The San Joaquin Valley faces a defining water challenge: how to secure reliable supplies, manage flood risk, and protect ecosystems across one of California’s most productive regions. The Unified Water Plan (UWP) lays out a comprehensive strategy for the eight-county Valley—San Joaquin, Stanislaus, Merced, Madera, Fresno, Kings, Tulare, and Kern—spanning the San Joaquin River and Tulare Lake hydrologic regions through 2040 and beyond. Congress directed the effort under Public Law 111-11, with funding from the U.S. Bureau of Reclamation. The California Water Institute (CWI) at Fresno State developed the plan in coordination with the Water Blueprint for the San Joaquin Valley. The plan pairs a regional strategy for water supply reliability, flood management, and ecosystem needs with a sobering conclusion: even an estimated $18 billion to $33 billion in infrastructure investments and management actions would not fully close the Valley’s projected water supply gap.