The California drought has presented unexpected challenges to water resource recovery facilities (WRRF). This paper will provide detailed examples of challenges facing existing California facilities and the corrective actions that were implemented to overcome these challenges. Process design and policy considerations for a future “low flow” norm win be presented. Challenges to be discussed include decreased influent wastewater flows, increased wastewater influent pollutant concentrations reduced alkalinity loadings, changed plant process treatment capacity ratings, and impacts to recycled water use and availability.