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Siskiyou County, California — public water systems

At a glance

69 active public water systems are filed under Siskiyou County, California in EPA's SDWIS records, together reporting 40,908 people served. The largest is City of Yreka, which reports serving 7,825 people. 30 are community water systems serving people where they live; the other 39 are non-community systems, such as schools, workplaces, campgrounds and gas stations with their own supply.

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

Active systems

69

Population served

40.9K

Community systems

30

Groundwater share

89.9%

How does Siskiyou County compare with other California counties?

Siskiyou County has the 37th-most active public water systems among the 201 counties listed for active California systems in EPA records; among the 72 with 3 or more systems, the median has 73. Its systems report 40,908 people served in total, the 48th-largest county figure in the state and less than 0.1% of the statewide total. The average system here reports serving 593 people, well below the California average of 5,706. Population figures are what each system reports; people served by more than one system, such as a wholesaler and the town that buys from it, are counted by each.

Where does Siskiyou County's drinking water come from?

By primary water source, Siskiyou County's active systems draw on groundwater (62, 90%) and surface water (7, 10%). Overall, 90% rely mainly on groundwater (including purchased groundwater) and 10% on surface water, compared with 85% and 15% across California. Groundwater means the system draws its water from wells or springs fed by underground aquifers. The county's largest system, City of Yreka, draws primarily on surface water.

What kinds of water systems operate in Siskiyou County?

Siskiyou County's active systems break down as 30 community systems (43%), 9 non-transient non-community systems (13%) and 30 transient non-community systems (43%). A community water system serves at least 15 connections used by year-round residents, or regularly serves at least 25 year-round residents. Homes, apartments and mobile-home parks are served by these. A non-transient non-community water system regularly serves at least 25 of the same people for more than six months a year, but not where they live. Schools, factories, office buildings and hospitals with their own supply are typical examples. A transient non-community water system serves places where people do not stay long, such as gas stations and campgrounds, and regularly serves at least 25 people a day for at least 60 days a year. EPA lists their owner types as private (41%), local government (30%), federal government (22%) and state government (7.2%).

