2026 Rankings

Worst Infrastructure: California — 2026 Rankings

Last updated: October 18, 2026

1,715 ZIP codes ranked by Infrastructure Stress Indicator #1: ZIP 93563 (Valyermo, CA) - 69/100

Out of 1,715 ZIP codes with infrastructure data in California, these areas have the highest modeled infrastructure stress indicator values, computed from area-level data on infrastructure age, funding gaps, violation history, and lead indicators. The indicator is not a measured failure probability or forecast.

Statistic Value
ZIP codes ranked 1,715
Highest stress indicator 69/100
Median stress indicator 38/100
Average stress indicator 38/100
State California

Top 100 ZIP Codes by Infrastructure Stress

Rank ZIP Code City State Infrastructure Stress Stress Level Safety Score
1 93563 Valyermo CA 69/100 Very High —
2 95419 Camp Meeker CA 66/100 Very High —
3 94573 Rutherford CA 65/100 Very High —
4 93106 Santa Barbara CA 64/100 Very High —
5 93741 Fresno CA 64/100 Very High —
6 94512 Birds Landing CA 64/100 Very High —
7 95637 Guinda CA 64/100 Very High —
8 95930 Clipper Mills CA 64/100 Very High —
9 93429 Casmalia CA 63/100 Very High —
10 93554 Randsburg CA 63/100 Very High —
11 94130 San Francisco CA 63/100 Very High —
12 95601 Amador City CA 63/100 Very High —
13 95986 Washington CA 63/100 Very High —
14 94021 Loma Mar CA 62/100 Very High —
15 95319 Empire CA 62/100 Very High —
16 95735 Twin Bridges CA 62/100 Very High —
17 96063 Mineral CA 62/100 Very High —
18 94569 Port Costa CA 61/100 Very High —
19 96009 Bieber CA 61/100 Very High —
20 92332 Essex CA 60/100 High —
21 92398 Yermo CA 60/100 High —
22 93541 Lee Vining CA 60/100 High —
23 95606 Brooks CA 60/100 High —
24 95675 River Pines CA 60/100 High —
25 96108 Davis Creek CA 60/100 High —
26 96121 Milford CA 60/100 High —
27 90704 Avalon CA 59/100 High —
28 93545 Lone Pine CA 59/100 High —
29 94707 Berkeley CA 59/100 High —
30 96057 Mccloud CA 59/100 High —
31 96115 Lake City CA 59/100 High —
32 93562 Trona CA 58/100 High —
33 94116 San Francisco CA 58/100 High —
34 95253 Victor CA 58/100 High —
35 95439 Fulton CA 58/100 High —
36 95560 Redway CA 58/100 High —
37 96068 Nubieber CA 58/100 High —
38 96110 Eagleville CA 58/100 High —
39 96113 Herlong CA 58/100 High —
40 91125 Pasadena CA 57/100 High —
41 93226 Glennville CA 57/100 High —
42 93522 Darwin CA 57/100 High —
43 93921 Carmel By The Sea CA 57/100 High 67/100
44 94108 San Francisco CA 57/100 High —
45 94117 San Francisco CA 57/100 High —
46 94122 San Francisco CA 57/100 High —
47 94127 San Francisco CA 57/100 High —
48 94940 Marshall CA 57/100 High —
49 95221 Altaville CA 57/100 High —
50 95354 Modesto CA 57/100 High 75/100
51 95429 Dos Rios CA 57/100 High —
52 95564 Samoa CA 57/100 High —
53 95612 Clarksburg CA 57/100 High —
54 95698 Zamora CA 57/100 High —
55 95714 Dutch Flat CA 57/100 High —
56 95715 Emigrant Gap CA 57/100 High —
57 95939 Elk Creek CA 57/100 High —
58 96010 Big Bar CA 57/100 High —
59 96017 Castella CA 57/100 High —
60 96038 Grenada CA 57/100 High —
61 96085 Scott Bar CA 57/100 High —
62 96090 Tehama CA 57/100 High —
63 91104 Pasadena CA 56/100 High 58/100
64 91962 Pine Valley CA 56/100 High —
65 91980 Tecate CA 56/100 High —
66 92333 Fawnskin CA 56/100 High —
67 92339 Forest Falls CA 56/100 High —
68 93526 Independence CA 56/100 High —
69 93666 Sultana CA 56/100 High —
70 93928 Jolon CA 56/100 High —
71 94114 San Francisco CA 56/100 High —
72 94118 San Francisco CA 56/100 High —
73 94123 San Francisco CA 56/100 High —
74 95318 El Portal CA 56/100 High —
75 95514 Blocksburg CA 56/100 High —
76 95563 Salyer CA 56/100 High —
77 95653 Madison CA 56/100 High —
78 95974 Richvale CA 56/100 High —
79 96023 Dorris CA 56/100 High —
80 96112 Fort Bidwell CA 56/100 High —
81 96118 Loyalton CA 56/100 High —
82 96133 Topaz CA 56/100 High —
83 96135 Vinton CA 56/100 High —
84 91001 Altadena CA 55/100 High 58/100
85 92060 Palomar Mountain CA 55/100 High —
86 93641 Miramonte CA 55/100 High —
87 94010 Burlingame CA 55/100 High —
88 94110 San Francisco CA 55/100 High —
89 94112 San Francisco CA 55/100 High —
90 94121 San Francisco CA 55/100 High —
91 94602 Oakland CA 55/100 High —
92 95312 Cressey CA 55/100 High —
93 95466 Philo CA 55/100 High —
94 95493 Witter Springs CA 55/100 High —
95 95565 Scotia CA 55/100 High —
96 95585 Leggett CA 55/100 High —
97 95818 Sacramento CA 55/100 High 83/100
98 95936 Downieville CA 55/100 High —
99 95943 Glenn CA 55/100 High —
100 96015 Canby CA 55/100 High —

