Definition
A lake is a naturally occurring body of water contained in a depression of the earth's surface, surrounded by or substantially enclosed within land, and supplied by drainage from a surrounding watershed. It is distinguished from a river or stream by the absence of a defined directional current as the body's primary characteristic, and from a pond chiefly by size — though no universal acreage threshold separates the two at common law.
Lakes carry significant legal weight in property, water rights, and public trust doctrine. The legal significance of a lake turns on two principal questions: (1) whether the lake is navigable or non-navigable, and (2) whether it is natural or artificial. These determinations control ownership of the lakebed, riparian rights of abutting landowners, and the scope of public access.
Common Language
Modern common usage (Wiktionary): A large, landlocked stretch of water or similar liquid; also, informally, a large quantity of any liquid.
Historical common usage (Webster's 1913): Webster's 1913 is not instructive here — its primary entry for "lake" covers a pigment (madder lake, Florentine lake), not the body of water, which reflects the alphabetical conventions of that edition rather than any legal relevance.
The gap between common and legal meaning is meaningful in one specific direction: in ordinary usage, a lake is simply a large landlocked body of water. In law, size alone is insufficient. A body of water called a "lake" may be legally treated as a pond, a reservoir, or even an arm of a navigable river depending on its navigability, origin (natural vs. artificial), and the jurisdiction's public trust doctrine. The label does not control the legal classification.
Core Elements
For purposes of legal classification, the following elements are relevant:
1. Natural depression: The basin must be naturally formed. Artificial impoundments are generally treated differently under water rights and public trust analysis, even if they resemble lakes in appearance and size.
2. Enclosed by land / not part of the ocean: A lake is distinguished from a bay, sound, or tidal water. The Great Lakes present a recognized exception — they have been characterized as inland seas and subject to modified navigability analysis.
3. Supplied by drainage: Lakes are fed by watershed runoff, tributary streams, or groundwater. This distinguishes them from isolated artificial ponds.
4. Navigability: Whether a lake is navigable in law (historically capable of supporting commerce, not merely navigable in fact) determines whether the lakebed title vests in the state or may be held privately.
Recognized Forms
/SUBTYPES
Navigable lake: A lake meeting the federal or applicable state navigability test. The lakebed is generally held by the state in trust for the public. Abutting landowners hold riparian rights but not lakebed title.
Non-navigable lake: Lakebed title may vest in abutting landowners, typically to the center of the lake under the ad medium filum rule, though state law varies considerably. A grant of land to a natural pond or lake extends only to the water's edge absent contrary indication.
Artificial lake / reservoir: Created by impoundment or excavation. Generally not subject to the public trust doctrine in the same manner as natural lakes; rights are governed by the instrument of creation and applicable state water law.
Inland seas (Great Lakes): Lakes Ontario, Erie, Superior, Huron, and Michigan have been treated as a distinct category. Different states border them, and they have been subjected to navigability and public trust analysis analogous to tidal waters in some respects.
Why It Matters in Research
Researchers navigating water rights, riparian law, or public lands history will find that the word "lake" in older sources does not carry a stable legal meaning — the term was borrowed from physical geography and applied unevenly across jurisdictions. Several navigational traps are worth noting.
First, the navigability question is everything, and it was contested. Sources from the late nineteenth and early twentieth centuries frequently disagree about whether particular lakes are navigable, and the federal test (capable of being used in interstate commerce) diverges from various state tests. A lake deemed non-navigable under one state's rule may be navigable under another's. Researchers working with pre-1900 state land grants or patents involving lakeshore property must identify which navigability standard was operative in that jurisdiction at the time.
Second, the distinction between lake and pond was not consistently drawn in historical legal sources. Some jurisdictions tied the distinction to acreage (Maine's historical rule, for example, treated lakes over ten acres as state property for public benefit), while others used navigability, commercial use, or common reputation. Anderson's note that "each case depends largely upon its own facts" accurately reflects the common law posture, but it makes systematic research difficult.
Third, abutting-landowner title rules vary sharply. The ad medium filum aquae rule (title to the center line) applied to rivers was sometimes extended to non-navigable lakes, sometimes not. Grant language "to the lake" or "bounded by the lake" was interpreted differently depending on whether the lake was natural or artificial, navigable or not, and the jurisdiction.
Fourth, the Great Lakes require separate treatment. Do not apply interior lake doctrine to research involving Great Lakes boundary disputes, fishing rights, or submerged lands — the public trust and navigability frameworks applied there are distinct.
Historical Dictionary Support
The historical dictionaries agree on the physical baseline: a lake is a large body of water in a surface depression, supplied by drainage, and distinguished from a river by the absence of a primary directional current. Black's (both editions) and Bouvier's share nearly identical language, drawn from Webster's geographical definition — a reminder that the legal definition was essentially borrowed from physical geography and never fully theorized at common law.
Bouvier's adds doctrinal texture, noting the Maine rule (lakes over ten acres belonging to the state for public benefit), the principle that tidewater below navigable lakes vests in the state, and the tension between abutting landowner claims and public rights. Anderson's contributes the important caveat on grant construction: a conveyance to a natural pond or lake extends only to the water's edge, and mere surrounding ownership does not automatically carry lakebed title — though this too varies by jurisdiction.
What the historical dictionaries do not resolve cleanly: the artificial-vs.-natural distinction, the treatment of reservoirs, and the precise scope of public rights in non-navigable lakes. These questions were developing in courts throughout the period covered by these sources, and the dictionaries reflect the uncertainty rather than settling it.
Jurisdictional Note
Lakebed title rules and public access rights vary substantially by state. Western states applying prior appropriation doctrines treat lake water rights differently from eastern riparian jurisdictions. The public trust doctrine's reach over non-navigable lakes is recognized in some states and rejected in others. Researchers should not assume that doctrine from one state's cases generalizes nationally.