In 1991 the National Research Council, pointing to a shortage of qualified hydrologists in both the short term and the foreseeable long term, called for hydrologic science to be formulated as an independent scientific discipline with distinct training and research programs to bring about “a coherent understanding of the role of water in the planetary-scale behavior of the Earth’s system.”  Although hydrology has existed as a focused, quantitative discipline addressing water storage and flux for almost a century, an array of public and private institutions noted that the next frontier in hydrologic sciences lies in the integration between disciplines, and the evaluation of linked physical, biological, and chemical processes at various spatial and temporal scales.  Faculty at UC Davis understood these recommendations and were already pursuing a vision to formalize hydrologic science as a Graduate Group at UC Davis.  Thus, UC Davis has always been and remains at the forefront of vision and action for producing the world’s leaders in the science and management of complex, integrated water problems.
The Hydrologic Sciences Graduate Group was established in Fall 1991 to provide a comprehensive, unified hydrologic science curriculum with a new multidisciplinary emphasis that takes advantage of the broad range of expertise in water-related disciplines at UC Davis.  As set forth in the 1992 degree requirements (which remain in force today), the resulting degrees (i.e., PhD degree, MS Plan I (Thesis) degree, and MS Plan II (Comprehensive Exam) degree) incorporate a vigorous integration of fundamental chemistry, physics, biology, math along with derivative ecology, geophysical science, and engineering as well as a modicum of law, economics, and policy.  This design broadens the skills and knowledge of the natural science or engineering student interested in any aspect of water-related phenomena. The program expands the boundaries of the traditional discipline of hydrology to encompass the nexus between water and linked constituents yielding complex phenomena and systems.  That is why the Graduate Group is named Hydrologic Sciences (plural form) instead of just Hydrology or Hydrologic Science.  The HSGG program draws on the historic strengths of several water-related educational and research programs on campus.  HSGG faculty have a well-established history of governmental and non-governmental stakeholder collaboration, forming the foundation for producing societally important educational, research and outreach outcomes.
Since its founding, HSGG is administered by the Department of Land, Air and Water Resources within the College of Agricultural and Environmental Sciences.  HSGG bylaws were most recently updated and approved by Graduate Council in 2011.  HSGG bylaws and degree requirements are posted as pdf documents on the HSGG and Graduate Studies websites. HSGG adopted the Graduate Council mentoring guidelines.  There has always been a student handbook to aid graduate students, with recent updates occurring in 2006 and 2012.