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AquaCensus

California public water systems

7,479 active systems regulated under the Safe Drinking Water Act, serving a reported 42.7M people across 201 counties.

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

Active systems

7,479

Population served

42.7M

Community systems

2,997

Groundwater share

85.1%

System types in California

2,997

Community water system

1,466

Non-transient non-community water system

3,016

Transient non-community water system

Largest water systems in California

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The largest active public water systems in California by population served
#Water systemCountyPopulation servedTypeSource
1Los Angeles-City, Dept. of Water & PowerLos Angeles3,875,566CommunitySurface 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

Sonoma441 systemsFresno328 systemsKern327 systemsMonterey307 systemsSan Bernardino306 systemsSan Joaquin302 systemsLos Angeles275 systemsTulare274 systemsMadera202 systemsRiverside197 systemsSan Diego191 systemsStanislaus191 systemsNapa188 systemsShasta174 systemsSan Luis Obispo171 systemsSacramento164 systemsSanta Barbara150 systemsMendocino144 systemsEl Dorado124 systemsSanta Clara121 systemsMerced120 systemsTuolumne117 systemsPlacer116 systemsInyo112 systemsTehama109 systemsPlumas108 systemsSanta Cruz96 systemsVentura95 systemsHumboldt90 systemsYolo88 systemsButte86 systemsContra Costa84 systemsMono84 systemsNevada82 systemsLake81 systemsImperial76 systemsSiskiyou69 systemsAmador67 systemsMariposa67 systemsSan Benito63 systemsSolano63 systemsYuba62 systemsCalaveras51 systemsLassen51 systemsSan Mateo51 systemsMarin46 systemsOrange46 systemsKings43 systemsTrinity42 systemsAlpine35 systemsSutter35 systemsGlenn34 systemsSierra32 systemsDel Norte31 systemsColusa29 systemsAlameda27 systemsModoc16 systemsHarris12 systemsKing George9 systemsSan Francisco8 systemsDuPage8 systemsWashoe6 systemsPulaski5 systemsEl Paso5 systemsJackson5 systemsAdams4 systemsMidland4 systemsWeld3 systemsConejos3 systemsWashington3 systemsBrazoria3 systemsRandall3 systems
Jefferson2 systems
Faulkner2 systems
Blaine2 systems
Bonneville2 systems
Allegan2 systems
Clark2 systems
Cleveland2 systems
Creek2 systems
Klamath2 systems
Umatilla2 systems
Marion2 systems
Linn2 systems
Northampton2 systems
Somerset2 systems
Allegheny2 systems
Beaver2 systems
Greene2 systems
Westmoreland2 systems
York2 systems
Bexar2 systems
Ector2 systems
Fort Bend2 systems
Gillespie2 systems
Harrison2 systems
Travis2 systems
Whatcom2 systems
Boone1 systems
Benton1 systems
Carroll1 systems
Saline1 systems
Garland1 systems
Craighead1 systems
Crittenden1 systems
Arapahoe1 systems
Denver1 systems
Eagle1 systems
Park1 systems
Garfield1 systems
Logan1 systems
Mineral1 systems
Hinsdale1 systems
Appling1 systems
Butts1 systems
Clay1 systems
Long1 systems
Peach1 systems
Screven1 systems
Thomas1 systems
Bonner1 systems
Kootenai1 systems
Owyhee1 systems
Twin Falls1 systems
St. Clair1 systems
McHenry1 systems
Cook1 systems
Dorchester1 systems
St. Mary's1 systems
Genesee1 systems
Oakland1 systems
Cass1 systems
Grand Traverse1 systems
Kalamazoo1 systems
Montcalm1 systems
Roscommon1 systems
Tuscola1 systems
Van Buren1 systems
Livingston1 systems
Osceola1 systems
Calhoun1 systems
Lenawee1 systems
Hennepin1 systems
Itasca1 systems
Ramsey1 systems
Churchill1 systems
Nye1 systems
Pershing1 systems
Darke1 systems
Franklin1 systems
Fulton1 systems
Lucas1 systems
Morgan1 systems
Pickaway1 systems
Richland1 systems
Trumbull1 systems
Tulsa1 systems
Coos1 systems
Curry1 systems
Lincoln1 systems
Clackamas1 systems
Baker1 systems
Yamhill1 systems
Chester1 systems
Monroe1 systems
Cambria1 systems
Centre1 systems
Northumberland1 systems
Butler1 systems
Fayette1 systems
Lawrence1 systems
Dauphin1 systems
Lancaster1 systems
Aiken1 systems
Berkeley1 systems
Charleston1 systems
Jasper1 systems
Fall River1 systems
Aransas1 systems
Bandera1 systems
Blanco1 systems
Burnet1 systems
Chambers1 systems
Coryell1 systems
Galveston1 systems
Hale1 systems
Hays1 systems
Henderson1 systems
Kendall1 systems
Lubbock1 systems
Montgomery1 systems
Parker1 systems
Tarrant1 systems
Victoria1 systems
Piute1 systems
Wasatch1 systems
Weber1 systems
Gloucester1 systems
Lewis1 systems
Klickitat1 systems
Okanogan1 systems