California Institute for Water Resources
California Institute for Water Resources
California Institute for Water Resources
University of California
California Institute for Water Resources

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The Water Talk podcast is back for a second season

Join us for season 2 of Water Talk, new episodes weekly starting April 2, 2021.

The podcast Water Talk launched its second season on Friday, April 2. This season focuses in part on drought, a water issue at the top of many minds during this relatively dry rainy season.

"In California, drought is not 'if,' it's 'when,' said Water Talk co-host Faith Kearns, academic coordinator with the California Institute for Water Resources in the preview episode.

"The second season includes a diverse group of guests from every corner of the state, border to border," said co-host Samuel Sandoval, a UC Cooperative Extension specialist in the UC Davis Department of Land, Air, and Water Resources.

The weekly podcast will feature discussions of agriculture, water policy, environmental and social justice, land and wildlife management, water for cities, Indigenous perspectives on water, climate change, and other issues related to California water.

"We thought a lot about the geography of the state, the identities of the people whom we were speaking with, the experts we were talking with, and the topics," said co-host Mallika Nocco, a UC Cooperative Extension specialist in the UC Davis Department of Land, Air, and Water Resources.

Water Talk hosted by Mallika Nocco, Faith Kearns, and Sam Sandoval, production support from Claire Bjork and Victoria Roberts.

Some aspects of the podcast were modified in the second season. Instead of recording during a live event, as was done in the first season, each episode was recorded with only the co-hosts. In addition, two production assistants, Claire Bjork and Victoria Roberts, supported the development of each episode through a UC ANR Renewable Resources Extension Act grant.

Listeners can subscribe, hear, and download all the episodes in Spotify, Apple, and Google podcasts, as well as on the podcast's webpage Follow @podcast_water on Twitter.

Posted on Monday, April 5, 2021 at 12:40 PM
  • Author: Kat Kerlin

From the Ground Up: Climate Change and Environmental Justice in California

Michael Mendez at the Port of Long Beach. Photo by Keith Carlsen.

Michael Mendez is an assistant professor in the School of Social Ecology at UC Irvine, and has spent time doing public policy work as an advisor, senior legislative consultant, lobbyist, and as a gubernatorial appointee during the passage of California's internationally acclaimed climate change laws. Most recently, Governor Newsom appointed Michael to the Los Angeles Regional Water Quality Control Board, which regulates water quality in a region of 11 million people. He is author of the book Climate Change from the Streets (Yale University Press).

You've had really interesting experiences on your way to joining the faculty at UC Irvine. Can you tell us a bit more about your path and how it has shaped the work you do now?

As a scholar, my work is situated at the intersection of climate change, public health, and public policy. I am an interdisciplinary researcher, and my interests are centered on environmental justice. Many environmental hazards are disproportionately threatening low-income communities of color, and I came to this field because of my personal experience growing up in an immigrant community in Los Angeles that faced multiple environmental threats. I saw from an early age that individuals and social movements were focusing on how contamination, landfills, and bad air quality were affecting those communities. They sought to produce alternative environmental futures. That really motivated me.

I was also in a voluntary school busing program and traveled from my neighborhood towards a wealthier, white, affluent area. At a young age, I'd be up early and on the bus every day, seeing the differences between the neighborhoods I traveled through. That made me wonder why these communities looked so different. That eventually led me to study urban and environmental planning at MIT. Shortly thereafter, I was invited by my local assembly woman, Cindy Montanez, to work for her in the state capitol. She had a strong passion for environmental justice issues and was thrilled that I was from the district she represented, and that I understood the issues.

I ended up working for several years in the California legislature, and in a few other related policy positions. Eventually I wanted to continue my academic career and was accepted to the city and regional planning department at UC Berkeley for my doctoral program. I endeavored to have a stronger voice on environmental policy and justice issues. Working for politicians, I was in many ways in the seat of power and could make a lot of change, but not necessarily have as much of an independent voice as I wanted to. In addition, the environmental field tends to be pretty white and male. I wanted to be part of that next generation of thought leadership and scholarship around these issues, and serve as a role model for younger people of color.

Your book, Climate Change from the Streets: How Conflict and Collaboration Strengthen the Environmental Justice Movement, is focused on climate change and inequality. In it, you argue that local knowledge, culture, and history must be central to addressing climate change. Can you talk a bit more about this?

