful valley. “water = jobs,” and “help! solve the water crisis,” read signs jutting out of private farmland along the two-lane freeway. these signs, while somewhat present in years past, are far more abundant now.
farmers have raised justified concern for years, and now all they can do is try to be louder. while drought is not a new threat, many were slow to recognize it as a problem that demands immediate action. nasa released a report earlier this year affirming there’s only one year’s worth of fresh water left in state resource stores. this surprised many california residents who, unfortunately, take water for granted despite years of drought warnings. but now the mass public recognizes that this drought will affect them personally, that california is going to have to drastically change or otherwise be uninhabitable.
water demands remain high for the large population and enormous agricultural industry, so scientists and policymakers desperately seek a solution that goes beyond what conservation alone can do. some find an answer in desalination.
desalination plants have popped up all along the california coast in recent years. the newest one, to be finished later this year, sits on the carlsbad coast in san diego county. as the largest desalination plant in the western hemisphere, the facility will produce 50 million gallons of water a day, the equivalent of one olympic-size swimming pool every 18 minutes. the plant takes in ocean water via pipeline and purifies it to a potable state using reverse osmosis, which pushes salt water through a membrane with holes small enough for only water molecules to penetrate. this is a safe and well-studied process, yielding positive results for water quality.
desalination has proven useful in other dry areas, such as saudi arabia and israel. whether it is the best solution for california, however, raises debate. at first glance, desalination appears a good option in the face of drought. enormous stores of ocean water can be utilized for drinking and growing food without disturbing bodies of fresh water that we’ve damaged enough. with the largest population and one of the largest economies in the united states, desalination could help respond to the large water demands upon which everything and everyone depends.
however, the project has met a significant amount of opposition. even before purification begins, the process of water collection necessitates a large pipe projecting into the ocean that could disturb the sea life that dwells there. once the water enters the desalination plant, it must undergo an energy-intensive treatment process. and when desalination is complete and ready for distribution, the purified water will cost more than natural fresh water, putting increased pressure on farmers who require large quantities.
despite the relatively large output capabilities of the new carlsbad plant, water demands remain greater. those 50 million gallons per day equate to only 7% of san diego’s water needs. but, while this is not enough to answer all water demands, it may still be useful in supplementing them. bob yamada, the water resources planning manager of the san diego county water authority, notes that desalination is “not a silver bullet. it’s part of a diverse mix of supplies that we have and will continue to stitch together to achieve that reliability objective.”
the decision to build a desalination plant was not an easy one and comes only as a last resort in the face of extreme drought conditions. the project is opposed on many reasonable grounds, yet something must be done to remedy california’s chronically dry conditions. conservation is always the first step, and yamada claims it “has always been and continues to be a focus of the conservancy,” but california is getting desperate, forcing policymakers to seek other options.
we’re placing demands on the land that it simply can’t handle. in an ideal world, we could solve the drought by conservation, but in reality we may not be able to avoid desalination-based solutions. the pros and cons of desalination, as well as new changes in technology, leave the debate with a lot of gray area.
what is certain is that californians take great pride in our state. every year, as i gaze down the yosemite valley, i’m filled with pure gratitude for where i grew up. whether we find a sustainable solution in desalination or not, i’d hope that californians continue to fight to preserve our state.
(photo: the construction site of the carlsbad, calif., desalination plant. / georgia lawson)