More than 6,000 New Jersey buildings will be engulfed by seawater by 2050, study predicts

The latest study to warn that the New Jersey coast is especially vulnerable to sea level rise predicts that 53 square miles of currently above-water land will be under water at high tide by 2050, potentially swallowing 6,125 buildings.

In addition, tens of thousands of other properties still above that line will be exposed to semi-regular or regular flooding.

The study by Climate Central sounds alarms about the impact on municipal tax bases and potential conflicts as landowners find that their properties could be claimed by government if they fall below what’s known as the boundary tide line — the divide between private property and public tidelands and waters. That boundary moves inland as sea levels rise.

Those shifting boundary lines have “significant implications” for property owners and local property tax revenues — a primary source of funding for schools and services, the study found.

Don Bain, a climate engineer and principal author of the study, is a senior adviser to Climate Central, a New Jersey-based nonprofit staffed with scientists and journalists. Bain also lives in Chester County and is familiar with the Jersey Shore.

“The trick is that those tide lines are moving,” Bain said. “They’re gradually moving inland and upslope as the overall water level is increasing. As they move, they take property.”

He explained that conflicts could arise if property owners seek to acquire a building permit and are told by a municipality that they can no longer build on their land because it has essentially become public property. Or, conflict could occur if a property owner is sent tax bills for property that is underwater and unusable.

New Jersey is also faced with sinking land due to its geology. That exacerbates the impact as the Atlantic Ocean rises and the land drops.

Taxpayers will ultimately bear the costs, the study warns. Not only will local tax bases erode because of flooding and shifting boundaries, but governments will have to pay to remove buildings, septic systems, underground storage tanks, and toxic sources on abandoned land. They’ll have to pay for improved stormwater systems, utilities, as well as sand and beach replenishment.

Some of that is already happening in New Jersey, which has a Blue Acres program spun from the wreckage of Hurricane Sandy that struck the coast 10 years ago. The state set up the fund to aid residents whose homes are damaged by floods from storms. Blue Acres is also used to buy private property that frequently floods or that is prone to flood during regular high tides.

The Northeast is one of the nation’s areas most affected by sea-level rise, seeing twice as many days of high-tide flooding as compared with 2000, according to a report in August from the National Oceanic and Atmospheric Administration. High-tide flooding, known as “sunny day” flooding, occurs without being driven by a storm. Tides are higher because of rising seas.

“People need to get used to the idea that flooding is going to be permanent,” Bain said. “People are used to the concept of a flood being something that comes and goes, and leaves behind a mess, but then the water goes away. What we’re talking about here is that when the water comes in, it stays.”

In fact, chunks of New Jersey along the Delaware Bayshore have already fallen into the water, leaving the state to buy out homeowners.

» READ MORE: Another N.J. hamlet on the Delaware Bayshore is razed, a victim of sea rise

For its study, Climate Central analyzed 51 million U.S. properties. It found that up to 648,000 parcels may be partly below tidal boundary levels by 2050, relative to 2000. More than 48,000 parcels may be entirely below the tidal boundary level by 2050.

Louisiana, Florida, North Carolina, and Texas may lose collectively 3.8 million acres and are the states most at risk. Virginia, New Jersey, and New York are next most vulnerable.

The study looked at properties in 505 counties. The authors provided an online tool to download reports on 255 counties.

By 2050, 44,785 parcels, representing 1% of New Jersey’s land with a taxable value of more than $6 billion over 17 counties, are projected to be below water level.

The study found that, in New Jersey, Hudson County, just west of the Hudson River and New York, faces the greatest loss. But Shore areas regularly visited by Philadelphians also are at risk.

» READ MORE: South Cape May: Jersey Shore's Atlantis, swallowed by the sea

The most visible effect of sea level rise is the change in the amount of land exposed to flooding or submergence at high tide. Where terrain slope is gradual near the Shore, a small change in sea height can extend the high tide waterline significantly inland, the study says.

In Atlantic County, for example, 4,198 properties now above the boundary tide line are projected to fall below it by 2050. That represents $131 million of assessed taxable value. Some of those parcels might already be lower than tidelines but are protected today by coastal defenses such as seawalls.

Also by 2050, 1,181 now mostly dry parcels will fall into a high-tide risk zone, defined as land where elevation is lower than or equal to the water at high tide.

Bain says that at some point, it will become too expensive to keep replenishing sand on New Jersey’s beaches.

» READ MORE: How much sand has been brought in to battle erosion on New Jersey beaches?

So far, the U.S. Army Corps of Engineers has spent $2 billion piping in 200 million cubic yards of sand to the state’s beaches, with more than $50 million worth of beach-nourishment projects in the pipeline for the fall. In fact, no state has had more sand pumped on its beaches.

Beach projects are “a temporary fix,” Bain said. “And those costs are only going to go up. They are going to be harder to fund as time goes on.”