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California food choices won’t save much drought water, researchers find

Can you help fight the California drought by consuming only foods and beverages that require minimal water to produce?

One cup of lettuce uses only one gallon of drought water. (Gregory Urquiaga/UC Davis)
Well, as the old saying goes, the devil is in the details. In a recently published paper, Daniel Sumner, director of the UC Agricultural Issues Center at UC Davis, and research assistant Nina M. Anderson mine the details of this issue to help us all better understand just what impact our food choices can have on conserving California's precious water.

To begin with, not all water drops are equal because not all water uses impact California's drought, the researchers explain.

Drought-relevant water

So just what water does qualify as California drought-relevant water? You can definitely count surface water and groundwater used for agricultural irrigation as well as water used for urban purposes, including industrial, commercial and household uses.

And here are a few examples of what water is not relevant to California's drought:

Rain that falls on un-irrigated California pastureland is not relevant to California's drought.
-- Water used in another state to grow animal feed that is consumed by California livestock;

-- Water used in another state to produce young livestock that are later shipped to California for food production; and

-- Rain that falls on un-irrigated California pastureland. (Studies show that non-irrigated, grazed pastures actually release more water into streams and rivers than do un-grazed pastures, the researchers say.)

In short, California's drought-relevant water includes all irrigation water, but excludes rainfall on non-irrigated California pastures as well as any water that actually came from out-of-state sources and wound up in livestock feeds or young livestock eventually imported by California farmers and ranchers.

Also, the amount of water that soaks back into the ground following crop irrigation doesn't count – and that amount can be quantified for each crop.

Comparing water use for various foods

I think you're getting the picture; this water-for-food analysis is complicated. For this paper, the researchers examined five plant-based and two animal-based food products: almonds, wine, tomatoes, broccoli, lettuce, milk and beef steak.

In teasing out the accurate amount of water that can be attributed to each food, the researchers first calculated how much water must be applied to grow a serving of each crop or animal product. Then they backed off the amount of water that is not California drought-relevant water, arriving at a second figure for the amount of drought-relevant water used for each food.

They provide a terrific graph (Fig. 3) that makes this all quite clear, comparing total applied water with California drought-relevant water used for the seven food products.

Milk and steak top the chart in total water use, with 1 cup of milk requiring 68 total gallons of water and a 3-ounce steak requiring 883.5 total gallons of water.

But when only California drought-relevant water is considered, one cup of milk is shown to be using 22 gallons of water and that 3-oz steak is using just 10.5 gallons of water. (Remember, to accurately assess California drought-water usage, we had to back off rainwater on non-irrigated pastures and water applied out of state to raise young livestock or feed that eventually would be imported by California producers.)

“Remarkably, a serving of steak uses much less water than a serving of almonds, or a glass of milk or wine, and about the same as a serving of broccoli or stewed tomatoes,” write Sumner and Anderson.

Still skeptical? Check out their paper in the January-February issue of the “Update” newsletter of the Giannini Foundation of Agricultural Economics at http://bit.ly/1XKZxxC.

Bon appetit!

Posted on Tuesday, March 22, 2016 at 4:45 PM
Tags: Consumers (1), Crops (2), Daniel Sumner (1), Drought (20), Food (1), Livestock (2), Water (84)

California’s delta: On the front lines of the state’s water issues

Stephanie Carlson researches native California fish populations in "intermittent streams" in the Sacramento-San Joaquin Delta. Photo: Edward Caldwell.
On June 3, 2004, a small trickle of water started to flow through a levee on the Jones Tract, a patch of farmland west of Stockton that sits below sea level. Of California's 27 million acres of irrigated croplands, the tract's 12,000 acres weren't exactly at the forefront of anyone's mind. But within a few hours the rivulet had become a deluge, opening a 350-foot-long gash in the wall that was built to hold back the waters of the Sacramento–San Joaquin Delta. The land quickly became a lake, submerging asparagus fields, corn silos, and dozens of homes beneath 60 million gallons of water. Repairing the break required six months of constant pumping and cost approximately $100 million; farmers throughout the Central Valley, who depend on the delta's 1,100-mile-long network of levees, had a new reason to lose sleep at night. The cause of the initial rupture was a beaver, working to expand its home.

California water: Few natural resources are as impressive, or as imperiled. Whether it's supplying 40 million domestic users, cooling the server farms of Silicon Valley, or irrigating the actual farms that supply half of the nation's produce, the importance of the state's aquifers and headwaters cannot be overstated. (Lake Tahoe, Yosemite Falls, and white-water rafting on the Kern and American Rivers feel like an embarrassment of riches.) While the potential for a multi-decade drought has grabbed headlines, however, California's water supply faces assault from a host of lesser-known factors including infrastructure failure, pollution, habitat loss, and plain old political chaos. This issue is strongly interdisciplinary, so it's only natural that UC Berkeley College of Natural Resources professors and students have been at the forefront of analyzing the problems and beginning the search for solutions. Several Berkeley professors have even served on the Delta Independent Science Board (DISB), a group of experts appointed by the state to oversee the quality of scientific research on California's contentious delta water issues.

