Most cities have an underground web of electric wires. Baltimore’s is unlike any other.

Next time you’re walking around Baltimore, glance down. It won’t be long before you see the word “conduit” written on a manhole cover.

Crews sometimes crowd around open manholes to work on underground cables that can be tangled like a pair of wired headphones. It’s a rare window into an unseen underworld of tubes that carry information and electricity, called conduits.

While conduits are common, Baltimore appears to be the only major U.S. city to own such a sprawling subterranean system. Typically, these systems are owned by private entities, such as utilities.

Baltimore began building its underground matrix of tubes, dubbed a “subway for wires,” in the 1890s. To this day, some 80% of Baltimore’s conduit is either terracotta or Orangeburg, an outdated material made of wood pulp; the rest is the more modern PVC pipe.

The 741-mile conduit network is between 2 and 20 feet below ground and accessed via 12,000 manholes. Underground neighbors include steam, natural gas and water lines.

The system is hidden from view, but a spate of explosive underground fires in recent years has laid bare its condition: The conduit is aging, deteriorating, and in need of improvement.

As owner, the city is responsible for the conduit’s maintenance and, until recent years, capital improvements to the system. The city leases space to tenants, including Baltimore Gas and Electric, Comcast and others.

In 2023, Mayor Brandon Scott agreed to a controversial deal permitting BGE to drastically reduce its rental payments in exchange for temporarily taking over capital improvements. The way BGE finances that work enables it to recoup its costs — plus profit — from utility customers. Many other elected officials disagreed with Scott’s decision or questioned why it was made so quickly.

The six-year agreement reached its midpoint this year, and the city had until July 1 to decide whether it wanted to continue. The Scott administration notified BGE last week that it wanted to renegotiate rather than renew.

Understanding the agreement’s impact has been challenging, city and BGE officials have said, since there is no analogue for Baltimore’s unique ownership structure.

To fact-check that assertion, The Banner combed archives and spoke with local stakeholders, other municipalities and national experts on underground conduit systems. Former city transportation employees couldn’t think of comparable examples. Neither could BGE, which owns the conduit everywhere else it operates.

Some cities, including Milwaukee, Wisconsin; Lincoln, Nebraska; and West Des Moines, Iowa, own underground infrastructure that carries telecom wires. That can pave the way for expanded internet access. But Baltimore’s system is singular for its size and because it carries both telecom and electrical cables.

Maryland archives suggest that in the first part of the 20th century, Baltimore was one of only a few North American cities — in addition to Erie, Pennsylvania, and Quebec City, Canada — that owned its conduit system. A 1937 Baltimore Sun article stated that Baltimore had “easily the largest municipally owned conduit system in the United States.”

The Banner reached out to nine of the top public administration schools in the nation and even an association of city managers to find an expert — or anybody, really — to discuss Baltimore’s rare conduit ownership structure.

Only one academic raised her hand.

Leah Brooks, a professor of public administration at George Washington University, has not studied municipally owned conduit systems, but she studies the financing of infrastructure projects and was fascinated to hear about Baltimore and its deal with BGE.

To Brooks, the arrangement pits a monopolistic conduit owner, the city, against a monopolistic utility, BGE. There is “nothing competitive here,” she said. There is little incentive for either party to prioritize efficiency or fiscal responsibility, she said, calling it “the worst possible economic outcome” for BGE’s customers.

Baltimore’s conduit arrangement has historically created tension between landlords and tenants, particularly over rental fees. In the 2010s, BGE protested rent increases by not paying bills and later sued the city.

BGE unsuccessfully tried to purchase the system for $100 million in 2015, and four years later, then-City Council President Jack Young introduced legislation that sought to bar the conduit’s privatization.

Young was concerned about the city having to pay rent to BGE, and he worried that it would disrupt city ambitions to install municipal broadband, an effort that has been slow to materialize despite city ownership.

That proposal eventually went to voters, who approved a 2022 ballot measure to prevent the conduit from being sold.

Public ownership also comes with responsibility: Baltimore is in charge of maintaining the system.

That’s put city leaders in the hot seat as the system has been repeatedly hit by dangerous fires. Last year, the city hired a consultant to investigate the blazes, which can turn 300-pound manhole covers into projectiles. The City Council also held hearings.

The conduit quietly exists beneath our feet, perpetually bringing us energy and occasionally erupting, but the public doesn’t know precisely where it lies. The city has declined to provide a map, citing the potential threat of terrorism.

BGE spokesperson Nick Alexopolus offered to take reporters on a tour of a worksite to show BGE’s improvement efforts, but only if Baltimore’s Department of Transportation, which oversees conduit maintenance, agreed.

Transportation spokesperson Kathy Dominick repeatedly rejected the idea, saying that to view the conduit even from a distance would pose safety and security concerns.

Jamie Kendrick worked at the Department of Transportation from 2007 to 2012 and oversaw the conduit system as a deputy director. When Kendrick learned in 2015 that BGE offered only $100 million for ownership of the system, he was flabbergasted.

“My mind exploded when I heard the number,” said Kendrick, who now runs a municipal consulting business.

Kendrick said that, given the massive cost it would take to build a comparable conduit system, Baltimore’s system should be valued in billions of dollars — not millions.

“Some cities have a conduit system that is limited to their own street lighting systems, but nothing as comprehensive,” he said. “The city’s never taken full advantage of this.”