The declaration qualifies state and local governments for millions in federal aid to clean up debris and pump sand onto shorelines battered by two severe storms in November.
But local officials said some work would likely wait until next winter because the window for dredging the coastal inlets that typically supply sand for such projects closes this month, to protect spawning winter flounder populations.
"What we can do this year will be a Band-Aid approach to get as much material as we can back there" on the beaches, said Suffolk County spokesman Mark Smith.
Exactly how much federal aid Long Island will get depends on more detailed damage calculations to be done in coming weeks, said Dennis Michalski, a spokesman for the New York State Emergency Management Office.
"We've got a ballpark number, and that number can go up and can go down," he said. The Federal Emergency Management Agency will reimburse 75 percent of the cost, with state and local governments responsible for the remaining 25 percent, Michalski said.
"Whatever funds we get will help us in our future efforts to protect our valuable shorelines," Suffolk County Executive Steve Levy said in a statement. Levy said Suffolk was seeking a second declaration to defray costs from the blizzard that immobilized Long Island last month.
While there may not be enough time to coordinate contracts and equipment to dredge sand this winter, local governments have until April 1 to place sand on the beaches. The beaches become off-limits when endangered birds such as piping plovers return to nest in the spring. Smith said Suffolk was talking with the Army Corps of Engineers about using sand dredged from Shinnecock Inlet last month.