Louisiana Administrative Code
Title 43 - NATURAL RESOURCES
Part XXVII - State Lands
Subpart 1 - Land Information Mapping and Map Records System
Chapter 5 - Ground Control
Section XXVII-509 - Permanent Monumentation

A. The density and distribution of permanent horizontal control monumentation within each project area shall be sufficient to provide local horizontal control to facilitate the implementation of land parcel corner ties, map accuracy check surveys, map updates, and related surveying and mapping activities. The required combined average density of existing and/or new permanent horizontal control monuments to be recovered or otherwise established within each separate area classification pursuant to these standards shall be as follows.

B. All existing horizontal control monumentation within the project area and up to 1/2 mile beyond the limits of the project area which is published by NGS as part of the National Geodetic Horizontal Reference System shall be recovered and paneled prior to flying of aerial photography.

C. All new horizontal control monumentation established in conformance with the average density requirements set forth above shall be constructed in accordance with the applicable guidelines set forth within NOAA Manual NOS NGS 1, Geodetic Bench Marks, latest edition. Unless otherwise superceded by more stringent project requirements, all new permanent horizontal control monuments shall be minimum 10 inches diameter by 36 inches deep cast-in-place or precast concrete with embedded brass disc as shown in §521, Appendix A. All new horizontal control monuments shall be paneled prior to flying of aerial photography.

D. All new permanent horizontal control monuments established shall be set in intervisible pairs consisting of a horizontal control monument and companion azimuth mark to provide local azimuth. Azimuth marks may consist of clearly definable existing features such as the tops of towers, spires or other existing points which are visible from the closest adjacent permanent control monument and which can be satisfactorily described, referenced and recovered. In the absence of clearly definable existing features within the vicinity of any new permanent control monument, a companion azimuth mark shall be constructed in conformance with the requirements set forth within §521, Appendix A. All azimuth marks should be located at least 1,500 feet away from adjacent permanent horizontal control monuments whenever possible.