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Posts Tagged: Water

The Water Girls

If you're struggling with triple-digit temperatures, think about the honey bees. They need to collect water for their colony to cool the hive so...

A honey bee, its proboscis extended, collects water from the edges of a birdbath. (Photo by Kathy Keatley Garvey)
A honey bee, its proboscis extended, collects water from the edges of a birdbath. (Photo by Kathy Keatley Garvey)

A honey bee, its proboscis extended, collects water from the edges of a birdbath. (Photo by Kathy Keatley Garvey)

For worker bees: Two's company, three's a crowd, and four is a work party. Bees collecting water from a birdbath. (Photo by Kathy Keatley Garvey)
For worker bees: Two's company, three's a crowd, and four is a work party. Bees collecting water from a birdbath. (Photo by Kathy Keatley Garvey)

For worker bees: Two's company, three's a crowd, and four is a work party. Bees collecting water from a birdbath. (Photo by Kathy Keatley Garvey)

'The Water Girls'--six of them--collecting water at a Vacaville birdbath. Note the absence of  birds. (Photo by Kathy Keatley Garvey)
'The Water Girls'--six of them--collecting water at a Vacaville birdbath. Note the absence of birds. (Photo by Kathy Keatley Garvey)

'The Water Girls'--six of them--collecting water at a Vacaville birdbath. Note the absence of birds. (Photo by Kathy Keatley Garvey)

A honey bee  heading back to her colony after collecting water to cool down the hive. (Photo by Kathy Keatley Garvey)
A honey bee heading back to her colony after collecting water to cool down the hive. (Photo by Kathy Keatley Garvey)

A honey bee heading back to her colony after collecting water to cool down the hive. (Photo by Kathy Keatley Garvey)

Posted on Thursday, June 6, 2024 at 8:00 AM
Focus Area Tags: Environment, Innovation, Natural Resources, Yard & Garden

Water risks to agriculture: Too little and too much

"To make agriculture resilient to climate risks, we need to engage in holistic solutions that integrates environmental, social, economic and policy considerations," said Tapan Pathak, left, shown adjusting moisture sensors in a strawberry field.

Water is among the most precious resources on the planet. Some areas don't get enough; some get too much. And climate change is driving both of those circumstances to ever-growing extremes.

Two UC Merced experts in civil and environmental engineering took part in a recent report by the Environmental Defense Fund examining the issue and potential solutions. Associate Professor of Extension Tapan Pathak and Professor Josué Medellín-Azuara co-authored the report, "Scarcity and Excess: Tackling Water-Related Risks to Agriculture in the United States," and wrote the section pertaining to California.

In addition to climate change, disruptive human interventions such as groundwater over-extraction, sprawling drainage networks and misaligned governance are driving up water-related agricultural costs, particularly in midwestern and western states, the researchers found.

The problem is magnified in California, which hosts the largest and the most diverse agricultural landscape in the U.S., Pathak and Medellín-Azuara wrote, with gross revenues from farms and ranches exceeding $50 billion.

"Due to the favorable Mediterranean climate, unique regional microclimate zones, a highly engineered and developed water supply system, and a close connection between producers and research and cooperative extension institutions, California's agricultural abundance includes more than 400 commodities, some of which are produced nowhere else in the nation," the UC Merced researchers wrote.

Policies and funding are needed to support farmers’ efforts to adapt to drought and flood risks, write the report authors.

But the state's varying climate and water needs pose a challenge. Though most of the precipitation falls in the northern part of California, the southern two-thirds of the state account for 85% of its water demand. And all of those crops must be watered in the summer, when there is little, if any, rainfall.

Some of the water comes from snowpack developed through winter storms and stored in reservoirs as it melts. Much of it comes from the Colorado River.

"Substantially less water is captured and stored during periods of drought, imperiling California's water supply and putting agricultural water needs at risk," Pathak and Medellín-Azuara wrote.

Climate change, with increasing periods of drought between excessively wet winters, magnifies that risk.

"Further, the rate of increases in the minimum temperatures in the Sierra Nevada is almost three-fold faster than maximum temperatures, resulting in potential decrease in the snowpack, earlier snowmelt, and more water in liquid form as opposed to snow," the researchers wrote. "According to the California Department of Water Resources, by 2100, the Sierra Nevada snowpack is projected to experience a 48% to 65% decline from the historical average."

Climate change is also expected to affect the availability of water from the Colorado River.

Climate extremes such as heat waves, drought and flooding - giving rises to increased weeds, pests and disease - are already significantly impacting agriculture and the broader economy, Pathak and Medellín-Azuara wrote.

