Groundwater provides up to two-thirds of Californias freshwater supply. Achieving sustainable groundwater management has significant economic, ecological and social consequences, which the Sustainable Groundwater Management Act of 2014 aims to address. Previous work investigating natural resource decision-making has shown that more effective and sustainable solutions emerge when participants jointly grapple with and develop a shared understanding of data and problems. This project focuses on two tools critical to collaborative decision-making. First, researchers will examine the use of collaborative models as decision support tools that promote a shared understanding of the groundwater issues, starting assumptions, and possible solutions. Second, we will explore the value of acquiring data using geophysical methods to inform specific management decisions. The research team brings together experts from geophysics, collaborative modeling, and dispute management to investigate the role that shared learning has on more sustainable groundwater management in California.