What are riparian boundary lines? As the name implies, they are boundary lines associated with riparian properties. Sometimes they are referred to as lines for the allocation of riparian rights or simply “riparian lines.” Similar to their upland brethren, they are a demarcation of the limits of the property rights of the riparian owner out into the body of water in front of the riparian lands. These are the riparian boundary lines.

As with terrestrial boundaries, the question ultimately becomes: Where are they located? Before one can deal with that question, there must to be an understanding of what these lines represent. In other words, what are the riparian rights? This is the same two-part question that faces any surveyor who attempts to make a boundary determination on the upland. “What” is the boundary (the legal question of title) and “where” is it located (the factual question of location)?

Riparian Rights

The word “riparian” originated from the Latin word ripa, meaning riverbank. An owner of land adjoining a river or stream is said to have taken title which is riparian in nature. The owner is properly referred to as a riparian owner, and the parcel of land is distinguished as a riparian parcel. Technically speaking, and in contrast, the owner of land abutting pooled waters (or surface waters), such as oceans, lakes, or ponds, are said to have “littoral rights,” and the property is said to be littoral in nature. However, the rights associated with both types of properties have become almost indistinguishable in American jurisprudence and the two terms are now almost synonymous.

To shorten this discussion, we will limit it to riparian rights along shorelines where the tide ebbs and flows. It is almost universally accepted under English and American common law that waters influenced by the tide are “navigable in fact” for title purposes. Meaning that the submerged lands (or tidelands) are owned by the sovereign, subject to certain rights granted to the owner of the riparian uplands. In addition to common law rights, many states have also enacted specific riparian rights legislation to further describe and define those rights. Alabama and Florida have such legislation.

Alabama: “The owner of riparian lands upon navigable waters in the State of Alabama may install in front of their respective riparian lands wharves, docks, warehouses, sheds, tipples, chutes, elevators, conveyors and the like for receiving, discharging, storing, protecting, transferring, loading and unloading freight and commodities of commerce to and from vessels and carriers, and may use their riparian lands in connection therewith and dredge out and deepen the approaches thereto, and may charge and collect reasonable tolls for the use thereof. All such structures are to be subject to such lines and limitations as may at the time of making such improvements be laid or placed by any authority of the United States, or of the State of Alabama, who may have authority to control harbor and pier lines.”1  

Florida: “Riparian rights are those incident to land bordering upon navigable waters. They are rights of ingress, egress, boating, bathing, and fishing and such others as may be or have been defined by law. Such rights are not of a proprietary nature. They are rights inuring to the owner of the riparian land but are not owned by him or her. They are appurtenant to and are inseparable from the riparian land. The land to which the owner holds title must extend to the ordinary high watermark of the navigable water in order that riparian rights may attach. Conveyance of title to or lease of the riparian land entitles the grantee to the riparian rights running therewith whether or not mentioned in the deed or lease of the upland.”2

A couple of observations. The Alabama statute defines some important and valuable riparian rights of the riparian owner and tells us “where” they are located. They are located “in front of their respective riparian lands.” The Florida statute also describes important and valuable riparian rights. The statute tells us the rights “are not proprietary” and are “not owned” by the riparian owner. The statute also tells us where they begin, at the “ordinary high watermark,” but not where they end or where they are located laterally. As with any boundary line, eventually the landowner will need to know where they are located. This can be lucrative work for the land surveyor. 

Beginning and Ending

The beginning and ending points of the riparian boundaries are relatively simple concepts, maybe not so simple in practice. According to NOAA,3 we have twenty-four coastal states. Fifteen of those states observe the mean high-water line and nine observe some other line. All of the public domain states observe the mean high-water line because of the Supreme Court decision in Borax v. City of Los Angeles.4 Ordinarily property rights, including riparian rights, are determined by state law. The question of the demarcation line between uplands and sovereign submerged lands in the public domain states is necessarily a federal question because the United States owned those lands and never sold any land below the mean high-water line. That’s what the Supreme Court determined in Borax.

The terminal points of the riparian boundaries are also a federal question. The Constitution of the United States gives the federal government paramount authority “to regulate commerce with foreign nations and among the several states.”5 This includes the regulation of all the waters of the United States and interstate navigation upon those waters. This is known as the federal navigational servitude. The states also have regulatory power over their own waters, subject to the paramount power of the federal government. Thus, the riparian boundaries will terminate when they meet the paramount interests of the state and federal government. This is why improvements in the tidelands must be permitted. 

