PS Module 5: Areas of Practice

What distinguishes a boundary survey from other survey types?

A boundary survey determines the location of property lines based on legal descriptions, recorded plats, physical evidence, and applicable law. It is an exercise in professional judgment — not merely measurement. The surveyor must research records, evaluate evidence (monuments, occupation, testimony), apply legal principles, render a professional opinion on boundary locations, and set monuments. Other survey types (topographic, construction) do not require this legal analysis.

What are the key components of a subdivision survey?

A subdivision survey includes: (1) a boundary survey of the parent tract, (2) design of new lots meeting applicable regulations (minimum area, frontage, setbacks, access), (3) establishment and monumentation of new lot corners, (4) preparation of a plat showing all lots, streets, easements, and dedications, (5) compliance with local subdivision ordinances, and (6) recording the plat as a public record. The surveyor creates new boundaries in a subdivision — it is an original survey.

What is a construction staking survey?

Construction staking (layout) provides horizontal and vertical positions in the field for builders to construct improvements according to design plans. The surveyor establishes reference points, offset stakes, grade stakes, and other markers showing where buildings, roads, utilities, and other features should be placed. Cut/fill information, offsets, and stationing are marked on stakes or hubs. Accuracy requirements depend on the type of construction.

What is an as-built survey?

An as-built survey documents the actual location, dimensions, and elevations of improvements after construction is complete. It compares what was built to what was designed, revealing any deviations from the plans. As-builts are used for final acceptance, regulatory compliance, facility management, and future reference. They typically show horizontal positions, floor elevations, utility inverts, and other constructed features.

What is a geodetic survey?

A geodetic survey establishes control points with positions referenced to the national geodetic reference frame (NSRS), accounting for the curvature of the Earth. Geodetic surveys provide the framework for all other surveys in an area. They use high-precision instruments and methods (GNSS, EDM baselines, precise leveling) and are adjusted to meet FGCS accuracy standards. Results are published as part of the national control network.

What is a mining survey?

A mining survey supports surface and underground mining operations, including: (1) establishing and maintaining control networks (surface and underground), (2) claim surveys and mineral rights boundary determination, (3) volume computations for excavation and stockpiles, (4) shaft alignment and tunnel guidance, (5) subsidence monitoring, and (6) regulatory compliance. Underground surveys present unique challenges: limited visibility, confined spaces, and the need to transfer position and orientation underground.

What is the surveyor's role in subdivision design?

The surveyor designs the lot layout, street pattern, and infrastructure alignment to comply with local regulations while meeting the developer's objectives. This includes: (1) determining the parent tract boundary, (2) designing lots meeting zoning requirements (area, width, setbacks), (3) designing streets and cul-de-sacs meeting engineering standards, (4) establishing utility and drainage easements, (5) computing areas and preparing the final plat, and (6) coordinating with engineers, planners, and regulatory agencies.

What is a hydrographic survey?

A hydrographic survey measures and maps underwater topography (bathymetry) — the depth and shape of the bottom of water bodies. Uses include navigation charts, dredging design, dam and reservoir management, and coastal engineering. Methods include single-beam and multibeam sonar, LiDAR bathymetry, and lead lines. Hydrographic surveys must account for tides, water levels, and vessel motion.

What is a route survey?

A route survey establishes the horizontal and vertical alignment of a linear feature — a road, railroad, pipeline, transmission line, or canal. It includes: (1) reconnaissance and preliminary alignment, (2) centerline establishment with stationing, (3) horizontal curve design (simple, compound, spiral), (4) vertical curve design (crest, sag), (5) cross-sections for earthwork computation, and (6) right-of-way determination. Route surveys require both design and boundary skills.

What is a right-of-way survey?

A right-of-way survey determines and maps the boundaries of a right-of-way (ROW) — the strip of land authorized for a road, railroad, utility, or other linear use. It includes: (1) researching the establishment of the ROW (dedication, condemnation, prescriptive use, grant), (2) determining the ROW width and alignment, (3) identifying encroachments and conflicts, and (4) preparing a plat and legal descriptions. ROW surveys combine boundary skills with route survey expertise.

What is a topographic survey?

