A survey map, also referred to as a property or plat map, is a detailed picture of a property. These are completed by professional surveyors and include information like boundaries, land descriptions, right of ways, access points, and more.

You’ll need a survey for buying and selling property, making changes such as a new structure, fence, or driveway, and settling boundary disputes. Being able to read and understand this map will help you make better decisions about a property you would like to purchase or what changes to make to a property you own.

A survey map will have a wide variety of symbols, lines, and alpha-numeric abbreviations. Understanding what these mean will give you a clear picture of the property. Keep in mind that the map is just one-half of the survey. There should also be a written report that details the property, ownership, places third parties can legally access the property (easements), and zoning to help you understand the map.

These are the common features you will find on all survey maps:

Scale

Survey maps are very precise. You will find a scale in one of the corners of the map. It will be written as a ratio. For example, 1:10,000 means that every inch on the map is 10,000 inches on the earth. Most survey maps are not drawn on grid paper so use a ruler to measure the exact distance.

Legend

There is not a universal legend for symbols for surveyors. While some are more common than others, a surveyor is free to use any symbol they want on their maps. This makes a legend essential. Somewhere on the map you will find a legend table that has both the symbol and the text explaining what that symbol stands for. There should be symbols for all the utilities and structures on the property including water meters, utility poles, fire hydrants, and manholes.

There will also be a compass indicating which way the map is oriented. You should be able to translate this map from the two-dimensional paper to the three-dimensional world. To determine the starting point, a surveyor will locate a nearby U.S. Geological Survey Marker or an easily identifiable spot, like a street intersection. Lines will be drawn from that point to a starting point on your property. Once you find the starting point, you will be able to follow the lines around your property using the measurements and angles indicated on the survey map.

Bold lines

The most prominent lines on the survey are the boundary lines. This is the most important data on the map and should be very clear. The lines will also have bearings and measurements that you could use to find the boundaries on the property. Bearings are angles measured in degrees, minutes, and seconds. Measurements are the length of the lines, often in feet.

Pins

There will be symbols on the map to indicate where the surveyor found property pins and where they placed new pins. These pins are the physical markers placed in the ground to help you identify where your property ends. Many property stakes are old and difficult to locate, so the surveyor can place new pins to make identification easier.

Other lines

You will find lots of other lines drawn on a survey map. The legend should tell you what each line means. Computer generated surveys will have dotted and dashed lines of varying sizes with different meanings. These lines can represent fences, buildings, pools, or bodies of water. Some lines may include letters for easy identification such as a “g” for gas lines or “w” for water lines.

Flood plain

The Federal Emergency Management Area (FEMA) has designated flood hazard areas around bodies of water. If your property is within one of those areas, it should be noted on the survey map.

Abbreviations

Because space is tight on a survey map, abbreviations are used. There are some abbreviations that are standard and easy to figure out, such as “conc” for concrete. Others are terms used specifically in this industry, and should be included on the legend, such as “CMP” for corrugated metal pipe. If you don’t see the abbreviation in the key, ask your surveyor for an explanation.

The Bureau of Land Management has a list of abbreviations that may be helpful if they are not included in the legend.

You may also have numbers on your survey map. Each parcel of land has a lot number so it can be found in public records. The lots surrounding yours may be numbered on the map. Some maps will even include the reference numbers for those lots so descriptions of the parcels can be located in the government offices.

A survey map is a useful tool for property owners to understand what they own, and what they are allowed to do to modify the property. It’s also helpful in making buying and selling decisions. A survey already may be on file with the tax assessors office. If they don’t have one or if it is old and out-dated, you can contact a surveyor to complete a new one for you.