Civil Engineering Reference
In-Depth Information
The BLM has regulations for the types of monuments used in public surveys.
Although a surveyor may be authorized to utilize other types of monuments, the
Regulation Post
is an alloyed iron pipe, zinc coated, 2 οΎ½ inch. in diameter and
cut to a length of 30 inch. The bottom of the pipe is split and spread. A brass cap
is affixed to the top of the pipe. Brass tablets are specified for installing in rock
where it is not possible to use the pipe. Monuments are marked for identification
of the corner. The Manual goes into detail on the form and abbreviations to be
used for marking monuments.
Many old monuments obviously do not conform to the present BLM require-
ments. Many of the older monuments were piles of rocks or piles of rocks with
wooden posts. Even trees could be marked and used if they happened to coincide
with a corner location.
Witness Corners
are monuments which are usually placed on a survey line near
a corner. Witness corners are used when it is not practical to place a monument on
the corner itself. For example, the corner may fall in the middle of a stream. It is
preferred that the witness corner be located within 10 chains of the actual corner.
7.9 Meandering
All navigable bodies of water and important lakes and rivers are distinct from pub-
lic lands. The mean high water line is the boundary between these bodies of water
and the public lands. The high water mark is defined as the line which the water
impresses on the soil by covering it for sufficient periods to deprive it of vege-
tation. A
Meander line
is a traverse consisting of straight line segments which
is run along the high water mark (Fig.
7.6
). Section lines are run to the meander
line and the intersection is called a
Meander corner
. The meander line therefore
begins at a section corner and ends at the next section corner (or township cor-
ner). All lakes having an area of 50 acres or more are meandered. Navigable rivers,
bayous and rivers which are not navigable but which are at least 3 chains across
are meandered on both banks. Shallow and intermittent streams are not meandered
even if they are more than 3 chains across. It is important to understand that the
meander lines are used for the purpose of calculating area. They are not an actual
boundary. The stream or other body of water is the actual boundary.
7.10 Restoration of Lost Corners
Restoration of lost corners under the PLSS is closely regulated by the Manual of
Instructions for the Survey of the Public Lands of the United States. This Manual
is in excess of 300 pages so it is only possible to cover a fraction of the material
here. We will therefore only be able to consider a few of the examples of the resto-
ration of lost corners.
