"There used to be 200 feet of sand and 12-foot dunes at high tide," said Monaghan, 80, a retired business owner. "You could walk all the way to the ocean," he said, gesturing to the inlet's mouth a block to the east.
The state Park Service last week fenced off the path to the beach because it leads now to an abrupt and treacherous drop-off. The 242 acres on the north side of the park have seen little erosion, however, and still attract visitors.
With its 10 decks and balconies, the Monaghans' three-story stucco home might be the envy of many who visit this quiet village in Cape May County's Upper Township.
But the Atlantic Ocean, whose proximity once delighted the Monaghans and their children and grandchildren, is suddenly a source of dread.
"One big storm-" Monaghan said, shaking his head at the memory of the giant waves and 20-knot winds that chewed at his property line for three days early last week.
They and their waterfront neighbors, along with Upper Township's mayor, want the state to build a stone jetty across the south side of the inlet's mouth - and quickly, before the cold-weather nor'easters start to howl.
"We have asked them for a hard structure," Mayor Richard Palombo said. "The situation needs a permanent solution."
But coastal geologist Stewart Farrell, who advises the state on beach erosion, predicts that a stone revetment "ain't gonna happen" for several reasons, including a price tag he estimates at $20 million to $30 million.
What's more, said Farrell, director of the Coastal Research Center at Richard Stockton College, help is already on the way. The Army Corps of Engineers is committed to a 16-mile sand replenishment project that will include Corson's Inlet.
The project has been in planning for several years, is estimated to cost between $50 million and $100 million, and will be paid for mostly by the federal government. The Corps' contractors are to lay 3.56 million cubic feet of sand in late November, starting at Route 623 in Ocean City and ending at Townsend's Inlet, the southern terminus of Sea Isle City.
This fall the Corps expects to launch several other large sand replenishment projects on beaches extending from Manasquan to Cape May.
Bob Considine, a spokesman for the New Jersey Department of Environmental Protection, which maintains Corson's Inlet State Park, last week said the department "is fully aware of the situation" in Strathmere.
The elevation of the homeowners' properties appears "stable," Considine said, and in light of the high cost of a jetty and the imminent federal project, "our plan is to let the Army Corps do its job."
The Monaghans dispute the DEP's assertion that the land around them is stable and insist they and their neighbors have done their part to protect their million-dollar homes.
In 2008, after a series of nor'easters scoured the inlet, they collectively paid $1.1 million to install a 1,000-foot-long, 30-foot-deep steel bulkhead that now fronts the inlet side of their properties.
Upper Township also spent $800,000 to secure the bulkhead with boulders, according to Palombo. The recent erosion has not only exposed the boulders but washed away the sand that supported them.
"Our share [of the bulkhead cost] was $115,000," said Monaghan, who, with his late son, Brian, created ITW Holographics, a Chalfont company that prints holograms. Brian Monaghan bought the house as a gift to his parents in 2002, weeks before he died at 34 of a rare cancer.
While the state is sympathetic to property owners anxious for their homes, Farrell said aesthetics was the other reason a jetty is unlikely here.
New Jersey's Park Service wants Corson's Inlet kept in a natural state, he said, free of the bare stone walls and jetties that already stabilize eight of the 11 inlets piercing New Jersey's 127-mile shoreline.
"Brigantine, Corson's, and Little Egg are the only unstructured inlets left," he said. While scenic, their hydraulics make them inherently unstable.
"Have you ever seen a fire hose get loose under pressure?" he asked. "It whips back and forth. If you ever took pictures over an inlet, you'd see it does the same thing over time." Channels and shallows "can migrate a thousand feet in a couple of years."
"You know why Avalon starts at Sixth Street?" Farrell said. "It's because Townsend's Inlet [on Avalon's north side] has eaten away five blocks" since the 19th century, including one whole block in a 1962 storm.
Avalon and the state have since laid down a dense wall of "armored stone" to halt further erosion on Townsend's northern shore, but the result, he said, "is a channel 35 feet deep, with currents that rip by and no beach" along the inlet.
The jetty that the Monaghans and other anxious homeowners are calling for would permanently eliminate the sand beach on Corson's south side, according to Farrell, and require the kind of hardscapes found along Shark River, Townsend's, Cape May, and most other coastal inlets.
While far less stable than a stone revetment, the tons of sand that the Army Corps will lay down this winter should give Strathmere's north-enders the protection they so sorely wish for, and restore the state park's now-vanished bird habitat, officials said.
"The birdies will have a very wide beach in 2015," said Farrell.
In addition to the endangered species that hatch their young there, the south shore of the park is also home to the American oystercatcher and "various species of sandpipers, gulls, herons, sanderlings, and ducks," according to the Park Service's website.
Until then, however, the Monaghans fear their expensive steel bulkhead will provide scant protection if a major storm hits.
"What if the wind forces the water behind it and starts hollowing out the sand?" Monaghan asked. "If more than a third of it is exposed, it could wash away."
Farrell, who knows the property, says such a scenario is unlikely.
"But if there really is a serious nor'easter or a close approach by a hurricane, these folks have a problem," he said. "There really isn't much that can be done about it in the next month and a half.
"That," he said, "is just a fact of life."
856-779-3841