HOUSE OVERSIGHT 016417 Port Covington area of Baltimore. Photographer: Sarah L. Voisin/The Washington Post via Getty Images In 2016, Baltimore's city council approved a $660 million financing package for a 235-acre mixed-use development, including new offices for Under Armour, along the city's waterfront. The area was already designated as an enterprise zone and a brownfield site, connoting additional lucrative tax breaks, and the project attracted a $233 million investment from Goldman Sachs's urban investment group. Then came the opportunity zone designation. The tax break is only supposed to apply to real estate purchased after the law took effect. But lawyers across the country quickly began working around that to get the benefits for projects planned before the law was passed. Many tax experts have recommended sales to new entities. So long as the seller owns no more than 20 percent of the buyer, the transaction counts as arm's-length and qualifies. Siegel said his firm, Weller Development, has found enough new investors to comply with the arm's-length requirement. The company has seen so much demand, he said, that he's looking to replicate the project elsewhere. "We've been fielding a lot of inbound interest," Siegel said, declining to name cities that have approached him. "That stimulated us to take this show on the road." Boulder Balks In mid-December, during a marathon city council meeting that stretched past midnight, Boulder became perhaps the first jurisdiction in the country to reject its own opportunity