San Luis Obispo County, California Water Systems

San Luis Obispo County, California

94 community water systems on record — 73 active, 21 inactive.

Every active community water system nationwide must produce a Consumer Confidence Report under the EPA's revised rule, effective for reports due July 1, 2027.

Data sourced from the EPA ECHO database (SDWA bulk download), last refreshed July 4, 2026. This is a record-keeping and public-information tool — it does not replace California’s official records. Always confirm current status with California before making decisions based on this information.

Community water systems in San Luis Obispo County, California

System name	City	Population served	Status
ADA'S LODGES	PASO ROBLES	25	Active
AFUERA DE CHORRO WATER COMPANY	SAN LUIS OBISPO	79	Active
AGNEWS RESIDENTIAL FACILITY	ATASCADERO	1,903	Inactive
ALMIRA WATER ASSOCIATION	PASO ROBLES	40	Active
ANZA VINEYARD ESTATES MUTUAL WATER CO	SAN LUIS OBISPO	60	Active
ATASCADERO LAKE - INACTIVE	ATASCADERO	25	Inactive
ATASCADERO MUTUAL WATER CO	ATASCADERO	30,618	Active
ATASCADERO STATE HOPSITAL	ATASCADERO	1,900	Inactive
ATASCADERO STATE HOSPITAL	ATASCADERO	1,900	Inactive
ATASCADERO STATE HOSPITAL	ATASCADERO	4,100	Active
AVILA BEACH COMMUNITY SERVICES DISTRICT	AVILA BEACH	1,630	Active
AVILA BEACH COUNTY WATER DIST	AVILA BEACH	0	Inactive
AVILA VALLEY MUTUAL WATER CO	SAN LUIS OBISPO	75	Active
BARON CANYON MUTUAL WATER CO.	SAN LUIS OBISPO	81	Active
BASSI RANCH MUTUAL WATER CO.	GROVER BEACH	85	Active
BEAR VALLEY WATER COMPANY	SAN LUIS OBISPO	45	Active
BELLA VISTA MOBILE LODGE	CAYUCOS	200	Inactive
BROOKSIDE TRACT	NIPOMO	44	Inactive
CALIFORNIA MENS COLONY	SAN LUIS OBISPO	8,900	Inactive
CALIFORNIA MENS COLONY	SAN LUIS OBISPO	8,900	Inactive
CALIFORNIA MENS COLONY	SAN LUIS OBISPO	15,000	Active
CALIFORNIA VALLEY COMMUNITY SE	LEY	30	Inactive
CALLENDER GROVE MUTUAL WATER	SAN LUIS OBISPO	126	Active
CAMBRIA COMM SERVICES DIST	CAMBRIA	5,532	Active
CANYON CREST MUTUAL BENEFIT WC	ARROYO GRANDE	133	Active
CAYUCOS BEACH MUTUAL WATER COMPANY	CAYUCOS	2,567	Active
CHORRO VALLEY PIPELINE - SLO COUNTY	SAN LUIS OBISPO	0	Active
CITY OF ARROYO GRANDE UTILITIES DIVISION	ARROYO GRANDE	17,963	Active
CITY OF GROVER BEACH PUBLIC WORKS DEPT	GROVER BEACH	12,701	Active
CITY OF PASO ROBLES WATER DIVISION	PASO ROBLES	31,176	Active
COUNTRY HILLS ESTATES	ARROYO GRANDE	60	Active
DESIGN ALLIANCE - INACTIVE	SAN LUIS OBISPO	25	Inactive
DOUBLE J MOBILE ESTATES	THOUSAND OAKS	43	Inactive
EDNA VALLEY RANCH EAST	ARROYO GRANDE	132	Active
GARDEN FARMS C.W.D.	ATASCADERO	440	Active
GERALD E BREWSTER - INACTIVE	SAN LUIS OBISPO	25	Inactive
GOLDEN STATE WATER COMPANY - EDNA	HAWTHORNE	1,493	Active
GOLDEN STATE WATER COMPANY - LOS OSOS	HAWTHORNE	5,924	Active
GOLDEN STATE WATER COMPANY - NIPOMO	RANCHO CORDOVA	4,506	Active
