When an original survey line reached a lake, a navigable river or tidewater, the surveyor stopped, set a meander corner, and did not attempt to run the line across. Later, he traversed the shore from one meander corner to the next in a series of short courses. That traverse is the meander line, and it appears on the plat as a dotted or irregular line following the water.
The purpose of the meander line was arithmetic. To sell land fronting on water the government had to know how much land there was, and the only way to compute the area of a parcel with a curved side is to approximate that side with measured courses. The meander line was that approximation. It was not intended to be, and generally is not, the boundary of the land.
What was meandered
- Meander line
- A traverse of short courses run along the bank of a meanderable body of water, between meander corners, for the purpose of computing the area of the fractional parcels fronting on the water.
Not every trickle was meandered. Instructions specified size thresholds, and those thresholds changed over time, which is one reason two adjoining townships surveyed decades apart can treat similar water differently. Broadly, navigable streams and streams of about three chains and upward in width were meandered, along with lakes above a stated minimum area, commonly forty acres under earlier instructions and twenty-five acres under later ones. Tidewater was meandered at the line of mean high water.
- Water below the threshold was not meandered. The survey lines were simply run across it and the sections remained regular.
- The plat shows what was actually meandered, so the plat and the field notes settle the question for any particular section.
- Meandering produced fractional sections, which were covered by government lots with computed acreages.
- Where the shoreline was long or complex, special meander corners were set so that interior subdivisional lines reaching the water could be controlled.
- Islands existing at the date of survey were meandered and surveyed separately; islands that appeared later were not part of the original survey.
Why the meander line is not the boundary
The general rule, applied throughout PLSS country, is that a patent of a fractional lot fronting on meandered water conveys the land to the water, not merely to the meander line. The reasoning follows from what the survey was doing. The government offered the land bordering the lake or river; the meander line was the surveyor's means of measuring it; and a narrow strip of land left between the meander line and the water would serve no purpose and was never intended to be retained.
The practical consequences are large. The acreage stated on the plat is the surveyor's computation of the area between the aliquot lines and the meander line at the date of survey. It is a description of quantity, not a limit on the grant. And because water moves, the actual quantity today may differ substantially from the plat figure in either direction.
A boundary that moves
If the water is the boundary, then the boundary is ambulatory: it follows the water as the water changes, subject to the character of the change. Four processes are distinguished, and the distinction determines whether the boundary moves.
| Process | What happens | Effect on the boundary |
|---|---|---|
| Accretion | Gradual, imperceptible deposit of material along the bank | The boundary follows the water; the riparian owner gains the new land |
| Reliction | Gradual, imperceptible withdrawal of the water exposing land | The boundary follows the water; the riparian owner gains the exposed land |
| Erosion | Gradual, imperceptible wearing away of the bank | The boundary follows the water; the riparian owner loses land |
| Avulsion | Sudden and perceptible change, such as a river cutting a new channel in a flood | The boundary generally remains at the former location of the water |
The line between gradual and sudden is the operative one, and it is drawn by evidence: aerial photography, historical surveys, gauge and flood records, soil profiles and vegetation. A surveyor asked to locate a water boundary is often really being asked to determine whether a change was avulsive, which is a question of history as much as of measurement.
Working with meander lines in practice
The meander line remains useful even though it is not the boundary. It fixes the extent of the original survey, it supports the acreage of record, and it is often the only thing tying the lot lines to the water at the date of survey. Retracing it is standard work when the position of the historical shoreline matters, as it does when apportioning accreted land or resolving a claim of avulsion.
- Recover the meander corners at the ends of the traverse; they are ordinary monumented corners and are frequently the best surviving evidence on that side of the section.
- Take the meander courses and distances from the original field notes and compute the traverse in coordinates from the recovered meander corners.
- Compute the area of the fractional lot from those coordinates and compare it with the acreage on the plat as a check on the reduction.
- Locate the present water boundary by its legal definition for the water body in question, which is a separate determination from the historical meander line.
- Compare the historical and present positions, and assemble the evidence needed to characterise the change as gradual or avulsive.
- Report the meander line and the present water boundary as two distinct lines, and say clearly which is the boundary and which is historical.
The last point is the one that prevents trouble. A plat that draws the meander line as though it were the property line invites everyone who reads it to reach the wrong conclusion. Label it for what it is: the line the original surveyor ran in order to compute an area, preserved because it is evidence, not because it is a boundary.