Rincon Water is a member or partner with the following:
- American Backflow Prevention Association (ABPA)
- American Public Works Association (APWA)
- American Water Resources Association (AWRA)
- American Water Works Association (AWWA)
- Association of California Water Agencies (ACWA)
- Association of Records Managers and Administrators (ARMA)
- California Association of Sewage Agencies (CASA)
- California Municipal Treasurers Association (CMTA)
- California Native Plant Society (CNPS)
- California Society of Municipal Finance Officers (CSMFO)
- California Special Districts Association (CSDA)
- California Special Districts Association – San Diego Chapter (CSDA-SD)
- Cal Tech Universities Research Association
- Colorado River Water Users Association (CRWUA)
- Cross Connection Control Advisory Committee of San Diego County (CCACSD)
- Escondido Chamber of Commerce
- Fire Districts Association of California (FDAC)
- Government Finance Officers Association (GFOA)
- Institute for Local Government (ILG)
- Irrigation Association (IA)
- Lake Hodges Fire Safe Council
- Metropolitan Water District of Southern California (MWD)
- National Notary Association (NNA)
- National Oceanic & Atmospheric Administration National Weather Service (NOAA)
- National Water Resources Association (NWRA)
- San Diego County Water Authority (SDCWA)
- San Diego County Farm Bureau (FB)
- Southern California Water Committee (SCWC)
- Southern California Water Utilities Association (SCWUA)
- Urban Water Institute (UWI)
- Water Education Foundation
- Water Environment Federation (WEF)
- WateReuse Association
- Western Coalition of Arid States (WESCAST)