San Diego County, California — public water systems

194 active public water systems serve San Diego County, reporting 3.7M people served.

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

Active systems

194

Population served

3.7M

Community systems

Groundwater share

84%

Water systems in San Diego County

Active public water systems in San Diego County, California
#	Water system	County	Population served	Type	Source
1	San Diego, City of	San Diego	1,385,379	Community	Surface water
2	Helix Water District	San Diego	277,668	Community	Surface water
3	Otay Water District	San Diego	238,008	Community	Purchased surface water
4	Sweetwater Authority	San Diego	191,282	Community	Surface water
5	Oceanside, City of	San Diego	171,483	Community	Purchased surface water
6	Escondido, City of	San Diego	137,044	Community	Surface water
7	Vista Irrigation District	San Diego	132,430	Community	Surface water
8	Vallecitos Wd	San Diego	113,500	Community	Purchased surface water
9	Cal-Am Water Coronado	San Diego	106,000	Community	Purchased surface water
10	Carlsbad Mwd	San Diego	95,158	Community	Purchased surface water
11	Padre Dam Mwd	San Diego	93,980	Community	Purchased surface water
12	Olivenhain Mwd	San Diego	86,458	Community	Purchased surface water
13	Poway, City of	San Diego	49,888	Community	Surface water
14	Camp Pendleton (South)	San Diego	42,219	Community	Groundwater
15	San Dieguito Wd	San Diego	40,405	Community	Purchased surface water
16	Ramona Municipal Wd	San Diego	37,047	Community	Purchased surface water
17	Nas North Island & Nab Coronado	San Diego	36,990	Community	Purchased surface water
18	Pine Valley Border Patrol Station	San Diego	36,604	Non-transient non-community	Groundwater
19	Lakeside Wd	San Diego	35,500	Community	Purchased surface water
20	Fallbrook PUD	San Diego	35,237	Community	Purchased surface water
21	Rincon Del Diablo Mwd (Id-1)	San Diego	30,757	Community	Purchased surface water
22	Valley Center Mwd	San Diego	29,938	Community	Purchased surface water
23	Yoga Center Mother'S Kitchen	San Diego	27,884	Transient non-community	Groundwater
24	San Diego Mountain Lodge	San Diego	26,641	Transient non-community	Groundwater
25	Dhs Border Patrol Hwy 94 Checkpoint	San Diego	25,083	Non-transient non-community	Groundwater under influence of surface water
26	Auerbach Farms	San Diego	25,068	Non-transient non-community	Groundwater
27	Rainbow Municipal Wd	San Diego	23,536	Community	Purchased surface water
28	Santa Fe I.D.	San Diego	21,578	Community	Surface water
29	Dhs Boulevard Border Patrol	San Diego	20,270	Non-transient non-community	Groundwater
30	South Bay Rod & Gun Club Inc..	San Diego	18,900	Transient non-community	Groundwater
31	Palomar Christian Conference Center	San Diego	13,050	Community	Groundwater
32	Indian Hills Camp	San Diego	13,032	Community	Groundwater
33	Camp Pendleton (North)	San Diego	12,651	Community	Groundwater
34	Lake Henshaw Resort Inc..	San Diego	9,913	Community	Groundwater
35	Warner Springs Ranch Resort LLC	San Diego	4,831	Non-transient non-community	Groundwater
36	Palomar Observatory	San Diego	4,416	Community	Groundwater
37	Mataguay Scout Reservation	San Diego	4,000	Transient non-community	Groundwater
38	Del Mar, City of	San Diego	3,919	Community	Purchased surface water
39	Bandy Canyon Ranch Corp	San Diego	3,564	Transient non-community	Groundwater
40	Borrego Wd	San Diego	3,429	Community	Groundwater
41	Rincon Del Diablo Mwd (Id-A)	San Diego	3,275	Community	Purchased surface water
42	Cuyamaca Water District	San Diego	2,923	Community	Groundwater
43	Pine Valley Mutual Wc	San Diego	2,645	Community	Groundwater
44	Schoepe Scout Reservation at Lost Valley	San Diego	2,500	Transient non-community	Groundwater
45	Majestic Pines Community Sd	San Diego	1,768	Community	Groundwater
46	Julian Community Services District	San Diego	1,517	Community	Groundwater
47	Mountain Empire High School	San Diego	1,000	Non-transient non-community	Groundwater
48	De Anza Springs Resort	San Diego	1,000	Transient non-community	Groundwater
49	Rancho Pauma Mutual Wc	San Diego	899	Community	Groundwater
50	Descanso Community Water District	San Diego	870	Community	Groundwater