The state's drought from 2012 to 2016 led to about 540,000 acres of fallow farmland in 2015, costing the state's economy $2.7 billion in gross revenue and 21,000 jobs. With the lack of precipitation, farmers increasingly pumped groundwater to irrigate crops, depleting those resources.

The report goes on to recommend policies, programs and tools be developed for agricultural resilience, including:

  • Changing land use and crop management practices to support a transition to an agriculture footprint that can be sustained by the available water supplies.
  • Increasing farmer and water manager access to important data and innovative technological tools to support their efforts.
  • Reimagining built infrastructure and better using natural infrastructure so regions are better equipped to handle weather extremes.
  • Developing policy and funding mechanisms to support mitigation and adaptation to water-related risks, avoid maladaptation and ensure food and water security.

"California's innovative agriculture needs to rapidly adapt to more volatile water availability, climate-driven higher water demands, and regulation protecting groundwater reserves, communities and ecosystems," Medellín-Azuara said. "The early adoption of more sustainable practices in agriculture will likely pay off dividends both in the short and long terms."

Added Pathak, "California faces significant challenges related to climate change, but it also presents opportunities for innovations, collaborations and sustained growth. To make agriculture resilient to climate risks, we need to engage in holistic solutions that integrates environmental, social, economic and policy considerations."


Posted on Monday, March 18, 2024 at 11:44 AM
  • Author: Patty Guerra, UC Merced
Focus Area Tags: Agriculture, Natural Resources

International water scholars convene in South Africa

Attendees gather for the 11th Biennial International Rosenberg Forum on Water Policy at the University of Cape Town, South Africa.

Water scholars from 18 countries gathered in South Africa for the 11th biennial Rosenberg Forum on International Water Policy. Hosted at the University of Cape Town's (UCT) Water and Production Economics (WPE) research unit, this year's forum included the most diverse group to date, in terms of discipline, geography and early-career professionals. The week-long event, Oct. 23-27, addressed water quantity and quality management, economic production and welfare implications in the Global South.

Glenda Humiston, advisory committee member and University of California vice president of agriculture and natural resources, and Soroosh Sorooshian, forum chair, advisory committee member and distinguished professor of the departments of Civil and Environmental Engineering and Earth System Science at UC Irvine played key roles in planning and facilitating this year's forum.

Innovative approaches to water management – lessons from the Western Cape

This year's Rosenberg Forum kicked off with a day-long tour to observe public water system infrastructure and research sites in the Western Cape. These activities were arranged by Djiby Thiam, professor of economics and director of Water and Production Economics Unit at the University of Cape Town.

“Given the growing population and economic development that characterize countries in the Global South, water demand is expected to grow, putting more pressure on the limited natural resources. And this may affect social welfare,” Thiam noted. 

During the tour, forum attendees discussed ongoing challenges and innovations in storm water management, blue-green infrastructure, aquifer recharge andwastewater treatment. Tour stops included an urban watercatchment site, the Berg River Dam, and a working farm that uses treatedwastewater for irrigation, among others.

Rosenberg Forum attendees learn about nature-based solutions to treat and use contaminated wastewater in the Western Cape from a local researcher.

Diverse perspectives to address water challenges

Wednesday and Thursday's sessions included presentations and panels addressing a range of topics related to challenges and opportunities to increase efficient and equitable water use in the Global South.

Wednesday's sessions emphasized the need to improve digital technology to address climate change, gender-inclusive approaches to climate-smart agriculture, wastewater reuse for irrigated agriculture, and the importance of building institutional capacity for policy changes. 

According to Caroline Gelderblom of the World Wildlife Fund International in South Africa, “there is increasing awareness that there is a need to build cross-sectoral extension efforts to improve both national and international water resource strategies.”

Extension strategies that address multiple welfare challenges are quickly being adopted across the globe, but further integration is needed, particularly in water-scarce regions.

Thursday's sessions explored issues related to water pricing, collective management of surface and groundwater water resources and new approaches to address water scarcity.

Unpacking water management complexities in the global south

Friday's discussions included a technical workshop where scholars and practitioners presented research on the complexities associated with water in agriculture, urban and mining sectors, climate-induced risks, and policy interventions. 

Organized by Thiam; Ariel Dinar, distinguished professor of environmental economics and policy at the UC Riverside School of Public Policy; and Christina Babbit, water stewardship senior manager of enterprise sustainability at Starbucks, the final day of the forum allowed scientists to present rigorous academic research on the policy interventions that are needed to address critical social, economic and environmental challenges in water management.

