Marin County, California — public water systems

47 active public water systems serve Marin County, reporting 285.6K people served.

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

Active systems

Population served

285.6K

Community systems

Groundwater share

76.6%

Water systems in Marin County

Active public water systems in Marin County, California
#	Water system	County	Population served	Type	Source
1	Marin Municipal Water District	Marin	186,895	Community	Surface water
2	North Marin Water District	Marin	61,691	Community	Surface water
3	Nps Ggnra	Marin	18,447	Community	Purchased surface water
4	Bolinas Community PUD	Marin	2,483	Community	Surface water
5	North Marin Wd - Pt. Reyes	Marin	1,841	Community	Groundwater
6	Csp - Angel Island St Park	Marin	1,622	Transient non-community	Groundwater
7	Nps Prns - Beaches	Marin	1,560	Community	Groundwater
8	Inverness Public Utility Dist	Marin	1,445	Community	Surface water
9	Nps Prns - Lighthouse	Marin	1,202	Transient non-community	Groundwater
10	Nps Prns - Glen and Wildcat Campgrounds	Marin	1,200	Transient non-community	Groundwater
11	Lawson S Landing	Marin	946	Community	Groundwater
12	Stinson Beach County Wtr Dist	Marin	583	Community	Surface water
13	Csp - Mt Tam Theatre Well	Marin	504	Transient non-community	Groundwater
14	Csp - Tomales Bay St Park	Marin	503	Transient non-community	Groundwater
15	Tomales High School	Marin	427	Non-transient non-community	Groundwater
16	Coast Springs - Cal. Water Service (Puc)	Marin	388	Community	Surface water
17	Nps Prns - Five Brooks	Marin	365	Transient non-community	Groundwater
18	Muir Beach Community	Marin	336	Community	Groundwater
19	Nps Prns - Laguna System	Marin	316	Transient non-community	Groundwater
20	Csp - Samuel Taylor St Park	Marin	310	Transient non-community	Groundwater
21	Skywalker Ranch	Marin	250	Non-transient non-community	Groundwater
22	Tomales Elem & Middle School	Marin	225	Non-transient non-community	Groundwater
23	Walker Creek Ranch Educational Center	Marin	212	Non-transient non-community	Groundwater
24	Estero Mutual	Marin	206	Community	Surface water
25	Hog Island Oyster Co.	Marin	172	Transient non-community	Groundwater
26	Marin French Cheese Co	Marin	143	Non-transient non-community	Surface water
27	Csp - Marconi Conference Center	Marin	120	Transient non-community	Groundwater under influence of surface water
28	Nicasio Ranch LLC	Marin	104	Transient non-community	Groundwater
29	Tony S Seafood Restaurant	Marin	103	Transient non-community	Groundwater
30	Camp Tamarancho	Marin	101	Transient non-community	Groundwater
31	Nick'S Cove	Marin	90	Transient non-community	Groundwater
32	Tomales Tin Building	Marin	82	Transient non-community	Groundwater
33	Nps Prns - Sky Camp Campground	Marin	75	Transient non-community	Purchased surface water
34	Csp - Mt Tam East Peak System	Marin	75	Transient non-community	Groundwater
35	Green Gulch Farm	Marin	75	Community	Groundwater under influence of surface water
36	Mcevoy Ranch Water System	Marin	66	Non-transient non-community	Surface water
37	Maif - Marshall Aqua Improvement Forum	Marin	50	Transient non-community	Groundwater
38	Tomales Church of the Assumption	Marin	50	Transient non-community	Groundwater
39	All Hands Ecology	Marin	50	Transient non-community	Groundwater
40	Marshall Boat Works	Marin	50	Transient non-community	Groundwater
41	Nicasio School	Marin	48	Non-transient non-community	Groundwater under influence of surface water
42	Slide Ranch	Marin	47	Transient non-community	Groundwater under influence of surface water
43	Nicasio Valley Ranch Mutual	Marin	36	Community	Groundwater
44	Blue Mountain Center	Marin	35	Community	Groundwater
45	Shoreline School Dist: Bus Garage	Marin	26	Transient non-community	Groundwater
46	Devils Gulch Ranch Water System	Marin	25	Transient non-community	Groundwater
47	Diekmann'S General Store	Marin	25	Transient non-community	Groundwater