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Engineers Take on Drought in California

June 2, 2015

The drought in California threatens one of America’s prime agricultural regions. How can engineers keep the water flowing? 

This is the second article in a series on water crises and solutions. Part I sketches out the scale of water cycle engineering challenges, Part III explores problems related to rising sea levels in Florida.

Over three quarters of California is currently experiencing long-term extreme to exceptional drought, according to the US Drought Monitor. Reservoirs are down by a total of 11 trillion gallons, leaving many lakes, rivers and wells practically dry. The existing state Water Plan has proved unable to cope with the conditions. Finally, after four long, dry years, politicians have recently started to put conservation measures in place, ordering cities and towns to reduce water use by 25% from June.

Megaprojects to Defeat Drought

Large-scale engineering projects are already under way to address some of the underlying issues. In Northern California, levees in the 1,600 square mile Sacramento-San Joaquin Delta, originally built to encourage the conversion of the wetlands to cropland, had the side-effect of preventing spring flooding. The peat-rich land has now dried out, and in places, the ground has dropped to 15 feet below sea level. The concern is that the sea will breach the levees, and the delta will become contaminated by sea water, affecting the water supply to Southern California.

Engineers Take on Drought in California Engineer Jobs Getty Images

Credit: Getty Images

The $23bn Bay Delta Conservation Plan involves building massive tunnels which will carry up to 67,000 gallons of fresh water per second toward the southern California Aqueducts from further up the Sacramento River, rather than from the pumps in the Delta. If the levees are breached, the drinking water supply won’t be affected. It won’t solve the problem, but it’ll mitigate the consequences.

Meanwhile, other elements of the water supply system are aging rapidly. The Banks, Edmonston and and Tracy Pumping Plants lift the water up to 2,000 feet on its 450-mile journey to Los Angeles, supplying 24 million Californians with drinking water. But when Banks came online in 1963, the entire population of California was just 15 million. Fifty years later, it’s operating at double its intended capacity. Replacing it will be a major challenge.

Desalinization, much touted as the perfect solution thirty years ago, is making a comeback.  Santa Barbara is planning to bring back its decommissioned desalinization plant at a cost of around $40m, and in San Diego, the new Carlsbad plant will come online later this year. But it’s not a universally popular solution. Not only is it an expensive way to generate fresh water, the saline by-products get dumped back into the ocean, seriously affecting fish, corals and other wildlife. Desalinization also has high energy demands, which in turn places demands on the water supply.

However, some engineers refuse to be defeated. Bay Area start-up Trevi Systems is developing a low-power desalinization technique that works through forward osmosis. Water molecules are pulled across a membrane, leaving salt and impurities behind. When low temperature heat is applied, the bioengineered solution separates out like oil, allowing clean water to be siphoned off. This reduced power requirement means that the plant can run on renewable energy. Another local startup, WaterFX, is testing a system that uses parabolic mirrors to produce 14,000 gallons of fresh water a day through evaporation in a solar still. The salt remains as a dry by-product that contains useful chemicals, instead of brine. “We saw the opportunity to take something that was costing quite a lot of money as a waste product and turn it into something of value,” explained co-founder Aaron Mandell.

Water reuse is a critical part of the solution. Through a combination of water-saving practices, water reuse, and recaptured storm water, California could save enough to supply its entire urban population for a year, according to a recent report from the Pacific Institute and the Natural Resources Defense Council.

In San Diego, the Pure Water initiative involves building a plant that will treat used water with three different techniques: membrane filtration, reverse osmosis, and ultraviolet disinfection. “I honestly believe this is the real future for California,” says Halla Razak, San Diego’s director of public utilities. “We take pristine water from rivers and lakes; we treat it and we clean it; and then we use it. Then we treat it again to a pretty high standard before we dispose of it in the ocean and rivers. We’ve already spent time and energy, but then we’re letting go of it. The best thing for California is once we already possess that water and it’s treated to a high level, to treat it further and reuse it.”

Agricultural Impacts of Drought in California

Engineers Take on Drought in California Engineer Jobs CraneStation

Credit: CraneStation

The main problem, however is the seemingly insatiable demands of agriculture. All the recent water restrictions have focused on urban consumption, but it’s the farming sector that most needs to be addressed. Farming accounts for 80% of California’s water usage, but the agriculture sector was explicitly exempted from Governor Brown’s sweeping water restrictions, since they rely on groundwater, rather than federal water supplies.

The current poster child for inappropriate farming is almonds. A single almond takes an entire gallon of water, and California’s growing contingent of almond farmers use an incredible 10% of the state’s water, a little over a trillion gallons a year. Between them, they supply over 80% of the world’s almonds, and over 70% of the crop is exported, mainly to China. Is that really the best use of a dwindling resource?