The technical workshop allowed scholars to test research methodologies that influence policymaking and, according to Thiam, are rigorous enough to be shared with an academic audience. 

Technical manuscripts from this workshop will be published in a special issue of the Journal of Applied Economic Perspective and Policy. 

History of the Rosenberg Forum

In 1996, the forum was established as an endowment gift from Bank of America's former chairman and CEO Richard Rosenberg. His vision was to bring together international scientists and policymakers to address global water issues through information-sharing, dialogue and data-driven decision-making. 

Biennially, the forum convenes experts from around the world to identify approaches to reduce conflict in the management of water resources. The Rosenberg Forum is a program of the University of California Agriculture and Natural Resources' California Institute for Water Resources.

Posted on Monday, November 20, 2023 at 8:31 AM
  • Author: Hope Zabronsky, Academic Coordinator for Climate Smart Agriculture
Tags: Rosenberg Forum (1), water (86)
Focus Area Tags: Natural Resources

UCCE offers water measurement and reporting course Nov. 6

Water diverted onto a crop field. Photo by Khaled Bali

California water-rights holders are required by state law to measure and report the water they divert from surface streams. For people who wish to take the water measurements themselves, the University of California Cooperative Extension is offering in-person training to receive certification on Nov. 6 in Davis.

At the workshop, participants can expect to

  • clarify reporting requirements for ranches.
  • understand what meters are appropriate for different situations.
  • learn how to determine measurement equipment accuracy.
  • develop an understanding of measurement weirs.
  • learn how to calculate and report volume from flow data.

The training is scheduled for 9 a.m. to 12:30 p.m. on Nov. 6 at the UC Agriculture and Natural Resources building at 2801 2nd Street in Davis.

“We are limiting the number participants for the water measurement training to 30 people per session,” said Larry Forero, emeritus UC Cooperative Extension livestock and natural resources advisor. “If you need this training, please register soon.” 

Registration is $30 and pre-registration is required. To register, visit If you have questions, email Forero at or Sara Jaimes at or call (530) 224-4900.


Senate Bill 88 requires that all water right holders who have previously diverted, or intend to divert, more than 10 acre-feet per year (riparian and pre-1914 claims); or who are authorized to divert more than 10 acre-feet per year under a permit, license or registration; to measure and report the water they divert. Regulatory requirements for measurement and reporting are available on the State Water Resources Control Board Reporting and Measurement Regulation webpage. The legislation requires that installation and certification of measurement methods for diversion (or storage) greater than or equal to 100-acre feet annually be approved by an engineer/contractor/professional. 

California Cattlemen's Association worked with Assemblyman Bigelow to allow a self-certification option. Assembly Bill 589, which became law in 2018, allows any water diverter who completes this UC Cooperative Extension course on measurement devices and methods (including passage of a proficiency test) to be considered a qualified individual when installing and maintaining devices or implementing methods of measurement.


Posted on Monday, October 23, 2023 at 10:05 AM
Focus Area Tags: Agriculture

UCCE San Diego advisor educates growers on complex water regulations

‘Ag Order' for San Diego County expected to be enforced by end of 2023

Gerardo "Gerry" Spinelli looks for symptomatic agave plants at Altman Plants Nursery in Vista. Photo by Saoimanu Sope.

Generally known for its steady warmth and picturesque beaches, San Diego County is also home to nearly 5,000 small farms and is an economic hotspot for nurseries and floriculture. But the great diversity of ornamental crops that dominate the growing region and complexity of regulations make compliance challenging for growers, some of whom grow over 400 crop varieties.

“The regulatory environment for the growers is still complicated and overwhelming because, along with the Regional Water Board, growers are regulated by the County of San Diego,” said Gerardo “Gerry” Spinelli, University of California Cooperative Extension production horticulture advisor for San Diego County.

To help growers with compliance, Spinelli is prioritizing education and expanding growers' knowledge. By partnering with organizations such as the Farm Bureau of San Diego County and the San Diego Region Irrigated Lands Group, Spinelli works to reach more than 1,200 growers, supporting them as they navigate regulatory agencies.

Formally referred to as the Regional Water Quality Control Boards, the Regional Water Board aims to develop and enforce water quality objectives and implement plans to protect the beneficial uses of California's waters.

Members of the Sunlet Nursery pose with Johanna Del Castillo Munera, Assistant Professor of Cooperative Extension at UC Davis Department of Plant Pathology, and Spinelli. Photo by Gerry Spinelli.

A unique place to grow in California 

About 10 years ago, the Regional Water Board created the Agricultural Order (Ag Order), a set of rules outlining how growers manage water discharge from agricultural operations.

