In Praise of the Lowly Sponge

The battering by Hurricane Sandy of New Jersey, New York and Connecticut is the Beta test of what is coming our way.  Sea level has risen about one foot in the last century.  It is projected to rise by ten times that amount in the next century.  As the storm taught us, it’s not the inch  here or there lapping at a boardwalk or a rocky shore that matters; it’s the sheer volume of water pushed by tide and hurricane force winds over miles of ocean up over the land and up rivers penned in by urban America that brings the devastation.

The sliver lining of the damage is that the silence about such matters has been broken.  Led by Governor Cuomo and Mayor Bloomberg “climate change” is now being spoken of on the front pages,  or, as Cuomo has it, extreme weather events.  Bloomberg’s surprise endorsement of Obama says it squarely.

Not that many haven’t been aware of the problem for decades.  Jim Dwyer reports in his October 30th column in the NY Times:

 In the summer of 1991, I watched a kind of horror movie. Federal emergency planners ran a slide show of pictures of familiar New York sites that had been doctored to show the effects of a Category 4 hurricane on the city. The entrance to the Brooklyn-Battery Tunnel, nine feet underwater. Nathan’s in Coney Island, fully submerged. Diapers floating off the shelves at the Toys “R” Us on the Belt Parkway in Brooklyn. Kennedy International Airport, 24 feet underwater. It seemed far-fetched.

He also says that on Monday night, at Pearl Street & Greenwich, which was once the Hudson River shore and is now four blocks inland, he stood ankle deep in the storm risen river.

Which leads us to a key  and indisputable issue: the man-made re-purposing of marshland, wetlands, bogs for human use. These great nature-made sponges have been filled, diked, asphalted and built upon for two hundred years and are no longer there to protect us.

[For a nice demonstration of this click on this schematic of lower Manhattan’s shore line since 1660]

Dwyer points this out in his November 2 column, in praise of the return of Climate Change to the public discourse:

About 300,000 acres of tidal wetlands around New York City have been filled in by human development in the 19th and 20th centuries. All that remains are 15,500 acres, according to a 2009 report prepared by the United States Army Corps of Engineers and the Port Authority of New York and New Jersey.

Those wetlands, on the margins of the islands and the coastline, act like sponges, slowing and baffling tidal forces. The 2009 report proposed restoring or creating 18,000 acres.

Over time, these natural sponges were replaced — in New York and in many port cities — by hundreds of miles of sea walls, hardened edges. They allowed the land closest to the water to be developed, but the hard edges are in a losing war with rising sea levels and strong storms. This week, the ruins are everywhere: dozens killed, billions in property destroyed, transportation shut down, blackouts for millions.

On the same page as Dwyer’s column is a tragic write up of what Staten Island has endured — the epicenter of storm related deaths.  The same issue comes up.

Dr. William Fritz [interim president of CUNY College of Staten Island] said Staten Island no longer had “what I like to call sponges, that absorb the energy of hurricanes.”

“Jamaica Bay is a natural sponge with dunes and marshes that can do that,” he said. “Barrier islands in North Carolina did that. What have we done on Staten Island? We’ve hardscaped our sponge. We’ve made roads and parking lots and houses and paved over the sponge. We’ve created an urban area, and you no longer have a sponge.”

Dr. Fritz said the development was “one of the reasons we have that much property destruction, and I think some of the deaths.”

As the conversation surges forward many proposals will be put forward, many aimed at improving construction company bottom lines rather than being the best solution for the specific purpose.  A good place to start is the Room for Debate section of the Times today, led by the co-chairs of the New York City Panel on Climate Change.

Now that New York has experienced devastating coastal flooding, how can we recover and rebuild in a way that will enable infrastructural resilience to inevitable future storms, while minimizing a loss of life and livelihoods? Both “hard” engineering interventions – like sea walls and innovative subway and tunnel closings – and “soft” approaches – like reconstructed wetlands and smart designs for coastal communities – are needed.

Interestingly, MOMA in NYC, has just taken down a jump-out exhibit called Rising Tides: Projects for New York’s Waterfront in which architects, urban designers, engineers looked at options to deal with precisely what has just happened.  Although it’s down, video are still available, here.

If you want to get really down and dirty here is the Metropolitan East Coast Assessment site.