Worst Infrastructure: Riverside Metro — 2026

Out of 36 ZIP codes with infrastructure data in the Riverside metro area, these areas face the highest estimated risk of water pipe failure based on infrastructure age, funding gaps, and violation history.

Statistic	Value
ZIP codes ranked	36
Highest risk	46%
Median risk	28%
Average risk	30%

Top 36 Highest Risk ZIP Codes

Rank	ZIP Code	City	State	Pipe Failure Risk	Risk Level	Safety Score
1	92405	San Bernardino	CA	46%	High	75/100
2	92411	San Bernardino	CA	43%	High	72/100
3	92401	San Bernardino	CA	42%	High	72/100
4	92404	San Bernardino	CA	42%	High	65/100
5	92410	San Bernardino	CA	41%	High	75/100
6	92501	Riverside	CA	38%	Moderate	83/100
7	92506	Riverside	CA	37%	Moderate	83/100
8	92408	San Bernardino	CA	36%	Moderate	75/100
9	92335	Fontana	CA	35%	Moderate	70/100
10	91762	Ontario	CA	34%	Moderate	83/100
11	92504	Riverside	CA	34%	Moderate	83/100
12	92407	San Bernardino	CA	33%	Moderate	70/100
13	91764	Ontario	CA	31%	Moderate	78/100
14	92507	Riverside	CA	30%	Moderate	83/100
15	92509	Riverside	CA	30%	Moderate	78/100
16	92503	Riverside	CA	29%	Moderate	83/100
17	92505	Riverside	CA	29%	Moderate	83/100
18	91761	Ontario	CA	28%	Moderate	83/100
19	92553	Moreno Valley	CA	28%	Moderate	83/100
20	92402	San Bernardino	CA	26%	Moderate	75/100
21	92403	San Bernardino	CA	26%	Moderate	72/100
22	92406	San Bernardino	CA	26%	Moderate	72/100
23	92412	San Bernardino	CA	26%	Moderate	72/100
24	92413	San Bernardino	CA	26%	Moderate	72/100
25	92414	San Bernardino	CA	26%	Moderate	72/100
26	92415	San Bernardino	CA	26%	Moderate	72/100
27	92418	San Bernardino	CA	26%	Moderate	72/100
28	92423	San Bernardino	CA	26%	Moderate	72/100
29	92424	San Bernardino	CA	26%	Moderate	72/100
30	92427	San Bernardino	CA	26%	Moderate	72/100
31	92557	Moreno Valley	CA	26%	Moderate	83/100
32	92337	Fontana	CA	23%	Moderate	75/100
33	92551	Moreno Valley	CA	21%	Moderate	83/100
34	92336	Fontana	CA	19%	Low	72/100
35	92508	Riverside	CA	16%	Low	83/100
36	92555	Moreno Valley	CA	16%	Low	83/100

Methodology

Infrastructure risk rankings combine four data sources, each weighted equally (25%): (1) EPA Drinking Water Infrastructure Needs Survey (DWINS 2023) — state-level 20-year funding gap per capita for pipe replacement, treatment, and storage; (2) Census ACS housing vintage — percentage of homes built before 1980, when lead solder and galvanized pipes were common; (3) EPA SDWIS violation and enforcement data — system-level compliance history; (4) Lead and Copper Rule indicators — service line material inventories and 90th percentile lead testing results. The combined score is normalized to a 0-100% probability scale.

Data sources: EPA DWINS 2023, Census ACS, EPA SDWIS, Lead and Copper Rule data. Last updated: 2026-06-04.

Frequently Asked Questions

What does pipe failure probability mean?

Pipe failure probability estimates the likelihood of water main breaks, lead contamination from corroded pipes, or service disruptions based on infrastructure age, state funding gaps, violation history, and lead indicators. It is not a prediction of imminent failure, but a risk assessment based on known factors.

How is infrastructure risk calculated?

The risk score combines four equally weighted factors: state-level infrastructure funding gap per capita (from EPA DWINS 2023), housing vintage (Census ACS pre-1980 housing percentage), water system violation and enforcement history (EPA SDWIS), and lead exposure indicators (service line probability and testing results).

What can homeowners do about aging infrastructure?

Test your tap water annually, especially for lead. Check if your home has a lead service line through your water utility. Consider a whole-house water filter (NSF/ANSI 53 certified). Review your water system Consumer Confidence Report for violation history.

Does high risk mean my water is unsafe right now?

Not necessarily. Infrastructure risk indicates long-term vulnerability, not current contamination. However, areas with aging pipes and high violation counts have a statistically higher chance of water quality issues. Regular testing is the best way to verify your water safety.