A method on a computing device for defining a buffer zone around a buried asset at an above surface location is provided. The method includes receiving and storing buried asset data points, wherein each buried asset data point comprises a geographical coordinate and a precision data value corresponding to the geographical coordinate, for a buried asset, wherein the buried asset data points correspond to signals that were detected and read from the buried asset at the above surface location. The method further includes generating a first data structure that represents a two dimensional area comprising a buffer zone at the above surface location, wherein the first data structure is generated by defining an area around each geographical coordinate, wherein a size of each area is based on the precision data values of the buried asset data points.