New York City’s parks are green oases amid glass, concrete, and steel. But though they feel transportive, they’re often not far away from the city’s edge—and particularly those parts of the city’s silhouette that are bordered by waves. Roughly half of the land managed by the NYC Parks Department is directly on the water. That proximity to the shoreline makes these blissful parcels especially vulnerable to flooding, storm surges, and other consequences of wild weather.

When Hurricane Sandy made di…