NEW ORLEANS — Much water has traveled through the $14.6 billion, world-class flood-defense system built in and around New Orleans since Hurricane Katrina wreaked havoc on the Gulf Coast in August 2005.

Many tears have flowed, as well, on what has been — and remains — a long, grueling and inspirational road to recovery for a city and region left for dead by the worst natural disaster in our nation’s history, a so-called 100-year storm.

Among the many buildings in disrepair was the Superdome, which served as a shelter of last resort for 25,000 to 30,000 displaced residents who remained in the city to ride out the storm.

That was then. This is now, and forever.

After 11 long years, the Big Easy is back in the game, back in its rightful spot as arguably the best destination to decide the NFL championship.

On Sunday, the new-look Mercedes-Benz Superdome will serve as the backdrop for one of the world’s most celebrated sporting events — Super Bowl XLVII — between the AFC champion Baltimore Ravens and NFC champion San Francisco 49ers. It will mark the 10th Roman-numeral game to be played in New Orleans, the seventh inside the Superdome and the fifth under the watch of Saints owner Tom Benson.

It, too, is the first in New Orleans since Katrina (2,714 days ago) and the first since Feb. 3, 2002 (4,018 days ago). And it couldn’t come fast enough for those city, state, national and NFL leaders who crafted a successful course of action to get the Superdome up and running in time for the start of the 2006 regular season.

Men like NFL Commissioner Paul Tagliabue and commissioner-in-waiting Roger Goodell, Superdome executive Doug Thornton and Benson, among others. The Super Bowl’s return to New Orleans is a direct result of countless man-hours by many local movers and shakers, beginning but not ending with the aforementioned.

They wanted to restore some semblance of normalcy to the lives of the millions who felt Katrina’s wrath. Mission accomplished.

For Saints fans and others affected by Katrina, time seemed to stop on the night of Sept. 25, 2006, when the Saints defeated the Atlanta Falcons 23-3 before an emotional sellout crowd at the Superdome. And now comes the next step on the road back: Super Bowl XLVII.

“The game has evolved so much since I’ve been a part of it, and that’s been a very enjoyable part of it for me,’’ said Benson, who purchased the Saints in May 1985. “It’s a constant evolution, but to be part of a sport with such rich tradition, coupled with such a great future, is something we all take pride in being part of.’’

No doubt, there will come a time during Sunday’s game when Thornton, Goodell and Benson will reflect on those dark days following Katrina and how far the city of New Orleans has come in its recovery efforts, beginning with the rebuilding of the Superdome.

“For Tom Benson, this Super Bowl has to be a very fulfilling moment, perhaps more than any of the first four he has been associated with as Saints owner,’’ said Thornton, senior vice president for SMG, which oversees the running of the Superdome. “He cares deeply about New Orleans. He knows, and we know, that without the Saints coming back after Katrina and all of us joining hands and taking a blind leap of faith that we were going to get it done, we wouldn’t be hosting this Super Bowl.

“I’ll go one step farther. Without Mr. Benson and the Saints, there would be no rebuilding of the Superdome. We would have never gained the momentum to put the Superdome back together after Katrina without the commitment of the Saints and support from the NFL to allow them to be here and support us.

“Think about the consequences if we had failed. Tom Benson, Paul Tagliabue and then-Gov. Kathleen Blanco all made a big blind leap of faith. We all held hands and jumped off into the deep end of the pool. We depended on one another to get the job done. For that, Tom Benson deserves a lot of credit. Without that support, you could argue that the sports landscape in New Orleans would have been permanently altered.’’

Goodell echoed that sentiment, acknowledging Benson’s many contributions over the years as chairman of the league’s influential finance committee.

“Tom Benson has been an outstanding owner,’’ Goodell said in a statement. “He has been at the forefront of many important league issues. He is a smart businessman who understands his customers and community. The role the Saints played in reviving the spirit of New Orleans after Katrina was remarkable, and Tom Benson deserves the credit.’’

To appreciate the distance covered since Katrina, know that it cost taxpayers $161 million just to repair and refurbish the Superdome in time for the 2006 season. On top of that, another $320 million has been spent in subsequent upgrades to get the 38-year-old building looking its Sunday best for Super Bowl XLVII and other major events to come.

“It’s a fixture in the city,’’ Thornton said. “You can’t drive anywhere without seeing it. You can’t think about going to an event unless you’re coming here. (It’s) the living room of New Orleans.’’

All that’s left is to sit back and enjoy the game — courtesy of a city and region on the mend.