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St. Patrick’s Day and The Many Uses of Dye Tablets

St. Patrick’s Day is tomorrow and it's celebrated in many ways across the United States. From parades to dances to corned beef and cabbage, there’s one common thread that binds together any St. Paddy’s Day tradition: the color green.

Hulk-colored clothing. Chartreuse-hued cupcakes. Emerald-tinted beer. There’s never a lack of green-decorated or -dyed memorabilia to celebrate the Irish holiday, including green waterways.

Several U.S. cities get into the St. Paddy’s Day spirit by dyeing bodies of water green, something we at the Portland Water Bureau take special note off for reasons we are about to explain. To commemorate the upcoming Fix-A-Leak week, let’s take a look at a few of these cities and find out what dyeing water has to do with finding household leaks.

Chicago River dyed greenChicago

Chicago began dying the Chicago River green in 1962 after Mayor (?) Richard Daley noticed that the dye tablets used to detect leaks from plumbing gave water the perfect shade of Irish green. Since then, this tradition has grown to attract worldwide attention each year. At 9:15 a.m. on the day of the Chicago St. Patrick’s Day Parade, members of the local plumbers union hop aboard several boats on the Chicago River and begin the dyeing process.


Each year on St. Patrick’s Day, the City of Tampa, Florida, dyes the Hillsboro River green with an orange powder called “Bright Dyes,” a fluorescent “dye tracing product” which is also used to detect leaks from plumbing.

The river stays a bright green for just a few hours before the tide washes out the color.

Tweet of Indianapolis Greening of the Canal eventIndianapolis

In its 21st consecutive year, Indianapolis, Indiana, dyes a portion of its downtown canal green for the annual Greening of the Canal event which features live music and celebrity appearances. The City uses 10 gallons of concentrated liquid dye which colors the water for about two to four days.

Not Just for Dyeing Rivers Green

While no waterways are dyed green in Oregon for St. Patrick’s Day, we do use dye for another purpose: to detect leaky toilets.

How does this work? So glad you asked.

Place a dye tablet – or a few drops of food coloring – in your toilet tank. If the dye color leaks into the toilet bowl, you have a leak! Fixing leaks, which can be done at home, helps you to conserve water and save money on your water bill.

You may not be able to see a green waterway in Oregon on St. Patrick’s Day, but why not start your own annual leak-detecting custom this St. Patrick’s Day knowing you’re joining a proud history of American water conservation?

Find how you can save water and money, and how to order a Water Efficiency Kit, at


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