UC Davis Professor of Law Emeritus Harrison (“Hap”) Dunning passed away at the end of March 2025 at the age of 86. You can read the details of his life in the Davis Enterprise Obituary, including the story of his extensive work in the Civil Rights Movement in the 1960s, but he is best known in the UC Davis community for his work on water law and the public trust doctrine. From serving on the Governor’s Commission to Review California Water Rights Law in the 1970s to his work on the California Water Commission and the Bay Delta Advisor Council, he lived a life of service to the California water community. California’s public trust doctrine is built in part on Prof. Dunning’s legacy of scholarship, which includes a foundation public trust conference at UC Davis that resulted in several papers cited in the California Supreme Court’s Mono Lake decision. He received the Mono Lake Committee’s 2014 Defender of the Trust award “for his extraordinary work defending the public trust and protecting the public’s natural heritage at Mono Lake and its tributary streams.” The University of California flag at the Memorial Union flew at half-staff for three days to recognize Professor Dunning’s passing.
Below we share remembrances from just a few of the many of the water law professionals inspired by Professor Dunning.
“Hap Dunning was my Environmental Law and Water Law Professor at King Hall in the early 1970’s. His teaching inspired me to practice environmental and natural resources law with the California Attorney General’s Office for three decades, and eventually to follow in his footsteps as an environmental law professor at Berkeley Law and King Hall. Hap organized and led the nation’s first legal conference devoted to the public trust doctrine, which in turn produced legal scholarship that was cited frequently in the California Supreme Court’s landmark 1983 “Mono Lake” decision.”
– Richard M. Frank, UC Davis Professor of Environmental Practice and long-time Co-Director California Environmental Law & Policy Center
“Hap was so gentle, so kind, so thoughtful and perceptive, and was always focused on incremental change for the good of all. I was his RA for two years in the early 1990s while I earned my law degree at King Hall. He funded me to perfect the footnotes of his papers and to track the implementation of the Mono Lake Decision. When I asked how I could get involved in instream flow work locally, Hap connected me with Lois Wolk for an introduction to the Putah Creek Council, and that began my work toward the Putah Creek Accord’s new flows for our own creek.
The impact on California water law stemming from Hap’s 1980 Public Trust symposium at UC Davis can’t be overestimated. It set the intellectual framework for the Public Trust Doctrine to be applied to California water allocations, starting with the National Audubon/Mono Lake decision of the California Supreme Court in 1983. Not only did Hap’s work help save Mono Lake, the Public Trust Doctrine and Fish & Game Code section 5937 ([which] must release water to keep below-dam fish in “good condition”) became the legal basis for permanent flows for Lower Putah Creek and countless damned streams in California. Hap and Peter Moyle inspired Karrigan Bork, with a small group of us, to write the definitive law review piece on section 5937—presented and published via the 30-year follow up to the first UC Davis Public Trust Doctrine symposium. Of course, the instream flow work continues today, in part with Bring Back the Kern’s suit to guarantee instream flows through Bakersfield and further downstream.
One sentence from Hap could change one’s life for years and thinking forever. I recall in our Public Land’s class Hap stepping outside law to ground everyone in resource demand management. On another occasion he introduced the benefits of integrated pest management. Hap wanted collaborative problem-solving lawyers, not merely contentious litigators. When I was mayor of Davis, I am positive he never praised me, he’d just ask “what are you working on that’s important?” I loved that—Hap was always nudging progress forward. Recently, it was a joy to catch up with Hap at backyard house concerts.
Hap’s work changed California water law and will do so for decades to come. His was a life well lived; we should all be so fortunate. I will miss him dearly.”
– Joe Krovoza, former Davis Mayor, retired lawyer, and a leader in development across the UC system
“Professor Dunning transformed my life with his Water Law class. He taught not only the complexities of water law but also the history of California water diversion. He commanded respect for the subject matter and would not excuse any absences. When I decided to skip a class to protest a proposition regarding an important civil rights issue, he told me to write a 5-page essay about why he should excuse my absence. Needless to say, the absence was excused.
Later in life when I returned to teach at UC Davis, he was always supportive. One day, I was asked to teach a class for retired professors, and I could see Professor Dunning through the Zoom lecture beaming at me. He was a true professor—one who inspired students, commanded respect, and genuinely loved his students.”
