Hurricane Sandy crippled parts of the New York City subway system for weeks, and in some cases, months or even years. With future flooding a rising risk, can the city protect its subway system in the years to come? The Atlantic's CityLab website looked at the question this month (see: "Can New York City Waterproof Its Subway?" by Laura Bliss).

Since Sandy struck, the site reported, "the Metropolitan Transit Authority has been spending about $4 billion in mostly federal disaster funds to repair and harden its train yards and subway tunnels. Two of those tubes have been fixed, three more are underway, and there’s still a lot more work to come: In July, much to Brooklynites’ ire, the MTA announced plans to shut down the L train for 18 months in 2019 in order to repair outstanding Sandy-related harm to the Canarsie Tunnel."

So what are the options for preventing a repeat of the Sandy catastrophe? One relatively low-cost option is the Flex-Gate — "a soft cover that sits spooled in a container perpendicular to subway entrance railings, ready to unfurl, horizontally, over the entire staircase opening along built-in tracks." Other options include inflatable plugs made of resilient fabric. Below, a New York Times YouTube video looks at research into tunnel plugs.

For more background: NPR discussed the options for flood control in the subways in October, 2015 (see: "To Flood-Proof Subways, N.Y. Looks At Everything From Plugs To Sheets").