This data set builds directly on the original "Organizational structure and institutional types of community water systems in California" data set published in October 2021 by Dr. Kristin Dobbin and Dr. Amanda Fencl which reflected active Community Water Systems in California as of December 2018 (you can find this original data on Dryad under the following DOI: https://doi.org/10.25338/B8NS7Z). This 2023 update provides a current snapshot of the organizational and institutional structures of active California Community Water Systems with improvements to the accuracy and granularity of the data as we have further developed our understanding of these topics through this and other projects. See the accompanying README file for a complete breakdown of all changes and improvements.