Site survey types: USGS topo, NRCS soil survey, boundary, ALTA/NSPS

One-line orientation

Site data comes from different sources at different precisions — the exam tests whether you can match the survey to the task: USGS/NRCS for early planning, a stamped boundary or ALTA survey for design and legal/transaction work.

Key points

• USGS (US Geological Survey) topographic data:
  • Regional topographic maps, elevation, hydrology, and land-use information.
  • Use in early planning and feasibility to understand natural features.
  • Limit: not precise enough for detailed design or construction — a licensed surveyor is required for design-phase accuracy.
• NRCS (Natural Resources Conservation Service) soil survey maps:
  • Map soil types, distribution, and characteristics across an area.
  • Flag erosion potential, drainage/percolation (relevant to septic and stormwater), slope categories, and shrink-swell potential that affects foundations and pavement.
  • A soil-mapping/suitability reference — not a property-line document.
• Boundary survey: a licensed surveyor establishes property lines and dimensions. The legal description may use metes-and-bounds, a recorded plat, or the rectangular system. Additional survey content depends on scope and jurisdiction.
• ALTA/NSPS survey:
  • Combines fieldwork and records research.
  • Shows boundaries, easements, and access to rights-of-way; optional add-ons include topography and utilities.
  • Standard for real-estate transactions and what an architect typically needs in hand to begin design.
• Topographic survey (related): a surveyor-grade survey of detailed land features and contours for siting and grading — distinct from USGS regional topo data.

Site surveys: what each source delivers

USGS and NRCS are planning-grade references; a stamped boundary survey gives the legal lines.

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Key

• delivers
• optional add-on (blank = not typically included)
• highlighted cell = the ALTA tell — easements & rights-of-way, which a boundary survey omits

The ALTA/NSPS survey adds easements and rights-of-way — the tell — and is the transaction-grade survey architects start from. A surveyor-grade topographic survey is its own product again: contours and spot elevations measured on the ground, not the planning-grade contours USGS or NRCS supply.

Confusions / comparison

Survey	Primary purpose	Shows	Grade
USGS topo	Regional planning / feasibility	Topography, elevation, hydrology, land use	Planning (not design-precise)
NRCS soil survey	Soil mapping	Soil types, erosion, drainage, shrink-swell	Planning / reference
Boundary survey	Establish property lines	Property lines + dimensions; description method varies	Legal / design as scoped
Topographic survey	Siting / grading	Detailed land features + contours	Design (surveyor-grade)
ALTA/NSPS survey	Real-estate transaction	Boundaries + easements + ROW (opt. topo/utilities)	Design / legal / transaction

Related

→ Legal land descriptions (this module): metes-and-bounds, plat, and the rectangular system behind boundary surveys · Property Condition Assessment (this module): the building-condition counterpart to a land survey · Property rights (this module): easements and rights-of-way an ALTA survey reveals.