In February 2009, the State Water Resources Control Board (SWRCB) adopted Resolution No. 2009-0011, which established a statewide Recycled Water Policy. This policy encourages increased use of recycled water and local stormwater. It also requires local water and wastewater entities, together with local salt/nutrient contributing stakeholders to develop a Salt and Nutrient Management Plan (SNMP) for each groundwater basin in California. A SNMP Work Plan was jointly prepared by the Central Basin and West Coast Basin Stakeholders and approved by the Los Angeles Regional Water Quality Control Board (LARWQCB) in December 2011.

The objective of the SNMP is to manage salts and nutrients from all sources "…on a basin-wide or watershed-wide basis in a manner that ensures attainment of water quality objectives and protection of beneficial uses." The SNMP was finalized in February 2015 and included the following:

The SNMP was developed through a collaborative process involving major stakeholders in the Central Basin and West Coast Basin (CBWCB), including the Water Replenishment District of Southern California (WRD), Los Angeles County Department of Public Works, West Basin Municipal Water District, Los Angeles Department of Water and Power, Sanitation Districts of Los Angeles County, Metropolitan Water District of Southern California, Council for Watershed Health, City of Los Angeles Bureau of Sanitation, and other interested parties. The CBWCB stakeholders also worked collaboratively with the Los Angeles Regional Water Quality Control Board (LARWQCB) to develop the SNMP. WRD was the lead agency managing and facilitating development of the CBWCB SNMP.

A Substitute Environmental Document (SED) was also prepared in conjunction with the SNMP to comply with California Environmental Quality Act (CEQA) requirements. LARWQCB was the lead agency for purposes of CEQA, while the CBWCB stakeholders conducted the CEQA analysis and worked in collaboration with LARWQCB to prepare the SED. Both the Draft SED and Draft SNMP were submitted to LARWQCB in August 2014 for their review. A Basin Plan Amendment was subsequently prepared by the LARWQCB based on the approved SNMP and was adopted (Resolution R15-001) by the LARWQCB Board on February 12, 2015. The SNMP and SED were both finalized following adoption of Resolution R15-001 by the LARWQCB Board on February 12, 2015.