The $119 Billion Sea Wall That Could Defend New York … or Not

The quickest and least costly option the Corps is considering, a $14 billion project taking nine years, includes only shore-based measures.

In an interview, Mr. Jones said a cost-benefit analysis favored what the agency called middle-ground options. These, costing $43 billion to $47 billion, propose multiple smaller barriers, across, for example, the Narrows between Staten Island and Brooklyn, and the entrances to Jamaica Bay, Newtown Creek and the Gowanus Canal.

In a paper written with the Stony Brook University oceanographer Malcolm Bowman and others, Ms. McVay Hughes, the former community board leader, argued for “a tiered approach,” including the giant outer barrier and shore-based measures aimed at protecting against sea-level rise.

The paper called the outer barrier the fairest solution because a district-by-district approach would likely give priority to wealthy and commercial areas at the expense of less affluent neighborhoods.

But Annel Hernandez, the associate director of the New York City Environmental Justice Alliance, said none of the Corps proposals addressed the problems increasingly plaguing low-lying, working-class communities: polluted storm water runoff and the increasing frequency of floods from high tides, known as “sunny-day” flooding.

“Instead of committing to one multibillion-dollar project, we can have more ecologically grounded shoreline protection across the city,” said Ms. Hernandez, who also works closely with a South Bronx community development organization called the Point.

Paul Gallay, who heads Riverkeeper, an advocacy group for the Hudson, said: “Barriers are a shiny object, a silver-bullet fix luring us away from where need to go. The danger of one big wall is that if it fails, we’re all in danger. We need layered solutions.”