Supply vs. demand

Professors and Delta Independent Science Board members Vincent Resh (right) and Richard Norgaard stand on a levee on Sherman Island along the Sacramento River. (Photo: Edward Caldwell)
When asked to name the three greatest threats to California's water, Richard Norgaard, Berkeley professor of energy and resources (and the DISB's first chair, who still serves on the board), couldn't be more clear.

“Issue number one, one, and one is that a substantial portion of the acreage in agriculture is supported through groundwater overdraft, even in normal-rainfall years,” he says.

According to the U.S. Geological Survey, California's cities, factories, and farms soak up about 38 billion gallons every day. And while most people think of water in terms of rivers, lakes, and rain, over a third of the state's supply comes from aquifers deep underground. Only one in six Californians relies on groundwater alone to supply their domestic needs.

“We've been mining water to expand use beyond surface-water allocations,” says Norgaard. “Groundwater is close to gone, and agriculture is saying, ‘Where's our water, where's our water, where's our water?'”

Given that much of California is a desert — and that decades-long droughts are not impossible — intelligently managing California's limited supply is crucial. Gov. Jerry Brown recently ordered municipalities to cut home water usage by a whopping 25 percent, and California residents gave themselves a well-deserved pat on the back when usage for July 2015 surpassed that target by 6 percent. But there's one problem: Domestic use accounts for only 10 percent of California's total water consumption. Agricultural use, on the other hand, accounts for closer to 40 percent.

At first glance, that doesn't seem entirely inappropriate. Fruits, vegetables, and nuts, not to mention Northern California's incomparable wine and cheese — why shouldn't the farmers who feed half of the nation take half of the water that the state has to offer?

“Do you know what percent of the state's economy is agriculture?” asks Vincent Resh, a professor in the Department of Environmental Science, Policy, and Management (ESPM) and another DISB member. “Less than 2 percent.” It's a very vocal 2 percent, though, and there are volumes of case law — and a good amount of political muscle — dedicated to maintaining the status quo. “I'm very sympathetic toward the plight of farmers in the delta,” Resh continues. And farmworkers are the poorest of California's poor, with seasonal unemployment rates reaching upwards of 60 percent. “It's the human side of the story that I've become extremely sensitive about.”

Nonetheless, Resh recalls being on a delta tour that was packed with people who identified themselves as delta farmers.

“They were all talking about how this has been their family heritage for generations, but they were working as lawyers and bankers," Resh said. "They were really talking about a way of life that was long gone for them personally, but a memory that they were holding on to. Actually, this ‘way of life' idea is true of many of the contentious water issues in California. The controversies over who gets the water in the Klamath River in Northern California and Oregon are as much about way of life as they are about water for agriculture and salmon.” 

A fragile water system

Nobody is suggesting an outright end to farming in California, but it's becoming increasingly clear that change is coming. One looming problem is the fragility of the levee system. Drive around Sacramento's rural environs and you'll realize that a lot of farmers actually do their work below sea level, with nothing but a hodgepodge system of peat dams and concrete rubble to restrain the brackish delta waters. Overactive beavers, like the one on the Jones Tract, are the least of the problem.

Like everyone else in California, the engineers who watch over the delta's levee system are at the mercy of probability, breathing a sigh of relief every day that goes by without the catastrophic shaking of the Big One.

“In any given year, there's not a large chance of a huge earthquake,” says David Sunding, UC Agriculture and Natural Resources Cooperative Extension specialist and chair of the UC Berkeley Department of Agricultural and Resource Economics. “But those risks accumulate over time. And by the time you look two decades into the future, there's a two-thirds chance of a very large quake that will affect the delta's water system.”

Even an apparent bounty — consecutive years of high rainfall — poses risks. River flows would rise along with reservoir levels, placing added stress on levees so that even a minor structural failure could set off a chain reaction, flooding fields and devastating crops.

“The current proposals for achieving reliable water supply and ecosystem health may be controversial, but it's clear that something has to be done — we can't have the status quo.”
— Vincent Resh

Inherent in either of these scenarios is the threat to drinking water. The delta houses the State Water Project, two massive pumps that send water to Southern California. If the levees are overtopped, the salt water of the bay will infiltrate the Sacramento and San Joaquin rivers, rendering the supply undrinkable.

