After Getting Back to Normal, the Big Job Is to Face a New Reality The Brooklyn-Battery Tunnel was flooded. The waters surrounding New York City have been rising an inch a decade, and the pace is picking up. First, life has to be rewound to Friday, Oct. 26 - the last weekday before Hurricane Sandy crippled and disoriented the New York area. To make that happen, repairs to damaged power grids, transportation networks and housing will grind on for weeks, if not months, at a staggering cost. But the bigger question is what occurs after that. Basic restoration leaves everything just as vulnerable to the next monster storm. Hurricane Sandy is now a gauge of the region's new fragility. Climate change and extreme weather are presenting government - and the public - with some overwhelming choices. The authorities must not only reopen the Queens-Midtown Tunnel, but also ponder whether to put up sea gates or install inflatable plugs to protect it. Shorted-out circuits in Consolidated Edison's flooded substation in the East Village stand a foot off the ground in metal sheds. They always seemed impervious to flooding but no longer are. In New Jersey, the historic Hoboken train terminal had five feet of water sloshing in the waiting room and switches and power substations exposed to salt water. Will it do just to dry them out? More broadly, officials must ask whether it is sensible to replace buildings on the Manhattan waterfront, the Jersey Shore or the Long Island coast - and continue to dare nature. After all, the waters surrounding New York have been rising an inch a decade, and the pace is picking up. In recent days, elected officials, including Gov. Andrew M. Cuomo, a Democrat, have warned that bold steps are needed, that to simply mop up is a fool's errand. Experts agree. "It's a no-brainer for New York," said J. David Rogers, a professor of geological engineering at the Missouri University of Science and Technology. You've got such enormous assets and infrastructure that you want to protect. But some experts also say that after rhythms return to normal, a no longer frazzled public may rebel if taxes and fees rise sharply to pay for better defenses. The cost of the repairs alone will certainly reach tens of billions of dollars. Far-reaching solutions will cost many billions more. And the cost of not doing them, Professor Rogers said, includes the threat that disrupted businesses might abandon an environment that feels unsafe. New Orleans, he noted, was the banking and insurance capital of the South until the great flood of 1927. There is evidence of what is possible. The Netherlands, one of the world's lowest-lying countries, has made storm protection a function of national security. Following the severe flooding in 1953 that killed more than 1,800 people in the Netherlands, the Dutch strengthened their oceanfront defenses to what is known as 10,000-year protection - something that will repel a menace that has a 0.0001 percent chance of occurring in a given year. With climate change rejiggering storm calculations, there is talk of elevating that protection to the 100,000-year level. Not that the Dutch system has an unblemished record of success. Environmental experts point out that by the 1970s, the large-scale building projects had caused environmental damage. More recent efforts to harmonize the defenses with nature leave enormous gates open to allow water to flow. The gates can be shut in the face of a storm. In New Orleans, the Army Corps of Engineers erected 100-year protection after Hurricane Katrina. Already, most experts feel it is inadequate; efforts are under way to imagine a 500-year defense system, though such an undertaking remains years away. While New York building codes generally set standards to account for 100-year protection, Professor Rogers said he believed that the city should consider nothing less than 500-year protection. Few Simple Solutions Robert D. Yaro, president of the Regional Plan Association, an independent urban research group, said the region should consider measures like storm barriers and sea gates, as well as better ways to seal transit stations, tunnels and utility plants against water. Power companies, he said, need to rethink continually putting wires back on telephone poles - when winds knock them down - rather than burying them, as costly as that can be. Robert G. Bea, a professor of civil and environmental engineering at the University of California, Berkeley, said he was unimpressed by the aggressive plans trumpeted by some politicians, including those that call for a levee around New York. Some solutions could end up causing more problems, Professor Bea said. He said tightening and improving the current system might be more sensible than an enormous new system. "At least with the current system, you know where it's weak," he said. In New Jersey, the storm surge swamped the electric switch yards and substations of Public Service Electric and Gas. But Ralph LaRossa, the utility's president, expressed skepticism about the need for making all of its equipment stormproof. Reporting was contributed by Charles V. Bagli, David W. Chen, Patrick McGeehan and John Schwartz.