However, although it would be easy to blame the almond farmers for excessive water consumption, the reality is that throughout the United States, we’re responsible for putting a huge demand on California’s natural resources. Although states like Kansas and North Dakota are the places most people associate with growing America’s food, California supplies most of our fruits and vegetables: 99% of our artichokes and walnuts come from California, as do 97% of our kiwis and plums, 95% of our celery and garlic, 90% of our wine, 89% of our cauliflower, and 71% of our spinach and carrots. If California’s water supply fails, the effects will be felt across America, and beyond. Already, we can see the early signs of the drought hitting consumers everywhere. In 2015, over 500,000 acres of California farmland will remain unplanted, as farmers don’t have enough water to sustain their crops. Produce prices will inevitably rise, and the entire US will have to import more food, which may have undesirable geopolitical side-effects.

ers Take on Drought in California Engineer Jobs Anthony Artusa

Credit: Anthony Artusa

That’s not mere journalistic licence: the USDA is closely monitoring the likely impact of the drought, as are academics. “10 to 20 percent of some crops will be lost. I would expect a 28 percent price increase for avocados and 34 percent for lettuce over the next couple of months,” claimed Timothy Richards, a professor of agribusiness at Arizona State University. He added that the price increases would also affect berries, broccoli, grapes, melons, tomatoes, peppers and packaged salads. Meanwhile, California’s Department of Food and Agriculture commissioned a report from scientists and economists at the University of California, Davis, which forecast that agriculture would lose $2.2bn this year, and over 17,000 jobs in the state.

Engineering Smarter Agriculture

The answer, then is to reduce the amount of water used by agriculture. That’s where Tyler Scheid’s hoping to pave the way.

“We need to get smart,” he says. “We need to be using less water, but maintaining or increasing our production levels and yields. What you have to realize is that water, despite everything, is still cheap, so farmers don’t have any real incentive to conserve it. It’s always best to play safe and over-irrigate, because under-irrigation is risky. What this means is that we’re all using far more water than we need.”

Scheid, technology consultant at Scheid Vineyards, takes pride in showing off his new precision farming system. Despite California’s unprecedented drought, he’s used his background in environmental engineering and high-tech water management systems to ensure that his 4.200 acres of vines are healthy, and that he’s growing some of the best grapes in Monterey County.

Engineers Take on Drought in California Engineer Jobs Heidi Scheid

Credit: Heidi Scheid

The solution, according to Scheid, is automated agricultural technology that delivers precisely the required amount of water, when and where it’s needed. “Our new irrigation system gives us a huge amount of control over what we’re doing. We use neutron probes to analyze moisture and determine exactly which plants need water, and how much. We can automatically and remotely inject both water and the fertilizer directly into the ground, which minimizes loss through evaporation, and using pulse irrigation reduces run-off.”

The biggest advantage of the system is that it takes the guesswork out of the water usage. “Traditionally, farmers have to go out in the field, decide which areas need irrigating, turn on valves, and then come back when they think they’ve applied enough water. With this kind of engineered solution, we’re able to respond to the actual needs of the plants. Not only are we using sensors on the ground, but we can also use drones to look at the crops remotely and see exactly what their status is. Remote sensing techniques like NDVI (normalized difference vegetation index) give us instant analysis of an area without having to go and visit it, and we can respond immediately to the plants’ current needs.”

Advanced agricultural systems also cut down on the human resources required to run a farm. “Farmers need to be see how these techniques can make them more profitable,” says Scheid. “For example, how much can a person do in a day, driving around in a tractor, turning valves on and off? We know that shorter, more frequent irrigation sets are more efficient in terms of water use, as well as better for yields, but you can’t expect farmers to hire more people to do all that extra work. With a remote or automated system, we can do more sets at no extra cost, even through the night. In fact, we’re saving on labor costs. That’s a huge benefit. And that means less tractor movement, which cuts down fuel bills, maintenance bills, and so on.”

It’s too early to quantify how much difference Scheid’s new system will make in terms of water consumption, but the math looks promising from a financial point of view. “Just with the increased production, we believe it will pay for itself in two harvests,” he claims. “Farmers shouldn’t be thinking of this as a long-term investment. It’s something they can do right now.” And if farmers across all of California could reduce their water consumption by just 10%, the total savings would add up to more than every household in the state put together.

Scheid is clearly passionate about the need for technical innovation in agricultural engineering. “We desperately need smart people to develop these technologies and understand how important it is to our economy, to all of us, but agricultural engineering just isn’t sexy. People get attracted to the pizzazz in Silicon Valley, but this is a monster opportunity that people seem to be blind to. It’s partly a cultural thing: there’s no Starbucks here, there’s a lot of remote work, you just gotta love that life. We have ranches down by Pasa Robles and most of our people in the tech side would rather commute an hour because they don’t want to live in the Central Valley. It’s really, really hard to recruit the people who can get fired up about this. But it’s the way we have to go.”

 

This is the second article in a series on water crises and solutions. Part I sketches out the scale of water cycle engineering challenges, Part III explores problems related to rising sea levels in Florida.

 

Featured Image Credit: Cedrennes
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