The Secret Behind Dyeing the Chicago River Green

Chicago River is dyed green

Other cities have tried, but none can replicate the verdant emerald hue that surges through the Chicago River every St. Patrick’s Day. What’s the secret behind Chicago’s beloved tradition of dyeing the river green? Plumbers.

Chicago Plumbers Union Local 130 St. Patrick's Day

History of Dyeing the Chicago River Green

While Chicago’s annual St. Patrick’s Day parade first stepped off in 1956 (led by Mayor Daley), the river got the green treatment in 1962.

Why does Chicago dye the river green? In 1961, Stephen Bailey, the Business Manager of Chicago Plumbers Local 130, noticed the bright green stain covering one plumber’s overalls. The culprit was a dye that plumbers used to detect leaks in pipes. It turned water the perfect color of green associated with the Emerald Isle of Ireland.

Chicago River dyed green

The next year, the Plumbers Local Union transformed the river for St. Patrick’s Day. Using 100 pounds of the dye, the Chicago River flowed bright green for a whole week!

Chicago River is dyed green for St. Patrick's day

How Long Does the Chicago River Stay Green?

Today, the honor of dyeing the Chicago River green is still done by Chicago Plumbers Local 130. How do they turn the Chicago River green? These days, they use just 40 pounds of dye and the green magic lasts for several hours.

Typically, about six plumbers in two boats dye the stretch of the river between Columbus Drive and Orleans Street. One motorboat dumps the dye and the other boat stirs the water to create the nearly neon green hue.

Chicago plumbers dye the Chicago River green

Watching the plumbers dump the dye into the river, you’ll notice that it’s an orange powder. After a moment, the orange on the water turns green, perhaps due to a leprechaun’s magic. For the best views of the Chicago River dyed green, you’ll want to visit the Chicago Riverwalk in the morning or early afternoon. By late afternoon, the Chicago River’s vibrant green color begins to fade back to its natural emerald hue.

Is the Chicago River’s green dye safe?

Fear not, the environmentally-friendly dye that turns the Chicago River green is made from vegetables. However, one secret you won’t learn is the dye’s formula. That’s one St. Patrick’s Day secret that the Chicago Plumbers Local 130 are keeping to themselves.

Plumbers dye the Chicago River green on St. Patrick's Day

When is the Chicago River Dyed Green?

Chicago celebrates St. Patrick’s Day on the Saturday before the official holiday on March 17. Typically, the Chicago River dyeing occurs around 10 a.m. with the Chicago St. Patrick’s Day parade following around noon in Grant Park.

How to See the Chicago River Dyed Green

The bridges over the Chicago River are often closed to pedestrians and traffic during the hour or so that the river is being dyed. Sometimes, the Chicago Riverwalk is also closed. Some of the best views to watch the plumbers dye the Chicago River green are on Upper Wacker Drive.

Walk along Upper Wacker Drive to find different vantages of the green river. While it’s sure to be busy, it isn’t difficult to find a good view if you’re patient. Most people want to get their photo by the river and move on. I recommend offering to take photos for folks and then snagging their spot by the river when they walk away. Find different views by crossing the river on one of the bridges that are open likely further west on the river.

St. Patrick's Day on the green Chicago River

Where to Stay in Chicago to See the River Dyeing

The Chicago River runs through the heart of the city, making it easily accessible for visitors who want to experience the iconic river dyeing. With thousands of people flocking to see the plumbers dye the Chicago River green, driving and parking in the Loop is not recommended, although it is possible. If you’re planning to visit the Chicago River dyeing, stay within walking distance of the Loop or take public transit.

If you want to be able to walk to the Chicago River dyeing, book a room in the Loop, River North, and or West Loop neighborhoods. Hotel prices may be higher than average during St. Patrick’s Day weekend in Chicago, so you may opt to stay a bit further from the downtown Loop area. The neighborhoods of Lincoln Park, Lakeview, Wicker Park, Logan Square, and the South Loop are all just a few stops away on public transit from the Chicago River dyeing.

Fortunately, the Loop is accessible from anywhere in Chicago via the ‘L’ train lines or bus system. Check the CTA system map to see if your hotel or house rental is near a Chicago train or bus line. If you’re traveling from the Chicagoland suburbs you can take a Metra commuter rail line to get downtown. Check the Metra maps and schedules.

I’ve added a handy map below to check the latest hotel rates near the Chicago River dyeing location. You can also check Chicago hotel rates on Hotels.com, Booking.com, and Expedia or try home rentals (great for bigger groups) on Vrbo.

From Chicago to Ireland

“The road from Chicago to Ireland is marked in green,” Stephen Bailey once said, according to the Chicago St. Patrick’s Day Parade Committee website. He traced the Chicago River’s path to the Illinois River, then to the Mississippi, up the Gulf Stream and across the Atlantic to the Irish Sea. Chicago and the Plumbers Union have certainly made their mark on this centuries-old holiday, and that’s no blarney.

Want to discover other hidden gems in Chicago? Check out my books Secret Chicago: A Guide to the Weird, Wonderful, and Obscure and Chicago Scavenger!

Marina City with the Chicago River dyed green

Sources

Like this story? Pin it for later.

Jessica Mlinaric founded Urban Explorer in 2010 to inspire curious travelers by highlighting history, culture, and hidden gems in Chicago and beyond. She is the author of 'Secret Chicago' and 'Chicago Scavenger.' Jessica has visited 20+ countries and 30+ U.S. states. She has more than 16 years of experience as a marketing strategist and works as a freelance writer and photographer.