Posts Tagged: water
University of California students are taking a long journey through California to trace the state's complicated and critical water supply. The recent graduates and upper-division co-eds from UC Merced, UC Santa Cruz, UC Berkeley and UC Davis are part of the UC Water Academy, a course that combines online training with a two-week field trip for first-hand knowledge about California water.
The tour began June 18 at Lake Shasta, the state's largest reservoir, and followed the water's course to the Sacramento Valley, through the Sacramento-San Joaquin Delta and south along the Delta-Mendota Canal. Since a key water destination is agriculture, the UC Water Academy toured the UC Kearney Agricultural Research and Extension June 23, where research is underway to determine how the state's water supply can be most efficiently transformed into a food supply for Americans.
“You're visiting a place ideal for growing high-quality fruits and vegetables, because of the Mediterranean climate and low insect and disease pressure,” said Jeff Dahlberg, director of the UC KREC.
UC Cooperative Extension water management specialist Khaled Bali joined the students next to his alfalfa research plot, where different irrigation regimens are compared to determine the maximum yield that can be harvested with the minimum amount of water.
“It used to be that the No. 1 objective was to maximize yield,” Bali said. “But with the limited supplies and the cost of water, now the No. 1 objective is to get the maximum economic return. Growers might be better off selling some of their water to other jurisdictions.”
A water tour wouldn't be complete without an introduction to drought research. A recently planted sorghum trial provided the backdrop.
“California is a great place to study drought tolerance,” Dahlberg said, “because you can induce a drought by withholding irrigation.”
The sizable field contains 1,800 plots with 600 sorghum cultivars under three irrigation schemes: one irrigated as usual, one in which water is cut off before the plants flower, and the final one where water is cut off after the plants flower.
“Every week, a drone flies over to collect data on the leaf area, plant height and biomass,” Dalberg said. “Hopefully we will get associations with gene expression and this phenotype data."
Dahlberg and his collaborating researchers believe identifying the genes responsible for drought tolerance in sorghum will help scientists find drought-tolerant genes in other cereal crops – such as wheat, corn, rice and millet. “This will go a long way to feeding the people of the world,” he said.
There is still much to learn about sorghum drought tolerance – is it conferred by the plant's waxy leaves, the way stomata are controlled, accumulation of sugar in the leaves, or a mechanism in the roots?
“These are all questions you will have to answer to feed the world,” Dahlberg said. “That's why I would encourage you to continue studying water. There's a lot for you to get into.”
A third-year earth science student at UC Santa Cruz and a member of the academy, Denise Payan, said the sense of responsibility for the future is not daunting, but encouraging.
“It makes me feel like I can make a difference,” she said. The tour through California is shaping her plans for the future, which may include a career at the intersection of geology and biology.
“This has opened my eyes to a lot of issues,” she said.
The next stop for the UC Water Academy is the vast Tulare Lake basin to learn about groundwater recharge before heading east to the Owens Valley and the shores of Mono Lake. From there the academy turns to the Sierra Nevada to visit San Francisco's water supply, which is collected by Hetch Hetchy Dam. The field trip ends with a two-day rafting trip on the American River.
The UC Water Academy is offered through UC Water and led by UC Merced professor Joshua Viers and UC Cooperative Extension water management specialist Ted Grantham. In addition to the two-week tour, students participated in weekly online meetings and complete a project on communicating California water issues to public stakeholders. Students receive 1 unit of academic credit.
The UC California Institute for Water Resources (CIWR) has announced the recipients of six grants to address the most critical water issues in the state. For this program, the Institute leverages funds it receives from the Water Resources Research Act of 1964 through the Department of Interior.
CIWR, which is part of UC Agriculture and Natural Resources, facilitates collaborative research and outreach on water issues across California's academic institutions and with international, federal, state, regional, nonprofit, and campus communities.
Small grants to support initial work will be dispersed to the following projects (click the headline for more information):
Suitability of alfalfa for winter groundwater recharge
Helen Dahlke, professor in the Department of Land, Air and Water Resources, UC Davis
One proposed solution for recharging overdrawn aquifers is flooding farmland during the rainy season. Optimizing agricultural groundwater banking for specific crops can be challenging. The goal of this project is to better understand how alfalfa, which is grown year-round, responds to winter flooding.
Fish habitat response to streamflow augmentation
Ted Grantham, UC Cooperative Extension specialist in the Department of Environmental Science Policy and Management, UC Berkeley
Declining water levels can degrade or eliminate fish habitat during California's summer season. Storing water off-channel during the rainy season can improve flow during the summer. The study is designed to gain a better understanding of the relationship between stream flow and habitat.
Remote sensing of turfgrass response to irrigation
Amir Haghverdi, UC Cooperative Extension specialist in the Department of Environmental Science, UC Riverside
Turfgrass is common in urban landscapes and provides valuable recreation areas and ecosystem services. This project will help determine the best irrigation strategies for common turfgrass species.
Habitat restoration impacts on water management
Eric Palkovacs, professor in the Department of Ecology and Evolutionary Biology, UC Santa Cruz
The natural conditions of the Sacramento-San Joaquin Delta have been changed by habitat alteration and non-native predacious fish introduction. This project will examine the interplay between altered habitat and predatory fish, and how they impact native salmon populations.
Evaluating water conservation policy in California
Leah Stokes, professor in the Department of Political Science, UC Santa Barbara
During the recent drought, California required that on-average urban water districts conserve 25 percent of their water. While some districts were successful, others failed to meet their target. This project will examine how variation in policy – pricing, messaging and penalties – and drought severity affected water conservation.
