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Robert M. Hagan Endowed Chair, Water Management & Policy

The Robert M. Hagan Endowed Chair in Water Management & Policy was created to develop and apply new methods and approaches to the resolution of water problems through innovative combinations of science, policy and management; respond to inquiries from concerned persons and groups such as water district directors and staff, elected officials, state and federal government, agriculture, business and other special interest groups; facilitate access to information and to experts; and bring information needs to the attention of appropriate people and groups that may lead to expanded or modified research activities of greater value-added to the public. Dr. Thomas Harter held the chair from 2007 to 2020, as an expert in groundwater hydrology and groundwater issues pertaining to rural and agricultural areas. His research encompasses groundwater resources assessment and modeling, surface water-groundwater interaction, vernal pool hydrology, drought assessment, groundwater banking, assessment and monitoring of groundwater quality impacts from farming, including the fate and transport of nutrients and salts, pathogens, pharmaceuticals, and naturally occurring steroid hormones in California’s aquifer systems.


Research Activities 2014-2020:

My applied research and my extension programs engaged on issues at the nexus between groundwater and agriculture. Our research work investigates groundwater supply and groundwater quality issues relevant to agriculture in California. 

Innovative Approaches to Understanding and Managing Groundwater-Surface Water Interactions in Agricultural Basins -

Many Northern California streams, particularly those where streamflow is not or little affected by upstream reservoir releases, depend on groundwater discharge (what hydrologists call “baseflow”), particularly during the summer and fall, when precipitation is minimal. Many of these streams support important instream and riparian ecosystems. To the degree that groundwater pumping for irrigation or urban uses has impacted groundwater levels, baseflow is affected as well. The Scott Valley, near the Oregon Border, is home to native populations of chinook and coho salmon. Groundwater pumping for irrigation has affected late summer and early fall flows in the Scott River. Through Siskiyou County Cooperative Extension and the Scott Valley Groundwater Advisory Committee, we have been engaging with agricultural landowners and the community in Scott Valley to implement a Groundwater Study Plan. Funded by the North Coast Regional Water Board, we have developed and updated an integrated hydrologic model of the Scott Valley groundwater basin to study the relationship between crop water needs, groundwater pumping for irrigation, and streamflow.  Initial model results spawned a 3-year field study of alfalfa irrigation, soil moisture dynamics, and evapotranspiration. The work improved our understanding of water use in alfalfa crops in Northern California and led to significant updates in the hydrologic model. Model results have been vetted with the local community. The Groundwater Advisory Committee has suggested several potential groundwater management practices, including winter recharge and in lieu recharge, that are now being tested in pilot studies and evaluated using the hydrologic model. The tools we have developed have been used for water rights applications to perform winter recharge, and to comply with reporting requirements related to the adjudicated portion of the Scott Valley.  We anticipate that our work will be contributing significantly to the development of a Groundwater Sustainability Plan for the Scott Valley, required under new groundwater legislation.

Managed Aquifer Recharge in Agricultural Basins -

The 2014 Sustainable Groundwater Management Act requires groundwater basins with significant overdraft, land subsidence, seawater intrusion, water quality degradation, or groundwater pumping induced reduction in streamflow to develop sustainable groundwater management practices. Managed aquifer recharge is seen as an important tool to capture winter runoff not currently allocated to water users and in excess of instream flow requirements. We have partnered with several colleagues at the Center for Watershed Sciences, UC Water, and with the Public Policy Institute of California to implement cutting edge research that will significantly support sound future decision making by water management districts, reservoir operators, state agencies (including water rights division) to increase the amount of managed aquifer recharge using California’s large agricultural landscape as a venue. Agricultural managed aquifer recharge may include winter irrigations in various forms, recharge through unlined canals and set aside land (recharge basins), in lieu recharge, and other forms. Evaluation of water quality implications are another important research topic as these may include threats from flushing of legacy contamination but also benefits by increasing the amount of clean water recharge into potentially contaminated groundwater. We are developing several assessment and modeling tools to evaluate potential increases in groundwater recharge that may be realized, to address water quality issues, but also to understand potential improvements in groundwater-surface water interactions resulting from additional recharge.

