The water came in fast. The storm had passed, the winds subsided, but the water kept coming.

It spilled over the railroad tracks along Front Street in Slidell and rushed toward William Tell Street a block away, where Mike and Nancy Zimmerman lived.

About 1 p.m. on Aug. 29, 2005, the water in the street was about 2 feet high, still below the floor of their raised house. Mike waded down the street to get his flat boat off a trailer he had parked at a local car wash. A neighbor went with him.

In the half-hour it took them to unhook the boat and return, the water rose 5 additional feet.

Nancy clambered onto a porch railing and stepped into the boat. The trio floated across the street — clearing their 4-foot-high fence with ease — to rescue Nancy’s elderly mother.

After a stop at Slidell City Hall, where Mike used his boat to assist in some rescues, the group boated to the Eden Isles neighborhood, where they stayed with family who had a second story, sharing Cokes and a box of cereal for dinner.

“I have never seen a more clear night in all my life,” Zimmerman said. “It was so serene and quiet.”

In the canon of Katrina remembrances, New Orleans rightly dominates. But the storm also ravaged other low-lying communities along the Gulf Coast, including much of Slidell.

While the danger of another storm remains a real fear in St. Tammany Parish, the efforts tied to that determination are just beginning, and the parish’s coastal areas remain vulnerable.

Slidell Mayor Freddy Drennan still laments how north shore communities were relegated to the periphery after Katrina. “They have no idea how hard this city was hit,” he said.

Drennan was police chief when the storm hit and is proud of how the city has rebounded. But the effects of the storm linger, and one key solution remains elusive.

“We are spending billions of dollars on levees for small areas. Why don’t we build something to protect the whole Lake Pontchartrain?” he asked.

Drennan is referring to the idea of placing gates at the Rigolets, the spot where Lake Pontchartrain and the Gulf of Mexico meet. The gates are a favored option for many north shore residents who fear storm surge from the Gulf.

Parish President Pat Brister is one of them. She calls putting some sort of mechanism there “the answer” to stopping surge.

The project is on the state’s master plan, Brister said, but there’s no telling when it might happen. Officials in Mississippi oppose the idea, saying it could lead to greater surges along that state’s coast.

“Whether we will ever reach that place where we get it built, I don’t know,” Brister said.

While local politicians wait for state and federal authorities to address the Rigolets issue, they have embarked on an ambitious set of projects to mitigate the impact of future storms.

The parish has helped build levees around certain neighborhoods, including King’s Point and Oak Harbor. It has cleared canals of debris and is working on getting levees erected along a system of canals in and around Slidell. Officials are hoping to divert some of the water from those canals into Fritchie Marsh on Slidell’s southeastern side so that one day the marsh will act as a buffer against surges.

But two of the most important initiatives aren’t necessarily visible. The parish is helping to install a communications infrastructure that will allow all agencies, including police and fire departments, to communicate more easily. The system will allow individual departments to talk among themselves or address a range of agencies simultaneously, Brister said. That should help correct one of the biggest problems revealed during Katrina: the inability to get different groups of responders onto the same frequency.

The parish’s second major initiative had to be pushed through Baton Rouge. Last year, the Legislature passed a bill creating the St. Tammany Levee, Drainage and Conservation District. The new political subdivision encompasses St. Tammany’s coastal zone — roughly, the area south of Interstates 12 and 10 that was the hardest hit in recent storms. When the Legislature created the district, it removed St. Tammany from the Southeast Louisiana Flood Protection Authority-East, of which it had been a part.

Brister said no projects had been done in St. Tammany, and the parish is better off with its own levee board.

“I don’t begrudge the south shore anything that they have. They needed it,” she said. “There was no reason why some of our projects could not have been done, too.”

The new district gives the parish the freedom to do just that.

The nine-member board began meeting earlier this year; so far, the meetings have been largely organizational. The board has tentatively secured some seed money from the state Coastal Preservation and Restoration Authority and is planning a comprehensive analysis of the parish’s flood defenses, according to Henry DiFranco, the board’s secretary.

Protecting the parish from storm surge and flooding is a big project, DiFranco said, and that means taking the long view. “It can’t be solved overnight,” he said.

That last sentiment is what worries some who remember Katrina too clearly.

“If we get another Katrina, we are going to get hammered again,” said Drennan, the Slidell mayor.

Those fears are also felt on the western side of the parish, which didn’t get as much damage from Katrina as Slidell and the eastern side did, but which witnessed firsthand the danger of such storms in 2012, when Isaac pushed a wall of water over Mandeville’s seawall and several blocks into the city. Madisonville, a little farther to the west, also was hard hit.

Mandeville City Councilman Rick Danielson has been campaigning for greater flood protection since he was elected in 2012.

“From a surge standpoint, we are vulnerable,” he said. Very few measures have been put in place since Katrina and Isaac, he noted.

Even for people who evacuated before Katrina, the threat of another storm gnaws at them.

Jay and Margaret Albert’s lakefront home on Carr Drive “came apart like a matchbox,” Jay Albert said.

The Alberts rebuilt, raising their house 18 feet off the ground, which is 2 feet higher than FEMA required. The house probably would survive another Katrina. But if it were wiped out, Albert doesn’t think he could do it again.

Nancy Zimmerman has similar feelings.

“This time, we are getting out in our truck and car and not looking back,” she said.

Follow Faimon A. Roberts III on Twitter, @faimon. Follow Sara Pagones on Twitter, @spagonesadvocat.