New estimates by the Department of City Planning show that the risk to Lower Manhattan posed by sea-level rise and extreme weather events will increase in years to come, as the focus of climate change converge with aggressive real estate development.
Projections shared at the June 27 monthly meeting of Community Board 1 (CB1) predict that by the year 2050, more than 60,000 residential units will be situated within the flood plain, up 39,230 today — an increase of more than 50 percent. During the same interval, the overall number of buildings located within the local floodplain will jump from 1,750 to 2,790 structures — an increase of 60 percent.
This map illustrates how and where the zones shown in the first photo are predicted to expand incrementally by the 2020s.
These changes will be driven in part by the expanding footprint of the local floodplain, defined as the catchment in which planners predict a statistically significant likelihood of water penetration in a given time period. But this dynamic is also powered by the breakneck pace of development in Lower Manhattan, where thousands of new residential units are now under construction (or conversion from former office properties), and more are planned for the years ahead.
The areas in pink on this image indicate how far into Lower Manhattan daily high tides are expected to penetrate by the 2080s.
This places CB1 (a collection of neighborhoods encompassing 1.5 square miles, bounded roughly by Canal, Baxter, and Pearl Streets, and the Brooklyn Bridge) in a unique position. Other communities around the five boroughs that face extreme flood risk, such as the Rockaway peninsula, are seeking to slow development, at least temporarily, while they formulate resiliency plans to hold back rising waters. But Downtown currently has no plan in place to protect residents or businesses, with the exception of the 92 acres of landfill between West Street and the Hudson River, where the Battery Park City Authority has both outlined a preliminary blueprint for doing so, and also has the means to fund it. But the absence of such a plan for Lower Manhattan as a whole has not tempered the pace of development.
Matthew Fenton