In order to create a contour map or a topographic map, the data and information obtained by the surveyor must be not only horizontally accurate, but also vertically accurate. A single point of reference, called a benchmark is used as a basis for the vertical data collection. The benchmark that is used can have several different characteristics depending on what it is that the client needs. Some characteristics of a benchmark are as follows:

  • Benchmark Location – The benchmark can be a random point determined by the surveyor or it could be something permanent in nature such as the corner of a concrete pad or a survey monument.
  • Benchmark Elevation – The benchmark can be given a random elevation number or the exact number of feet above sea level can be determined.

The establishment of a benchmark is the first step to having a topographic survey performed. This is the point that all of the data will be compared to and will be the basis of the topographic survey performed and a drawing created.

Information provided should not be considered legal advice and all buyers, agents and title companies should consult their attorneys for legal advice.