What is a common use of benchmarks in surveying?

Benchmarks are critical reference points that provide a standard for measuring elevation. They are permanently fixed objects or points, often marked by a brass or aluminum disk embedded in the ground, that convey a precise elevation above sea level or another reference point. In surveying, benchmarks serve to ensure consistent and accurate elevation measurements, making them vital for various construction, engineering, and land surveying projects.

When determining how high or low land or structures are compared to a chosen reference point, surveyors utilize benchmarks to gauge elevation differences accurately. This is especially important in ensuring that buildings are constructed to the appropriate height relative to flood zones or when laying out pipelines and roads that require precise elevation. Consequently, the correct response highlights the essential role benchmarks play in elevation determination.

In contrast, while establishing property lines, measuring land parcels, and identifying property ownership are also important aspects of surveying, they do not typically involve the use of benchmarks as their primary tool. These activities focus more on boundary delineation and ownership verification rather than elevation assessment, which is the specific purpose of benchmarks.