There are two types of property ownership recognized by law, jus privatum and jus publicum. Everybody’s familiar with jus privatum, also known as fee simple ownership. It means that you have title to a parcel of property, which confers upon you certain rights with respect to that property. Historically, private property rights have been defined as:
The right to control the use of your property.
The right to the benefits that accrue from your property.
The right to sell or transfer your property.
The right to exclude others from access to your property.
On the other hand, few people are familiar with jus publicum, also known as the public trust. Jus publicum ownership is always vested in the state, never in a private party. Unlike jus privatum, jus publicum is not transferrable. Furthermore, in any case where jus publicum can be established, it overrides jus privatum. Therein lies the rub. That enables the state to use jus publicum to abrogate your private property rights, without your consent and without compensation, in any situation where jus publicum can be established.

The idea of public trust goes back to English Common Law.

“Both the title and the dominion of the sea, and of rivers and arms of the sea, where the tide ebbs and flows, and of all the lands below high water mark, within the jurisdiction of the crown of England, are in the King. Such waters and the lands which they cover either at all times or at least when the tide is in, are incapable of ordinary and private occupation, cultivation, and improvement and their natural and primary uses are public in their nature, for highways of navigation and commerce, domestic and foreign, and for the purpose of fishing by all the King’s subjects. Therefore the title, jus privatum, in such lands, as of waste and unoccupied lands, belongs to the king, as the sovereign; and the dominion thereof, jus publicum, is vested in him, as the representative of the nation and for the public benefit.”
— U.S. Supreme Court, Shively v. Bowlby (1894)After the American Revolution, the thirteen former colonies that made up the newly formed Union assumed the title and rights of the King to all navigable rivers within their respective territories. The jus publicum was held to be non-transferrable, acting as a permanent public easement on the jus privatum title for purposes of navigation, commerce, and fishing, as originally designated under English Common Law. At a time when rivers were the most practical means of transporting people and goods over long distances, the free use of navigable waterways was considered essential for the development of local and interstate economies.

As other states were admitted to the Union, they were guaranteed equal footing with the original thirteen, and so acquired the same title and rights to the navigable rivers within their jurisdiction.

Said rivers and waterways and all navigable waters of the said state shall be common highways and forever free as well to the inhabitants of said state as to all citizens of the United States without tax, duty, import or toll thereafter.
— Act for Admission of Oregon into the United States (1859)In accordance with the original intent of the law, jus publicum was traditionally defined as the specific public rights associated with using rivers as “highways of navigation and commerce” and for purposes of fishing. While a highway is dedicated to public use, no sane person would claim the right to sit down in the middle of a highway and have a picnic. That is not one of the designated purposes of a highway. Likewise, it never occurred to anyone to claim that recreation would be an applicable purpose for which to invoke jus publicum. — Up until 25 years ago, that is, at which time the state of California came up with the notion that the definition of jus publicum could be extended to include whatever purposes the state might find convenient.

The objective of the public trust has evolved in tandem with the changing public perception of the values and uses of waterways. … [T]he traditional triad of uses – navigation, commerce and fishing – did not limit the public interest in the trust res. … “In administering the trust the state is not burdened with an outmoded classification favoring one mode of utilization over another.”
— California Supreme Court, National Audubon Society v. Superior Court of Alpine County (1983)In that case, the California Supreme Court extended jus publicum to include non-navigable tributaries of Mono Lake. The court ruled that the state could prevent the Department of Water and Power for the City of Los Angeles from using its legally owned water rights because the usage interfered with the supply of water to Mono Lake. The water rights were deemed to be a public trust for “environmental and human considerations” having nothing to do with the traditional jus publicum rights relating to navigation, commerce, or fishing. The court rejected a regulatory takings claim because the land was held to be exempt from fee simple title on the grounds that it was a public trust and, therefore, no compensation was due to the plaintiff for the loss of their water rights.

That ruling opened the door for other states to expand the scope of jus publicum beyond its original intent, in whatever ways captured their imagination.

The nature of the ownership includes two components: fee simple title (the jus privatum) and dominion as the publics trustee over the natural resource for public trust uses such as navigation, commerce, fisheries and recreation (the jus publicum).
— Oregon Department of State Lands, Rogue River Navigability Report (2008 ) Oregon, quietly and without fanfare, slipped “and recreation” into the list of rights held in trust for the public under jus publicum. Nobody blinked so, by precedent, the “right” to recreation is now part of the legal definition of the public trust in the state of Oregon. What difference does that make? If you own riverfront property, the traditional definition of jus publicum guaranteed passage for boats on the river without your explicit consent. The new and improved definition declares that anybody who wants to may have picnics and parties in your backyard (at least the part of it that extends below the high water mark). In the course of carefree recreation, people often make noise, leave litter, and sometimes do damage to property. But there’s nothing you can do about that, because the state of Oregon declared they have as much right to use your property for recreation as you do. You can ask them to pick up their litter, but you can’t enforce it. And, if they damage your property, you can try to sue them, if you can find out who they are… But you have no legal right to keep them out, or to restrict what they may do while they’re enjoying your property.

Oregon was not the first state to include recreation in the definition of jus publicum. In 1999 (National Association of Home Builders v. New Jersey Dept. of Environmental Protection), riverfront property owners were compelled to allow a public pathway along the river, through their property, with no compensation for takings, because the right to access the river for recreational purposes was ruled a public trust. Because the path is on their property, the “owners” have the responsibility of maintaining it (just like a public sidewalk) and, presumably, they also carry the liability if anyone should get hurt while traversing it.

In 2002 (Esplanade Properties, LLC v. City of Seattle), the Ninth Circuit Court used the state of Washington’s expanded definition of jus publicum to prohibit residential development of privately owned shoreline properties. Because the recreational use of the shoreline is considered a public trust, no compensation was awarded to the fee simple “owners” of the property.

According to The Idea of Property: Custom and Public Trust, in 2001 (R. W. Docks & Slips v. Wisconsin), the Wisconsin Supreme Court “expanded the public trust doctrine to include recreation and preservation of scenic beauty.” Subsequently, Florida and other states “expansively interpreted” the public trust doctrine to include both recreation and scenic beauty, as well. When the state can rule that the public’s “right” to scenic beauty supercedes the private property rights of individuals, one has to wonder if there are any limits to the ever-expanding powers of state government to abrogate our property rights for whatever arbitrary purpose they may declare.

When the state declares your property, or some part of your property, to be a public trust, it can legally deprive you of the traditional rights associated with private property ownership. In the cases cited above, property owners were deprived of the right to control the use of their property, the right to economic benefits accruing from their property, and the right to exclude others from access to their property. Yet, as long as the justification is based on jus publicum (or expanded definitions thereof), the state is not required to pay any compensation for takings under the laws of eminent domain. Because jus publicum is non-transferrable, the state will claim the property rights in question never did actually belong to you (though you will continue to owe property taxes on the property).