A topographic survey maps the physical features and elevations of a site, including contours, buildings, roads, utilities, vegetation, water features, and other surface details. It provides the base information for engineering design, site planning, and development. Accuracy and detail requirements depend on the project — a building site needs more detail than a large-area preliminary study.

What special considerations apply to ALTA/NSPS surveys of commercial properties?

Commercial ALTA surveys often involve: (1) complex legal descriptions with metes and bounds, plat references, and exceptions, (2) multiple easements (access, utility, parking, drainage), (3) zoning compliance (setback lines, FAR, parking ratios via Table A Item 6), (4) extensive improvements to locate, (5) encroachments affecting title insurance, and (6) tight deadlines driven by commercial transactions. Table A items are typically more extensive for commercial work.

What is a floodplain survey and what does it involve?

A floodplain survey determines the relationship of a property to flood hazard areas as defined by FEMA. It includes: (1) determining site elevations tied to NAVD 88, (2) identifying the base flood elevation (BFE) from FEMA Flood Insurance Rate Maps, (3) preparing an Elevation Certificate if applicable, and (4) showing flood zone boundaries on the survey. ALTA/NSPS Table A Item 8 specifically addresses flood zone classification.

What are the key considerations for a condominium survey?

Condominium surveys must define three-dimensional property boundaries — not just land, but individual units within a structure. Key considerations: (1) the parent tract boundary survey, (2) building dimensions and unit boundaries referenced to the structure, (3) common elements (hallways, lobbies, parking, mechanical rooms), (4) limited common elements (balconies, storage), (5) compliance with the condominium act of the jurisdiction, and (6) preparation of a condominium plat showing all units, common elements, and air rights.

What is a control survey and how does it support other survey work?

A control survey establishes a network of points with known positions and/or elevations that serve as the framework for subsequent detailed surveys. The control network provides: (1) consistent datum and coordinate basis for all work on a project, (2) reference points for future surveys and construction, (3) independent checks on measurements, and (4) a connection to the national geodetic reference system if needed. The accuracy of all dependent surveys is limited by the accuracy of the control.

What is the difference between an easement survey and a right-of-way survey?

An easement survey locates and maps a specific easement (access, utility, conservation, etc.) relative to the property boundary — determining its width, location, and any encroachments or conflicts. A right-of-way survey specifically addresses the linear corridor for transportation or utility infrastructure, which may include multiple easements, dedications, and takings. Right-of-way surveys are a specialized subset that combines boundary and route survey skills.

What is a photogrammetric survey and when is it appropriate?

A photogrammetric survey uses overlapping aerial (or ground-based) photographs to create maps, orthophotos, digital elevation models, and 3D measurements. It is appropriate for: (1) large-area topographic mapping, (2) corridor mapping (roads, pipelines), (3) volume computations, and (4) monitoring change over time. It requires ground control points surveyed to known accuracy. Photogrammetry is efficient for large areas but may not capture features hidden by vegetation or structures.

What is a LiDAR survey?

LiDAR (Light Detection and Ranging) uses laser pulses to measure distances to the ground and objects, creating dense 3D point clouds. Airborne LiDAR can penetrate vegetation canopy to map ground surface. Uses include: topographic mapping, floodplain analysis, corridor mapping, forestry, and coastal zone management. LiDAR provides high-density elevation data but requires ground control and classification of point returns (ground, vegetation, buildings).

What is a monitoring (deformation) survey?

A monitoring survey measures changes in position or shape of structures or ground over time. Applications include: (1) dam deformation, (2) bridge movements, (3) landslide monitoring, (4) building settlement, (5) tunnel convergence, and (6) mining subsidence. Methods include precise leveling, EDM, GNSS, tiltmeters, and automated total stations. Accuracy requirements are very high because the measurements of interest (movements) are often very small (millimeters).

What staking procedures are used for vertical construction?

Vertical construction staking includes: (1) building corner layout from offset hubs, (2) column and footing locations, (3) floor elevation benchmarks (using a level or total station), (4) batter boards for foundations, (5) plumb transfer for multi-story structures (optical plummet, laser plummet), and (6) elevator shaft and core alignment. Tolerances are tight — typically 1/4 inch or less for structural elements — and the surveyor must verify that construction remains within tolerance as the structure rises.