The floods in Houston caused a blackout, inundated medical center streets with up to 9 feet of water, and forced evacuations of patients from the district's 6,900 hospital beds, some airlifted from rooftops by helicopter. The campus sustained more than $2 billion in damage.
"Allison was a significant event for us and fortunately we learned a lot," Tucker said.
A review of the area's flood weaknesses led officials to create a list of 112 projects, including widening the bayou and building culverts that funnel water away from the campus. But many of the projects were based on acknowledging that even if planners couldn't ensure that all the water from a future storm would stay out, they could at least work to limit the damage.
TMC's member hospitals moved their electrical vaults and backup generators out of basements to areas above flood level. They rejiggered the way they used their space, rebuilding and moving facilities like research labs, many of which were destroyed by the flood, to higher floors. Scores of existing buildings were fitted with flood gates, and new buildings were built surrounded by berms. Underground tunnels were outfitted with 100 submarine doors, some 12 feet tall. The bill was $756 million, paid by the Federal Emergency Management Agency, not including millions more spent on the public works projects.
Variants of some of those flood mitigation measures could be put to work in New York, experts said, with a focus on protecting the infrastructure and centers of activity critical to its function.
— SUBWAYS AND TUNNELS: Sandy exposed the weaknesses of the 108-year-old subway system, including the large number of stations in flood-prone neighborhoods and the overall porosity of a network ventilated by thousands of grates set into sidewalks.
In recent years the Metropolitan Transportation Authority, which runs the system, has begun looking for ways to defend it from water. After flooding from a 2007 storm forced closure of part of the system, the agency spent $157 million on a host of projects, including one that closed half the 1,600 grates along a low-lying avenue in Queens, raised others and installed water-activated mechanical closing devices on still more. It also hired an architecture firm to design raised grates that double as street furniture.
But those changes were designed to prevent flooding caused by rain, not storm surge, and were limited by a capital budget with little room for projects not directly related to transportation, said Projjal Dutta, the MTA's director of sustainability initiatives.
"Sandy just upped that bar hugely," Dutta said. The agency is studying how subway systems elsewhere protect themselves from floods, including some that have installed gates or built drainage tunnels. But the MTA has not reached a decision on how to move forward, and hardening the system against a surge like Sandy's will require significant additional funding, he said.
While New York is designing raised entrances for a new subway line, it is far behind newer systems, like Bangkok, where most station entrances are raised several feet above street level.
Defending the system from a major flood will likely require numerous changes to seal off its many entry points. One answer could come from researchers at West Virginia University, funded by the Department of Homeland Security, who are developing inflatable plugs to seal off underwater tunnels in case of a breach.
A 16-foot-wide prototype was tested in the Washington, D.C., Metro system in 2008, with highly pressurized smoke proving its ability to seal off a tunnel with irregular contours, said Ever Barbero, a professor of aerospace and mechanical engineering at West Virginia who developed the plug. Barbero said plugs, which could be made to varying sizes, could also be used to seal highway tunnels like the ones that flooded in New York.
After New York was hit by Sandy, "I told my co-workers we have our work cut out for us for the next 20 years," Barbero said.