Adjudicated in 1944, City of Pasadena v City of Alhambra et al. was the first basinwide adjudication of groundwater rights in California. The Raymond Basin Management Board was appointed Watermaster in 1984.
The Raymond Basin Management Board regularly monitors groundwater quality in cooperation with local, regional, and state agencies.
The Raymond Basin Management Board is responsible for managing water supply from groundwater fed by local precipitation, imported State Water Project and Colorado River Project water, and recycled water sources.