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AquaCensus

California public water systems

7,892 active systems regulated under the Safe Drinking Water Act, serving a reported 46.6M people across 246 counties.

Dataset updated . Source: EPA SDWIS/ECHO, refreshed quarterly.

Active systems

7,892

Population served

46.6M

Community systems

3,008

Groundwater share

84.1%

System types in California

3,008

Community water system

1,469

Non-transient non-community water system

3,415

Transient non-community water system

Largest water systems in California

The largest active public water systems in California by population served
#Water systemCountyPopulation servedTypeSource
1Los Angeles-City, Dept. of Water & PowerLos Angeles7,751,132CommunitySurface water
2East Bay MUDAlameda1,442,800CommunitySurface water
3San Diego, City ofSan Diego1,385,379CommunitySurface water
4San Jose WaterSanta Clara1,039,920CommunitySurface water
5Sfpuc City Distribution DivisionSan Francisco848,019CommunityPurchased surface water
6Eastern Municipal WdRiverside666,581CommunityPurchased surface water
7City of FresnoFresno545,716CommunitySurface water
8City of Sacramento MainSacramento527,979CommunitySurface water
9Long Beach Utilities DepartmentLos Angeles466,772CommunityPurchased surface water
10Irvine Ranch Water DistrictOrange444,800CommunitySurface water
11City of AnaheimOrange348,593CommunitySurface water
12Alameda County Water DistrictAlameda344,000CommunitySurface water
13City of Santa AnaOrange310,539CommunityPurchased surface water
14Riverside, City ofRiverside298,398CommunityGroundwater under influence of surface water
15Santa Clarita Valley Water AgencyLos Angeles294,090CommunitySurface water
16Gswc - SouthwestLos Angeles277,740CommunityPurchased surface water
17Helix Water DistrictSan Diego277,668CommunitySurface water
18Coachella Vwd: Cove CommunityRiverside270,000CommunityGroundwater
19Cws - BakersfieldKern267,881CommunitySurface water
20San Gabriel Valley Water Co.-El MonteLos Angeles248,000CommunityGroundwater
21Otay Water DistrictSan Diego238,008CommunityPurchased surface water
22San Gabriel Valley Wc - FontanaSan Bernardino237,700CommunitySurface water
23Modesto, City ofStanislaus218,771CommunityPurchased surface water
24San Bernardino CitySan Bernardino214,665CommunityGroundwater
25Cucamonga Valley Water DistrictSan Bernardino211,069CommunitySurface water

