Richard Tatum knew this section of the London Avenue Canal levee as a child decades ago.

“I caught my first fish right here,” he said as he gazed at the site of a key breach in the city’s levee system during Hurricane Katrina in 2005.

Shoddy workmanship and poor engineering led to numerous such breaches in levees and floodwalls. As a result, 80 percent of New Orleans and all of St. Bernard Parish ended up underwater.

On Saturday, Tatum, 65, and his friend Kathleen Crighton, 63, joined a few hundred others who came to see the Levee Exhibition and Garden that the group Levees.org has created on an empty lot at 5000 Warrington Drive in Gentilly, with help from the Parkway Partners organization and the New Orleans Redevelopment Authority.

If Tom Lee, 94, had his choice, he would be back in his old house on that lot on Warrington Drive. “I loved the neighborhood; I loved my neighbors,” said Lee, a soft-spoken man. But he just didn’t feel that at his age he could rebuild, he said.

So he’s especially pleased with the new memorial, which pays homage to his longtime house with a tan-brick patio that marks the footprint of his former home and contains a few yellow bricks from its exterior.

Crighton, a frequent traveler, said she often finds herself explaining to out-of-towners that Katrina did not cause the flooding of New Orleans in 2005. “The misconceptions are still there,” she said as she read the outdoor exhibits that show, step by step, how badly built levees were doomed to fail.

“When the London Canal breached, I knew that life would never be the same,” said neighbor Kathleen Whalen, who had already seen floodwaters in the city from the Lower 9th Ward but was just waiting for the pumps to catch up when she saw something new and frightening: water flowing in the opposite direction and rising rapidly.

Residents, like Whalen, who rebuilt nearby said they were glad to see the outdoor museum and garden built in an area close to the levee breach where few families have rebuilt.

“This very place symbolized death and destruction. It no longer does that,” said Gloria Decuir-Robert, of the Filmore Gardens neighborhood, home of the new exhibit.

Many visitors arrive in town wanting to understand why the city flooded, said Sandy Rosenthal, the founder of Levees.org. Often, she said, they have the notion that the flooding was caused by a lethal combination: a city built below sea level, a monster storm and local corruption.

The new museum’s exhibits, vetted by a series of independent experts, seek to disprove each of those beliefs. “It’s important that we not believe a fairy tale,” Rosenthal said.

With 70 percent of the nation’s population living in coastal cities vulnerable to flooding, it’s especially important to recognize what can cause disaster, City Councilman Jared Brossett said. “The Army Corps (of Engineers) did it all wrong,” he said, adding that citizens and policymakers alike must watch the Corps carefully to be sure its projects are adequately financed and constructed.

The Levee Exhibition and Garden is part of NORA’s Growing Green program. NORA received thousands of homes and lots that were sold to the Road Home Program by owners who opted not to rebuild. Not all of the lots were viable or sought-after for housing, said Jasmine Haralson, NORA’s director of community affairs. So the NORA staff sought “innovative ideas” to incorporate into the Growing Green program, she said.

To date, the program has worked with neighbors to create pocket parks, dog parks, rain gardens, vegetable plots, meadows, citrus groves and even urban forests on many of the lots.

In 2005, water flowed with such force out of the levee breach in Tom Lee’s backyard that the water picked up his brick house and moved it across the street. His neighbor Marceia Walker brought snapshots on Saturday showing his home slumped in the middle of a nearby intersection.

There’s no way to understand, just by gazing at a snapshot, that he and his wife, Caretha, had put down deep roots in that house since they had first moved there in 1979, Lee said. Often, he’d putter in the big yard and repair the home while Caretha, a master seamstress, created beautiful dresses and outfits in her sewing room.

Grandson Shedrick Williams, now 39, was raised there, with a basketball hoop in the backyard and a swing that hung from a branch of the yard’s massive pecan tree. Some years, his brother Glenn Laguand, chief of the Choctaw Nation Mardi Gras Indian tribe, would coax his little brother to put on one of the tribe’s feathered and beaded suits.

Then each night, as the sun went down, the little family would sit in the kitchen eating special dishes like his grandma’s smothered okra and desserts like the German chocolate cake made by his grandfather, a deft baker.

When Caretha Lee became ill in 2004, her husband nursed her in this house, then drove her to a nearby hospital, where she died. “I drove her from this house,” he said quietly.

Before the flood-damaged house was demolished, Lee climbed into the attic and retrieved a few pieces of his former life, including an eggshell-colored dress his wife had made for their 50th anniversary and some matching shoes.

As Katrina threatened the city from the Gulf of Mexico, he didn’t want to evacuate, but Williams and his wife, Paula, persuaded him to go.

A rescue hole cut into the roof of a still-empty neighbor’s house shows the struggles of those who remained behind.

The new levee exhibit shows, in detail, how the city’s communities were left ruined, not by Katrina’s wind and rain but by breaches in failed levees like this one, which 10 years ago washed away the carefully tended family home at 5000 Warrington Drive.