Nitrate in Groundwater -

Following the completion of a Report to the Legislature under SBX2 1 (2008), my research group has continued working on groundwater nitrate issues.  The SBX2 1 analysis of groundwater nitrate focused on the Tulare Lake Basin and Salinas Valley, while evaluation of landuse practices (water and fertilizer management) and alternative solutions for affected communities, costs, and policy analysis had state-wide implications. With funding from CDFA and SWRCB, we have expanded the groundwater nitrate analysis to the entire Central Valley. This includes the assessment of the Central Valley’s nitrogen budget dynamics with field-scale spatial resolution and over a 60-year time-spam, compilation of groundwater nitrate data, and extensive statistical and numerical modeling analyses to support our understanding of past and current impacts to groundwater, and to develop long-term solutions that will sustain groundwater quality in California’s agricultural basins. Using the same tools, we are also assessing long-term salinity issues in groundwater that may be detrimental to irrigation water quality (http://groundwater-nitrate.ucdavis.edu). As part of this work, my group continues to implement research groundwater quality issues related specifically to dairies. The Hagan Endowment has provided bridge funding to support students on a project to review the dairy reporting program required by the Central Valley Regional Water Board.


Teaching Activities 2014-2020:

Since 2012, I have been teaching HYD 144 “Groundwater Hydrology” an upper level and first year graduate course introducing students to basic concepts in Groundwater Hydrology. We consider groundwater in the context of several systems to emphasize the interdisciplinary nature of groundwater science: groundwater as a geologic and geographic system, groundwater as a fluid dynamics system, the geochemistry system of groundwater, and the groundwater management system. I brought many of my extension presentations into this class initially and it now feeds back into my extension presentations around California.

Since 2008, I teach an introductory groundwater modeling course, HYD 274 “Practical Groundwater Modeling” in tandem with Dr. Fogg’s more theoretical groundwater modeling course. The course is an extended version of a 3-day shortcourse that Dr. Fogg and I have provided annually through the Groundwater Resources Association since the late 1990s, as part of my cooperative extension program.

Since 2014, I have been teaching a 3-week intensive advanced graduate course at the University of Freiburg, Germany on “The Global Groundwater – Agriculture Nexus”.  The students are participating in the course full-time for three weeks. I teach daily (3-4 lectures) and include field trips and student presentations into the course.  The course is an outgrowth from the 1. Conference “Toward Sustainble Groundwater in Agriculture” in 2010 and builds on my California research and extension experience. We explore groundwater flow systems in agricultural basins, water rights, and water management; we explore groundwater quality impacts from agriculture on groundwater, and water quality regulations. We interview farmers, agricultural advisors, and regulatory agency staff. Each year, students pick a different world region to focus their work on.


List of students funded by the Endowment:

Olin Applegate, 7-11/2014, graduate student in Hydrologic Sciences, provided research to estimate relative salt loading to groundwater from dairy facilities
Taryn Parsons, 6-8/2015, graduate student in Hydrologic Sciences, initiated a research project to review the Central Valley Regional Water Boards’ dairy reporting program
Justin Brieno, Chris Connor, Sarah Hammarlund, Reilly Hoessner, Jonathan Huynh, Christina Leung, Scott Nelson, Yu Liao Peng, Harrison Qiu, Chris Walton, Kaelynn Woodward, and Kim Yea Na, 6-8/2015, undergraduate students, worked on data acquisition for the dairy reporting project
Johana Ramirez-Zapien, 7/2015 – 6/2016, undergraduate student in psychology, supported June 2016 conference organization
Kavitha Dhanukodi, 8/2016 – 3/2017, undergraduate student in computer sciences, provided data entry and data systems management support
Jessica Ho, 8/2016 – 9/2017, undergraduate student in environmental science and policy, author of “Groundwater in the News”, http://groundwater.ucdavis.edu/Groundwater_in_the_News/
Ariel Sim, 8/2016 – 11/2016, undergraduate student in statistics, provided technical support in statistical programming to analyze water level data
Giovanni Castaldo, 9/2017 - 9/2019, graduate student investigating existing domestic well water quality data to understand the effect of groundwater age and recharge sources on nitrate pollution.


Outreach and engagement activities 2014-2020:

My applied research program is closely intertwined with my cooperative extension program. The primary purpose of the Endowment has been to provide financial support to my cooperative extension program, either directly  by sponsoring events and by funding my participation in extension events, or indirectly by providing opportunities to develop applied research and information that supports our extension activities. My extension work has effectively four pillars:

  • continuing education through shortcourses, workshops, conferences, guest lectures, seminars, webinars, video-productions, extension publications, and roundtable discussions in various formats;
  • objective scientific-technical advising to policy- and decision-makers through technical advisory committees or through individual meetings, workshops, or committees and meetings with policy makers, stakeholder groups, industry groups, NGOs etc, at the local, state, and federal level;
  • international outreach and networking through research conferences, hosting visitors, and international workshop participation;
  • and through leadership engagement to advance our knowledge of water supply, water quality, and ecosystem impacts and needs at the groundwater-agriculture nexus.