Location, Location, Location

Most texts that deal with the subject of the location of riparian boundary lines discuss theoretical locations based on the shape of the shoreline, the location of the channel or line of navigable waters6 (a.k.a. deep waters), and some sort of equitable distribution of the available riparian areas. Very few, if any, discuss the problems associated with existing structures clogging up the available space. That’s what we are doing.

First, we need to recognize that riparian rights are not absolute rights. As the courts say, they are not “unfettered” rights and have been characterized as existing “in the nature of an easement.” The Florida statute quoted above tells us this, and so does the United States Constitution. They are not owned, they are granted, and the grant is subject to repeal or may be worthless like a quit-claim deed. 

Next, we need a working understanding of the boundary establishment doctrines. After all, these are boundary lines we are discussing. Just because they are projected over the tidelands does not mean that applicable boundary doctrines are not in play, especially the doctrines of acquiescence and repose relative to existing structures. These doctrines focus on the activities and inactivity of the adjoining landowners. The structures themselves become like a monument memorializing a previous riparian determination. Generally speaking, existing structures that enjoy long-held acceptance are not coming down, so they have to be dealt with.7 

We also need a working understanding of equity and equitable principles. Equity is not the law and the law is not necessarily equitable. Equity is justice administered according to fairness, but to the uninitiated can seem to be unfair. For example, “Equity Aids the Vigilant, Not Those Who Slumber on Their Rights.”8 This tells us that the last one to the party might not get any cake. That doesn’t seem fair, but it’s equitable. If the riparian boundary line determination ends up in court, equitable results are what the courts will strive for. We know this from the existing case law on the subject. 

Finally, we need to understand presumptions and inferences. We discussed these terms in detail in my August 2019 column. A presumption is a rule of law until rebutted. An inference is a conclusion that is valid when it is reasonable and makes common sense. We will be using inferences that are reasonable and pass the common-sense test to establish our principles for riparian boundary location when the shoreline is clogged with existing structures. I won’t call them presumptions of law, because I’m not sure that anyone has ever articulated them before, let alone a court. 

Riparian Boundaries in the Face of Existing Improvements

The above premises considered, there are reasonable and common-sense inference that can be made about riparian rights associated with unimproved properties in a highly improved shoreline environment, and the projection of the riparian boundary lines into the tidelands. 


  1. Riparian rights are not absolute rights;
  2. Existing improvements in the tidelands were permitted;
  3. Existing improvements in the tidelands are monuments that memorialize a previous riparian boundary determination;
  4. Even if not previously permitted, existing improvements that are at least 20 years old (period of repose) were approved by the acquiescence and acceptance of the adjoining landowners and other boundary establishment doctrines may apply;
  5. Equitable principles apply to the distribution of now available riparian-use areas in the tidelands; and
  6. Equitable principles also apply to the enforcement of regulatory requirements for the installation of new improvements in a highly improved shoreline environment.

I will use my next column in February to put these principles to the test with some case studies.



  1. § 33-7-50. Code of Alabama (1975).
  2. § 253.141.(1) Florida Statutes.
  3. National Oceanic and Atmospheric Administration.
  4. Borax v. Los Angeles, 296 U.S. 10 (1935).
  5. Article 1, § 8, United States Constitution.
  6. In this context we are talking about waters deep enough to support boats and actual navigation. All waters influenced by the tide are navigable for title or ownership purposes. 
  7. This does not mean that a court of competent jurisdiction cannot order the removal of an existing structure (which would be an extreme result), but the land surveyor certainly can’t. Therefore, the surveyor’s job will be to deal with the fact of the existing structure, not create fantasy or theoretical results that are never going to happen.
  8. Re, Edward D. and Joseph R. Re, Remedies, Cases and Materials, Fourth Edition, Foundation Press, New York, New York, 2000, “Maxims of Equity” at 29-31.  

Neither the author nor POB intend this column to be a source of legal advice for surveyors or their clients. The law changes and differs in important respects for different jurisdictions. If you have a specific legal problem, the best source of advice is an attorney admitted to the bar in your jurisdiction.