How many public water systems are in Louisiana?

Louisiana has 1,124 active public water systems in EPA SDWIS records, including 819 community water systems. Together they report serving 5.2M people.

What is the largest water system in Louisiana?

Baton Rouge Water Company is the largest active public water system in Louisiana, serving a reported 596,844 people.

Does Louisiana rely more on groundwater or surface water?

92.3% of Louisiana's active public water systems draw primarily on groundwater and 7.7% on surface water (including purchased supplies).

Louisiana public water systems

1,124 active systems regulated under the Safe Drinking Water Act, serving a reported 5.2M people across 78 counties.

Dataset updated July 2026 . Source: EPA SDWIS/ECHO, refreshed quarterly.

Active systems

1,124

Population served

5.2M

Community systems

819

Groundwater share

92.3%

System types in Louisiana

819

Community water system

125

Non-transient non-community water system

180

Transient non-community water system

Largest water systems in Louisiana

The largest active public water systems in Louisiana by population served
#	Water system	County	Population served	Type	Source
1	Baton Rouge Water Company	East Baton Rouge Parish	596,844	Community	Groundwater
2	New Orleans Carrollton Water Works	Orleans Parish	334,903	Community	Surface water
3	E Jefferson Ww District 1	Jefferson Parish	275,163	Community	Surface water
4	Shreveport Water System	Caddo Parish	192,378	Community	Surface water
5	Lafayette Utilities Water System	Lafayette Parish	169,389	Community	Groundwater
6	W Jefferson Ww District 2	Jefferson Parish	140,264	Community	Surface water
7	Schriever Water Treatment Service Area	Terrebonne Parish	116,460	Community	Surface water
8	Lafourche Water District 1	Lafourche Parish	81,609	Community	Surface water
9	City of Lake Charles Water System	Calcasieu Parish	79,500	Community	Groundwater
10	City of Bossier City Water System	Bossier Parish	78,960	Community	Surface water
11	Ward Ii Water District	Livingston Parish	73,506	Community	Groundwater
12	Tangipahoa Parish Water District	Tangipahoa Parish	72,504	Community	Groundwater
13	City of Alexandria Water System	Rapides Parish	66,798	Community	Groundwater
14	New Iberia Water System (Lawco)	Iberia Parish	59,928	Community	Groundwater
15	Monroe Water System	Ouachita Parish	57,000	Community	Surface water
16	St Charles Parish Dept of Waterworks	St. Charles Parish	52,879	Community	Surface water
17	New Orleans Algiers Water Works	Orleans Parish	52,785	Community	Surface water
18	St Bernard Parish Waterworks	St. Bernard Parish	44,783	Community	Surface water
19	Slidell Water Supply	St. Tammany Parish	35,547	Community	Groundwater
20	St John Water District 3	St. John the Baptist Parish	31,965	Community	Groundwater
21	Zachary Water System	East Baton Rouge Parish	31,569	Community	Groundwater
22	Natchitoches Water System	Natchitoches Parish	27,693	Community	Surface water
23	City of Denham Springs Water System	Livingston Parish	25,725	Community	Groundwater
24	Sulphur City of Water System	Calcasieu Parish	24,489	Community	Groundwater
25	Vermilion Waterworks District 1	Vermilion Parish	24,132	Community	Groundwater

By county

St. Tammany Parish170 systems Calcasieu Parish72 systems Lafayette Parish38 systems Caddo Parish35 systems Tangipahoa Parish33 systems Webster Parish31 systems Ouachita Parish29 systems St. Landry Parish28 systems Livingston Parish27 systems Ascension Parish27 systems Washington Parish26 systems Bossier Parish26 systems St. Martin Parish25 systems Rapides Parish24 systems Lincoln Parish22 systems Bienville Parish22 systems Vernon Parish20 systems Sabine Parish19 systems Jackson Parish19 systems East Baton Rouge Parish18 systems Union Parish18 systems Avoyelles Parish17 systems St. Mary Parish16 systems Morehouse Parish15 systems Natchitoches Parish14 systems Evangeline Parish14 systems Grant Parish13 systems Iberia Parish13 systems Winn Parish13 systems Iberville Parish13 systems Pointe Coupee Parish12 systems La Salle Parish12 systems Red River Parish12 systems Acadia Parish12 systems St. John the Baptist Parish12 systems Vermilion Parish12 systems Caldwell Parish11 systems De Soto Parish11 systems Claiborne Parish11 systems Richland Parish11 systems Allen Parish10 systems Orleans Parish10 systems East Feliciana Parish10 systems Beauregard Parish8 systems Concordia Parish8 systems Cameron Parish8 systems Jefferson Davis Parish8 systems Catahoula Parish7 systems Franklin Parish7 systems West Carroll Parish7 systems West Baton Rouge Parish7 systems St. Helena Parish6 systems Tensas Parish5 systems St. James Parish5 systems Plaquemines Parish5 systems Madison Parish4 systems East Carroll Parish4 systems Jefferson Parish4 systems West Feliciana Parish4 systems

Harris2 systems

Terrebonne Parish2 systems

Midland2 systems

St. Bernard Parish2 systems

Lafourche Parish2 systems

Montgomery1 systems

Assumption Parish1 systems

Panola1 systems

Grand1 systems

Tioga1 systems

Ontonagon1 systems

Lenawee1 systems

Ionia1 systems

Kent1 systems

St. Charles Parish1 systems

Orange1 systems

Logan1 systems

Accomack1 systems

Henry1 systems