Methodology

Infrastructure stress rankings combine four data sources, each weighted equally (25%): (1) EPA Drinking Water Infrastructure Needs Survey and Assessment (DWINSA 2023) — state-level 20-year infrastructure need per capita for pipe replacement, treatment, and storage; (2) Census ACS housing vintage — percentage of homes built before 1980; (3) EPA SDWIS violation and enforcement data — system-level compliance history; (4) available Lead and Copper Rule indicators — service line material inventories and testing results. The combined value is a normalized 0-100 comparative stress indicator, not a measured pipe-failure probability or a forecast.

Data sources: EPA DWINS 2023, Census ACS, EPA SDWIS, Lead and Copper Rule data. Last updated: 2026-10-18.

Frequently Asked Questions

What does the infrastructure stress indicator mean?

The indicator summarizes infrastructure funding gaps, housing age, violation history, and lead indicators on a 0-100 scale. It is a comparative heuristic, not a measured pipe-failure probability or a forecast of a water-main break.

How is infrastructure stress calculated?

The indicator combines four equally weighted factors: state-level infrastructure need per capita (EPA DWINSA 2023), housing vintage (Census ACS pre-1980 housing percentage), water system compliance history (EPA SDWIS), and available lead indicators.

What can homeowners do about aging infrastructure?

Ask your water utility or health department about testing your tap water, especially for lead. Check if your home has a lead service line through your water utility. If you use a filter, choose one certified under NSF/ANSI 53 for the specific contaminant, such as lead. Review your water system Consumer Confidence Report for violation history.

Does high stress mean my water is unsafe right now?

Not necessarily. Infrastructure stress is a screening indicator of long-term vulnerability, not a measurement of current contamination or a prediction of failure. For current conditions, check utility notices and the latest Consumer Confidence Report, and test your tap for contaminants of concern.

Explore More Rankings

How this ranking is calculated, data sources, and limitations: Rankings Methodology →


Related Rankings

Water Safety 2026 EPA violations and water quality scores Lead Risk 2026 Lead service-line indicators and system-level action-level exceedances Infrastructure 2026 Aging pipes, system age and remediation costs
Disclaimer: Rankings are based on EPA, FEMA, and federal agency data. They reflect historical patterns and risk indicators, not necessarily current conditions. For the most current information, contact your local water utility or request a Consumer Confidence Report.

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