California Sewer Spills-complete CIWQS data updated every three months

Click on the interactive dashboard below to analyze sewer spills for any collection system in California.

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Last update 09/30/2025

Q3 2025 Spill Trends-Insights from 7/1/2025-9/30/2025

There were 120 reported sewer spills in California for these three months–44 of which were category 1. This was down from 140 in the prior three months (6/1-9/30) and 160 in the same three month time period last year (2024). 2025 year to date is 493 spills while the 2024 number through 9/30/2024 was 632.