Mar 15, 2026, 4:02 p.mMar 15, 2026, 4:02 p.m
Last Saturday, March 14, the Chicago River in the US city of Chicago was colored bright green. This was made to celebrate St. Patrick’s Day.
St. Patrick’s Day is an Irish holiday and is actually a day of remembrance for the Irish Bishop Patrick. He lived in the 5th century and is now considered the first Christian missionary in Ireland.
Video: watson/nina bürge
The river has been colored by the Chicago Plumbing Company since 1962. Powder is thrown into the river water with two boats. This initially looks orange and later turns a bright green. The composition of the powder is top secret, but harmless to the environment and the animals in the water.
The color lasts for a few hours, but if the weather is good the river can stay bright green for up to a day. The powder then dissolves and is washed downstream.
The tradition began when plumbers discovered a paint that was then used to find leaky pipes.
In Chicago, St. Patrick’s Day is celebrated extensively every year. In addition to the coloring of the river, there is also a parade, which also took place on Saturday, March 14th. (nib)
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