While most people think of land surveys in the most basic sense—that is, the drawing of the boundaries of a property—there are actually many different ways of surveying that service many different industries. Property surveys are a large part of the business, but there are also surveys and surveyors that help the construction industry, the environmental sector, and many others. The kinds of surveys that are conducted would surprise most people, and some things that you might think are surveys aren’t surveys at all. Instead of the standard two-dimensional measuring from one point to another, today’s surveys not only measure the land, but also the air and water above and below us. Let’s take a quick look at a sampling of different types of land surveys available.
The most common and well-known surveys conducted today are boundary surveys, mortgage surveys, and topographic surveys. An ALTA survey, which is actually a shortened title for ATLA/ACSM, combines elements of all three with a set of standards put forth jointly by the American Land Title Association and the American Congress on Surveying and Mapping. ALTA surveys are most commonly used for commercial properties; by having a universal standard, companies can assure themselves of the level of thoroughness and be confident when the results are guaranteed by an ALTA survey.
Boundary Surveys are exactly what the name describes: a survey to establish the true boundaries of a given property. Through previously recorded markers and the establishment of new landmarks, a surveyor will establish the true boundaries of a property and then mark the corners and lines of the plot, using markers such as iron rods, pipes or concrete monuments in the ground, or nails set in concrete or asphalt. In the past, trees, piles of stones other less permanent markers were used, which led to confusion when the markers were either destroyed or changed.
Mortgage Surveys are simple surveys that for the most part determine land boundaries and building locations. They are usually required by title companies and lending institutions when they provide financing to show that there are no structures encroaching on the property and that any structures on the property meet current zoning and building codes. It is important to ensure that you are getting an officially licensed mortgage survey performed by a licensed land surveyor, and not a mortgage inspection, which is a substandard survey that does not adhere to any set standards and is not regulated or accepted as an official land survey.
Topographic Surveys are land surveys that locate natural and man-made features on a piece of property—for example, buildings, improvements, fences, elevations, land contours, trees and streams. These are measured for their elevation on a particular piece of land and presented as contour lines on a plot. Topographical surveys are sometimes required by the government. Engineers and architects also use topographical surveys to aid in the design of improvements or developments on a site.
One of the largest and most rapidly growing areas of land surveying is in the construction industry. Surveys are crucial tools from inception and planning to actual construction and maintenance afterwards. Most construction surveys fall under the discipline of civil engineering, which may require additional degrees and certifications in order to conduct. All construction projects begin with the Plot Plan or Site Plan, which set out the plan for the entire project including all existing and proposed conditions on a given site. As-Built Surveys are conducted several times during a construction project to verify for local and state boards that the work authorized is being completed to the specifications set on the plot plan. A Foundation Survey is a type of as-built survey that collects the positional data on a foundation that has been poured and is now cured. Foundation surveys are done to ensure that the foundation has both been constructed in the proper location and has been built in the proper manner according to the plan.
For existing structures, a Deformation Survey determines if a structure or object is changing shape or moving. By the taking of three-dimensional positions on specific points on an object, then letting a period of time pass before retaking and measuring the points, it can be determined whether a structure is shifting or moving, and by how much.
Although it may seem counter-intuitive, land surveyors are also responsible for performing Hydrographic and Bathymetric Surveys. Hydrographic surveys collect data relating to any body of water, and the data collected may include the water depth, bottom contours, the direction of the current, observing and recording high water marks and water levels, as well as location of fixed objects and landmarks for navigational purposes. They can also be conducted to gather information for engineering or resource management purposes, such as hydro power plants. Bathymetric surveys deal exclusively underwater, and map the seabed profile.
Geodetic Surveys fall under both the land and water category, as they map out the shoreline. Thomas Jefferson commissioned a geodetic survey in 1807 as the Survey of the Coast. Progress on the survey moved slowly at first as they did not even have the proper instruments to perform the survey until 1815. It still exists today as the National Geodetic Survey, and its responsibilities now include the interior lands of the United States as well as its coasts.
Wetlands Delineation and Location Surveys belong in a category all on their own; they are performed when construction work is being planned on or near a site containing defined wetlands. Local, state, or federal regulations vary, but wetlands are usually classified as areas that are completely inundated with water for more than two weeks during the growing season. Boundaries of wetlands are determined by observing the soil colors, vegetation, erosion patterns or scour marks, hydrology, and morphology of the land in question. Data is then collected on the locations of the placed flags and a plan is drawn to reference the boundary of the wetlands and compare it to the proposed boundaries of the surrounding plots or parcels of land and the construction work proposed within.
There are many other types of land surveys, but the examples presented above are the most common forms of land surveys that the general public is most likely to encounter.