“The worst-case scenario is three months without water,” Resh said. “And that's from Fremont down. Silicon Valley, Los Angeles, everything.”

Not just a human problem

Of course, farmers and thirsty urbanites aren't the only ones who need water. According to Berkeley Environmental Science, Policy, and Management associate professor Stephanie Carlson, “many of California's native fishes are declining, and the causes are rooted in habitat loss and the introduction of non-native fishes into California's waterways.” She emphasizes that our current multiyear drought may be the “nail in the coffin” for those populations already facing extinction.

Carlson's research focuses on understanding where and why fish populations are persisting. She found that several native fish, including commercially harvested salmon, live in “intermittent streams” — waterways that flow continuously in the wintertime but break into isolated pools during periods of low rainfall. As drought or human usage reduces stream flow, water quality deteriorates, resulting in higher temperatures and less oxygen. In pools that dry up completely, all fish die, of course, but some “refuge” pools persist through the summer — and these habitats do support fish.

Carlson's team has found that “the survival of imperiled salmon and trout varies among summers, but is highest after wet winters.” Following wet winters, streams flow longer into the summer, more pools persist, and water quality is improved. But, interestingly, “almost regardless of winter rainfall, most fish mortality is concentrated in late summer,” meaning that early, abundant fall rains may be as important as the previous winter's storms.

Carlson believes that these findings should guide management. Urban development in the Bay Area is spreading from flatlands to the hills.

“We need to focus our conservation efforts in those upper headwater streams — many of which are intermittent,” she says. Carlson also stresses that native fish have adapted to the seasonal shift from flowing streams to standing pools, while non-native fish have not — thus intermittent headwater streams may be important refuges for native fishes.

While diverting less water from streams during summer might help juvenile salmon, managing outcomes in the ocean is far more difficult. In 2007 and 2008, the West Coast Chinook salmon population collapsed, with the Sacramento River fall run reduced by 90 percent. Fisheries closed at a cost of millions of dollars, and the federal government declared a disaster. While the crisis was attributed to low ocean productivity beyond human control, human degradation of freshwater salmon habitats worsened the impact of poor ocean conditions.

Most salmon-breeding habitats in the Central Valley lie upstream of dams. Today, most Central Valley salmon are born in hatcheries; many circumnavigate the delta in trucks and are released into the San Francisco Bay. Because these fish don't swim through their natal rivers and the delta, they have no way to retrace their paths as adults. So they go everywhere, mingling with the broader gene pool. This “straying” erodes genetic differences among populations and increases the risk of collapse. It's possible that a more vibrant, genetically diverse salmon population could have better resisted the environmental disturbances of the mid-2000s.

“It's like having a broad portfolio of financial investments, as we've been taught with our 401(k)s,” Carlson says. “Maintaining multiple distinct populations with diverse traits and dynamics provides insurance against environmental change.”

—Excerpted from an article in the winter 2016 issue of Breakthroughs MagazineRead the complete article.

Posted on Friday, February 26, 2016 at 9:05 AM

Two key takeaways from new federal dietary guidelines

The Dietary Guidelines recommend Americans substitute water for sugary drinks. (Photo: public-domain-image.com)
The U.S. government's new dietary guidelines take a bold stand on reducing sugar intake but should do more to promote drinking water, according to nutrition experts from UC Agriculture and Natural Resources.

UC ANR's Nutrition Policy Institute (NPI) has led a push to get the government to make water the drink of choice in the guidelines and add an icon for water on the MyPlate food guide. The guidelines don't go that far, though they do include information that recommends drinking water – in the fine print.

“The guidelines' recommendation to substitute water for sugary drinks is based on solid science. These beverages are the single biggest source of added sugars for our country's kids – and this guidance is explicit and unambiguous and will boost our work in promoting zero-calorie drinking water as the beverage of choice,” said Nutrition Policy Institute Director Lorrene Ritchie. “However, this guidance is presented in a way that gives few Americans an opportunity to see it: on a tip sheet that explains how to use the components of MyPlate ‘to create your own healthy eating solutions — MyWins'. The public health community and the new National Drinking Water Alliance, coordinated through NPI, will build on the potential in this fine-print message by continuing drinking water education, promotion and advocacy.”

The Dietary Guidelines for Americans, updated every five years based on the latest advances in nutritional science, serve as a basis for federal nutrition policy and help set the tone for how Americans should eat. The 2015-2020 guidelines, published this month, recommend a “healthy eating pattern” with limited added sugar and saturated fat, less salt, and more fruits, vegetables and whole grains.

For the first time, the guidelines recommend a clear limit on added sugar of no more than 10 percent of daily calories.

“The science regarding the health risks of a high-sugar diet is strong,” Ritchie said. “Not only is sugar associated with chronic disease risk and obesity, but it also displaces foods known to protect and promote health.”

