The gentle hum rising through a rusted Remington manhole cover is the sound of a near ghost. Quiet but steady, audible only when traffic subsides and the hustle and bustle of a modern city street cooperate, flows a river, forgotten but not gone, and encased in an asphalt tomb.

Before colonizers arrived, the Piscataway, or “the people where the rivers bend,” lived here. Sumwalt Run flowed beneath an open sky as a tiny capillary connecting what is now North Baltimore to the Atlantic Ocean.

Now, that stream is contained within subterranean stormwater pipes.

“The primary reason why most of these streams were put underground was for development, and it’s still happening,” said Bruce Willen, the interdisciplinary artist behind the public art installation Ghost Rivers. “Cities around the country and around the world are still burying waterways so they can build houses and roads on top of them. It’s not something that just happened 100 years ago.”

From Wyman Park Dell to the Baltimore Streetcar Museum, a squiggly blue line made from thermoplastic, the same material as bike lane stripes, traces the underground stream across roads and sidewalks.

Cars, bikes and feet pass over the art piece, which Willen hopes reminds people of what lies beneath the asphalt.

A musician and former graphic designer, Willen likes doing work that makes people “engage with the places around them in different or unexpected ways.” He often imagines what Baltimore looked like 150 years ago — before the city modeled its (at the time) state-of-the-art sewer system after that of Paris, before the flow of the Jones Falls was replaced with the flow (and gridlock) of an interstate highway.

When he looks at the cityscape around him, Willen no longer sees just streetlights, roads and the rest. He sees lost ecology.

“I would love if [the art installation] does a little bit of that for other people, if they’re also able to start to see and engage with their own neighborhood or this neighborhood in a different way,” Willen said.

Willen’s rivers snake through North Baltimore with the blessing of the city Department of Transportation’s Placemaking program, which allows community organizations to create art on its public right of way that helps to beautify a neighborhood or create a sense of place.

With the help of art and environmental grants, including one from the Chesapeake Bay Trust, Willen finished phase one of the project in 2023. Phase two, slated for build this year, will complete the 1.5-mile installation. With the help of wayfinding markers and even a Google Maps virtual overlay, people can self-guide their exploration of Ghost Rivers. Willen also leads plenty of guided tours.

Bringing hidden infrastructure to the surface

Ghost Rivers is not just Willen’s homage to Baltimore’s past but an invitation to reflect on the city’s future. Climate change is fueling more extreme weather events, and increased development continues to swap grass and trees for pavement. Willen worries if Baltimore’s stormwater runoff system — which includes the now tunneled Sumwalt Run — will handle heavier rainfall down the line.

“We need to not only maintain [sewer and stormwater infrastructure that] we have but think about the future,” Willen said.

Baltimore’s sewer and stormwater runoff pipes are separated, but decades of housing development have caused wires to cross. Willen said that, when he and his partner bought their North Baltimore home, they had to test to make sure their plumbing was connected to the right system. Some past developers simply tapped into whichever one was closest, he said.

On a recent visit to the southwestern edge of the Ghost Rivers installation, where Sumwalt Run escapes into an open-air section of the Jones Falls, a foul stench filled the air and what appeared to be old toilet paper littered the ground. Willen’s best guess was that heavy rains from the previous days had popped open a nearby sewer cover.

Willen hopes Ghost Rivers makes people think more about this hidden infrastructure and what creative solutions Baltimore can implement to build a more resilient, sustainable future. Though he thinks digging up Sumwalt Run in a process called daylighting — uncovering buried waterways and restoring their surrounding environment — wouldn’t work for a variety of reasons, daylighting other streams could help make other communities healthier and more vibrant.

Where could daylighting make a meaningful impact? Willen said look no further than the Jones Falls. Baltimore began covering it with concrete decades ago to build Interstate 83, and urbanists have dreamt of tearing it out ever since.

“That can be a great opportunity for daylighting, creating this really amazing public park right in the center of the city,” Willen said. “At a certain point we’re going to have to decide — are we going to invest to rebuild this highway that has really divided the city?”

Think it can’t be done? Just ask Seoul, South Korea. In the early 2000s, it removed a decades-old highway that cut through the city and replaced it with nearly four miles of grass, trees and a public promenade along the buried Cheonggyecheon River.

Though it’s an extreme example, Willen said, the Cheonggyecheon could be a model for restoring local biodiversity, creating more public space and making the city work for the people who live in it and not just those who commute to it. Plenty of places across the United States are trying it, and though some experts think daylighting the Jones Falls is a pipe dream, there are plenty of dreamers out there.

Go on and dream, Baltimore.