A few times over the past few months, in various forums and conversations, MTA officials have expressed a surprised concern or a concerned surprise over the way the agency rebounded from Sandy. That feeling is captured in an article summarizing the Sandy fallout in The Times today. “The downside to it,” MTA Chairman Tom Prendergast said of the agency’s speedy rebound, “is I think sometimes it leaves people with the impression that we weren’t damaged that bad.”

It’s a perfectly normal feeling and one that nags at the post-Sandy work that remains to be done. The MTA had most subway lines up and running with in a week of the storm, and although it took seven months to rebuild the Broad Channel crossing, a casual rider could be forgiven for thinking things weren’t that bad. After all, the trains were running so what’s the problem?

Today, a year later, it’s not clear what the future holds for the subway system. The R train is offline, and the G will be shutdown for a few weeks next summer to repair storm damage from a flood that will have been over 20 months ago by the time of the shutdown. The MTA hasn’t started work on the other tunnels — 14th St., Rutgers Street — that suffered extensive flooding, and New Yorkers have a short memory. They haven’t complained much about the R train issues, but who will live with L train outages two and a half years after Sandy?

As the one-year anniversary of the storm arrives today, the MTA is working on recovery and resiliency. Later on Tuesday, Gov. Andrew Cuomo will announce $3.5 billion in funds for storm-related expenses, and some of that money will go toward waterproofing the subways. For a system will so many access points, hidden or otherwise, it’s a tall order, but as the Daily News recently chronicled, the agency has a few things on tap.

Placing water-proof “submarine” doors at subway entrances is the most effective way of keeping vulnerable stations like South Ferry from being flooded in a superstorm, according to sources familiar with an MTA analysis. The study of ways to prevent a recurrence of the damage the subway system suffered from Hurricane Sandy also recommends steel-and-glass enclosures framing station entrances. For subway tunnel portals, the analysis recommends flood gates or slate-and-frame removable barriers to keep water from rushing in and destroying the signal, communications and power systems inside – as occurred during Hurricane Sandy last October, the sources said.

Meanwhile, as these flood prevention efforts need to move forward, so too must recovery. For that, we turn to The Times:

The consequences, officials acknowledge, will be felt for years, most acutely in the form of persistent service disruptions that will dog riders across the system — in areas directly touched by the floods and in others where storm-related triage could delay scheduled work intended to keep the subways in a state of good repair. It can feel like far more than a year ago that the authority was cast as a hero of the storm, restoring much of its system more quickly than expected while other transit agencies flailed.

…On a 109-year-old system, where many pieces were approaching the end of their useful lives without the nudge from saltwater corrosion, and repair-related closings were already more rule than exception, latent damage and unpredictable failures have made tunnel inspections a near-impossible chore. The new maxim: Even if something looks as if it works, it might not…

Those charged with maintaining and upgrading the system have been confronted with a simple math problem: There are only so many hours in the day when shutdowns will not affect a wide swath of passengers, particularly in an age of booming off-peak ridership; likewise, there are only so many lines that can be repaired at one time without hamstringing the system.

These are the hidden challenges facing the MTA, and in a way, it’s a testament to the agency’s ability to make the most out of a bad situation that the subways are even running again. It’s when there’s too much time to build and too much money to spend that the MTA runs into problems. We’re a year away from a storm that nearly swamped the entire system, and things are generally moving smoothly because of the work behind the scenes. What’s next?

I keep coming back to Gov. Andrew Cuomo’s free-fare giveaway to commemorate the one-year anniversary of Sandy tomorrow. I hate to look a gift horse in the mouth, but what if that gift is more of an empty promise? What if that gift shows not compassion but an easy out for a governor who hasn’t taken much interest in the state’s most important transit network? What if that gift is just a throwaway?

The story broke on Friday when the Governor — supposedly without really consulting with the MTA — announced the free fares. R train riders in Brooklyn and A train riders in the Rockaways would enjoy a day with no fares. “These free rides,” Cuomo said in a statement, “are a thank you to the MTA riders in the Rockaways in Queens and those who use the R train in Brooklyn for taking the hardships of the storm in stride and for their understanding in the months since.”

A better thank you would be to invest in the system so that it won’t succumb to another storm and has the resources to run more constant service today, but that’s neither here nor there. Rather, it’s easy to see the flaws in Cuomo’s plan. Approximately 50 percent of all riders use Unlimited Metrocards and that total is likely higher for people who live in residential areas along the R and A corridors and who commute via subway every day. Again, as with the subway shutdown during Sandy, unlimited ride card holders are actually losing out on these benefits as Cuomo isn’t extending these cards by a day.

Today, The Times has more on this odd giveaway:

The arrangement, devised by the governor’s office about two weeks ago, has proved to be somewhat complicated. The R train connects with 12 other lines in Brooklyn, making it difficult for the Metropolitan Transportation Authority to prevent other subway line riders from capitalizing on the free rides at hubs like Atlantic Avenue-Barclays Center and Jay Street-MetroTech. The solution, officials said, will be to open the gates at entrances for the R train shortly after midnight on Monday and hope that only R train riders find their way through. There will be no other measure taken to prevent riders on other lines from taking advantage. The Cuomo administration predicted that few riders would seek an undeserved free ride.

…A spokesman for the governor said at one point on Friday that to avoid logistical hurdles, fares would be free in Brooklyn only along the southern tail of the R train, which includes few transfers between Bay Ridge-95th Street and Union Street.

