El Niño: Why Collection Systems Should Prepare Now
El Niño is the warm phase of a recurring climate pattern in the tropical Pacific. As ocean temperatures rise and winds shift, weather patterns can change far beyond the Pacific. In the United States, El Niño often increases the odds of a wetter winter across the southern states, though local conditions vary.
This year’s event could be unusually powerful. In its September outlook, NOAA reported a greater than 90% chance of a very strong El Niño during fall and winter 2026–27. It also estimated a 75% chance that the October–December period would exceed the strength of every El Niño in its record dating to 1950. That is a forecast, not a certainty, and even a historic event would not guarantee heavy rain in any particular community.
For wastewater and stormwater utilities, the practical question is how collection systems will respond if intense rainfall arrives. Monitoring rainfall, levels, and flow before storms begin can help teams spot rising conditions, investigate inflow and infiltration, and make better-informed response and planning decisions.
Read the one-page El Niño Flash Report for the key risks and ways ADS can help utilities prepare.
By Mary Zappe - Technical Business Development Manager, ADS Environmental Services
