After riding a four-year wave of mega-developments that included Lincoln Yards and the 78, Planning and Development Commissioner David Reifman resigned Monday with only two regrets: that he didn’t make more progress at the Michael Reese Hospital site and also at the lakefront parcel that once housed U.S. Steel’s South Works.

The South Works site “is 500 acres. That’s 10 times the size of Lincoln Yards, with unbelievable complications on environmental,” said Reifman, 59, whose resignation takes effect on inauguration day.

“We’ve told [U.S. Steel] the city cannot support another failing proposal from them. They’ve gotten that message,” Reifman said, adding that the site’s industrial past poses environmental problems, and U.S. Steel must be “realistic” about that.

“The city will need to step in and assist with that like we’ve done with other sites that are challenged,” Reifman said.

The Michael Reese site was purchased by the city for an Olympic Village that was never built when Chicago failed to land the 2016 Summer Games; it has been a financial albatross ever since.

Mayor Rahm Emanuel managed to pick a master development team, but there was no other apparent progress.

On Monday, Reifman disclosed there is a “long-term idea” to build a soccer stadium on the site that could be the future home of the Fire, if the professional soccer team that currently plays at SeatGeek Stadium in Bridgeview returns to Chicago.

“It could be a location for the stadium. … It could be a piece of the puzzle for Michael Reese. But, there are a lot of pieces of the puzzle for Michael Reese. Michael Reese is a large site, multi-phased development. It will need multiple uses to be successful,” Reifman said.

Even with those two exceptions, Reifman said he’s proud of the work he and Emanuel did and prouder still of the plan to let developers in a broader downtown area build bigger and taller projects, provided they share the wealth with long-neglected South and West Side neighborhoods.

With $47 million in grants already distributed and $169 million more in the pipeline, Mayor-elect Lori Lightfoot will have the seed money she needs to put an even greater emphasis on neighborhood development.

“We have success stories and momentum stories like Pullman, like Woodlawn, like Bronzeville, like Lawndale. We’ve concentrated resources in these places and we’ve done it rubbing nickels together at times. Allocations of New Market Tax Credits. TIF where we have it. Land sales. Whatever tools we have,” Reifman said.

“But with the development of the Neighborhood Opportunity Fund, we had a new vehicle to really focus on neighborhood economic development.”

Lightfoot convinced the City Council to delay the vote on $1.6 billion in subsidies for Lincoln Yards and the 78 for a few days, only to let it go through after convincing developers to bolster minority participation.

At the time, she told developers to “enjoy this moment in the sun because you’re never going to get a deal like this again out of the city of Chicago as long as I’m mayor.”

Reifman warned that, without TIF, Chicago will have few alternatives to bankroll infrastructure improvements, none of them good ones.

“Federal assistance, state assistance, taxes, which is the argument we made for why this was the right approach for Lincoln Yards and why it was the right approach for the 78,” he said.

With no job lined up, Reifman plans to remain “heavily involved in issues of urban development,” but steer clear of the projects in which he was directly involved.

He refused to comment on specifics of the latest mega-project in the works: One Central, which includes a wall of high-rises and a transit center near Soldier Field built on a platform above rail yards.

But, he said, “It further validates the general approach we took for how to make large projects work, which is put the burden on the developer to figure out how to front-fund. And allow for some re-payment through the revenues the project generates.”

Emanuel has spent the last four years trying to shed his “Mayor 1 percent” label and rehabilitate an image with black voters that took a beating after his handling of the Laquan McDonald shooting video.

The mayor hired Chicago Urban League President Andrea Zopp to serve as a $185,004-a-year deputy mayor and chief neighborhood development officer. Zopp has since moved on to World Business Chicago.

The mayor also proposed the Neighborhood Opportunity Fund and a series of incentive programs aimed at boosting minority contracting and employment.

He has used public buildings — like the new fleet maintenance facility and City Colleges headquarters in Englewood and the controversial new police and fire training academy in West Garfield Park — as catalysts for economic development.

Still, those neighborhood investments have been dismissed as too little, too late.

On Monday, Reifman argued that the “Mayor 1 percent” label was unfair.

“History is not written in a moment. It’s written over time. The story of Rahm Emanuel’s legacy has yet to be fully written,” he said.

“I think we’ll see over time that it’s a great legacy for the city — and, objectively, he will be seen as one of its greatest mayors in terms of addressing the issues he came here to address and creating a platform for equitable initiatives for our neighborhoods and downtown.”