Water management is increasingly complex with divergent competing pressures. While management challenges are exacerbated by drought conditions, in several basins there are significant shortages even under normal or average conditions (Scanlon et al., 2012;Vörösmarty et al., 2000). Moreover, these water management conflicts are expected to worsen under changing climate conditions (Crossman et al., 2013;Rajagopalan et al., 2018). Water markets are a useful management tool to facilitate more efficient allocation of water within agriculture and across other uses such as instream flows, and to enhance strategic water governance goals (Chong & Sunding, 2006;Landry, 1998;Richter et al., 2003). However, there are multiple impediments to well-functioning water markets, which both limit potential benefits of water trading, and affect feasible market structure and water transaction form and function. Transaction costs of water market participation, regulatory administrative costs, legal costs, monitoring costs, institutional transaction costs to adopt transformational policies, uncertainty over water availability, and imperfect measurement of consumptive use all affect water market and water transaction design, participation, and effectiveness