The new Ag Order for San Diego County, expected to be enforced by the end of 2023, will focus on nitrogen management and groundwater quality. However, new considerations are needed to address the variety of crops grown by a single farmer, a common practice in San Diego.

Calculating nitrogen input and output for more than 400 crop varieties is not feasible for small farmers, a challenge exacerbated by the meticulous attention needed for San Diego's high-end specialty crops like ornamentals, native plants and specialty fruit.

Furthermore, many San Diego growers have limited expertise and experience because they are entering agriculture as a second or third career. Many have become “accidental growers” in that they purchased land with a preexisting avocado or cherimoya grove, for example.

To help address these challenges, the grower community is emphasizing the need for more educational opportunities that are accessible and relatable. 

Members from regulatory agencies tour Olive Hill Greenhouse in Fallbrook hosted by the San Diego Region Irrigated Lands Group. Photo by Saoimanu Sope.

Equipping growers through education

Enrico Ferro, president of the San Diego Region Irrigated Lands Group – a third-party entity that manages water sample testing on behalf of growers – has relied on Spinelli's teaching to “bridge the gap” for growers, including himself.  

“Gerry has been great because he has expertise in nurseries, but the educational content he creates is relevant to all growers,” said Ferro, who is an avocado and citrus grower in San Diego's North County.

Spinelli, who specializes in containerized production in nurseries and floriculture, has been instrumental in providing technical assistance to growers since he joined Cooperative Extension in 2020.

“I started teaching over Zoom since I became an advisor during the pandemic, and I try to cover different topics for each training,” Spinelli said, adding that he teaches in English and Spanish, making his content more accessible to the grower community in San Diego.

For in-person educational opportunities, Spinelli created the “Last Wednesday” monthly meetings hosted at the Farm Bureau of San Diego County, which brings together growers and other agricultural experts to learn from one another. 

“We try to get our information out in creative ways and Gerry is instrumental in that. He's our primary source of really wonderful information delivered in an engaging way,” said Tasha Ardalan, program coordinator for the SDRILG. “He's proactive and is always willing to try new things, too.”

Spinelli with Javier Lopez, head grower at Altman Plants in Fallbrook. Photo by Gerry Spinelli.

Planning for San Diego's agricultural future 

Currently, the Ag Order is modeled around regulations for the Central Valley. As conversations and planning for San Diego County continue, Spinelli is supporting the Regional Water Board with information on nurseries and greenhouses in hopes that the final Ag Order will better serve San Diego growers. 

“I'm trying to help others understand how nursery and greenhouse production systems function, and how and why they are different from an almond orchard or tomato field in Fresno,” explained Spinelli.

Michael Mellano, CEO of Mellano & Company, a fresh cut flower grower and distributor in Oceanside, feels the impact of the Ag Order and its failure to account for variability. Growing over 100 varieties of flowers, Mellano said that for several plants there is little scientific research on how much nitrate to apply.

“Farmers want to do a good job. We make mistakes and we try to fix them as quickly as we can, and we try to educate others on what works,” said Mellano, who is also a member of the SDRILG. 

Growers like Mellano and Ferro agree that the farming community in San Diego needs to be given the latitude to solve problems within their means, an ability that requires an understanding of San Diego's uniqueness.

“San Diego is significantly different, and we need an Ag Order that is reflective of our differences,” said Valerie Mellano, SDRILG consultant and former UCCE environmental issues farm advisor. “In developing the new Ag Order, there's a huge opportunity for education and research, something that we know Gerry can easily do and continue to support us in.”

Thus far, Spinelli's educational content has reached two-thirds of SDRILG's 1,200 members. In addition to the live training sessions, growers can watch videos that cover topics such as evapotranspiration, irrigation distribution uniformity, water quality indicators and more on Spinelli's YouTube channel.

Since the Ag Order requires all growers to complete two hours of water-quality education, the SDRILG has agreed to apply one hour of credit to growers who attend a one-on-one session with Spinelli.

As San Diego's growers continue to leverage educational opportunities – whether it's alongside Spinelli, SDRILG or learning from one another – Spinelli emphasized that their success also relies on an ag order that adheres to a distinctive landscape, multitude of specialty crops and growers with varying expertise.

A variety of tropical ornamental plants grown at Olive Hill Greenhouse in Fallbrook. Photo by Saoimanu Sope.
Posted on Tuesday, August 8, 2023 at 1:19 PM
Focus Area Tags: Agriculture, Environment, Health, Natural Resources

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