Groundwater dynamics after California drought
Amelia Vankeuren, professor in the Department of Geology, Sacramento State University
As part of California's groundwater management act, some basins were designated as high management priorities. This project will characterize groundwater using age, location and temperature. This information will be valuable for stakeholders creating a groundwater sustainability plan.
While some people were spending spring break at the beach or catching up on their Netflix queue, students from the EcoGeoMorphology class at UC Davis were rafting down the Colorado River at the bottom of the Grand Canyon.
The class split in two groups for the 225-mile river journey. On March 10, the group embarked from Lee's Ferry, rafting 90 miles before hiking to the rim on March 19 along Bright Angel Trail. They passed the second group on their way down the same day. They traveled the remaining 135 miles to the next road access at Diamond Creek.
The class is conducted during winter quarter by the Department of Earth and Planetary Sciences and the Center for Watershed Sciences, in partnership with Campus Recreation's Outdoor Adventures. While its first trip to the Grand Canyon was in 2003, students have taken this optional trip for each of the past five years.
‘There's nothing quite like this'
The trip is the physical and visible representation of what the class is all about: Geologists, hydrologists and ecologists learning to communicate with each other and the public. It's a skill necessary in real-world careers, where working on environmental problems requires a variety of expertise that isn't always taught in siloed classrooms.
“I'm not a geologist myself, but you only have to look left to right at any moment, and there's nothing quite like this,” said Young while floating down the river, taking in the cliffs rising around him.
The classrooms are pretty spectacular: red walled caverns, ancient Puebloan ruins, rock formations and fossils, the river itself. It's the students' textbooks brought vividly and tangibly to life.
Along the way, Young described the life cycle of Century plants; explored the plants sprouting around Vasey's Paradise, a natural spring; and rubbed scale insects off prickly pear plants to expose the crimson dye they produce. At each step, he casually prodded the students to consider what it means to have a river running through a desert.
The group was unplugged, off-grid, and literally immersed in the river, rocks and landscape.
Geologists, ecologists, and hydrologists helped teach each other about rocks, plants, fish and flow rates—usually informally as they scrambled up a trail or gazed up at the vertical cliffs slowly floating past.
They slept each night under a sky bright with forgotten stars, to the sounds of softly strumming guitar and the nearby rushing river.
Over the course of eight days on the river, they traveled through about a billion years of geologic time.
Young had been on the trip once before, two years ago. He said it was just as impressive the second go-around.
“It's actually more spectacular on the second pass, which surprised me,” he said. “Just the magnitude and the grandeur of it, all that stuff. It's just more.”
A recent study led by UC Cooperative Extension specialist Van Butsic used high resolution satellite imagery to conduct a systematic survey of cannabis production and to explore its potential ecological consequences.
Published this spring in Environmental Research Letters, the study focused on the “emerald-triangle” in northern California's Humboldt, Mendocino, and Trinity counties, which many believe is the top cannabis-producing region in the United States.
The UC Berkeley-based Butsic and his co-author Jacob Brenner used Google Earth imagery to locate and map grow sites (both greenhouses and outdoor plots) in 60 watersheds. Most cannabis grow sites are very small, and have gone undetected when researchers used automated remote sensing techniques, which are commonly used to detect larger changes such as deforestation.
“We chose to use fine-grained imagery available in Google Earth and to systematically digitize grows by hand, identifying individual plants. Most plants stand out as neat, clear, little circles,” said Brenner, who is on the faculty of the Department of Environmental Studies and Science at Ithaca College. “The method was laborious — it took over 700 hours — but it proved to be highly accurate.”
Butsic and Brenner paired their image analysis with data on the spatial characteristics of the sites (slope, distance to rivers, distance to roads) and information on steelhead trout and Chinook salmon, both of which are listed as threatened species under the federal Endangered Species Act. These and other species are vulnerable to the low water flows, soil erosion, and chemical contamination that can result from nearby agriculture.
Results of the study show 4,428 grow sites, most of which were located on steep slopes far from developed roads. Because these sites will potentially use significant amounts of water and are near the habitat for threatened species, Butsic and Brenner conclude that there is a high risk of negative ecological consequences.
“The overall footprint of the grows is actually quite small [~2 square kiliometers], and the water use is only equivalent to about 100 acres of almonds,” says Butsic, who is in the Department of Environmental Science, Policy, and Management at Berkeley. According to Butsic, California currently has more than one million irrigated acres of almonds.
He stresses that the issue lies in the placement of the sites: “Close to streams, far from roads, and on steep slopes — cannabis may be a case of the right plant being in the wrong place.”
Last year, California legislature passed laws designed to regulate medical marijuana production, and state voters will weigh in on whether to legalize recreational marijuana this coming fall. Given these changes as well as the profitability of cannabis production, Butsic expects that marijuana cultivation will expand into other sites with suitable growing conditions throughout the region. He and Brenner assert that ecological monitoring of these hotspots should be a top priority.
Bills recently signed into law by Governor Jerry Brown have made some advances in this direction — requiring municipalities to develop land use ordinances for cannabis production, forcing growers to obtain permits for water diversions, and requiring a system to track cannabis from when it is first planted until it reaches consumers.
But the researchers say that regulation will likely be a constant challenge because it will rely on monitoring procedures that are just now emerging, as well as voluntary registration from producers and budget allocation from the state for oversight and enforcement.
“Some of the same fundamental challenges that face researchers face regulators as well, primarily that cannabis agriculture remains a semi-clandestine activity,” says Brenner. “It has a legacy of lurking in the shadows. We just don't know — and can't know — where every grow exists or whether every grower is complying with new regulations.”
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
“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 Magazine. Read the complete article.