WEST LEBANON — On Tuesday morning, the 10 stores included in the Target shopping plaza on Route 12A remained closed, shuttered behind floodgates after high water levels had threatened residents and businesses along the Upper Valley’s waterways the night before.

But while the middle of the shopping center’s parking lot was inundated with stormwater, which edged up to the floodgates, the buildings remained dry and undisturbed through the worst of the wet weather.

At 9 p.m. on Monday night, Danielle Gordon walked the perimeter of Target — the 87,000-square-foot superstore — with her 5-month-old daughter tucked away under her blue raincoat. As floodwaters rose, Gordon, 38, of White River Junction, managed a team of over 30 people who had responded to a Facebook post from her mother asking for help putting up floodgates around the stores in the shopping center.

Gordon’s family owns A.C. Lawn Mowing, which is in charge of caring for the plaza. In addition to Target, T.J. Maxx and Joann Fabrics and Crafts were among the stores still closed on Tuesday.

The day’s steady rainfall had slowed to a drizzle, but the waters of the Mascoma River, which skirts the shopping center, were swollen and strained against its banks. Thick tree branches spun in circles, swiftly pulled along by the river’s current.

The work crew put black gating around the windows and entrances to the department store. Some workers came in the evening after getting off their primary jobs. Others started early, arriving around noon.

“We have to make sure no one’s in the stores before we close them off,” Gordon said. “Then we need to go through and check that there’s not any gaps in the gates.”

Tough plastic panels were drilled into the ground, mounted onto the wall and then sealed up with silicon.

Remembering a lesson learned the hard way after Tropical Storm Irene in 2011, which washed out some of her family’s property in Hartford, Gordon was careful to avoid finding reassurance in the slowing rain.

“The worst flooding during Irene happened hours after it had stopped raining,” she said.

Just north of the plazas on 12A, Melinda Perron, 41, and her children, 14-year-old Mya and 10-year-old Ryan Kulo, also were watching the river from outside their apartment at Romano Circle, a housing complex owned by the Lebanon Housing Authority. Perron said she and Mya had evacuated their apartment on South Main Street during Irene.

“I think this one was a little bit scarier because (the water) was a little bit closer to home,” Perron said in a Tuesday phone interview.

They left to go to Perron’s parents’ in Pomfret on Monday evening at about 6 p.m., bringing a change of clothes each and their three cats: Dexter, a gray tiger; Si, a Siamese; and a kitten, Khioni. “They were definitely not impressed with the car ride,” Perron said of the cats.

Their decision to leave came after they noticed that the water level of the Connecticut River had risen and “it was still raining,” she said.

Early Tuesday morning, a flood gauge on the Connecticut River in West Lebanon reported that the water crested at 23 feet around 3 a.m., according to data from the National Weather Service.

Like Perron and her kids, seeing the rising threat of flooding spurred A.C. Lawn Mowing into action at the shopping center.

“It’s tough when the owners of the plaza are in California and the managers of the plaza are in Massachusetts,” said Chuck Gordon, Danielle’s father.

Chuck thinks of A.C. Lawn Mowing as the “on-site” property manager, which can see conditions that the far-flung managers and owners can’t.

“We’re over here trying to be the eyes and ears of the situation,” he said. “They don’t know what’s going on; they don’t know how high the waters are.”

A.C. Lawn Mowing had performed two previous trial runs, overseen — and mandated — by the New Hampshire Fire Marshal. The material for the gates is stored at Target year-round, but this was the first time the Gordons’ company has had to put the gating up for actual flooding.

“We had to make Target (safety) commitments because we’re in a floodplain,” Chuck said. Until Target set up shop in the plaza in 2021, taking over most of the space previously occupied by Kmart, the floodgates weren’t required by the state.

“Being from New Orleans, that was really exciting being able to do that,” said Mike Blatt, who responded to the Facebook message and turned out to help Monday night. Blatt owns TBC Guides, a Hanover-based fishing tour company.

“During Katrina, we just had sandbags,” he said, referring to the 2005 hurricane that walloped Louisiana and other Gulf Coast states with disastrous flooding. “But this was a pretty intricate system. And for $30 an hour, people from all walks of life showed up to get it installed.”

The night was “a long one,” said Danielle Gordon, who was in the plaza with her brother until 1 a.m.

Under blue skies the next day, the Gordons — along with some people returning from their shift the night before — began the arduous task of undoing their work.

In Pomfret, Perron’s parents live a couple miles from the White River and up the hill from a brook, but they were safe from any flooding. The family returned home Tuesday morning so Ryan could attend soccer camp in downtown Lebanon.

“We’re all good,” Perron said, adding that she hopes “this doesn’t happen again.”

Staff Writer Nora Doyle-Burr contributed to this re port. Frances Mize is a Report for America corps member. She can be reached at fmize@vnews.com or 603-727-3242.