Survey Types
Topographic Survey
Maps the shape of the ground and everything sitting on it, so somebody can design against real numbers instead of guesses.
A boundary survey deals in two dimensions. A topographic survey adds the third. It records elevation across the site and draws contour lines connecting points of equal height, then layers in the visible features: buildings, pavement, trees, utilities, ditches, culverts.
Who orders one and why
Usually a civil engineer, an architect, or a developer, because you cannot design drainage without knowing which way water runs. Around Tulsa that question matters more than people expect. Much of the metro drains toward the Arkansas River, and detention requirements on new development are a normal part of the approval process.
- Site design for a new building, parking lot or subdivision
- Grading and drainage plans, including detention pond design
- Earthwork quantities, so a contractor can price cut and fill honestly
- Floodplain analysis and drainage studies
- Road, driveway and utility design where slope matters
- Additions to an existing building where the pad elevation has to match
What ends up on the drawing
Contours at a stated interval, usually one foot or two feet depending on how flat the site is and what the engineer asked for. Spot elevations at critical points like inlets, slab corners and pavement transitions. Existing improvements. Visible utilities and their rim and invert elevations where the surveyor can safely open a structure. Trees over a certain size if the city or the client wants them shown.
Everything ties to a stated vertical datum, usually NAVD 88. That matters because two surveys on different datums will disagree by a couple of feet and nobody will understand why.
Tell the surveyor what the data is for. A topo for a drainage study needs different coverage than a topo for an architect placing a building. Scope it against the actual design task and you avoid paying for detail nobody uses, or worse, finding out mid design that the coverage stopped twenty feet short of where you needed it.
Boundary and topo together
Most site work needs both. The topo shows the ground, the boundary shows what you are allowed to build on. Ordering them at the same time is normally cheaper than ordering them separately, because the crew mobilizes once and the control network gets used twice.
How the field work happens
Depends on the site. Open ground with clear sky is fast with GPS. Under heavy tree canopy GPS gets unreliable and the crew works with a total station from established control. Large or awkward sites are increasingly flown with drone photogrammetry or scanned with lidar, then verified against ground shots. Each method has a different accuracy profile, which is worth asking about if your design has tight tolerances.
What you receive
A sealed drawing, and almost always a CAD file, because the engineer is going to design on top of it. Ask for the format your design team actually uses and confirm the drawing will come in with real coordinates rather than floating at an arbitrary origin. That one detail saves hours downstream.