GOLDEN STATE WATER COMPANY-CYPRESS RIDGE	RANCHO CORDOVA	2,026	Active
GRAN CIELO MUTUAL WATER COMPANY	SAN LUIS OBISPO	139	Active
GRANDE MOBILE MANOR	ARROYO GRANDE	55	Inactive
GREEN RIVER MUTUAL WATER CO.	PASO ROBLES	350	Active
H2O, INC	ARROYO GRANDE	70	Active
HALCYON WATER SYSTEM	HALCYON	110	Active
HEDGER WATER SUPPLY - INACTIVE	LOS OSOS	25	Inactive
HERITAGE RANCH CSD	PASO ROBLES	2,956	Active
HIDDEN HILLS MOBILODGE	SAN LUIS OBISPO	22	Inactive
HIGUERA APARTMENTS	SAN LUIS OBISPO	30	Active
IRISH HILLS MUTUAL WATER CO	SAN LUIS OBISPO	135	Active
KEN MAR GARDENS	ARROYO GRANDE	84	Active
LAGUNA NEGRA MUTUAL WATER CO.	ARROYO GRANDE	80	Active
LAS VENTANAS RANCH	SAN LUIS OBISPO	108	Active
LAUREATE WATER COMPANY	SAN LUIS OBISPO	700	Active
LOPEZ PROJECT	SAN LUIS OBISPO	1,569	Active
LOS OSOS COMMUNITY SERVICES DISTRICT	LOS OSOS	7,086	Active
LOS ROBLES MOBILE HOME ESTATES	PASO ROBLES	420	Active
MESA DUNES MOBILE HOME ESTATES	ARROYO GRANDE	600	Active
MONTE SERENO MUTUAL BENEFIT WATER	SAN LUIS OBISPO	65	Active
MORRO BAY PW DEPT - WATER DIVISION	MORRO BAY	13,757	Active
MORRO ROCK MUTUAL WATER CO	CAYUCOS	2,181	Active
MUSTANG MOBILE VILLAGE	PASO ROBLES	31	Inactive
MUSTANG SPRINGS MUTUAL WATER	PASO ROBLES	30	Active
NACIMIENTO WATER COMPANY	BRADLEY	2,181	Active
NACIMIENTO WATER PROJECT	SAN LUIS OBISPO	0	Active
NIPOMO COMM SERVICES DIST	NIPOMO	13,771	Active
OCEANO COMM SERVICES DIST.	OCEANO	7,601	Active
PISMO BEACH WATER DEPARTMENT	PISMO BEACH	8,036	Active
RANCHO COLINA MOBILE HOME PARK	MORRO BAY	249	Active
RANCHO NIPOMO WATER COMPANY	ARROYO GRANDE	44	Active
RANCHO OAKS MOBILE PARK	OBISPO 93401	19	Inactive
RANCHO SALINAS MBWC	PASO ROBLES	50	Active
RESTHAVEN MOBILE HOME PARK	IRVINE	99	Active
RIM ROCK WATER COMPANY	GROVER BEACH	55	Active
S & T MUTUAL WATER COMPANY	LOS OSOS	591	Active
SAN LUIS OBISPO CSA 1G- BLACK LAKE	SAN LUIS OBISPO,	0	Inactive
SAN LUIS OBISPO WATER DEPARTMENT	SAN LUIS OBISPO	47,788	Active
SAN MIGUEL COMMUNITY SERVICES DISTRICT	SAN MIGUEL	2,600	Active
SAN MIGUELITO MWC	AVILA BEACH	1,600	Active
SAN SIMEON CSD	SAN SIMEON	462	Active
SANTA YSABEL RANCH MWC	SAN LUIS OBISPO	344	Active
SLO CSA NO. 10 - CAYUCOS WTP	SAN LUIS OBISPO	0	Active
SLO CSA NO. 12 - AVILA BEACH	SAN LUIS OBISPO	0	Inactive
SLO CSA NO. 16 - SHANDON	SAN LUIS OBISPO	1,085	Active
SLO CWWD NO. 23 - SANTA MARGARITA	SAN LUIS OBISPO	1,291	Active
SLOCSA #10A - CAYUCOS	SAN LUIS OBISPO	1,200	Active
SPANISH LAKES MUTUAL WATER CO	TEMPLETON	125	Active
TEMPLETON CSD	TEMPLETON	8,011	Active
TERRA DE ORO WATER COMPANY	ARROYO GRANDE	38	Active
VARIAN RANCH MUTUAL WATER	ARROYO GRANDE	105	Active
VISTA DE LAS FLORES WATER	ARROYO GRANDE	24	Inactive
WALNUT HILLS MUTUAL WATER CO	PASO ROBLES	486	Active
WOODLAND PARK MUTUAL WATER CO	ARROYO GRANDE	538	Active
WOODLANDS DEVELOPMENT	ARROYO GRANDE	3,862	Active