What is a topographical survey?
Topographical surveys, ground surveys, or Topo Surveys are accurate surveys produced by Land Surveyors to precisely depict the topography or terrain of an area of interest or parcel of land and its structures and features. Traditionally, topographical surveys have been measured with a theodolite, total station, or GNSS receiver, but laser scanners and drones are increasingly playing an increasing role in data collection. Large sites used to be the domain of manned aircraft that measured a topographical survey with Lidar or Photogrammetry. More recently, these large sites are being surveyed with a drone at a much-reduced cost compared to a manned aircraft and a traditional land survey.
A utility survey depicts underground and overground features and services with their connections overlaid upon a topographical survey. These services can be located with radio detection or ground penetrating radar. Utility services and their attributes (size & depth) are marked on the surface with paint and measured in the same way as a topographical survey.
What is included in a topographical land survey?
A topographical survey can be a 3d model, a 2d map or a plan showing physical features. Topographical features surveyed could be structures, utility covers, areas of ground cover, trees or vegetation. Spot levels are shown with breaklines to control the shape of the surface model and contours to join points of equal level.
Typically, utility service covers and other service markers are identified, sometimes with underground services traced and marked with overhead services, depending on client specifications. Adjacent or overlooking features can be included to assist in assessing the setting of a site in the wider landscape, in a street scene or in assessing the proximity of critical topographical features. For example, picking up adjacent overhanging trees so that root protection areas can be calculated.
Typical equipment used on a project site to gather topographic data
- Theodolites / Robotic Total Stations:
A total station (pictured below) can be used by a team of surveys (or just a surveyor in the case of one-man robotic total stations) to measure horizontal and vertical angles, as well as distances. The surveyor or assistant surveyor walks around the site with a detail pole. Codes are recorded on a data logger at the survey pole or instrument end. - GNSS satellite positioning systems:
Often referred to as ‘GPS,’ this is the American global positioning system. It is just one of several satellite constellations in orbit around the Earth. A Global Navigation Satellite System (GNSS) base station or receiver collects positions relative to the satellite positions. - Levels/Precise levels:
Often referred to as Dumpy Levels, these devices transfer height or level information from one point to another. - 3d laser scanners:
Terrestrial laser scanners or mobile laser scanners can gather large amounts of data per second. This is far quicker than the above tools. Increasingly these scanners are hand-held, mounted on vehicles or on a drone. Ground-based LiDAR can have limitations due to restricted sight lines. Most survey equipment needs a clear line of sight to make accurate measurements. - Drones:
Drones are at the cutting edge of topographical mapping and collect data quickly, safely, and cost-effectively. They can be integrated with traditional equipment. Drones carry various sensors to measure points using photogrammetry or LiDAR. Due to the clearer site lines, drones have a significant advantage over ground-based survey equipment. Drones are the fastest way to gather survey data—up to 80% faster, in fact!
See how drones can supplement a survey with improved deliverables, safety, and speed of data acquisition.
Why do you need a topographic survey?
A topographical survey provides a comprehensive overview of the land, helping identify potential problems and plan future development. This type of survey is also helpful in determining where construction can and cannot occur. Additionally, a topographical survey can help with the design process, allowing engineers and architects to envision the project accurately before breaking ground. Topographic surveys form one of the critical starting points whenever land is to be developed or redeveloped.
planning application for a new religious
building on a city-centre brownfield site
Typical uses for topographic surveys
adjacent to a small river with sections
to help the client assess flooding
the dwelling and adjacent land
Add clarity, context and understanding with a topographic survey
For many projects, a topographical land survey can be combed with a hydrographic survey, a measured building survey, or an underground utility survey, adding flexibility, understanding and context to a topo survey. As a result, usability can be vastly improved. Our surveyors can add various kinds of spatial data to a topo survey.
Highway access and visibility assessments:
Add data beyond a site to include adjacent highways or other rights of way to assess safety, overlooking etc.
Street scene surveys:
Add elevation of frontages around a site to enable a fuller understanding of how a project sits within adjoining properties. Newtown survey for a planning application
Planning applications:
A Land Surveyor can employ various techniques to acquire offsite data, in a discrete, non-invasive way. Overlooking can be an important factor. We can use remote survey methods to measure roof and window heights. We can accurately measure offsite trees to indicate the Root Protection Areas of overhanging trees.
