San Diego County Water Authority
Carlsbad Municipal Water District
City of Del Mar
City of Escondido
Fallbrook Public Utility District
Helix Water District
- El Cajon
- La Mesa
- Lemon Grove
- Spring Valley
- Unincorporated areas around El Cajon
City of National City**
City of Oceanside
Olivenhain Municipal Water District
- 4S Ranch
- Carlsbad
- Elfin Forest
- Encinitas
- Fairbanks Rancho
- Leucadia
- Olivenhain
- Rancho Santa Fe
- San Diego
- San Marcos
- Santa Fe Valley
- Solana Beach
Otay Water District
- Bonita
- Chula Vista
- Eastlake
- El Cajon
- Jamul
- La Mesa
- Otay Mesa
- Rancho San Diego
- Spring Valley
Padre Dam Municipal Water District
Alpine
- Blossom Valley
- Crest
- Dehesa
- El Cajon
- Flinn Springs
- Harbison Canyon
- Lakeside
- Santee
Camp Pendleton Marine Corps Base
City of Poway
Rainbow Municipal Water District
- Bonsall
- Fallbrook
- Rainbow
Ramona Municipal Water District
Rincon del Diablo Municipal Water District
City of San Diego
San Dieguito Water District
Santa Fe Irrigation District
- Fairbanks Ranch
- Rancho Santa Fe
- Solana Beach
South Bay Irrigation District**
Sweetwater Authority
- Bonita
- Chula Vista
- National City
Vallecitos Water District
- Carlsbad
- Escondido
- Lake San Marcos
- San Marcos
- Vista
Valley Center Municipal Water District
Vista Irrigation District
- Escondido
- Oceanside
- San Marcos
- Unincorporated areas
- Vista
Yuima Municipal Water District
**The Sweetwater Authority is a service organization for the city of National City and the South Bay Irrigation District.
