Definition
Flowage refers to the overflowing of water onto land, and by extension to the legal rights, duties, and burdens arising from such overflow. In property law, it most commonly appears in two contexts: (1) the natural servitude requiring a lower landowner to receive water that drains or flows naturally from an upper estate, and (2) the right acquired — typically by grant, prescription, or eminent domain — to flood or back water onto another's land, as in the operation of a mill dam or reservoir.
Common Language
Modern common usage (Wiktionary): A flowing or overflowing of liquid.
Historical common usage (Webster's 1913): An overflowing with water; also, the water which thus overflows.
The common meaning describes a physical phenomenon. The legal meaning carries the additional freight of property rights and obligations: who must bear the burden of that overflow, under what conditions, and what compensation, if any, is owed. A researcher encountering "flowage" in a legal document should ask not merely whether water moved, but whose land bears the burden and on what legal basis.
Core Elements
The legal concept of flowage typically turns on four questions:
1. Natural vs. artificial cause. Natural flowage from an upper to a lower estate is generally a recognized servitude that the lower owner must tolerate without compensation. Flowage caused or increased by human activity — drainage works, dams, irrigation — may give rise to liability or require a separately acquired right.
2. Existence of a defined watercourse. Courts have distinguished between diffuse surface water and water moving in a defined channel. The natural flowage servitude has been applied even where no well-defined banks exist, but the absence of a natural watercourse affects how courts analyze the rights and remedies involved.
3. The flowage easement or right. Where an owner affirmatively backs water onto neighboring land — as a mill operator flooding an upstream meadow — a flowage right or flowage easement must be established. This right is a property interest, separately compensable in takings proceedings.
4. Damages and compensation. Unauthorized flowage onto another's land is a cognizable injury. The measure of damages and available remedies depend on whether the interference is temporary or permanent, and whether the cause is a private actor or a government project.
Recognized Forms
/SUBTYPES
Natural flowage servitude: The burden on a lower estate to receive water that drains from a higher estate through the natural lay of the land. Recognized as a passive obligation rather than an affirmative grant.
Flowage easement: An affirmative right, acquired by grant, prescription, or condemnation, authorizing the holder to flood or back water onto land belonging to another. Common in mill, dam, and reservoir contexts.
Why It Matters in Research
Flowage sits at the intersection of water law, property law, and takings doctrine, and the relevant legal framework has shifted considerably over time and across jurisdictions. Researchers working in nineteenth- and early twentieth-century sources will encounter the term primarily in mill and riparian contexts, where flowage rights were routinely acquired by mill operators and their successors. As municipal water projects and federal dam construction expanded through the twentieth century, flowage easement language migrated into condemnation proceedings and federal water project records — a different corpus from the mill cases where the doctrine developed.
The term is easy to overlook in historical indexes because it appears both as a physical description (the fact of overflow) and as a shorthand for the legal right or servitude. A document describing "flowage of the meadow" may be describing either a natural condition or the exercise of an acquired easement; context and era determine which.
Researchers should also note that surface water law — which governs diffuse runoff not moving in a defined channel — developed on a partly separate doctrinal track. Some jurisdictions apply the natural flowage servitude to surface water broadly; others distinguish sharply between surface water, defined watercourses, and artificially collected water. Conflating these categories in historical sources can produce misleading research results.
The connection to highway drainage (referenced in Bouvier) is a recurring pattern in nineteenth-century cases: an upper landowner drains onto a road, road drainage then damages a lower neighbor, and the question becomes who bears liability. This triangular fact pattern appears frequently enough in older case reporters to warrant attention when tracing flowage doctrine.
Historical Dictionary Support
Bouvier's defines flowage by reference to Webster's physical definition and then immediately pivots to the legal servitude, treating the natural drainage burden on lower estates as the primary legal content of the term. Bouvier's correctly notes that the servitude applies even in the absence of a well-defined watercourse — a point that was litigated and not self-evident, since the natural watercourse doctrine otherwise structured much of nineteenth-century water law.
Bouvier's entry is truncated in the available text and does not address the flowage easement as an affirmative property right, nor the takings dimension that became significant as public water projects multiplied. Researchers relying solely on Bouvier's will have the servitude concept but will miss the substantial body of doctrine around acquired flowage rights, condemnation of flowage easements, and compensation for government-caused flooding — all of which developed largely after Bouvier's principal editions.
Jurisdictional Note
Flowage law varies meaningfully by jurisdiction because states differ in their treatment of surface water — civil law (natural flow) states impose stricter obligations on upper owners not to increase natural flowage, while common enemy doctrine states give landowners broader latitude to divert surface water. These differing baseline rules affect both the natural servitude analysis and the liability questions that arise from artificial drainage.