I come to academia as a second career, and my work emphasizes the connection between theory and practice. My research has public policy implications because I focus on real world problems facing disadvantaged communities of color. My book provides an on-the-ground view of how environmental justice groups and people of color are influencing the climate change policymaking project in California, as well as globally.

While California is often seen as a global leader on climate change, I shed light on the work environmental justice groups did to rescale the focus to include the neighborhood level, and to direct reduction strategies to the hardest hit communities. In particular, these groups have been able to transform the idea of climate change as an abstract, global challenge to one centered on local issues. We understand that burning fossil fuels creates, of course, carbon and greenhouse gas emissions, but it also emits local pollution that stays at the neighborhood level and affects people's health.

Oftentimes, environmental justice groups are framed as irrational non-experts, which is not the case. These groups have challenged California's climate change programs, improved them, and they continue to innovate. In addition, other states and countries, including our national government, are now looking toward California as they begin similar work. It took over ten years to get to a point where people of color are leading and connecting climate change to racial and environmental justice. My book is the first to tell that story.

Your current research includes drought in disadvantaged communities. Can you talk a bit about these efforts?

In my post-doctoral work, I collaborated with the Community Water Center, the leading water justice group in the state, on drought resiliency and groundwater issues. During California's last extreme drought, I was doing my field work and visited East Porterville, which was ground zero for how water injustice was hitting migrant communities, particularly undocumented Latino migrants. They had very little water, and what they had was often contaminated. At the same time, their water rates were incredibly high for what was essentially undrinkable water. This was affecting people with some of the lowest incomes in the state. The drought was exacerbating these disparities.

Based on that experience, I believe our priority should be ensuring people have safe and affordable drinking water. The human right to water is important and powerful. California is the first state to adopt it as a normative, bold statement. It doesn't yet have teeth but it's a valuable statement that can guide policy, and that is slowly happening.

You have recently been appointed by Governor Newsom to the Los Angeles Regional Water Quality Control Board. That appointment is just beginning, but can you talk a bit about what kinds of things you'll be working on?

It's a major responsibility to be on the board, which is an important regulatory body that regulates water pollution for a region of 11 million people. This is the most technical board I have ever been on. I've been on the city planning commission, on the state mining and geology board, I've advised on air quality and drought issues. But from a regulatory perspective, water is extremely technocratic and has a long federal history that is tied to how we regulate things regionally.  

My goal with the board is to follow through with my history of policy and research focused on providing better opportunities for low-income communities of color, particularly those experiencing environmental injustice. The key topics I will focus on include making our water policies and regulations more inclusive and putting the needs of people of color at the forefront. I also want to move forward on thinking more explicitly about climate change and water resiliency with an equity lens.

What is most exciting to you about what you're working on now?

Right now, I'm most excited about the wildfire research that I'm doing with migrant advocacy and environmental justice groups. This is community-based, engaged work, and my project collaborators are also research partners and co-authors. I originated some of this work after the Thomas Fire in Ventura and Santa Barbara counties, where I worked with an Indigenous migrant rights group to understand the effects of fire on undocumented migrants, and to advocate for better policies. We were equal partners in terms of policy, briefings, presenting at academic and policy related conferences, and working on media campaigns.

I've now been approached by new partners to do similar work in Sonoma County – a joint project that is not extractive. Many times the research process can be extractive, where an academic comes in, collects data, time, and resources, and community groups never see it and don't get credit for telling their own story and having their own voice. This is particularly important with groups like undocumented migrants because this is a stigmatized and exploited population, and therefore my research design and approach should be different as well.

Posted on Monday, March 15, 2021 at 5:57 PM

Growers and researchers refine date palm irrigation

New research gives California date growers the data they need to apply a more precise amount of irrigation water to meet the trees' needs to produce a healthy crop. Photo by Ali Montazar.

California's $86 million date industry produces more than half of the nation's dates. Most of the fruit is grown in the arid Coachella Valley. Despite efforts by growers to conserve water, data was lacking on date palms' actual water use to refine the best irrigation management for the crop until a recent research project led by Ali Montazar, UC Cooperative Extension irrigation and water management advisor for Imperial and Riverside counties.

