California · PWS CA1910155

Gswc - Southwest

What Gswc - Southwest filed with DWR about the water it produced and the water it billed for, 2016–2024 — and what the filing does and does not let anyone verify.

Non-revenue water, FY2024
6.5%
Computed from filed system input and billed consumption.

2026-09-05-f0dfea5a6026.csvSheet1 AN1401

Where this figure comes from

(system input − billed authorized) ÷ system input × 100

  • system input volume 8,006 sheet Sheet1, cell AN1401 · converted to million gallons from acre-feet
  • billed authorized consumption 7,482 sheet Sheet1, cell AQ1401 · billed metered plus billed unmetered, converted to million gallons from acre-feet

From data/archive/ca-dwr-water-loss/2026-09-05-f0dfea5a6026.csv (SHA-256 f0dfea5a6026881d), retrieved 2026-09-05 from the published source.

Recoverable annually
$1.5M
Apparent loss is valued at this utility's own reported retail price of water. Real loss is NOT included — DWR publishes a variable production cost whose unit it does not declare, so no dollar figure is put on the leaked water. The real recoverable total is higher than this by an amount this filing does not let anyone state.

2026-09-05-f0dfea5a6026.csvSheet1 DH1401

Where this figure comes from

cost of apparent losses + cost of real losses, both as computed in the filed audit

  • cost of apparent losses, as filed 1,461,385 sheet Sheet1, cell DH1401

From data/archive/ca-dwr-water-loss/2026-09-05-f0dfea5a6026.csv (SHA-256 f0dfea5a6026881d), retrieved 2026-09-05 from the published source.

Balance check
inapplicable
DWR derives water losses from system input minus authorized consumption, so this decomposition holds by construction.

What the record shows

6.5% non-revenue water in FY2024, higher than 29% of the 545 California systems that filed that year.

6.5% non-revenue water in FY2024, against 545 California filings for the same yearA strip of 545 filings on a 0 to 64% axis. The median is 9.2%. This system is 6.5%. 1 filing above 64% are drawn at the right edge.0%10%20%30%40%50%60%This system 6.5%California median 9.2%

Compliance record

3 violations on EPA's record for this system as of 2026Q2, of which 1 is health-based. 3 resolved, and 0 still open.

Nothing on the record is open as of 2026Q2.

Counted as distinct violations, not as rows: EPA's export carries one row per enforcement action taken against a violation, so a row count would multiply this system's record several times over. A violation here is a breach of a reporting, monitoring or contaminant-level rule as reported to EPA — it is not a measurement of the water, and this site has none.

Source: US EPA, Safe Drinking Water Information System, via the ECHO national download, 2026Q2. How we hold it.

Who filed this audit

Golden State Water Company - Southwest filed this audit for FY2024 and operates no other system in the export that year. California keys its export on the filing organization and not on the system, so the two coincide here rather than by definition.

Every figure on this page is read from DWR's published export as this site holds it: a 184-column extract of DWR's 190-column file. Six columns naming individuals, including the contact and the third-party validator, are removed before the bytes are committed, so the click path behind each figure lands on the extract and not on DWR's original. The column letters differ from DWR's for that reason.

Water balance, FY2024 · 8,006 MG system input
Billed 7,482 MG Unbilled authorized 29.9 MG Apparent loss 148.4 MG Real loss 345.6 MG

DWR derives water losses from system input minus authorized consumption, so these parts sum to the whole on every filing. What a filing can get wrong is which of these numbers were measured.

Where these volumes come from
  • System input 8,006 MG sheet Sheet1, cell AN1401 · converted to million gallons from acre-feet
  • Billed authorized 7,482 MG sheet Sheet1, cell AQ1401 · billed metered plus billed unmetered, converted to million gallons from acre-feet
  • Unbilled authorized 29.9 MG sheet Sheet1, cell AW1401 · unbilled metered plus unbilled unmetered, converted to million gallons from acre-feet
  • Apparent loss 148.4 MG sheet Sheet1, cell CC1401 · converted to million gallons from acre-feet
  • Real loss 345.6 MG sheet Sheet1, cell CE1401 · converted to million gallons from acre-feet

From data/archive/ca-dwr-water-loss/2026-09-05-f0dfea5a6026.csv (SHA-256 f0dfea5a6026881d), retrieved 2026-09-05 from the published source.

Filed history, 2016–2024
Year NRW Input (MG) Recoverable
2024 6.5% 8,006 $1.5M
2023 6.1% 7,885 $1.1M
2022 6.7% 8,257 $1.2M
2021 5.6% 8,416 $1.1M
2020 6.0% 8,543 $1.1M
2019 6.6% 8,482 $679,000
2018 5.6% 8,952 $672,000
2017 5.3% 8,758 $682,000
2016 6.0% 8,669 $619,000

Comparable systems

The same size band — over 50,000 connections.

SystemBasis for comparisonNRW
Moulton Niguel Water Districtover 50,000 connections 5.8% FY2025
Huntington Beachover 50,000 connections 3.9% FY2024
Santa Rosaover 50,000 connections 5.4% FY2024
Sacramento County Water Agency - Laguna Vineyardover 50,000 connections 20.8% FY2024
Otay Water Districtover 50,000 connections 5.3% FY2025
Bakersfieldover 50,000 connections 15.3% FY2025
Lac Waterworks District 40, Region 4 & 34over 50,000 connections 4.9% FY2024
Sgvwc - Los Angeles Countyover 50,000 connections 4.4% FY2024

Where is it going?

This page says how much — roughly $1.5M a year. It cannot say which accounts, which zones, or which meters. That takes your billing history, your meter reads, and your production data reconciled against each other.

Our Water Loss Recovery Snapshot is three weeks, one flat fee, and the deliverable is a ranked list of specific accounts and zones with dollars and a confidence on each.

See what the Snapshot delivers Email us about Gswc - Southwest

Sources and corrections. Every figure above is either filed by the utility or computed from filed figures, and each one says which. If a number here is wrong, it is either wrong in the filing or wrong in our reading of it — tell us which and we will correct the page and say what changed.

Cite as

Municorn.us, “Gswc - Southwest — water loss as filed”, Municorn water loss index, https://municorn.us/water-loss/ca/gswc-southwest/ (source filings retrieved 2026-09-05).

CC BY 4.0 — reuse and redistribution are permitted with attribution to Municorn.us and a link to this page. Terms, and the one 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.