The spokesman later clarified that the train would be free for all R train riders, adding that the transportation authority was working on an “implementation plan for those stations” where transfers could allow anyone to ride without paying. But some possible solutions — a temporary barricade or using security personnel to ask riders which train they were seeking — were perhaps unworkable. There are an estimated 65,000 daily R train riders in Brooklyn and 30,000 on the A train in the Rockaways. The authority has said that its average fare — accounting for those with unlimited-ride MetroCards and other discounts — is $1.76, meaning that the idea will cost about $167,000 even before including other Brooklyn passengers who might ride for free.

In a city where people will wait on line for upwards of 45 minutes for a free $3 ice cream cone, the governor expects everyone to adhere to the honor system while paying subway fares. The Onion couldn’t write a funnier joke if it tried.

This barrier at 148th Street protected the subway from what could have been catastrophic flooding throughout Manhattan. Photo: MTA New York City Transit / Leonard Wiggins

A year ago, New York City had no idea what was coming its way. As officials were scrambling and MTA crews hard at work reinforcing the system in advance of a storm called Sandy, We were waiting to hear if the subways would shut down, but the decision had seemingly already been made. By 7 p.m. on the 28th, no trains were running, and New Yorkers huddled in their homes to see just what Sandy would bring.

For the subway riders of New York, Sandy’s impact was immediate. We saw dramatic images of water-logged tunnels and video of the New York Harbor rushing into the stations in Lower Manhattan. It took the better part of a week for subway service to return to something approximating normalcy as the MTA had to combat flood waters and a major Con Ed power failure, and today, the R train is out of service for another year as the corrosive salt water essentially destroyed the infrastructure.

We still don’t know what the future holds for the other subway tubes that were flooded by Sandy. The Montague St. Tunnel took the worst of it, but the L train didn’t escape unscathed. In total nine subway tunnels flooded to some degree, and while the impact of saltwater depends upon the time of exposure, any contact between electrical equipment and the ocean will reduce the useful life of those components.

In this weekend’s New York Times Magazine section, as part of the paper’s look back at Sandy, Robert Sullivan went inside the subway system to tell the story of what happened before, during and immediate after Sandy. The piece is titled “Could New York City Subways Survive Another Hurricane?” and while Sullivan doesn’t offer up a clear-cut answer, it seems that the system is better equipped to withstand a storm even as resiliency efforts will continue for a few years.

Overall, I’d urge you to read through Sullivan’s piece. It talks of an agency dedicated to improving its response to storms while recognizing that it can’t seal off access points and call it a day. That — the knowledge and human creativity that came out of Sandy — is what will protect the subways when there’s another storm heading our way. There are some interesting stories and key takeaways. So let’s jump in.

On the interconnectedness of the subway system and why protecting 148th St. mattered:

[The plywood wall] endured, with about three inches to spare. The triumph might seem like a small one in the face of Sandy’s destruction, but it wasn’t. Here’s what it prevented from happening: After flooding the No. 3 line tracks to the south, and destroying millions of dollars worth of equipment, the Harlem River would have continued south, following Lenox Avenue to about 142nd Street, a junction where the 3 line joins the 2 line, which runs to and from the Bronx. By consulting both the Slosh maps and its own topographical maps, the transit authority determined the water would have flowed toward the Bronx, via what’s called the Harlem River-Lenox tunnel, and then east to 149th Street on the Grand Concourse. Then, in the worst case, the water would have moved through a connecting track, and like liquid moving through a Krazy Straw, the Harlem River would have flowed south through another under-river crossing, the Harlem River-Jerome tunnel, to 125th Street in Manhattan. From there, it would have flooded the downhill Lexington Avenue line — which happens to be the busiest one in the city, carrying more people every day, 1.8 million of them, than any other American subway system — to about 103rd Street, where the tracks rise, up toward Carnegie Hill.

On the speed and power of the floodwaters:

Inside the control center, the TV told them the surge had arrived. “All of a sudden the phones start lighting up, and you don’t have enough hands, you don’t have enough ears,” Mazzella says. “It’s nuts, the 6-Wire” — the internal communications line, which connects to the Police and Fire Departments — “starts going off, and you’re hearing that there are explosions down at the Con Ed plant, that there’s water cascading into the system here. . . .” The boards began to come back to life, the sensors in the tunnels registering the water as moving trains. New York City Transit had estimated that flooding would close a few of the 14 tunnels that go under the city’s waterways (called “tubes”), but at this time it looked as if nine of them would be lost.

On how pumps inside the Joralemon St. tunnel outperformed those near East Broadway:

It was the sound of old-school subway technology, a pneumatic pump powered by pressurized air from pipes that run all the way back up to 149th Street, where a compressed-air station was unaffected by Con Edison’s power outage downtown. There are dozens of air-compressor pumps all along the Lexington Avenue line; each one of them removes about 200 gallons of water per minute and is about 60 years old, having replaced early-20th-century models. Jezycki refers to these pumps as his Studebakers. They were struggling, but succeeding enough to keep the tunnel clear, draining the water that chased out Joe Leader before flowing downhill toward the East River tube. Aboveground, the plywood had kept the water out of the air vents.

There’s a lot more to take in — including one person questioning how the MTA spent $500 million on a station at South Ferry that didn’t have some flood protections — but I think these are the key points. It’s exceedingly difficult to protect the subways because of the redundancies and connections and because of Manhattan’s geography. It sounds as though only a few inches separated the city from a true public transit disaster that would have wiped out even larger chunks of the subway system.

Another Sandy will head our way at some point. It won’t be tomorrow but it may be next year, in five years or in 15 years. We won’t know until then if we’ve learned our lessons, and the subways will be forever vulnerable simple because they are the lowest point. For now, though, they’re back, and that, by itself, was a very impressive feat.