16
SEPTEMBER 6-12,2018
Our Town|Downtowner otdowntown.com
WATER Rainfall and flooding
Post-Sandy flooding near South Street Seaport. Photo: NYC Department of Small Business
40 -
25 20 -
inches
30 -
11 to 21
35 -
inches
18 to 39
50 -
inches
Since 1900, New York’s coastal sea levels have risen over a foot — nearly twice the global rate
22 to 50
inches
SEA LEVEL RISE
15 -
MIDDLE-RANGE PROJECTIONS
10 50-
2050s
2080s
2100
HIGH-END PROJECTIONS predict levels could rise
Even if drastic emissions cuts were immediately imposed on a global scale, New York would still be left to contend with sea level rise that is “locked in” to our future by greenhouses gases already in the atmosphere. The city has already begun preparing for this new reality, but many areas remain vulnerable. “Sandy was a form of shock therapy,” said Steven A. Cohen, the former executive director of Columbia University’s Earth Institute. Since 2012, the MTA has installed marine doors on lowlying subway entrances to prevent stations from becoming inundated during future floods; Con Edison has fortified the East Side substation that flooded during Sandy and caused electricity outages in much of Manhattan; and the city has worked to upgrade infrastructure in flood-prone areas. Work is still in progress — and funding is still being sought — for a number of consequential measures, including the Lower Manhattan Coastal Resiliency Project, which will seek to defend the downtown waterfront with measures such as temporary floodwalls that could be deployed before storms and raised earthen berms along the Battery. Other storm surge protection plans are grander in scale. The U.S. Army Corps of Engineers is currently accepting public comments on a number of proposals to protect the region from coastal storms with new infrastructure, one of which would include a five-mile long barrier across the mouth of New York Harbor from Sandy Hook to Breezy Point. Enck, the former EPA official, cautioned against a harbor barrier, which the Regional Plan Association estimated could cost $10 to $36 billion to build and between $100 million and $2.5 billion each year to maintain. “I think that is very ill-advised and the city should weigh in with the Army Corps of Engineers and say: stop wasting time on that multi-billion-dollar boondoggle and help us with real resiliency steps,” she said. “Walls on the land are fine to block water, but if you put walls in the water it just pushes the water other places and also potentially does permanent damage to the Hudson River.” The myriad impacts of climate change extend beyond the oft-cited examples of sea level rise and increased coastal flooding. Instances of intense rainfall are projected to increase in the coming decades. In New York City heavy precipitation sometimes leads to a phenomenon known as combined sewage overflow in which untreated wastewater is discharged directly into the city’s rivers and bays. Continuing the New York’s tree planting initiative, which has added over one million new trees to the city since 2007, and creating and preserving green space to absorb rainfall will be crucial for preventing combined sewer overflow, Cohen said.
Read this article online at otdowntown.com to view the interactive map.
Satellite image showing the 100-year (dark blue) and 500-year (light blue) projections of the NYC floodplain. Image courtesy of NYC Panel on Climate Change
I think [a harbor barrier] is very ill-advised and the city should weigh in with the Army Corps of Engineers and say: stop wasting time on that multibillion-dollar boondoggle and help us with real resiliency steps. Walls on the land are fine to block water, but if you put walls in the water it just pushes the water other places and also potentially does permanent damage to the Hudson River.” Judith Enck, EPA regional administrator during the Obama administration for New York and New Jersey
more than six feet by 2100
MANHATTAN POPULATION LIVING WITHIN THE 100-YEAR FLOODPLAIN
THE COST $19 billion Cost of 2012’s Hurricane Sandy in damage and lost economic activity
$90 billion Potential cost of a similar event in 2050, due to projected sea level rise
Today: 89,100
2050s: 214,500
2080s: 275,600
2100: 317,700
Each icon represents approximately 25,000 people.