The Trump administration has unexpectedly halted a project to protect the New York City region from flooding during dangerous storms like Hurricane Sandy — a decision that came six weeks after President Trump took to Twitter to ridicule the study’s most expensive proposal, a giant sea wall that could have cost billions of dollars.
The Army Corps of Engineers’ announcement that the project was “indefinitely postponed” surprised some of its own officials, and local politicians and advocates said the decision was stunning at a time when climate change is threatening New York’s future with intensifying storms.
In a statement, the Corps’ New York office said only that the study was suspended because it did not receive funding in the agency’s work plan for 2020. Officials there refused to comment on whether they believed that Mr. Trump had influenced the decision. But a senior administration official said the project was shelved because it was too expensive and unfocused.
While Mr. Trump cannot single-handedly cancel a Corps project — the funding is allocated by Congress, and its work plan is determined jointly by Corps officials, the Department of Defense and the White House Office of Management and Budget — the unusual suspension of an ongoing project quickly led to speculation that politics had played a role.
Mr. Trump’s tweet, in January, criticized one of the five possible proposals to reduce storm flooding along New York Harbor and its rivers: a sea barrier with retractable gates that would stretch from New Jersey to Queens.
The president had called that option “foolish” a day after The New York Times published an article about the proposals. He overstated the barrier’s cost at $200 billion — it was estimated at $119 billion, and later revised to $62 billion — and advised New Yorkers to get “mops and buckets ready.”
A senior Trump administration official said that while the administration “remains committed to helping communities address their flood risks,” the New York project and three others that were also recently suspended in Baltimore, New Jersey and Rhode Island had “little or no programmatic direction or end in sight” and that the Corps was reviewing their scope.
The official said that Corps engineers should not have been surprised, because “it is required that these studies have a reasonable cost and scope. These particular ones did not.”
The Army Corps’ headquarters did not immediately respond to a request for comment.
“We can only speculate, but I think the tweet gives a clue as to the reason” for the suspension, said Robert Freudenberg, vice president for energy and environment at the Regional Plan Association, an urban research and advocacy group. “This is a president who gets good headlines for his base out of acting against ‘blue’ states, and there’s a disturbing pattern of stalling or trying to end projects that are important to the Northeast.”
Julia Arredondo, a City Hall spokeswoman, called cancellation “unacceptable” and “dangerous.” She urged the decision makers “to reverse course immediately and finish evaluating the options they are considering to protect New York City and the region.”
According to the Corps official in charge of the project, Clifford S. Jones III, it is highly unusual for a Corps project to lose funding after more than three years of work at a cost of several million dollars.
“This doesn’t happen,” Mr. Freudenberg said. “This is an in-progress study.”
In recent months, the Trump administration has tangled with officials in New York — his birthplace and a center of liberal opposition to his policies. It has, for instance, barred New York residents from Trusted Traveler programs, such as Global Entry, because of the state’s immigration policies. The administration may also delay congestion pricing, the state’s plan to charge drivers a fee to enter the heart of Manhattan.
The sea barrier project had drawn criticism because it addressed flooding only from storm surges, not from sea rise and storm water runoff. Some environmentalists and planning experts had criticized the wall options that the Corps was focusing on, saying the structures would create flooding outside the walls and trap pollutants, harming the recovering ecology of the Hudson River and New York Harbor.
But even critics were dismayed on Tuesday over the suspension of the study and the loss of billions of federal dollars to help the New York area address flooding dangers.
“The federal government’s decision to abandon the Army Corps’ storm surge study is reckless, and it exposes our region to the ravages of the next superstorm,” New York City’s comptroller, Scott M. Stringer, said in a statement.
Mr. Stringer — who wants to create flood walls, dunes, wetlands and levees to protect the city in lieu of a large barrier — had called for the project to be reframed, not canceled. The Corps study had only included one proposal without sea walls.
Canceling the whole project strips New York and New Jersey of their main chance to get federal aid to address flooding, he said, adding, “There is no other study underway at this scale that could give federal dollars to protect our people, our businesses and our ecosystems.”
Mr. Jones, the Corps official, said that his engineers were disappointed and that the New York office was seeking more information about the cancellation.
“When you’re working on something, you never like to be caught in a position where you’re shut down in the middle before you even finish your mission,” he said.