A lawsuit by the City Club of New York and others has halted the $200 million project.

By Alex Ulam

A federal judge has halted Pier 55 in New York City’s Hudson River Park, a constructed island of 2.75 acres expected to cost $200 million.

Plans for Pier 55, by the British design sensation Thomas Heatherwick and Mathews Nielsen Landscape Architects, call for a sloping, verdant extravaganza atop hundreds of mushroom-shaped concrete pilings driven into the riverbed. The new parkland was designed to do double duty as performance space and would be largely paid for by the billionaire Barry Diller and his wife, the fashion designer Diane von Furstenberg, who had established a nonprofit to maintain the place and establish programming for the venues.

But now, owing to a lawsuit by the City Club of New York and other opponents, the permit for Pier 55 has been revoked and the entire project may be scrapped. According to the judge’s ruling, the plans for Pier 55 failed to address key aspects of the Clean Water Act and didn’t comply with the New York State law that created the five-mile-long Hudson River Park. The pier’s opponents argue that the new pier would cause unnecessary harm to a government-designated estuarine sanctuary because of the massive amount of liquid concrete required to build hundreds of pilings. Douglas E. Lieb, a lawyer for the City Club, said that the environmental reviews for the project failed to establish whether “[p]lunking this thing down in the water is worth the environmental harm it is going to cause.”

Lieb said that the environmental reviews for Pier 55 also did not adequately consider whether the project’s basic purpose was water-dependent as required by law, namely whether “the structure actually needs to be in the water.”

Officials for the Hudson River Park Trust (HRPT), the organization that runs the existing park, aren’t giving up. “We have won four challenges in four courts on this project,” a HRPT spokesperson said in a prepared statement. “Not one of those decisions determined the proposed project would harm the environment—and neither does this one. But even if [it is] largely procedural, we are deeply disappointed by this ruling, and are reviewing it carefully to determine our next steps.”

Adrian Benepe, a former New York City Parks commissioner who is also a former HRPT board member, said that he viewed the court decision as a temporary setback. “I find the decision baffling,” Benepe said. “Given my 35 years of park building, I expect that this park will get built.”

Roland Lewis, the president of the Metropolitan Waterfront Alliance, an influential advocacy group, said that the judge’s ruling reaffirmed various government regulations for the development of waterfront properties, which, he said, encourage the inclusion of water-based activities such as historic educational boat tours, ferry traffic, or recreational boating.

“What was interesting about the ruling is that the judge hit on something that is very important to us,” Lewis said. “Whether it [the pier] was or was not a water-dependent use was an issue for the park [HRPT] to consider.”