From The Bay-Delta Science Conference and – The Sacramento and San Joaquin water-year type indices are fundamental to the State Water Project and Central Valley Project operations as every year, how much water is allocated to whom depends on whether the hydrology is expected to be wet, above normal, below normal, dry, or critically dry.  The water-year classifications were last revised in 1991 and were indexed to historical climatic conditions; however, as California’s precipitation patterns and rain/snow mix continue to change, this framework may need to be revised. At the 2021 Bay-Delta Science Conference, Wyatt Arnold, an engineer with the Department of Water Resources Climate Change Program, discussed a study he did with colleague Romain Maendly looking at how water year types could potentially be recalibrated and the implications of that for Delta water management. (more)