Drought is best defined by its impacts to water users or the environment at a specific location since impacts are determined by local conditions. Hydrologic conditions causing impacts for water users in one location may not cause impacts for water users in a different part of the state or with a different water supply. Individual water suppliers may use criteria such as rainfall/runoff, amount of water in storage, decline in groundwater levels, or expected supply from a water wholesaler to define their water supply conditions. Although California’s water supply infrastructure provides a means to mitigate impacts for most water users, other types of impacts (increased wildfire risk, stress on vegetation and wildlife) remain.

Click here for basic background on drought in California. Additional detailed information is provided in the DWR reports below.