– Holly Cooper, Co-director of the UC Davis Immigration Law Clinic
“I write as a former Board President of the Tuolumne River Trust. I recruited Hap to join the Board in 2008. He served with distinction until December 2024—many years as Vice President.
The Tuolumne River Trust benefited from Hap’s understanding critical regulatory decisions and legal proceedings, such as the yet-unfinished relicensing of Don Pedro Dam, as it has inched forward since 2011.
Aside from Hap’s long-time support of TRT, we honor his contributions to the environmental movement as a leading expert on water law at King Hall, through his groundbreaking work on public trust law that laid the foundation for critical decisions that have protected Mono Lake, as a long time board member of The Bay Institute, and as member of the California Water Commission and Bay Delta Advisory Council.
Hap and his children, Thad and Ashley, inspired TRT to establish our Board-Designated Endowment, The Cascade Fund. We recognized the founders of the fund by naming those initial contributions as the Harrison C “Hap” Dunning Founder’s Circle.
We will miss his intellectual brilliance, collegiality and quick smile.” – Susan Stern, Board Member of the Tuolumne River Trust
“Hap Dunning was an outstanding teacher and mentor. In my time at King Hall, I took three of his courses: Environmental Law, Water Law, and Public Land Law.
All were excellent, but Public Land Law was my favorite. It combined the history of the development of the West with the provisions of the federal laws that apply to our public lands, parks, and monuments, such as the Mining Act of 1872.
When I told Hap that I was interested in environmental law, he suggested that I go into the field of water law, which led to my career in that field. Hap’s influence on his students extended to helping them find internships or other experiences in environmental or water law. For many years, Hap directed students to Jan Stevens in the Land Law Section at the California Attorney General’s Office for internships and other forms of legal experience in the real world. Those of us who were fortunate to work with Jan and his colleagues benefited enormously.
Hap gave me the opportunity to work on the conference on the Public Trust Doctrine held at King Hall in the Fall of 1980. I worked on the Proceedings of the conference and edited the professional articles in the Law Review Symposium volume that resulted. Several articles from that UC Davis Law Review volume were cited by the California Supreme Court in its 1983 Mono Lake decision.”
– Virginia Cahill ’81, former Deputy Attorney General in the California Office of the Attorney General and advocate for the California Department of Fish and Game in the Mono Lake public trust hearings
“Hap’s mentorship, intellectual curiosity, generosity of spirit, and kindness influenced the trajectory of my life. He guided me to an internship with the California Attorney General’s Office, where I am just retiring from a 29-year public service career. And he enthusiastically encouraged me to pursue teaching, which I have been doing since 2005 and will continue into my next chapter. Hap absolutely smashed it in this life—there must be hundreds, if not thousands, whose stories he shaped like my own. I am forever grateful to have known him.”
– Tracy Windsor, former Senior Assistant Attorney General for the California Attorney General’s Office, Natural Resources Law Section, current Lecturer in the UC Davis Department of Environmental Science & Policy the School of Law, and incoming Co-Director of the California Environmental Law & Policy Center
“It is not an exaggeration to say that taking Professor Hap Dunning’s water law class changed the trajectory of my life. I arrived at UC Davis curious about environmental law and left passionate about water. Hap was not content to for his students to merely read and understand cases, he encouraged them to look deeper into law’s evolution as a reflection of societal change. Once bitten with the water law bug, I had the tremendous privilege of attending Hap’s Colorado River seminar and receiving his mentorship through numerous externships. He was fiercely intelligent, generous, and kind, even hosting groups of Environmental Law Society students at potluck dinners in his own home. I have endeavored in my own career to be a water lawyer that would make him proud and to imbue my undergraduate and graduate water law students with a passion for knowledge and justice. I’ll be happy if I can be one tenth of the teacher Hap Dunning was. He touched many lives and is sorely missed.”
– Tina Cannon Leahy, Attorney Supervisor for the California State Water Resources Control Board, Lecturer in the UC Davis Hydrology Department, and Co-Chair of the Advisory Board for the California Environmental Law & Policy Center
Donations to honor Hap Dunning’s memory can be made to his namesake fund at the Tuolumne River Trust or the Harrison F. Dunning scholarship fund at Dartmouth College.
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Thank you for these well deserved tributes to Hap, who inspired many including me. His generous patience taught me contours of the law and regulatory framework that enriched my thinking.