The mayor of Manville is sharing concerns over the connection between new development and flooding after Warren County experienced severe flooding over the weekend.

The mayor and others are saying that warehouses and apartment complexes that have been built take away the ground cover needed to absorb heavy rainfall.

Manville Mayor Richard Onderko says that his heart goes out to those in Warren County dealing with flood damage. His town knows what that is like.

“We’re on guard, you know? I don’t sleep very well when it’s raining, because we have to watch the amount of rainfall we get in a short period of time,” he says.

Tropical Storm Ida devastated Manville in 2021 and Onderko says he is worried it could happen again.

“We've got three major rivers to contend with, so to speak. The Millstone River, the Raritan River and the Royce Brook. And we're at the bottom of that, the so-called bathtub. So everything drains through here,” he says.

The mayor says new apartment complexes and warehouses springing up throughout suburban New Jersey can make flooding worse because stormwater simply runs off roofs and pavement and isn't absorbed like it is by woods and wetlands.

“Impervious coverage is any hard surface whether it's a road, a roof,” Onderko says. “The amount of impervious cover going into a watershed is troubling.”

In Warren County Monday morning, Gov. Phil Murphy said he was open to discussing development.

“You do a postmortem on something like this after anything of this magnitude,” Murphy said.

Onderko says that development should be limited.

“I think at some point in a watershed they should have a limit. If you hit 30, 40, 50% impervious, you shut it down, there's no more development,” he says.

He says he is worried about 12 acres of planned warehouse development just across the border in Hillsborough.

“I'm very concerned over that. Not just for flooding and stormwater. But for truck traffic. It's a quality-of-life issue,” he says. “Manville's going to feel more of the brunt the next time we flood because of all the stormwater runoff.”

The mayor says the danger zone for Manville is 5 to 6 inches of rain over five or six hours. Anything more is a major event. He says he has two rain gauges at home to monitor the rain.