What is the purpose of a control point in surveying for earthwork?

• A. Measures soil moisture
• B. Sets drainage slope
• C. Controls equipment temperature
• D. Provides a fixed reference for layout and grade verification

Answer: (D)

In surveying for earthwork, a control point serves as a fixed reference with known coordinates and elevation that anchors the project layout. This point lets surveyors transfer the design from plans to the ground, establishing exact lines, offsets, and grade elevations so that cuts and fills are placed where intended. By tying all measurements to this stable reference, the team can verify that the actual ground matches the design throughout construction and catch any drift early, which helps prevent errors from compounding as work progresses. A control point isn’t about measuring soil moisture, setting drainage slope directly, or controlling equipment temperature; those tasks use other tools and methods. Its main purpose is to provide a fixed reference for layout and grade verification.