The banks of the Chicago River have long been a heartland of industry, protected by laws to thwart real estate developers’ desire to build there.

But that tradition has taken a sudden turn, for better or for worse.

The Clybourn Corridor Planned Manufacturing District (PMD), one such area along the western edge of Lincoln Park, may soon lose its protected designation. Ald. Brian Hopkins (2nd Ward) has proposed a plan to the City Council to remove its status as a PMD, making way for the construction of homes and stores.

The PMD’s roots began during the 1980s, when a myriad of young professionals were migrating to the inner city. To meet the new demand for housing, developers began converting vacant industrial buildings into residential areas.

Coincidently, nearby manufacturers came under pressure to sell their buildings because the smoke and noise from their operations proved to be bothersome for residents.

To protect manufacturers and the hundreds of jobs they provided, local aldermen, who largely control zoning in their wards, implemented the first PMD: the Clybourn Corridor. Its boundaries roughly stretch from Clybourn Avenue and the Chicago River, to Dickens and North Avenue. Today, there are 15 such designations in the city, the last created in 2007.

By 2013, however, the Clybourn Corridor PMD began to undergo significant change. The Finkl Steel Mill, the largest of the manufacturers in the area, relocated to the South Side to expand its operation. Last fall, the mill was demolished, leaving 40 acres of vacant lot.

Hopkins and his allies argue that this vacant land, as well as the properties currently in use by existing manufacturers, can be the site for new residential and commercial areas. These would in turn generate much-needed property taxes and jobs.

“For many years, planned manufacturing districts in Chicago have been sacred. They have been protected by city staff (and) protected by mayoral administration,” Hopkins said to DNAinfo. “Under new leadership, there has been a change of philosophy.” 

At the same time, advocates for the PMD to remain contend that the designation has laid the foundation for manufacturers there to flourish, like the Finkl Mill did during its 100 year stay. Once the PMD in the Clybourn Corridor is lifted, other PMDs in the city might be lifted too, hampering the ability for Chicago manufacturers to prosper.

Krista Kahle Elam, director of sustainable economic development at North Branch Works, a business advocacy group in the area, said the manufacturers she represents are deeply concerned by recent developments.

“The PMD was created 30-some years ago specifically so that industry would have a place to be,” she said. “And some of the businesses have made huge investments in their facility in this area, strategically.”

Manufacturers’ proximity to the river and nearby highways and railroads allow for the transportation of goods to and from the PMD, an advantage that may not be available elsewhere.

And without laws to protect them, the manufacturers are vulnerable to be bought out by developers, whose businesses are often more profitable.

Winifred Curran, a professor at DePaul who specializes in urban geography, said that removing one PMD could lead to a slippery slope.

“If you can change the PMD in one place, what’s to stop you from changing it in the other PMDs? That puts speculative pressure on any PMD in the city,” she said.

Chicago’s PMDs also have a wider significance across the nation.

“Other cities were jealous of the PMD, they wished their cities would institute a similar program,” Curran said. “It’s quite disappointing to see Chicago undo something that it was once respected nationally.”

Curran did acknowledge the potential resulting from the PMD’s removal, however. 

“Then, of course, there’s tremendous value to be realized in opening up this space to residential and commercial use. That’s so much more profitable than industrial use.”

That is the view held by RANCH Triangle Community Conservation Association, an advocacy group for residents.

“The Clybourn Corridor PMD should be transferred to a neighborhood hungry for economic development, the area comprising the PMD should be opened to residential renewal and a portion of the additional property tax revenue used to train young Chicagoans in skilled manufacturing trades,” the group wrote in a document outlining their position.

They suggested the construction of tech businesses there, like those on nearby Goose Island.

According to RANCH, the city forgoes an estimated $13 million a year of property taxes that could be collected from residential buildings. These types of buildings tend to generate higher property taxes than factories.

If the City Council does approve the plan to remove the Clybourn Corridor PMD, Hopkins said the next step is to update the nearby Clybourn Metra station and build a new CTA stop and bridge.

Members of the community will discuss issues surrounding the PMD removal at DePaul on May 3, co-hosted by students of the Sustainable Urban Development program. Advocacy groups like North River Works and developers like Sterling Bay, who has purchased properties in the corridor, are expected to be represented at the parley.