Membership as of September 2002 is listed below. Names followed by [desc] have agency contact information available, and in some cases a description of the agency and its responsibilities.

• Members
  • Calleguas Municipal Water District [desc]
  • Chino Basin Watermaster [desc]
  • Eastern Municipal Water District [desc]
  • Indian Wells Valley Water District [desc]
  • Kern County Water Agency [desc]
  • Main San Gabriel Basin Watermaster [desc]
  • Mojave Water Agency [desc]
  • Orange County Water District [desc]
  • Raymond Basin Management Board [desc]
  • San Bernardino Valley Water Conservation District [desc]
  • Six Basins Watermaster [desc]
  • Tehachapi-Cummings County Water District [desc]
  • Upper Los Angeles River Area Watermaster [desc]
  • Water Replenishment District of Southern California [desc]
  • Western Municipal Water District [desc]
• Affiliates
  • Bookman Edmonston / GEI Consultants [desc]
  • Cadiz, Inc. [desc]
  • CH2M Hill [desc]
  • Komex H2O Science [desc]
  • Metropolitan Water District of Southern California [desc]
  • Montgomery Watson [desc]
  • Narver Associates [desc]
  • Psomas and Associates [desc]
  • City of Riverside [desc]
  • San Gabriel River Water Committee [desc]
  • Santa Clara Valley Water District [desc]
  • Stetson Engineers Inc. [desc]

** An Affiliate is defined in the Bylaws as follows: Any entity or organization (such as a public agency, municipality, engineering or law firm, or other professional consulting firm) which has a direct interest in the management of water supplies in California may be admitted as an Affiliate, upon written application, approval by the Board of Directors of the Corporation and timely payment of such dues and fees as the Board may fix from time to time. Acceptance to membership as an Affiliate shall authorize full participation in all activities of the Corporation but shall not include any voting rights.