“California dates are grown in the hottest and most arid climate in North America and require substantial amounts of water in order to bring a successful crop to fruition,” Albert Keck, Coachella Valley date grower and chairman of the California Date Commission, wrote in a letter of support for this project. “In addition, there is scant modern research specifically and technically focused on growing dates in North America.”

Montazar said there is a lack of irrigation management information on date palms worldwide. Therefore, "the information developed in this study is expected to have a worldwide impact,” he said.

To determine the evapotranspiration rate and crop coefficients for California date palms, Montazar teamed up with scientists at UC Davis, California Department of Water Resources, USDA Agricultural Research Service, and USDA Salinity Laboratory.

The experiment was carried out in six date orchards in the Coachella and Imperial valleys. The sites represent various soil types and conditions, irrigation management practices, canopy characteristics, and the most common date cultivars in the region.

“The findings of the project indicate that there is considerable variability in date palm consumptive water use, both spatially and temporally,” Montazar said. In other words, the amount of water the trees use varies considerably depending on each site's growing conditions. He estimated the water needs for date palms planted in different soil types in the low desert region.

“Growers will be able to use the science-based information and tools developed by this project to determine their date palm water needs and optimize the efficiency of water and fertilizer use in their groves,” Montazar said.

Fruit bags protect dates from insect damage and dust and prevent the fruit from falling to the ground. Photo by Ali Montazar.

The peer-reviewed article “Determination of Actual Evapotranspiration and Crop Coefficients of California Date Palms Using the Residual of Energy Balance Approach” is published in the journal MDPI Water.

“With a large quantity of new date plantings in the region, coupled with increasingly limited water resources in the Colorado River Basin Watershed, the knowledge anticipated to be developed by this research project has the potential to yield large dividends through not only improved water use efficiency, but also best management practices and crop quality,” said Keck of the California Date Commission.

Although the research focused on Coachella Valley dates, Montazar said the results are likely to be useful to growers who have orchards with similar varieties, irrigation practices, and canopy and soil features in other locations. 


Montazar's co-authors are Robert Krueger of the USDA-ARS National Clonal Germplasm Repository for Citrus and Dates; Dennis Corwin of USDA-ARS U.S. Salinity Laboratory; Alireza Pourreza UC Cooperative Extension specialist based at UC Davis Department of Biological and Agricultural Engineering; Cayle Little of California Department of Water Resources; Sonia Rios, UC Cooperative Extension advisor in Riverside County; and Richard L. Snyder UC Cooperative Extension specialist emeritus in the UC Davis Department of Land, Air, and Water Resources. The date palm irrigation project was funded by the CDFA Specialty Crop Block Grant Program. 

Posted on Thursday, February 18, 2021 at 2:05 PM
  • Author:

Growing the right tree in the right place with the right amount of water

An almond orchard in bloom in an area used for boron rootstock trials. Photo by Katherine Jarvis-Shean.

Finding a tree that produces the right amount of tasty fruit or nuts under the unique growing conditions of a given orchard takes a lot of science and a little bit of art. It's a mix and match process that involves finding a tree base, or rootstock, that is well-adapted to a particular place and also manages to get along well with the fruit or nut tree cultivar that is grafted to it.

“Rootstocks are incredibly important in agriculture because they help us produce a uniform product under very different growing conditions,” says Katherine Jarvis-Shean, an orchard systems advisor with the University of California Division of Agriculture and Natural Resources in Yolo, Solano, and Sacramento counties. She is researching rootstocks that can tolerate high levels of boron, which she says manifests as a kind of salt toxicity, for the almond, walnut, prune, and pistachio trees she specializes in.

“Boron is an issue up and down the state. Here in the Sacramento Valley, it is found in both soils and irrigation water. Some of that is natural and some of it comes from recirculating irrigation water, which then further concentrates boron in the soil,” says Jarvis-Shean.

“In other areas of California with boron-heavy groundwater, ‘clean' surface water irrigation can help dilute it.” However, this is not the case in the Sacramento Valley. “Here, we have a decent amount of rainfall that helps leach some boron out of the soil. But, it's become a bigger problem with the shift from annual crops like tomatoes and corn to perennial crops like almonds,” says Jarvis-Shean. “Almonds, in particular, tend to build up boron in the tree itself over time, though it doesn't pose any food safety concerns. It does, however, get in the way of yield, which is the thing we care about at the end of the day.”