Two major legislative initiatives over the past 20 years have dominated my advising activities over the past 10 years:  First, the 2002 sunset of the agricultural waiver in California’s Porter-Cologne Water Quality Control Act, which required Regional Water Boards and California’s agriculture to develop not only surface water discharge requirements for agriculture, but also groundwater waste discharge requirements. I have been a leading scientific voice in supporting the development of new, innovative regulatory programs that are suitable to agriculture rather than employing traditional groundwater monitoring and cleanup programs developed for industrial pollution. While our research has provided critical data, tools, and maps, my extension efforts have focused on facilitating the discussion between regulators, environmental NGOs, and agricultural stakeholders to educate and to help shape a scientifically sound, technically effective regulations. I have been actively engaged in the development of the Irrigated Lands Regulatory Program, the Dairy Regulatory Program, and CV SALTS.

Equally intensive has been my engagement with local and state agencies with regard to groundwater management, especially in agricultural regions and especially as it relates to drought water management. I have been actively involved in drought policy discussions in 2007-2009, and have provided extensive outreach, extension, and training to explain drought impacts on groundwater as the 2012-2016 drought began. With back-to-back dry years and droughts in the early 2000s, 2007-2009, and 2012-2016, governor Brown and the state legislature passed the 2014 Sustainable Groundwater Management Act (SGMA). As a science advisor, I was engaged in the drafting of SGMA, in the development of the initial communication and outreach strategy with the governor’s office and state leadership (CDFA, CalEPA, CalResources Agency), in the development of subsequent SGMA regulations through DWR (as a member of DWR’s practioner’s advisory panel), and in the development of technical support through DWR (DWR’s practioner’s advisory panel, modeling advisory panel, Butte County interbasin assessment technical advisory committee, SWRCB SGMA advisory panel, TNC-DWR Groundwater-Dependent Ecosystem advisory committee, and others). Through UC Water (http://ucwater.org) and Stanford’s Water in the West Programm, I have also been actively engaged in statewide discussions and workshops that have significantly informed the shaping of SGMA implementation.

As a Director on the Board of the Groundwater Resources Association (GRA) and as a Board Member for the Water Education Foundation (WEF), I have been able to conduct a significant part of my extension program through these organizations.  At WEF and GRA I am active on several committees, allowing me to reach out to a broad audience in California and providing high quality educational and outreach opportunity.

The Hagan Endowment has allowed me to sponsor several GRA-led workshops including the annual meeting of the Contemporary Groundwater Issues Council (CGIC). CGIC members include state leaders from the policy, management, and scientific arena. Each year, the Council engages in key emerging groundwater policy questions and has contributed significantly to the evolution of both groundwater quality and groundwater management policies and practices that have been put in place over the past eight years in the State of California.

The largest, most comprehensive, and most impactful activity funded by the Hagan Endowment over the past 3 years has been the 2nd International Science and Policy Conference “Toward Sustainable Groundwater in Agriculture” in Burlingame/San Francisco, June 28-30, 2016. The conference has been attended by over 300 participants from California, from across North America, and by attendees from Europe, Asia, Africa, Latin America, and Australia. The 3-day conference was preceded by a day of roundtable workshops on nitrogen policy and on groundwater management in the San Joaquin Valley.  Pre-conference workshops were co-organized with UC Water and with PPIC San Francisco.  The conference itself was organized under co-leadership between myself, Prof. David Rudolph from Waterloo University in Canada, and Jennifer Bowles and Sue McClurg, Executive Director and Deputy Executive Director of the Water Education Foundation, supported by their very talented staff.

The conference itself provided broad policy, technical, and management perspectives from agricultural stakeholders, and growers, from policy- and decision-makers, and from scientists and technical consultants on a wide range of topics related to groundwater in agriculture. Over three days, the conference staged 4 general panels and over 150 presentations in 4 separate tracks, plus a couple of outreach events to facilitate networking and exchange among conference attendees. The conference brought together a unique audience from the agricultural as well as from the groundwater field, growers, practitioners, experts, and decision- and policy-makers.  It provided an opportunity to showcase California’s advances in groundwater supply and quality management, to reflect on California’s approach vis-à-vis efforts in Europe, Australia, India, or China, and elsewhere, and to cross-pollinate ideas and relationships for future collaborations and networking.

