Kuchamaa · Photo: UncleMunkle · CC BY-SA 3.0Living in Potrero, CA: what to set up and who to call
The Twin Lakes Resort water system reported 14 health-based violations to EPA in the last five years: arsenic ×14. 77% of systems its size reported none. Potrero has no town government of its own, so San Diego County runs its elections and most services, and its children attend Mountain Empire Unified School District.
I’m new in town
What to set up in Potrero, and who provides it. Tap an answer for the details and where they come from.
Power, water and internet
Who to call to start service at a new address in Potrero.
Power comes from SDG&E
SDG&E (San Diego Gas & Electric Co.), an investor-owned utility, serves all of Potrero. Its homes paid an average of 45.8¢ per kWh in 2025, about $168 a month (its average across California, for customers on its standard service). California lets you buy power from another supplier; 79% of SDG&E’s home customers do, and SDG&E still delivers it.
Start or move service: sempra.com
Service territory: HIFLD Electric Retail Service Territories (map dated Aug 2023). Prices and customers: EIA-861, 2025.
Water comes from Twin Lakes Resort water system
The Twin Lakes Resort water system supplies Potrero: about 66% of residents live in its service area. About 34% of homes are outside any mapped community water system, most likely on private wells, which EPA doesn’t regulate. It draws ground water and serves 400 people in all.
14 health-based violations reported to EPA in the five years to October 2026: arsenic ×14, the latest beginning Apr 2025. 77% of the 15,074 systems serving 101–500 people had none.
The latest lead result on file, the 90th percentile of homes sampled in Jan 2022–Dec 2024, was 0.0 ppb, below the 15 ppb action level that applied. Results below detection are reported as 0, so 0 doesn’t mean no lead at any tap.
The system’s full record: EPA ECHO report
EPA SDWIS via Envirofacts (violations pulled Oct 9, 2026) and ECHO (lead samples, 2026Q3); service area: EPA Community Water System Service Area Boundaries v3.0. Violations are counted by the start of their compliance period. CA3701793.
Which providers serve Potrero
This card will list the home internet providers the FCC’s National Broadband Map shows in Potrero, the share of addresses that can get 100/20 Mbps and the share with fiber, with the map’s “as of” date.
Source to come: FCC Broadband Data Collection.
We don’t have Potrero’s trash rules yet
Pickup rules, the dump and recycling in Potrero.
Where your child goes to school
Public school districts and the school path by grade.
Potrero is in Mountain Empire Unified School District.
Test scores and every school: see Schools →U.S. Department of Education, NCES Common Core of Data, 2024–25. Enrollment rules and registration are the district’s.
No town hall: the county runs things
Potrero is unincorporated, so San Diego County is the local government.
Election office: FVAP local election office directory, updated Aug 2025; jurisdictions: EAC EAVS 2024. Registration rules and links: vote.gov, updated Nov 18, 2024.
Potrero is in ZIP code 91963
ZIP codes where Potrero residents live, with the share of the town in each.
| ZIP | Post office name | Share of Potrero | ZIP’s residents in Potrero |
|---|---|---|---|
| 91963 | Potrero, CA | 100% | 59% |
Census 2020 ZIP Code Tabulation Areas, by census block; post office names: GeoNames (CC BY 4.0). ZIPs created since 2020 are missing.
Getting around, the ER and the library
One line each; the subject pages have the rest.
ER: CMS hospital data. Library: IMLS Public Libraries Survey, FY2024.
Questions about living in Potrero
Who supplies Potrero’s drinking water, and has it had violations?
The Twin Lakes Resort water system (EPA ID CA3701793). It reported 14 health-based violations to EPA in the five years to October 2026: arsenic ×14. 77% of systems its size had none. Its latest lead 90th percentile was 0.0 ppb (Jan 2022–Dec 2024), against a 15 ppb action level.
Who provides electricity in Potrero?
SDG&E (San Diego Gas & Electric Co.), an investor-owned utility. Its homes paid about 45.8¢ per kWh in 2025 (EIA).
What ZIP codes are in Potrero?
91963. Census 2020 ZIP Code Tabulation Areas.
What school district is Potrero in?
Mountain Empire Unified School District.
How do I register to vote in Potrero?
In California you can register online until 15 days before Election Day, in person up to and including Election Day, or by mail (postmarked 15 days before). Elections here are run by the San Diego Registrar of Voters. Check your registration at voterstatus.sos.ca.gov.
Sources & dates
Every answer above names its source. Here they are with their dates.
- Water: EPA SDWIS (Envirofacts, pulled Oct 9, 2026), ECHO SDWA 2026Q3, EPA CWS Service Area Boundaries v3.0.
- Power: HIFLD Electric Retail Service Territories (map Aug 2023); EIA-861 final 2025.
- Trash: OpenStreetMap, Geofabrik extract of Oct 9, 2026. © OpenStreetMap contributors (ODbL).
- ZIP codes: Census 2020 ZCTA relationship files; GeoNames postal codes (CC BY 4.0).
- Schools: NCES Common Core of Data, 2024–25.
- Registration: vote.gov, updated Nov 18, 2024 (read Oct 10, 2026). Official sites and area codes: Wikidata.
- Election office: FVAP local election office directory (fetched Oct 10, 2026; each record dated), EAC EAVS 2024 jurisdictions; registration and lookup links from vote.gov’s state data, checked Oct 10, 2026.
- Internet (FCC): pending.