Topographic Surveys – Benchmark Elevations

A topographic survey typically shows contour lines of a property. Those contour lines have elevations assigned to them. The elevations are shown in relationship to the benchmark that has been established on the property and can be reported in one of two ways:

  • Assigned Elevations – This is when a surveyor assigns a value to an established benchmark. A typical elevation is 100 ft above sea level. The elevations shown on the drawing are shown in relationship to the benchmark.
  • Actual Elevation – The actual elevation of a property can be established using GPS, state plane coordinates, or FEMA benchmarks. This elevation is the true number of feet above sea level that the benchmark is located

Both types of elevation show an accurate depiction of the elevation change on the property. One of the biggest determining factors in making a choice is determining if the information is just for personal use, or are you going to be working with a utility company or government office that is going to want the information referencing the data that they have on file. That’s a question to as BEFORE you get started!