# Map of California public water systems

URL: /maps/california-water-systems/
Systems mapped: 585
Systems with a loss figure: 585
Shapes EPA modelled rather than a state or utility publishing: 2

> **Cite as:** Municorn.us, "Map of California public water systems", Municorn water loss index, https://municorn.us/maps/california-water-systems/ (source filings retrieved 2026-09-05).
> **Licence:** CC BY 4.0 — https://creativecommons.org/licenses/by/4.0/ — reuse and redistribution are permitted with attribution to Municorn.us and a link to this URL.
> **Caveat that must travel with these figures:** "Water loss" is at least three different quantities depending on the jurisdiction, and nothing here supports a comparison between states.

Each system is drawn on its service area and shaded by the most recent water loss figure it filed, in fifths of
California's own distribution. The bands are not a national scale: the regulators in this corpus measure different
quantities, and a figure from one state does not compare to a figure from another.

## What a shape is

Service areas come from the US EPA's national boundary layer, published as an estimate. EPA disclaims the spatial
accuracy of the features and names local government as the accurate source. In California, 2 of 585 shapes are EPA models rather than published boundaries.

A boundary is not a customer list and not a legal service territory. Being inside one does not make an address that
system's ratepayer.

## Not on the map

24 California system(s) have filings on this site and no boundary in EPA's layer:

- [Amador Water Agency - Pg&e](/water-loss/ca/amador-water-agency-pg-and-e/)
- [Big Bear Lake Department Of](/water-loss/ca/big-bear-lake-department-of-ca3600395/)
- [California - American Water Company - Los Angeles District - Bellflower](/water-loss/ca/california-american-water-company-los-angeles-district-bellflower/)
- [California - American Water Company - Sacramento District - Security Park](/water-loss/ca/california-american-water-company-sacramento-district-security-park/)
- [California American Water - San Diego District](/water-loss/ca/california-american-water-san-diego-district/)
- [California American Water Company - Bishop](/water-loss/ca/california-american-water-company-bishop/)
- [California American Water Company - Ryan Ranch](/water-loss/ca/california-american-water-company-ryan-ranch/)
- [California American Water-sacramento District-suburban/rosemont](/water-loss/ca/california-american-water-sacramento-district-suburban-rosemont/)
- [Coachella Valley Water District Id11](/water-loss/ca/coachella-valley-water-district-id11/)
- [Lake Arrowhead Comm Svcs District 3610087](/water-loss/ca/lake-arrowhead-comm-svcs-district-3610087/)
- [Lompoc](/water-loss/ca/lompoc-ca4210006a/)
- [Lompoc](/water-loss/ca/city-of-lompoc/)
- [Mid-peninsula Water District](/water-loss/ca/mid-peninsula-water-district/)
- [Norwalk](/water-loss/ca/norwalk-ca3901111/)
- [Sacramento County Water Agency](/water-loss/ca/sacramento-county-water-agency/)
- [Sacramento County Water Agency - Metro Air Park](/water-loss/ca/sacramento-county-water-agency-metro-air-park/)
- [Sacramento County Water Agency - Northgate 880](/water-loss/ca/sacramento-county-water-agency-northgate-880/)
- [Sonoma County Water Agency](/water-loss/ca/sonoma-county-water-agency/)
- [Thousand Oaks](/water-loss/ca/thousand-oaks-ca5610020a/)
- [Thousand Oaks](/water-loss/ca/thousand-oaks-ca5610020b/)
- [Tuolumne Utilites District - Cedar Ridge](/water-loss/ca/tuolumne-utilites-district-cedar-ridge/)
- [Tuolumne Utilites District - Phoenix Lake](/water-loss/ca/tuolumne-utilites-district-phoenix-lake/)
- [Tuolumne Utilites District - Scenic View](/water-loss/ca/tuolumne-utilites-district-scenic-view/)
- [Tuolumne Utilities District](/water-loss/ca/tuolumne-utilities-district/)

Source: US EPA Office of Research and Development, retrieved 2026-09-09, archived as data/archive/epa-cws-boundaries/2026-09-09-ca.geojson, extracted from
https://github.com/USEPA/ORD_SAB_Model/raw/refs/heads/main/Version_History/PWS_Boundaries_Latest.zip. Figures: California Department of Water Resources, as filed.