“There have been steps taken” to rebuild better, said Tim Dillingham, executive director of the American Littoral Society. Houses have been elevated, and in New Jersey there are discussions about bigger and better dune systems, he said. But he cautioned, “When you really look at the macro — large scale — we are still going in and building in places that are risky.”

Massive beach nourishment projects will restore beaches but require expensive upkeep and affect ecosystems. Individuals and communities are racing to rebuild sea walls that hasten erosion. And federal taxpayers will foot the bill to rebuild communities that continue to be at risk.

One developer recently went so far as to advertise 24 waterfront acres for sale. The ad acknowledges that the property “has historically been wetlands” — on which development is barred — but noted that the storm had filled it in with sand.

The Army Corps said it would be mindful of advances in thinking about climate change. “We are more integrated with the science agencies than ever before on issues related to climate variability, and the science informs the actionable engineering decisions we make,” said Moira Kelley, a spokeswoman for the assistant corps secretary for civil works.

And agencies are striving to better prepare for storms. In April, the Sandy Rebuilding Task Force — which is focused on regional resiliency — required that those using storm recovery funds to rebuild had to take additional measures to reduce flooding risks. In New Jersey, tougher building codes and the Federal Emergency Management Agency’s new flood maps mean homes are being elevated and floodproofed. New York has committed to using natural infrastructure where possible. And New Jersey and New York are offering voluntary buyouts to homeowners in flood-prone areas: New Jersey will use $300 million of federal money to buy as many as 1,000 homes, while New York has committed an initial $197 million to buying what it hopes will be over 2,000 homes.

In New Jersey, the goal is to target contiguous properties to restore floodplains. State officials said the effort was unprecedented — even if it applied to only a fraction of homes. “We’d have to buy out 200,000 if you wanted to move everyone from potential harm,” said Larry Ragonese, press director of the New Jersey Department of Environmental Protection.