The Hagan Endowment supported the conference not only through the engagement of the Water Education Foundation in the conference. Through the Hagan Endowment we also employed an undergraduate student, Johana Ramirez-Zapien, for nearly a year to help the organizational efforts on the UC Davis side of preparing for the conference. Several graduate students were supported that worked as moderators, photographers, and session facilitators during the conference. After the conference, a computer science undergraduate student, Kavitha Dhanukodi, also supported by the Hagan Endowment, developed the post-conference website, which include a complete video-channel featuring nearly 100 presentations taped at the conference and the complete set of presentations and speaker bios, http://ag-groundwater.org. We were able to successfully leverage the Hagan Endowment support with the National Science Foundation, which supported the conference through a $50,000 grant that was used to cover travel support toward our over 60 invited speakers.

Besides my leadership roles with GRA and WEF, I am also the Chair of the Hydrologic Science Graduate Group, a position I took on in 2016, and Associate Director of the Center for Watershed Sciences.

Between July 2014 and June 2020, I have given nearly 600 invited talks, presentations, and guest lectures reaching a face-to-face audience of over 25,000 attendees. These engagements include, among many others, county agricultural industry and other public meetings throughout central and northern California, state and regional ag industry meetings, international food service industry meetings, meetings with local, state, and federal government leaders, and keynote presentations at the National Academy of Sciences, at the national Renewable Natural Resources Foundation, and the Center for Strategic and International Studies in Washington, D.C.. The Hagan Endowment has provided the financial support for me to travel to many of the extension meetings held aross California.

The contributions of the Robert M. Hagan Endowment for Water Management and Policy includes not only the financial support for a broad and diverse cooperative extension program, but is also providing a prestigious honor that has greatly raised the profile and visibility of my cooperative extension appointment over the past ten years. I greatly appreciate the efforts and vision of Professor Bob Hagan and his water district and agricultural partners in putting together this important endowment. My commitment is to continue our efforts in Bob’s spirit - to provide excellent science, education, and information to stakeholders and policy- and decision makers in effective ways as California moves toward a sustainable future for agriculture and the groundwater resources that agriculture and our communities depend on.


Stewardship Report 2007-2014

The following is a synopsis of the Hagan Endowed Chair activities during the first seven years of the program:

