In 2015, the William and Flora Hewlett Foundation launched a three-year, $6-million California Drought Initiative to help ensure that local communities and natural systems both have adequate and sustainable water supplies. This board-approved action was a response to 1) approval of a $7.5-billion water bond in California, 2) landmark state legislation to create a groundwater management system, and 3) a gripping 5-year drought that ended early in 2017.  Now in the initiative’s final year, Hewlett Foundation seeks to evaluate its strengths and weaknesses and understand lessons learned that are important for future California-specific and/or other charitable investments associated with the foundation’s broader western conservation portfolio.