By Thomas Ankerson, 
The conversation
As Americans flock to the beaches this summer, their toes are sinking into some of the most contested real estate in the United States.
It was not always like this. In the mid-20th century, when the U.S. population was half what it is now and the coast was still a kind of frontier in many states, Laissez-faire and absent coastal landowners tolerated people crossing their beach front property. Now, however, the coast has been crowded. Homeowners are far more inclined to seek to exclude a growing population of bathers seeking access to less and less beach.
On most US coasts, the public has a stated right of "lateral" access. This means that people can move along the beach along the wet sand between high and low tide, an area that is generally public property. The oceanfront owners' control generally stops at the high tide line or, in a very few cases, at the low tide line.
But as climate change raises sea levels, homeowners are trying to stiffen their shores with levees and other types of shielding, squeezing the sandy beach and the public into an ever-shrinking space.
As the director of the Conservation Clinic at the University of Florida School of Law and the Florida Sea Grant Legal Program, and as someone who grew up with sand between my toes, I have studied beach law and policy for the most part. of my career. In my opinion, the collision between sea level rise and coastal development, known as "coastal compression," now poses an existential threat to beaches and the public's ability to reach them.

The beach as a public trust
Beachfront property law has evolved from ideas dating back to ancient Rome. The Romans regarded the beach as a "public domain", captured in a quote from Roman law that is often quoted: "By the law of nature these things are common to all mankind; air, running water, the sea and, consequently, the shores of the sea ".
The judges of medieval England developed this idea into the legal theory known as the "doctrine of public trust," the idea that certain resources must be preserved for use by all. The United States inherited this concept.
Most states place the boundary between public and private property at the midline of high tide, an average tide during a 19-year astronomical epoch. This means that at some point in the daily tidal cycle there is usually a public beach to stroll along, even if it is wet and sometimes narrow. In states like Maine that set the limit at mean low tide, you have to be willing to wade.
Early beach access laws in coastal states are largely designed to ensure that daily activities like fishing are all in! and harvesting seaweed for fertilizer could occur regardless of who owns the beachfront. However, public recreation increasingly became the primary use of beaches and state laws evolved to recognize this change.
For example, in 1984, the New Jersey Supreme Court extended the scope of the Public Trust Doctrine beyond the tide line to include the recreational use of the dry sand beach. In a pioneering move, Texas codified its common law in 1959 by enacting the Open Beaches Act, which states that the sandy beach up to the vegetation line is subject to a public easement.
Additionally, Texas allows this easement to "roll" as the coast migrates inland, which is increasingly likely in an era of rising seas. Recent litigation and amendments to the law have modified its application somewhat, but the basic principle of public rights on privately owned dry sand beaches still applies.
Most states that grant the public access to dry sand on otherwise private property do so under a legal principle known as customary use rights. These rights evolved in feudal England to grant landless villagers access to the manor's lands for civic activities that had been carried out since "time immemorial", such as the ritual maypole dance.
The Oregon Supreme Court led the way in judicial enforcement of customary use rights to beaches in 1969, declaring all dry sand beaches in the state open to the public. 
Florida did the same in 1974, but its Supreme Court decision has since been construed to apply parcel by parcel.
Like Texas, North Carolina, Hawaii, and the US Virgin Islands, they have enacted laws recognizing regular use of the sandy beach, and the courts have upheld the laws.
Sand wars in Florida
Florida has more sandy beaches than any other state, a year-round climate to enjoy them, and a seemingly limitless appetite for growth, all of which make beach access a chronic hot spot.

Throughout the Florida Panhandle, pitched battles have raged since 2016, with beachfront owners and private resorts asserting their private property rights to the dry sandy beach and calling sheriffs to evict the locals. When bathers responded by asserting their customary use rights, Walton County, which was not a liberal stronghold, backed them and passed the local equivalent of a customary use law.
The Florida Legislature stepped in and removed the local right to pass customary use laws, except in accordance with a complicated legal process that only a few local governments have initiated. Critics argue that the law has made it difficult for communities to establish lateral public access to beaches and has done little to resolve ongoing disputes.

How about just adding sand?
Erosion is both an enemy and a possible savior of beach access. As rising sea levels erode beaches, pressure increases to harden shores. But shoreline shielding can actually increase erosion by interfering with the natural supply of sand. The addition of more levees makes it increasingly likely that in many developed areas the dry sandy beach will almost disappear. And what was once the wet sand public beach, the area between mid-high and low tide, will become two horizontal lines on a vertical boardwalk.
An alternative is to add more sand. Congress authorizes and funds the US Army Corps of Engineers to restore beaches with sand mined from the shoreline or trucked from ancient inland dunes. States generally must match these funds, and beachfront property owners occasionally collaborate collectively.
But federal regulations require the communities that receive these funds to ensure adequate access to the nurtured beaches from the street, including parking. And new beaches built from submerged shores must be kept for public access until sea level submerges them again. 
This requirement, along with more arcane property rights issues, led Florida's Walton County landowners to fight a beach nutrition project that would have protected their property from erosion. They took the case to the Supreme Court of the United States and lost.
Beach nutrition is also a temporary fix. Good quality and easily accessible offshore sand supplies are already depleted in some areas. And accelerated sea level rise may exceed available sand at some point in the future. Squeezed between condos and coral reefs, South Florida's beaches are especially at risk, leading to some desperate proposals, including the idea of grinding glass to create beach sand.