Ventura County, California — public water systems

95 active public water systems serve Ventura County, reporting 882.8K people served.

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

Active systems

Population served

882.8K

Community systems

Groundwater share

54.7%

Water systems in Ventura County

Active public water systems in Ventura County, California
#	Water system	County	Population served	Type	Source
1	Oxnard Water Dept	Ventura	200,232	Community	Purchased surface water
2	Ventura Water Department	Ventura	113,500	Community	Surface water
3	Ventura Wwd No. 8 - Simi Valley	Ventura	94,738	Community	Purchased surface water
4	Cal American Water Co	Ventura	66,809	Community	Purchased surface water
5	City of Thousand Oaks Water Department	Ventura	53,157	Community	Purchased surface water
6	Camarillo Water Dept	Ventura	46,824	Community	Purchased surface water
7	Golden State Water Company - Simi Valley	Ventura	45,128	Community	Purchased surface water
8	Ventura Cwwd No. 1 - Moorpark	Ventura	35,514	Community	Purchased surface water
9	Camrosa Water District	Ventura	32,700	Community	Purchased surface water
10	City of Santa Paula	Ventura	31,018	Community	Groundwater
11	Port Hueneme City Water Dept	Ventura	21,407	Community	Purchased surface water
12	California Water Service Co - Westlake	Ventura	19,533	Community	Purchased surface water
13	Fillmore Water Dept	Ventura	16,419	Community	Groundwater
14	Triunfo Water & Sanitation District	Ventura	13,898	Community	Purchased surface water
15	Casitas Municipal Water Dist	Ventura	11,005	Community	Surface water
16	Naval Base Ventura County, Port Hueneme	Ventura	8,625	Community	Purchased surface water
17	Ojai Water System	Ventura	6,801	Community	Purchased surface water
18	Ventura River Water District	Ventura	6,100	Community	Purchased surface water
19	Naval Base Ventura County, Point Mugu	Ventura	5,700	Community	Purchased surface water
20	Pleasant Valley Mutual Water Co	Ventura	5,000	Community	Purchased surface water
21	Channel Islands Beach Csd	Ventura	4,560	Community	Purchased surface water
22	Meiners Oaks Cwd	Ventura	4,200	Community	Purchased surface water
23	Smith Forks Water System	Ventura	3,000	Transient non-community	Groundwater
24	Rio Mesa High School/Oxnard Uhs	Ventura	2,600	Non-transient non-community	Groundwater
25	Crestview Mutual Water Co	Ventura	2,079	Community	Purchased surface water
26	Cal American Wc - Las Posas Estates	Ventura	2,039	Community	Purchased surface water
27	Cal American Water Company - Piru	Ventura	2,003	Community	Groundwater
28	Ventura Cwwd No. 17 - Bell Canyon	Ventura	1,946	Community	Purchased surface water
29	Vineyard Avenue Acres Mwc	Ventura	1,820	Community	Groundwater
30	Ventura Cwwd No. 38 - Lake Sherwood	Ventura	1,759	Community	Purchased surface water
31	Cal American Wc - Rio Plaza	Ventura	1,709	Community	Groundwater
32	Ventura Cwwd No. 19 - Somis	Ventura	1,429	Community	Purchased surface water
33	Garden Acres Mutual Water Co	Ventura	1,335	Community	Groundwater
34	Vineyard Ave Estates Mwc	Ventura	1,200	Community	Purchased surface water
35	Limoneira Ranch #1	Ventura	1,187	Community	Purchased groundwater
36	Dempsey Road Mutual Water Co	Ventura	990	Community	Purchased surface water
37	Rio Manor Mutual Water Co	Ventura	983	Community	Groundwater
38	Nyeland Acres Mutual Water Co	Ventura	975	Community	Groundwater
39	Lake Piru Park - Uwcd	Ventura	960	Transient non-community	Surface water
40	Rio School Dist/Rio Del Valle School	Ventura	820	Non-transient non-community	Purchased surface water
41	Senior Canyon Mutual Water Co	Ventura	800	Community	Surface water
42	Cal American - Yerba Buena	Ventura	690	Community	Groundwater
43	Brandeis Bardin Institute	Ventura	665	Community	Purchased surface water
44	Glass House Camarillo Cultivation, LLC	Ventura	600	Non-transient non-community	Groundwater
45	Rancho Sespe Workers Imp Assoc	Ventura	600	Community	Groundwater
46	Rio School Dist/ Rio Real School	Ventura	550	Non-transient non-community	Purchased surface water
47	Usfs - Wheeler Gorge Campground	Ventura	500	Transient non-community	Groundwater
48	Thomas Aquinas College	Ventura	472	Non-transient non-community	Groundwater
49	Cloverdale Mutual Water Co.	Ventura	455	Community	Groundwater
50	Strickland Mutual Water Company	Ventura	429	Community	Groundwater