Statewide analysis
California Water Loss Intelligence
Every figure below is computed from the audits California urban retail suppliers filed with the Department of Water Resources — one row per supplier per accounting period. Unless a year is selected, each system is represented by its most recent audit, so systems reporting on different cycles are still counted once.
Median real loss
26.8
gal / connection / day
Systems analysed
609
604 with the metric
Real loss volume
318,704 AF
103.85B gal
Non-revenue water
482,638 AF
billed + unbilled shortfall
Median real loss share
6.4%
of water supplied
Reported cost of real loss
$249.9M
as valued by suppliers
25th percentile
15.0
gal / conn / day
75th percentile
50.0
gal / conn / day
90th percentile
93.2
gal / conn / day
Median per mile of main
1,692
gal / mile / day
How loss per connection is distributed
Systems grouped in 10-gallon steps; values above 200 are held in the final bar.
Statewide direction over time
Median and interquartile range of real loss per connection per day, by audit year (years with at least 10 audits).
Coverage changes year to year as suppliers file, so a shift in the median can reflect who reported as much as how they performed. Counts per year: 2016: 486 · 2017: 526 · 2018: 548 · 2019: 554 · 2020: 552 · 2021: 550 · 2022: 548 · 2023: 544 · 2024: 534 · 2025: 21.
Loss per connection against system size
One point per system. Large and small systems both appear across the whole range — size alone does not explain loss.
Largest real-loss volumes
Ranked by acre-feet of real loss in the represented audit.
| System | Real loss | Per connection |
|---|---|---|
| Los Angeles Department of Water and Power | 22,934 AF | 27.1 |
| East Bay Municipal Utility District | 11,231 AF | 26.3 |
| City of Fresno | 7,095 AF | 44.6 |
| City of San Diego | 6,879 AF | 16.4 |
| San Francisco Public Utilities Commission | 6,687 AF | 33.0 |
| City of Modesto | 6,526 AF | 80.9 |
| San Jose Water Company | 5,903 AF | 22.2 |
| City of Bakersfield | 5,846 AF | 94.6 |
| City of Riverside - Public Utilities | 4,736 AF | 61.7 |
| CWS BK Bakersfield | 4,514 AF | 59.2 |
| Sacramento County Water Agency - Laguna Vineyard | 4,462 AF | 74.2 |
| Eastern Municipal Water District | 4,336 AF | 21.5 |
| Contra Costa Water District | 3,302 AF | 47.2 |
| Azusa Light & Water | 3,087 AF | 115.8 |
| Coachella Valley Water District (Cove) | 2,969 AF | 23.4 |
Year-over-year movers
245 systems falling by 1+ gal/conn/day, 271 rising, 48 little changed, 45 not comparable.
Loss falling most
- City of Stockton−305.1 → 17.4
- City of Lompoc−218.9 → 117.4
- SCV Water - Tesoro−198.4 → 297.6
- Vernon Public Utilities−160.9 → 60.9
- Tuolumne Utilites District−148.4 → 14.8
- California - American Water Company - Ventura District - Piru System−105.8 → 150.6
- GSWC - Robbins−92.5 → 17.7
- Rubio Cañon Land and Water Association−82.2 → 17.8
- City of Los Banos−71.0 → 47.3
- City of Delano−58.5 → 20.1
- City of Reedley−57.4 → 241.6
- Humboldt Bay Municipal Water District−56.6 → 10.1
Loss rising most
- Sonoma County Water Agency+2,241.4 → 4,126.8
- Port Hueneme Water Agency+1,923.3 → 1,931.6
- SCV WATER-Regional+1,308.1 → 10,757.2
- City of Livingston+312.8 → 316.7
- City of Exeter+233.6 → 258.1
- Suburban Water Systems+185.5 → 195.2
- City of Corcoran+136.9 → 177.2
- Bertch Ocean View CSD+98.0 → 287.8
- Seal Beach+94.8 → 97.7
- City of Shafter+80.0 → 108.4
- City of Santa Fe Springs+77.2 → 114.8
- CWS AV Lake Hughes+63.9 → 136.2
Counties by real-loss volume
Counties from PWSID-matched service-area geography; systems without matched geography are excluded from this table only.
| County | Systems | Median gal/conn/day | Real loss |
|---|---|---|---|
| LOS ANGELES | 96 | 20.3 | 57,800 AF |
| RIVERSIDE | 30 | 42.9 | 25,908 AF |
| SAN BERNARDINO | 47 | 24.9 | 18,419 AF |
| SACRAMENTO | 31 | 50.4 | 17,655 AF |
| SAN DIEGO | 22 | 16.0 | 16,201 AF |
| ALAMEDA | 8 | 23.5 | 15,829 AF |
| KERN | 27 | 34.3 | 15,044 AF |
| ORANGE | 30 | 18.2 | 14,518 AF |
| SANTA CLARA | 13 | 28.8 | 14,179 AF |
| STANISLAUS | 14 | 39.8 | 12,416 AF |
| FRESNO | 9 | 44.6 | 10,903 AF |
| CONTRA COSTA | 8 | 38.9 | 8,200 AF |
| SAN JOAQUIN | 8 | 36.1 | 8,153 AF |
| SAN FRANCISCO | 1 | 33.0 | 6,687 AF |
| VENTURA | 22 | 20.2 | 6,154 AF |
| SOLANO | 9 | 51.5 | 5,926 AF |
| MERCED | 5 | 87.1 | 4,892 AF |
| PLACER | 22 | 35.1 | 4,865 AF |
| BUTTE | 7 | 53.5 | 4,032 AF |
| SAN MATEO | 17 | 17.0 | 3,701 AF |
| EL DORADO | 6 | 29.3 | 3,000 AF |
| SANTA BARBARA | 12 | 22.2 | 2,727 AF |
| YOLO | 4 | 40.7 | 2,655 AF |
| IMPERIAL | 5 | 31.6 | 2,320 AF |
| KINGS | 2 | 122.7 | 2,264 AF |
Data freshness. 4,919 audits across 609 systems, published Aug 7, 2026 from a source file dated Aug 7, 2026. The source is checked weekly and only republished when the file changes; the last check finished with status “success”.
Source: CA Urban Retail Water System Water Loss Annual Loss Audit Data. Method and formulas · Data check