  •  Led and directed a major 2010-2012 scientific study & policy outreach campaign for the UC Davis study SBX2 1 Nitrate in Drinking Water Report to the California Legislature, which included 3 full-day public workshops, 3 half-day public workshops, 4 full-day state-federal environmental agencies workshops; a year-long seminar discussion series with 16 events featuring invited state and federal agency and stakeholder leaders and representatives; a series of media planning events with public relations planners from 8 state agencies and university institutes; over 50 organized event presentations; development of a website with peak page view rates exceeding 3,000 (over 25,000 page views in the first five months), http://groundwaternitrate.ucdavis.edu; a media campaign with interviews that yielded nearly 400 national newspaper articles, online newsblogs, radio and TV news and feature program broadcasts; nearly 30 invited presentations and briefings to state, national, and international audiences, stakeholder groups, and state leadership (legislative briefing to state assembly members and senators, briefings with the governor’s office, individual and executive briefings with heads of seven state agencies – CalEPA, CDPH, CDFA, DPR, DWR, SWRCB, CalNR); and at least four state legislative initiatives during the 2012 legislative session.
  • Developed, led, and chaired a first and unique International Conference “Toward Sustainable Groundwater in Agriculture – Bringing together Science and Policy”, held near San Francisco in June 2010, which received enthusiastic reviews. I developed the idea for and also the structure of the conference; created a diverse Program Council of internationally recognized experts to help develop and advertise the program; contacted, managed, and brought more than 70 invited speakers to the conference, which had a total of over 130 oral presenters. I worked with the Water Education Foundation to organize the conference and raised more than $20,000 in support of the conference. Attendance was nearly 300 with a large California delegation, and national and international attendees from North- and South-America, Europe, Africa, Asia, and Australia. The interdisciplinary conference highlighted the broad array of technical, management, and regulatory issues at the groundwater-agriculture interface and brought together scientists, managers, and policy makers from around the globe. I also developed the conference website (with help from WEF) and the post-conference website http://ag-groundwater.org, which now hosts an extensive amount of conference materials (abstracts, presentations, a large number of videos) in lieu of conference proceedings. I was the guest editor of a special issue in Water Resources Research on the conference theme to organize post-conference publications.
  • Regularly provide groundwater policy and management support with significant impact to state and federal groundwater quality and management policy; this includes regular reports to the San Joaquin Valley Ag Water Committee of the Association of California Water Agencies (ACWA), and active participation in the Groundwater Resources Association (GRA) Legislative Liaison Committee, which is in charge of providing technical information and education to legislatures and their staff in the capitol; review of key groundwater tools and policy documents (e.g., guidance on groundwater modeling tools for water managers; review of ACWA’s statewide Groundwater Framework “Sustainability from the Ground Up: Groundwater Management in California – A framework”); frequent consultation with state legislative staff and occasionally with legislators, and frequently with regulatory agency staff and stakeholders on emerging implementation of groundwater-related regulations. Recommendations from our 2006 Report on Dairy Manure Management and subsequent technical comments on groundwater compliance monitoring provided to the Central Valley Water Board were implemented in the 2007 Dairy General Order, a major overhaul of groundwater quality regulations on confined animal facilities. Groundwater quality monitoring strategies that I helped develop for the dairy general order are currently proposed to also be implemented as part of a new Irrigated Lands Regulatory Program, and are likely to be reflected in a statewide salt and nutrient management and regulation policy by the State Water Board. Through meetings and extension presentations, I actively work with local landowners, local and state agencies, local and state policy makers, and a variety of stakeholder groups in the Scott River watershed, a pivotal salmon-spawning un-managed stream that currently is a focal point for statewide policy efforts to reform groundwater management strategies, especially with respect to groundwater-dependent ecosystems.
  • Since 2008, I am on the Board of Directors of the Groundwater Resources Association (GRA), a professional organization “dedicated to resource management that protects and improves groundwater through education and technical leadership”. We meet quarterly for one to two full days; and I lead their education committee, which meets monthly. As a board member, I have co-initiated and been instrumental in the development of three major new GRA programs: the 501(c)(3) GRA-WEF Scholastic Fund Program to support California college and graduate students with an interest in groundwater sciences (annually raises approximately $10,000); the David Keith Todd Distinguished Lecturer series, which annually nominates two internationally recognized, outstanding groundwater scientists and organizes and supports their lecture series at California academic institutions and professional society meetings; and the Contemporary Groundwater Issues Council, an advisory council to GRA leadership that brings together California’s top policy, agency, and academic leaders in groundwater science, policy, and management. As of May 2014, I am also on the Board of Directors of the Water Education Foundation (WEF).
  • Actively involved in the organization, programming, and hosting of statewide/national groundwater conferences led by GRA’s events committee (Groundwater Monitoring Conference, Groundwater Salinity Conference (2009), Biennial Groundwater Conference (2009, 2011), Groundwater Nitrate Conference 2005, 2012).
  • Main organizer and main instructor of continuing education programs offered through the Groundwater Resources Association (GRA), that includes three regularly taught shortcourses.
  • Maintained strong extension and workshop program (over 400 presentations during the appointment period) and frequent technical-scientific advisory activities with local, state, and federal agencies, and a highly visible workshop with the state legislature on topics related to groundwater resources, nonpoint source pollution, groundwater quality impacts from dairies, and design of groundwater monitoring well networks for nonpoint source pollution regulation; actively engaged in the development of state regulations, and associated outreach activities to a wide variety of stakeholder groups, on agricultural/rural groundwater issues, particularly on environmental impacts from a rapidly expanding dairy industry in the Central Valley, and on groundwater-surface water interaction in the Scott Valley/Klamath Basin. 
  • We maintain an extensive online presence with groundwater information, resources, course materials, and an up-to-date groundwater calendar, http://groundwater.ucdavis.edu. Between January 2006 and June 2012, the site received over 250,000 page views and averaged nearly 100 page views per day. Between 2009 and 2011, my publications available through that website are downloaded at an average rate of 134 downloads per day (nearly 100,000 downloads over a two-year period). My factsheets on water well construction, groundwater, and groundwater quality remain the most popular publications. In addition, http://ag-groundwater.org received nearly 500,000 hits and, to-date, had 38,000 page views from 19,000 visitors at over 11,000 unique IPs.