The earth bank aims to protect homes against a one-in-100-year tide and storm surge.

BBC: Ipswich flood defence work aims to protect dockside homes

The National Weather Service updated its storm-surge model to take into account larger and slower-moving storms and include better elevation and high tide data last year.

WSJ: After Sandy, More in New York City Could Face Storm Evacuations

As dunes build up absent a storm to knock them down they shift closer to the high-tide line, and nesting space shrinks.

WSJ: Wrecked Beaches Could Aid Plovers