To carry out her boron-tolerant rootstock research, Jarvis-Shean has been partnering with a grower to trial different options. “We really depend on grower collaboration, and he had been trying to figure this problem out on his own. He was willing to spend some money, in the form of dedicating some land and labor, on the problem in the short-term to have an answer in the long-term,” she says. “We've been able to help with more systematic investigation and analysis.”

The same almond orchard as above, but at harvest time. Photo by Katherine Jarvis-Shean.

 “This work was started by my predecessor, and I've continued it now for many years. We grow different sets of rootstocks with the same cultivar on top. We measure the effect of high boron conditions on nutrient uptake, water stress, and basically anything that might help explain yield differences over time,” she says. “Ultimately, the most important measurement comes at harvest.”

Her results have been incredibly valuable. “We've found that the ‘go-to' rootstock here is actually terrible at dealing with boron because it doesn't come from an area where there's a lot of salt build-up. Instead, we've found that peach-almond hybrids are best at managing the high boron conditions here,” says Jarvis-Shean. “We're getting yields that are on par with low boron levels, up to a point. Once you've got a lot of boron, you have to grow pistachios instead. They love boron and that's why we've seen big growth in pistachio acreage.”

In addition to her work on boron, Jarvis-Shean has also researched the effects of a changing climate on agriculture. “My doctoral work was about how tree crops and orchards respond to warmer winters. We studied almonds, pistachios, and walnuts and found if we don't adapt, we will be in a heap of trouble,” she says. “That's especially true with pistachio, cherry, and walnut. Almonds require the least amount of winter cold of any tree crop in California, so they're in a much better position.”

Jarvis-Shean notes that within the next forty years, winters are projected to be warm enough that in roughly a third of the Central Valley, current crop varieties “aren't going to cut it.” However, she says, “With proper support and incentives for breeding programs, we can figure out how to get these crops through a warmer future. It just takes time, energy, and money, and we're doing some of that work now. For example, we're testing chemical treatments that trick trees into thinking that winter has been cooler than it has been.”

In addition to her research on trees, Jarvis-Shean says her work is similar to that of all cooperative extension advisors, which is a grab-bag of issues that are important to the people she works with and include everything from discussing best practices with small, diversified farm operations to thinking about how soil health relates to water infiltration. For example, she explains, “Given that we do get decent rainfall, we'd like to store more water in the ground locally. That provides an incentive for growing cover crops in this area.”

Given the many issues growers in the Sacramento Valley are facing – climate change and labor among them – Jarvis-Shean says water remains a critical issue. “Water will continue to be a big concern for California agriculture. Warmer winters are an issue, but I think with enough time and money we can sort that out. It's a heavier lift to have enough water available and allocated to keep growing all these things, which has always been the case.”

Posted on Tuesday, December 15, 2020 at 9:05 AM

Improving drinking water safety, access, and consumption in the U.S.

Water fountain. Photo by Daniel Hooper on Unsplash.

Tap water stands at the intersection of multiple issue areas including water resources, the environmental impacts of beverage choices, and infrastructure needs. Tap water is also a public health issue. COVID-19, for example, has elevated the need for tap water access for basic hygiene such as handwashing.

The University of California, Agriculture and Natural Resources Nutrition Policy Institute (NPI), coordinator of the National Drinking Water Alliance, puts a focus on plain water as a healthy replacement for sugar-sweetened beverages. These beverages are the largest single source of added sugars in the American diet, a top source of calories, and a risk factor for numerous chronic diseases. However, concerns about tap water safety and barriers to access present challenges to making water the beverage of choice.

Lorrene Ritchie and Christina Hecht of NPI are among the co-authors of “Drinking Water in the United States: Implications of Water Safety, Access, and Consumption,” a new paper published online in Annual Review of Nutrition. The authors use a socioecological lens – considering the complex web of individual, relationship, community, and societal factors – to review the dynamics of drinking water consumption. This socioecological framework elucidates myriad factors that bear on the ability to drink tap water, including disparities in safety, access, and consumption.

