|Infrastructure Seminar Looks at NYC Storm Surge Barriers|
An international array of engineers and scientists gathered at the 2009 Infrastructure Group Seminar, "Against the Deluge: Storm Surge Barriers to Protect New York City," held at the Polytechnic Institute of New York University on March 30-31. The objective of the seminar was to begin to develop the scientific and engineering information base needed to evaluate storm surge barrier concepts and perhaps point the way to their further development.
Climate scientists from Stony Brook University and the Massachusetts Institute of Technology projected the growing threat of coastal flooding during severe storms and conceptual designs of storm surge barriers were presented by major engineering firms from New York, the United Kingdom, and the Netherlands. The speakers evaluated the consequences of storm surges and established the technical feasibility of storm surge barriers to protect the inner city and much of nearby New Jersey.
The seminar was presented by the ASCE Met Section Infrastructure Group with co-sponsorship from the Environmental Sciences Section of the New York Academy of Sciences and the Department of Civil Engineering of the Poly-NYU. "The proceedings of this seminar should be promoted as the first definitive work on protecting New York City from a major storm surge," said Dr. F.H. "Bud" Griffis, Chairman of the Department of Civil Engineering at Poly-NYU, the host of the seminar.
The seminar culminated in the presentation of four conceptual designs of the storm surge barriers:
Preliminary estimates of the costs of the barriers by the designers were $1.5 billion for the upper East River site, $1.1 billion for the Arthur Kill, $6.5 billion for the Narrows barrier, and $5.9 billion for the Gateway barrier system.
The presentations of the four conceptual designs of the barriers were preceded by an account of the first designs of storm surge barriers for New York City. These were done by two freshman engineering classes at Cooper Union led by Prof. Anne Ronan. Some creative ideas by the students included a series of "butterfly valve" barriers spanning the waterway, and a beachside boardwalk that flips up to become a sea wall.
Hugh Lacy, Anthony DeVito, and Athena De Nivo of Mueser Rutledge Consulting Engineers described the apparent suitability and applicability of various foundation options for the three internal barriers, showing the geologic cross-section at each barrier site.
The proposal to protect the New York Metropolitan Region from severe coastal flooding using storm surge barriers originated at Stony Brook University on Long Island. Prof. Malcolm Bowman of the School of Marine and Atmospheric Sciences at Stony Brook described the development and application of a combined meteorological-hydrodynamic model in 1992-1994 to demonstrate the hydrological feasibility of the operations of such barriers. This work has been extended by HydroQual, Inc., as described by Nicholas Kim and Brian George, with a three-dimensional hydrodynamic model coupled with a Geographic Information System to assess inundation events for projected sea level rise by 2020, 2050, and 2080. HydroQual estimates that the barriers would reduce the flooded area by 25 percent, the population affected by 20 percent, property value by 35 percent, and hazardous material/waste sites by 50 percent.
Joshua Friedman of New York City's Office of Emergency Management offered sobering statistics about the region's vulnerability to coastal flooding. A catastrophic storm surge, he told scientists, engineers, government officials and environmental advocates attending the two-day conference, will affect two million New Yorkers, 740,000 households, 272,000 buildings and 461 miles of roadways.
The New York District of the US Army Corps of Engineers was represented by three participants: Joseph Seebode, Deputy District Engineer, Thomas Creamer, Chief of the Operations Division, and Michael Scarano, Deputy Chief of the Regulatory Branch. Seebode and Creamer each joined one of the two review panels and Scarano described the role of the Corps of Engineers in administering navigational and environmental regulations.
The keynote address was given by Larry Roth, Deputy Executive Director of ASCE, who vividly described "The Lessons of Katrina." The likelihood of a similar devastating hurricane striking the Northeast was discussed by Sai Ravela of the Massachusetts Institute of Technology, who co-authored a paper with Kerry Emanuel. According to Emanuel, the MIT team has developed methods to make a good quantitative assessment of hurricane risk in New York City with "synthetic storms." "Considering the number of hurricanes recorded in the Northeast," said Ravela, "nature is not an adequate source of data." The technique is independent of historical hurricane data and is based on physics. It can be coupled with surge models to get quantitative estimates of surge probabilities by magnitude in New York.
The climatology and forecasting of New York City storm surges was discussed by Brian Colle of Stony Brook University. Colle described the history of minor (0.6 to 1 meter) and moderate (more than 1 meter) surges at the Battery between 1959 and 2007. Projecting this record to a future with a sea level rise of 12.5, 25, or 50 centimeters would increase the annual number of moderate flooding events to 4, 16, and 136, respectively. "This illustrates that New York City will become much more vulnerable to storm surges as sea level continues to rise," said Colle.
Larry Swanson of Stony Brook University emphasized the importance of the environmental effects of the barriers. Even though the barriers will be open almost all the time, the supporting structures in the waterways will restrict circulation in the harbor, likely resulting in a lower level of salinity in the harbor that may alter the harbor ecosystems. "Remember the controversy over Westway," Swanson said. "The striped bass won."
Douglas Hill introduced the program, arguing that, in the absence of public awareness and leadership by government agencies, the professional community—like the engineers and scientists attending the conference—had the responsibility to initiate action to protect the region from worsened coastal flooding.
Warren Kurtz, chairman of the first review panel, asked the audience to choose among three alternatives:
Note: The Seminar's presentations (in PDF format) have also been made available in the Infrastructure Group's listing of its past seminars. On December 3, 2012, ASCE National published Storm Surge Barriers to Protect New York City, a book that includes a collection of all the papers presented at the seminar.
|< Prev||Next >|
|ASCE National Website|