Nearly 3 million New Yorkers’ homes are now in evacuation zones that cover more than a third of the city’s population, under new maps released Tuesday.
In the wake of Superstorm Sandy, officials said last month, the number of zones would double and encompass about 600,000 more residents. Few storms are likely to require evacuating all six new zones. The plan is designed to give officials more flexibility in ordering evacuations and give residents a better picture of their flooding risk.
“The new zones incorporate the best available data and will help the city to more effectively communicate to those most at risk depending on the characteristics of a particular storm,” Deputy Mayor Cas Holloway said in a statement.
There have been only two mandatory evacuation orders in the city’s history: for Sandy and 2011’s Irene.
Despite public urging from Mayor Michael Bloomberg, text message alerts and police cars spreading the word with bullhorns in some neighborhoods, nearly two-thirds of residents stayed put after being ordered to leave for Sandy. The storm ultimately killed more than 40 people in the city.
The new zones reflect a new understanding of flooding hazards, and they assume that a storm surge will coincide with high tide.
Taken together, the new zones extend farther inland in some places, including lower Manhattan, parts of Brooklyn and the Bronx. Also, some areas shift from a lower-risk designation into the zone most likely to be evacuated. A few neighborhoods are now in the next-highest zone.