A brief review of the evidence comparing current trends in drinking water intake in the U.S. to requirements across age and racial/ethnic groups reveals that most people do not drink enough plain water. While fluids can come from a variety of sources, there are many benefits of choosing water over sugar-sweetened beverages. Primary among these are the health benefits. Consumption of sugar-sweetened beverages increases the risk of cardiovascular diseases, type 2 diabetes, fatty liver disease and other metabolic diseases, dental decay, certain cancers, and risk of mortality. In addition, water, especially tap water, is not only a healthy form of hydration but is affordable, has a smaller environmental footprint, and, often, is fluoridated to strengthen and protect tooth enamel.

However, to enable tap water consumption, U.S. tap water safety must be ensured. While most U.S. tap water meets federal and state standards, there are times and places where it does not. The paper makes policy recommendations to improve tap water safety in the U.S. For example, lead in drinking water remains a concern. As the authors note, “drinking water can represent 20% or more of an individual's total lead exposure” and the potential lead exposure for infants fed with formula made of powder reconstituted with tap water is a particular concern.

Regulatory mechanisms to reduce lead in drinking water include federal, such as the Lead and Copper Rule, and state, such as mandates for testing for lead in school or childcare tap water. Challenges to detecting and reducing lead in tap water range from the building-specific nature of lead in plumbing to the lack of consensus on an acceptable level of lead in drinking water. Strategies to reduce drinking water exposure to lead include, as examples, the San Francisco Public Utilities Commission program to provide no-charge home tap water lead testing for families in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC, a federal child nutrition program) and efforts in cities to remove and replace both the utility-owned and privately-owned portions of all lead service lines.

Crucially, the authors' advance the concept of “effective access” to drinking water, which includes not only physical elements but also strategies for drinking water education and promotion. They write: “Effective drinking water access is necessary to maximally promote consumption. Key components include safety and aesthetics of drinking water; characteristics, features, location, and placement of drinking water sources; upkeep and maintenance; availability of drinking vessels; and water-related education and promotion.”

Each of these components is reviewed with a discussion of strategies to achieve effective access across the lifecourse from pregnancy and infancy to older adulthood, focusing primarily on U.S. settings but including approaches from other countries. Recommendations for research, policies, and practices needed to ensure optimal water intake by all include protecting watersheds and sourcewater from contamination by industry, agriculture, and other human activities; enhancing oversight of public water systems; and supporting increased capacity among small and rural water systems.

It is also important to improve infrastructure from public water systems to taps; establish a health-based standard for lead from taps in homes, schools, and childcare facilities; issue U.S. Department of Agriculture (USDA) guidance for monitoring tap water safety and remediation in schools and childcare facilities that participate in federal nutrition programs; and disseminate best practices for school districts and childcare providers to resolve water quality issues. Furthermore, there is a need to counter misperceptions of tap water safety and place accurate information about water quality within a broader context of costs and relative risks so that consumers can make more informed beverage choices.

Access to appealing drinking water can be improved by strategies including requiring USDA monitoring of effective access to water in schools and childcare facilities that participate in federal nutrition programs (rather than simply the presence of a water dispenser); ensuring effective water access in all public settings (e.g., public buildings, parks) in addition to workplaces and restaurants; and reducing access to unhealthy beverages (e.g., sugar-sweetened beverages).

Finally, there is a need to emphasize drinking water in the Dietary Guidelines for Americans, including prominently featuring water on public-facing nutrition materials such as the MyPlate graphic, the ubiquitous nutrition-education tool in U.S. The new 2020-2025 Dietary Guidelines for Americans are currently in development. Enabling consumption of water – that is, making tap water safe, accessible, and appealing -- is an essential complement to work to discouraging consumption of sugar-sweetened beverages.

The review was published online in September 2020 by the journal Annual Review of Nutrition. Authors are Anisha Patel of Stanford Medicine Division of General Pediatrics, Christina Hecht and Lorrene Ritchie of University of California Nutrition Policy InstituteAngie Cradock of Harvard T.H. Chan School of Public Health, and Marc Edwards of Virginia Polytechnic Institute and State University. For more drinking water information and resources, visit the National Drinking Water Alliance, coordinated by the Nutrition Policy Institute.


Posted on Monday, November 2, 2020 at 3:20 PM

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