Orange County, California — public water systems

46 active public water systems serve Orange County, reporting 3.2M people served.

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

Active systems

Population served

3.2M

Community systems

Groundwater share

21.7%

Water systems in Orange County

Active public water systems in Orange County, California
#	Water system	County	Population served	Type	Source
1	Irvine Ranch Water District	Orange	444,800	Community	Surface water
2	City of Anaheim	Orange	348,593	Community	Surface water
3	City of Santa Ana	Orange	310,539	Community	Purchased surface water
4	City of Huntington Beach	Orange	201,000	Community	Purchased surface water
5	City of Garden Grove	Orange	174,226	Community	Purchased surface water
6	Moulton Niguel Water District	Orange	170,236	Community	Purchased surface water
7	Santa Margarita Water District	Orange	168,289	Community	Purchased surface water
8	City of Fullerton	Orange	139,461	Community	Purchased surface water
9	City of Orange	Orange	120,770	Community	Purchased surface water
10	Golden State Wc - West Orange County	Orange	114,379	Community	Purchased surface water
11	Mesa Water District	Orange	110,000	Community	Purchased surface water
12	City of Westminster	Orange	90,911	Community	Purchased surface water
13	Yorba Linda Water District	Orange	84,292	Community	Purchased surface water
14	City of Buena Park	Orange	81,998	Community	Purchased surface water
15	City of Newport Beach	Orange	68,572	Community	Purchased surface water
16	City of Tustin	Orange	66,600	Community	Purchased surface water
17	City of La Habra	Orange	63,118	Community	Purchased surface water
18	City of Fountain Valley	Orange	56,747	Community	Purchased surface water
19	El Toro Water District	Orange	51,800	Community	Purchased surface water
20	City of San Clemente	Orange	51,545	Community	Purchased surface water
21	Golden State Wc - Placentia/Yorba Linda	Orange	50,381	Community	Purchased surface water
22	City of Brea	Orange	48,479	Community	Purchased surface water
23	South Coast Water District	Orange	41,118	Community	Purchased surface water
24	Santa Margarita Water District-Id9	Orange	39,684	Community	Purchased surface water
25	City of Seal Beach	Orange	24,937	Community	Purchased surface water
26	Laguna Beach County Wd	Orange	18,404	Community	Purchased surface water
27	City of La Palma	Orange	15,948	Community	Purchased surface water
28	Trabuco Canyon Water District	Orange	13,659	Community	Purchased surface water
29	Golden State Wc - Cowan Heights	Orange	6,997	Community	Purchased surface water
30	Serrano Water District	Orange	5,659	Community	Purchased surface water
31	Joint Regional Water Supply System	Orange	3,947	Community	Purchased surface water
32	East Orange County Wd - Rz	Orange	3,464	Community	Purchased surface water
33	Knott S Berry Farm	Orange	3,000	Non-transient non-community	Purchased surface water
34	Eastside Water Association	Orange	2,000	Community	Groundwater
35	Smwd-Nichols Institute	Orange	1,600	Non-transient non-community	Purchased surface water
36	Los Alamitos Race Course	Orange	1,600	Non-transient non-community	Groundwater
37	Midway City Mutual Wc	Orange	1,305	Community	Groundwater
38	South Midway City Mutual Water Co.	Orange	891	Community	Groundwater
39	Canyon Rv Park	Orange	294	Non-transient non-community	Groundwater
40	Caspers Regional Wilderness Park	Orange	215	Transient non-community	Groundwater
41	Hynes Estates Mutual Water Co.	Orange	168	Community	Groundwater
42	Page Avenue Mutual Water Company	Orange	119	Community	Purchased surface water
43	Liberty Park Water Association	Orange	85	Community	Groundwater
44	Lazy W Ranch Water System	Orange	63	Transient non-community	Groundwater