Chicago River Dyeing: It's an Annual St. Patrick's Day Tradition, Not a One-Time Event

When: Saturday before St. Patrick's Day (or March 17 if Saturday).
Where: Between Columbus Dr. and Wacker Dr. (downtown).
Who: Chicago Journeymen Plumbers Local 130 (still).
Spectators: 400K+ line the riverwalk, bridges, buildings.

There is no single "year they dyed the Chicago River green." It's been an annual tradition since 1962.

The Origin

1961: Plumbers' Union Local 130 used 100 lbs of fluorescein dye (leak detection) to trace illegal sewage discharges. The river turned bright green.
1962: They did it intentionally for St. Patrick's Day. 100 lbs → green for a week.
Now: ~40 lbs of vegetable-based, EPA-approved orange powder (turns green in water) → lasts 6–12 hours.

San Antonio River Walk, Tampa Hillsborough River, Savannah fountains, White House fountain (since 2009), Dublin's River Liffey — all dye green for St. Pat's.

So the question isn't "what year" — it's "this year's date." The tradition is 60+ years strong.

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