Understanding the symbols on a survey map is essential for anyone reviewing property boundaries, planning improvements, or preparing for development. Because accurate measurements form the foundation for accurate site work, the map must convey information clearly and consistently. Survey symbols offer a clear, standardized way to represent key details in land surveying, making maps easier to read and apply without overcrowding them with text.
Why Survey Symbols Matter
Symbols allow surveyors to communicate complex details in a standardized way. Even though the drawing looks technical at first glance, learning the common markings makes it easier to understand what exists on the site and what may need attention before construction begins. This visual language also helps avoid errors during planning, permitting, and design phases related to land surveying.
How Civil Engineers Use Survey Drawings
Survey maps also provide essential information for civil engineering design work, helping them understand the land before planning grading, drainage, or infrastructure improvements. These are some of the details surveyors watch closely when doing surveys on land:
- Points that control slope direction
- Existing drainage paths
- Utility depth notes or invert elevations
- Right-of-way markings
- Existing improvements that affect design placement
Accurate symbols for these features ensure that engineering plans align with field conditions and local requirements.
Common Boundary and Property Line Symbols
Boundary information is typically the first detail most property owners look for. Straight or dashed lines show ownership limits, while corner markers such as iron pins, pipes, or monuments are usually noted with abbreviations. Typical boundary indicators include:
- Solid line: Existing property line
- Dashed line: Easements or setback lines
- Circle with abbreviation (IP, IPS): Iron pin or iron pin set
- “MON”: Permanent monument
These symbols help confirm where the legal limits of a property begin and end, supporting decisions related to site layout and improvements.
Elevation and Contour Symbols
Survey drawings also show how the land slopes and drains. Elevation symbols and contour lines illustrate changes in grade and are especially useful early in the design process. Surveyors represent elevation changes through several symbols, including:
- Contour lines: Continuous lines representing equal elevation
- Spot elevations: Individual points indicating height at a specific location
- Benchmarks: A known elevation point used for reference throughout the project
Utility and Infrastructure Symbols
Utilities appear on nearly every site, and each type has its own symbol style. Knowing how to read these helps identify potential conflicts before construction begins.
Standard Utility Markings
These common utility symbols help readers quickly distinguish between essential underground systems and understand how each one affects construction planning.
- W or blue line: Water lines
- S or green line: Sanitary sewer
- G or yellow dashed line: Gas
- E or red line: Electric
- TEL: Telecommunications
Because these systems often cross under structures or landscaping, correctly identifying each symbol prevents costly mistakes and supports accurate civil engineering work.
Topographic Features
Topographic symbols represent natural and man-made elements on the property. These details allow designers and contractors to see how the site currently exists. Examples of topographic symbols include:
- Tree symbols: Circles or clusters showing individual trees or groups
- Rock outcrops: Jagged shapes
- Fences: Straight lines with alternating markings depending on type
- Road edges or curbs: Parallel lines defining paved areas
These symbols help identify obstacles, preserve important features, and improve grading or drainage plans when paired with GPS survey data.
Interpreting Symbols From Modern Survey Methods
Modern surveying often includes data captured through a GPS survey, which enhances precision and efficiency. Many of the symbols remain the same, but the points originate from satellite-based measurements rather than traditional instruments.
What GPS-Based Symbols Represent
GPS-based symbols typically indicate control points tied to precise global coordinates, the individual on-site data points, and any Real-Time Kinematics (RTK) or static markers showing the method used. Together, these details verify measurement accuracy and make it easier for future surveyors or civil engineering professionals to repeat or validate the data as needed.
Tips for Reading a Survey Drawing
When reading a survey drawing, start with these steps:
- Locate the legend, which defines all symbols used on the drawing.
- Identify the north arrow and scale.
- Review boundary lines and corner markers first.
- Move on to topographic features and utilities.
- Confirm important labels: easements, setbacks, and benchmark notes.
Taking the drawing piece by piece makes the information easier to interpret. However, your surveyor should also explain their findings in detail. If you have any questions about your results, speaking with your surveyor is recommended.
Your Partner for Accurate Land Surveying and Clear Guidance
Interpreting survey symbols is easier with a reliable team guiding the process. Sisemore & Associates provides services in land planning, mapping, and land surveying, delivering clear drawings that support confident decisions for your project.
Whether you need boundary work, elevation data, utility mapping, or a detailed site analysis, our team can assist from initial measurements through final deliverables. Contact us to schedule your next survey or discuss your project needs.