The 50 largest water systems in Siskiyou County

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Active public water systems in Siskiyou County, California
#Water systemCountyPopulation servedTypeSource
1Yreka, City ofSiskiyou7,825CommunitySurface water
2Mt. Shasta, City ofSiskiyou3,642CommunityGroundwater
3Mt. Shasta Ski ParkSiskiyou3,500Transient non-communityGroundwater
4Lake Shastina C.S.DSiskiyou2,790CommunityGroundwater
5Weed, City ofSiskiyou2,662CommunityGroundwater
6Lake Siskiyou CampgroundSiskiyou1,800Transient non-communitySurface water
7Dunsmuir, City ofSiskiyou1,707CommunityGroundwater
8Caltrans-Collier Rest StopSiskiyou1,400Transient non-communitySurface water
9Mccloud C.S.D.Siskiyou1,317CommunityGroundwater
10Montague, City ofSiskiyou1,264CommunitySurface water
11Happy Camp C.S.D.Siskiyou1,100CommunitySurface water
12Caltrans-Weed Rest StopSiskiyou1,000Transient non-communityGroundwater
13Dorris, City ofSiskiyou887CommunityGroundwater
14Tulelake, City ofSiskiyou856CommunityGroundwater
15Etna, City ofSiskiyou720CommunitySurface water
16Fort Jones, Town ofSiskiyou695CommunityGroundwater
17Caltrans-Grass Lake Rest StopSiskiyou600Transient non-communityGroundwater
18Siskiyou Lake Highlands MwcSiskiyou549CommunityGroundwater
19Jh RanchSiskiyou403Transient non-communityGroundwater
20Fowlers Campground-StnfSiskiyou360Transient non-communityGroundwater
21R-Ranch Klamath RiverSiskiyou300Transient non-communityGroundwater
22Siskiyou Co. Rolling Hills MwcSiskiyou300CommunityGroundwater
23R-Ranch HeadquartersSiskiyou300Transient non-communityGroundwater
24Grenada Sanitary DistrictSiskiyou289CommunityGroundwater
25Hornbrook C.S.D.Siskiyou280CommunityGroundwater
26Lake Siskiyou M.W.C.Siskiyou277CommunityGroundwater
27Mdf-Medicine LakeSiskiyou250Transient non-communityGroundwater
28Lava Beds National MonumentSiskiyou245Transient non-communityGroundwater
29Ash Creek Fire Station-StnfSiskiyou240Transient non-communityGroundwater
30Caltrans-Dunsmuir Grade Insp. FacilitySiskiyou200Non-transient non-communityGroundwater
31Kidder Creek Orchard CampSiskiyou200Transient non-communityGroundwater
32Juniper Village Farm Labor HousingSiskiyou170Transient non-communityGroundwater
33Butteville Union SchoolSiskiyou165Non-transient non-communityGroundwater
34Pneuma Retreat Center - Stewart MineralSiskiyou150Transient non-communityGroundwater
35Doctor'S Park Owners AssociationSiskiyou150Non-transient non-communityGroundwater
36Monte Shasta M.W.C.Siskiyou150CommunityGroundwater
37Cal Ore Mobile EstatesSiskiyou146CommunityGroundwater
38Siskiyou Co.Service Area #5/CarrickSiskiyou143CommunityGroundwater
39Jubilee Railroad Wilderness LodgeSiskiyou140Transient non-communityGroundwater
40Abrams Lake Mobile EstatesSiskiyou135CommunityGroundwater
41Shadow Mountain MHPSiskiyou126CommunityGroundwater
42Weed Golf Club, Inc..Siskiyou112Transient non-communityGroundwater
43Sun Mountain M.W.C.Siskiyou106CommunityGroundwater
44Cove Mobile VillaSiskiyou105CommunityGroundwater
45Willow Creek SchoolSiskiyou100Non-transient non-communityGroundwater
46Big Springs Union Elem. SchoolSiskiyou95Non-transient non-communityGroundwater
47Mcbride Springs CampgroundSiskiyou80Transient non-communityGroundwater
48Tennant C.S.D.Siskiyou75CommunityGroundwater
49Callahan Water DistrictSiskiyou70CommunitySurface water
50Cal Fire-Deadwood Conservation CampSiskiyou65Non-transient non-communityGroundwater

All other water systems in Siskiyou County (19)

The remaining active systems filed under Siskiyou County, largest first, with the population each reports serving.

Siskiyou County water systems: frequently asked questions

How many public water systems are in Siskiyou County, California?

EPA's SDWIS records file 69 active public water systems under Siskiyou County, California: 30 community systems (43%), 9 non-transient non-community systems (13%) and 30 transient non-community systems (43%).

Who supplies drinking water in Siskiyou County, CA?

The largest community water systems filed under Siskiyou County are City of Yreka (7,825 people served), City of Mt. Shasta (3,642 people served) and Lake Shastina C.S.D (2,790 people served). Which system serves a particular address depends on its service area, which EPA's SDWIS records do not include; a water bill or the local utility can confirm it.

Does Siskiyou County's drinking water come from groundwater or surface water?

Of the 69 active public water systems in Siskiyou County, 90% draw mainly on groundwater and 10% on surface water, counting purchased supplies. The largest system, City of Yreka, uses surface water.

Where can I find a water quality report for Siskiyou County?

Each community water system must deliver an annual water quality report, called a Consumer Confidence Report, to its customers by July 1, covering the previous calendar year. 30 community systems are filed under Siskiyou County, so the report to look for is the one from the system that supplies your address.

How can I check violations for a water system in Siskiyou County?

Open the system's profile from the list on this page. Each profile shows the most recent Safe Drinking Water Act violations in EPA's records, with plain-English labels and whether each one is resolved. For current compliance status, EPA ECHO is the primary source.

More California water systems

About this data

Source: U.S. EPA Safe Drinking Water Information System (SDWIS) and SDWA violation records, via EPA ECHO, as published October 1, 2026 — AquaCensus refreshes it quarterly. See the methodology for how records are matched, cleaned and scored.

Cite as: AquaCensus, “Public water systems in Siskiyou County, California”, https://aquacensus.com/water-systems/california/siskiyou (data as of October 1, 2026).