OCEAN CITY — Tall dune grass covers one of the curb strips outside Mary Louise Hayes’ residence, and sea shells line her driveway.
Everything on her very green lawn serves one purpose: absorbing flood water and reducing the amount of polluted runoff that enters storm drains.
“They call me the queen of permeable surfaces,” Hayes said. “We’re built ‘flood smart.’”
But her home isn’t typical.
Nearly 85 percent of Ocean City consists of roads, sidewalks, driveways, parking lots and other impervious surfaces that water cannot infiltrate, according to 2015 data from the Department of Environmental Protection gathered using Geographic Information System tools.
Wetlands, beaches, bays and the ocean were not included in the calculations.
Ocean City is similar to other nearby shore towns, where building booms have left little grass, sand, dirt or other permeable materials to soak up rain. Small lots paired with high real estate values have encouraged people to build out properties to capacity, and now cities are struggling to turn back the clock.
Almost 78 percent of Atlantic City is impervious cover. In Margate, that number jumps to 91 percent, data show. Overall, 81 percent of the coastal communities in Atlantic and Cape May counties are impervious surfaces. New Jersey as a whole is at 12 percent — and that’s still too high, experts say.
Higher percentages mean decreased water quality.
Dr. Chris Obropta, an extension specialist in water resources at Rutgers University, says once a municipality sees more than 2 percent impervious cover, water quality is affected.
But in coastal communities, the problem is twofold. All that asphalt and pavement amplifies flooding. During storms, there are few spots for water to be absorbed. Overwhelmed stormwater infrastructure often cannot push it into the bays fast enough, so water lingers in roadways.
“The water just sits there,” Obropta said. “At the shore, your park is your beach. ... That’s where those high percentages come from.”
Over the past few years, he has conducted “impervious cover assessments” for several inland communities, where the issue is less severe. About 5 percent of Hammonton is impervious cover, mostly concentrated in the downtown. There, lots are larger and houses take up a smaller portion of tracts.
On the coast, though, overdevelopment has officials looking for ways to add green space wherever possible, often through zoning regulations.
In Ocean City, one- and two-family homes can have 50 percent to 70 percent impervious cover depending on which zone the lot is in, said Zoning Officer Ken Jones.
For at least 15 years, he said, the city has discussed requiring driveways to be made out of more expensive, permeable pavers. Since 2014, the city has mandated sod curb strips in most residential areas, after Hayes approached council members about the issue.
“I’m not saying don’t allow development, but you have to be mindful,” Hayes said. “If you have a bigger sponge, the water is going to get absorbed.”
Cape May City has the least impervious cover of all the coastal communities in Atlantic and Cape May counties, at 60 percent.
There, the city incentivizes people to incorporate porous materials in their lawns. If a person uses pavers, crushed stone, shells and other permeable matter on their property, they are allotted more impervious coverage, said Zoning Officer Skip Loughlin.
Stricter rules surrounding demolitions and redevelopment in the city’s historic district may also play a role.
But impervious-cover ordinances only apply to new construction or redevelopment, and cities can grant variances allowing homeowners to skirt the requirements, said Ocean City Zoning Board Chairman Dick Waddell. He estimates one in every three applicants looking to raise their house and extend their stairs is granted a variance for impervious-cover requirements.
SEA ISLE CITY — It was a familiar scene in town last September: A family driving through the…
That happens in towns across the Jersey Shore.
“You try to be sympathetic to Sandy victims,” Waddell said, “(but) it’s kind of one of my hot-button issues.”
There are solutions outside of enforcing construction codes.
A bill in the state Legislature would allow municipalities to set up stormwater utilities. Towns could charge property owners a fee based on the amount of impervious surface on their lot, and that money would go toward a fund for improving drainage systems. To reduce the cost, an owner would have to add more permeable cover to their lot.
In Millville, Rutgers has held workshops to teach South Jersey residents how to build rain gardens. The gardens can be constructed on a portion of a person’s lawn to capture rain before it hits an impervious surface. The university partners with the New Jersey Water Supply Authority Watershed Protection Program to offer rebates to homeowners who build rain gardens.
“Towns can provide incentives for homeowners to add stormwater management,” Obropta said.