As the authorities examine how they can protect New York City from extreme weather events like Hurricane Sandy, one of the nation’s most influential groups of engineers is pointing out that more than three years ago, it presented detailed warnings that a devastating storm surge in the region was all but inevitable.

The warnings were voiced at a seminar in New York City convened by the American Society of Civil Engineers, whose findings are so respected that they are often written into building codes around the world. Corporate, academic and government engineers at the meeting presented computer simulations of the storm-surge threat and detailed engineering designs of measures to counter it.

Officials from the city’s Office of Emergency Management and the United States Army Corps of Engineers took part in the seminar, serving on review panels or giving talks.

Participants in the 2009 seminar called on officials to seriously consider whether to install surge barriers or tide gates in New York Harbor to protect the city. Their views are contained in 300 pages of technical papers, historical studies and engineering designs from the seminar, copies of which the society provided to The New York Times.