Unprecedented Drought Challenges for Texas Water Resources in a Changing Climate: What Do Researchers and Stakeholders Need to Know?

Long‐range water planning is complicated by factors that are rapidly changing in the 21st century, including climate, population, and water use. Here, we analyze climate factors and drought projections for Texas as an example of a diverse society straddling an aridity gradient to examine how the projections can best serve water stakeholder needs. We find that climate models are robust in projecting drying of summer‐season soil moisture and decreasing reservoir supplies for both the eastern and western portions of Texas during the 21st century. Further, projections indicate drier conditions during the latter half of the 21st century than even the most arid centuries of the last 1,000 years that included megadroughts. To illustrate how accounting for drought nonstationarity may increase water resiliency, we consider generalized case studies involving four key stakeholder groups: agricultural producers, large surface water suppliers, small groundwater management districts, and regional water planning districts. We also examine an example of customized climate information being used as input to long‐range water planning. We find that while stakeholders value the quantitative capability of climate model outputs, more specific climate‐related information better supports resilience planning across multiple stakeholder groups. New suites of tools could provide necessary capacity for both short‐ and long‐term, stakeholder‐specific adaptive planning.Nielsen‐Gammon, Banner, Wong, and Tremaine were supported in part by the National Science Foundation Coupled Natural and Human Systems program, Grant AGS‐1518541, the Cynthia and George Mitchell Foundation Grant G‐1809‐55892, and by The University of Texas at Austin's Planet Texas 2050 Bridging Barriers research initiative. We thank Katharine Hayhoe, Ron Anderson, and Tim Finley for their insights and contributions to the manuscript. We thank the participants of the CNH project and the Texas Water Research Network for helping to define the problem and identify issues.Office of the VP for Researc