Landscape setting:
Understanding the wider landscape setting of a site can be important in planning applications. Assessing views into the site from adjacent land or rights of way can be a critical factor. More: How can drone surveys help with planning applications
Visual line of sight assessments:
For telecommunications having a clear line of sight can be very important. A survey can help you understand how a new building could impact existing telecoms. For acoustic surveys, a line of sight of sight model can help an acoustic engineer understand the propagation of sound.
Utility mapping:
A service trace survey can help map buried services using radio detection or ground-penetrating radar. Understanding the impact of critical wayleave or safety distances can be a lifesaver.
Flood impact assessment and prevention:
Understanding the topography of the land and how water accumulates and runs off the land can be critical
Asset management:
A robust inventory of assets could save you time and money. This could be for a local authority logging their street furniture onto their GIS system. An accurate plan of a site showing where and how your assets are located and connected could make your site operation more efficient.
Buried features:
A topographical survey is also the backbone of a utility survey or archeological survey. Underground physical features like old walls, utilities and voids can be detected with Ground Penetrating Radar (GPR), Radio Detection and Magnetometry and shown upon a base map of a land surveyor’s topo survey. These can be measured from the ground and the air. This involves the use of highly specialised survey equipment.
Boundary surveys:
Topo surveys can provide the backbone of a boundary survey. They are more accurate than land registry data and OS data. In the event of a dispute between neighbours, a boundary survey will be related back to title plans, Ordnance Survey data, historic aerial images and any other data about the site. When suitably compared and overlayed, the intended boundary position can be determined and compared to natural and built topo features on the ground.
Initial site survey after the site was purchased
Updated site survey after extensive renovation works. Survey update produced from a drone survey
Extract of the topo survey around the dwelling produced from a drone survey
3d model of drone survey for the creation of topo survey and measured survey
For a much wider view of a site’s context and setting, take your survey needs to the next level with a drone mapping survey
Frequently asked questions about topographic surveys
A topo survey is important for land planning, engineering, and construction. It accurately represents a piece of land’s physical features, such as its contours or elevation, water bodies, roads, and other features. This information is essential for a wide range of projects, from creating detailed maps of a golf course to building a bridge. A topo survey can also map natural resources such as minerals and land management activities.
No, not always, but it can help planners understand a planning application site. On a simple site, a topo survey might not be needed. A small, flat, and square with a potential building in the middle of the site and away from other features may only need a simple site location plan.
The primary purpose of topographic surveys is to accurately represent a piece of land’s physical features. Accurate land measurements are used for various applications, including engineering, construction, and land management planning. Topographic surveys can also map natural topographic features and natural resources such as minerals or forestry assets and create detailed terrain maps for recreational activities.
A topographic survey is a detailed and accurate map of a land area’s physical features, such as its contours or elevation, water bodies, roads, and other natural and man made features of a development site. An accurate map is an essential first step for any proposed site. It is typically used for engineering and design purposes, such as planning roads, buildings, landscapes, or dams.
During a topographical survey, data is collected regarding the location and elevation of points above sea level or a local site datum and any permanent man-made features, such as roads, buildings, fences, and rivers. Topographical surveyors also may measure slope, aspect, and land cover characteristics.
Yes, they are essentially the same. However, a boundary survey will have less information because its focus is different, with less emphasis on the shape of the terrain and more on the shape and position of boundaries. Both are land surveys carried out by a professional land surveyor.
This question can be complex as it depends on several factors. The size and complexity of the site will determine the amount of time spent on site; your specifications and the types of details you need us to measure all play a part in calculating cost. A base price for a day on site for a typical topographical survey could be £500. Using a drone for the survey will save time on site — cutting a day to an hour. This can save on the cost. Contact us today with your needs, and we can give you a bespoke quote that matches the same day.
Read more:
6 reasons why a drone land survey is a good idea
How a drone land survey can help with planning permission
Exploring the benefits of drone surveying in 2024
Tackling pain point in AEC industries: The power of drones and land surveying
What is a Land Surveyor, what they do and why?
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