And what's the simplest way to reduce sugar intake?

“Take a bite out of the added sugars in your diet by drinking plain water instead of sugary beverages,” Ritchie said. “This one simple lifestyle change can be an effective response to the latest nutrition science in the new Dietary Guidelines for Americans.”

Read more UC expert commentary on the new dietary guidelines

An initiative to maintain and enhance healthy families and communities is part of the UC Division of Agriculture and Natural Resources Strategic Vision 2025.

Posted on Thursday, January 21, 2016 at 9:45 AM
  • Author: Alec Rosenberg

International experts to discuss water pricing Feb. 2-3 in Sacramento

Although rain has begun falling in California after four years of drought, living with limited water is the new normal for Californians, according to University of California water experts. To manage its water for the future, California needs to look into a long-term set of policies that change the way water is valued and used in the state.

On Feb. 2 and 3, international experts will convene in Sacramento to share their experiences with the use of market-based incentives to address water scarcity. The workshop “Water Pricing for a Dry Future: Policy Ideas from Abroad and their Relevance to California” will be held at the University of California Center at 1130 K Street in Sacramento. The public is welcome to attend.

“The workshop will provide an opportunity for individuals in various sectors to interact with scholars from several countries who will illustrate how water-pricing mechanisms have been used creatively in their countries to promote water conservation,” said Ariel Dinar, UC Riverside professor of environmental economics and policy, who is co-organizing the workshop.

Experts from Australia, Brazil, Canada, Chile, China, France, Israel, South Africa, Spain and California, will present their water-pricing cases. California-based researchers, water district staff, representatives of government agencies and policymakers will be participating in the workshop.

“The discussions will help people realize how economic incentives might be used to address some of the challenges faced by California's water economy,” Dinar said.

Policies to address water scarcity include water-use quotas, water rights trading, promotion of water conservation technologies, and water pricing. Available water-pricing mechanisms can range from simple cost recovery to sophisticated economic incentives in the form of budget block-rate structures.

The workshop is sponsored by the University of California Center at Sacramento, UC Riverside School of Public Policy, UC Berkeley, UC Division of Agriculture and Natural Resources, Giannini Foundation of Agricultural Economics, Public Policy Institute of California Water Policy Center and Metropolitan Water District of Southern California.

For more information about the workshop, visit http://spp.ucr.edu/waterpricing. Registration is free, but space is limited and Jan. 26 is the last day to register.

Posted on Wednesday, January 13, 2016 at 3:46 PM
Tags: Ariel Dinar (1), drought (20), Water (84), water pricing (1)

UC ANR vice president Glenda Humiston visits the Imperial Valley

Humiston (in red jacket) stands on what was a Salton Sea boat ramp 12 years ago. The Imperial Irrigation District works with UCANR to deal with reduced water flows to the human-made body of water.
Glenda Humiston, the UC Agriculture and Natural Resources vice president who was appointed to her position last summer, toured the Imperial Valley yesterday to become familiar with agricultural and environmental issues in the state's southernmost desert region, reported Edwin Delgado in the Imperial Valley Press.

Humiston visited local farms, the Salton Sea, and UC Desert Research and Extension Center and UC Cooperative Extension in Imperial County. She had discussions with local farmers and industry representatives about renewable energy, drought and water issues, and agricultural production.

"It's great ot have our new vice president here to learn about the programs that we have here and discuss how we can improve them and bring more resources to the area," said Khaled Bali, director of UCCE in Imperial County. "That is basically my objective, bringing more resources to the area and have more collaborative projects."

Andy Horne, a Imperial County executive, said that solar farms have expanded in the county. Projects in place and those approved will cover about 4 percent of Imperial County farmland, a level the county intends to maintain. Humiston told the reporter that she is an advocate for farmland protection because the planet as a whole has a limited surface for cultivating crops.

"As we are dealing with things such as climate change and invasive species and drought, not only protecting those acres so that they are available but keeping them healthy and making sure water is available becomes ever more important," Humiston said.

Delgado reported that Humiston's trip to the Imperial Valley is part of an effort to visit all the UC Cooperative Extension offices and the nine research and extension centers around the state to familiarize herself with UC ANR efforts throughout California.

“The issues going on here are completely different than the Central Coast, Northern Sierras or Sacramento Valley,” Humiston said. “What is important is that we, the University of California, we have these offices in each and every county and that we have these research centers because if we are going to develop knowledge and find solutions and be able to implement those, we got to be able to have people in the ground here that can really dig into the real problem. You got to have people on the ground.”

Posted on Thursday, December 3, 2015 at 10:16 AM
Tags: Glenda Humiston (1), Khaled Bali (1), water (84)

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