By county

Sonoma440 systemsFresno328 systemsKern326 systemsMonterey310 systemsSan Bernardino310 systemsSan Joaquin302 systemsLos Angeles277 systemsTulare276 systemsMadera203 systemsRiverside199 systemsSan Diego194 systemsStanislaus192 systemsNapa186 systemsShasta174 systemsSan Luis Obispo167 systemsSacramento166 systemsSanta Barbara150 systemsMendocino144 systemsEl Dorado124 systemsPlacer121 systemsMerced120 systemsSanta Clara120 systemsTuolumne119 systemsLake115 systemsInyo111 systemsTehama109 systemsPlumas106 systemsSanta Cruz96 systemsVentura95 systemsCook94 systemsHumboldt90 systemsYolo88 systemsButte87 systemsMono85 systemsContra Costa84 systemsNevada83 systemsImperial76 systemsSiskiyou70 systemsMariposa67 systemsAmador67 systemsYuba63 systemsSan Benito63 systemsSolano63 systemsCalaveras52 systemsLassen51 systemsSan Mateo51 systemsMarin47 systemsOrange46 systemsTrinity43 systemsKings42 systemsDuPage42 systemsSutter35 systemsAlpine35 systemsGlenn34 systemsSierra32 systemsDel Norte31 systemsColusa29 systemsAlameda27 systemsWill26 systemsKane21 systemsModoc16 systemsMcHenry14 systemsHarris12 systemsWinnebago11 systemsTazewell11 systemsChampaign10 systemsPeoria9 systemsKing George9 systemsWashington8 systemsJackson8 systemsKendall8 systemsMcLean8 systemsMadison8 systemsSan Francisco8 systemsWashoe5 systemsBenton5 systemsSt. Clair5 systemsLaSalle5 systemsLivingston5 systemsKankakee5 systemsPulaski5 systemsEl Paso5 systemsClark4 systemsAdams4 systemsMonroe4 systemsSangamon4 systemsMidland4 systemsBoone3 systemsRandall3 systemsDeKalb3 systemsMacon3 systemsWoodford3 systemsDouglas3 systemsFulton3 systemsVermilion3 systemsClinton3 systemsRock Island3 systemsWeld3 systemsConejos3 systems
Greene2 systems
Cass2 systems
Whatcom2 systems
Lee2 systems
Union2 systems
Umatilla2 systems
Carroll2 systems
Clay2 systems
Jefferson2 systems
Trumbull2 systems
Bonner2 systems
Linn2 systems
Creek2 systems
Gillespie2 systems
Knox2 systems
Lawrence2 systems
Christian2 systems
Coles2 systems
Henderson2 systems
De Witt2 systems
Saline2 systems
Grundy2 systems
Iroquois2 systems
Jasper2 systems
Moultrie2 systems
Whiteside2 systems
Effingham2 systems
Marion2 systems
Harrison2 systems
Beaver2 systems
Allegheny2 systems
Somerset2 systems
Faulkner2 systems
York2 systems
Cleveland2 systems
Northampton2 systems
Ector2 systems
Bonneville2 systems
Blaine2 systems
Westmoreland2 systems
Brazoria2 systems
Travis2 systems
Allegan2 systems
Klamath2 systems
Dorchester1 systems
Kalamazoo1 systems
Screven1 systems
Little River1 systems
Miller1 systems
Columbia1 systems
Ashley1 systems
Ouachita1 systems
Nye1 systems
Hempstead1 systems
Stone1 systems
Pope1 systems
Searcy1 systems
Baxter1 systems
Richland1 systems
Hennepin1 systems
Yamhill1 systems
Owyhee1 systems
Tulsa1 systems
Piute1 systems
Ramsey1 systems
Okanogan1 systems
Coryell1 systems
Menard1 systems
Henry1 systems
Hancock1 systems
Hale1 systems
Lucas1 systems
Darke1 systems
McDonough1 systems
Stephenson1 systems
Perry1 systems
Macoupin1 systems
Chester1 systems
Schuyler1 systems
Jo Daviess1 systems
Franklin1 systems
Curry1 systems
Peach1 systems
Lancaster1 systems
Weber1 systems
St. Mary's1 systems
Genesee1 systems
Kootenai1 systems
Baker1 systems
Fayette1 systems
Crittenden1 systems
Garland1 systems
Northumberland1 systems
Aiken1 systems
Centre1 systems
Cambria1 systems
Twin Falls1 systems
Berkeley1 systems
Charleston1 systems
Arapahoe1 systems
Hays1 systems
Bandera1 systems
Fort Bend1 systems
Blanco1 systems
Lenawee1 systems
Churchill1 systems
Clackamas1 systems
Montcalm1 systems
Tuscola1 systems
Burnet1 systems
Oakland1 systems
Dauphin1 systems
Park1 systems
Pickaway1 systems
Denver1 systems
Garfield1 systems
Long1 systems
Lubbock1 systems
Aransas1 systems
Galveston1 systems
Logan1 systems
Pershing1 systems
Parker1 systems
Wasatch1 systems
Montgomery1 systems
Butts1 systems
Butler1 systems
Gloucester1 systems
Thomas1 systems
Morgan1 systems
Grand Traverse1 systems
Tarrant1 systems
Calhoun1 systems
Hinsdale1 systems
Mineral1 systems
Chatham1 systems
Leflore1 systems
Osceola1 systems
Van Buren1 systems
Coos1 systems
Craighead1 systems
Fall River1 systems
Bexar1 systems
Eagle1 systems
Itasca1 systems
Klickitat1 systems
Lewis1 systems