PS Exam Preparation

Comprehensive preparation for the NCEES Principles and Practice of Surveying (PS) exam. 5 modules covering all 5 exam domains with 50 in-depth topics.

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Lesson 7

Land Development Solutions

Learning Objectives

After completing this topic, you should be able to:

Describe the surveyor's role in the land development process from concept through construction
Identify regulatory requirements affecting subdivision and site development
Explain grading plan elements including cut/fill calculations and drainage design
Understand utility layout considerations and easement requirements
Apply setback, lot size, and frontage requirements from zoning and subdivision regulations
Describe construction staking procedures for buildings, roads, and utilities
Understand the relationship between preliminary and final subdivision maps

Overview

Land development is one of the most comprehensive applications of professional surveying. The surveyor serves as a critical member of the development team from initial feasibility through final construction, providing boundary definition, topographic data, design support, regulatory compliance, construction staking, and final as-built documentation.

The surveyor's involvement in land development extends well beyond simple measurement. Understanding regulatory frameworks, drainage principles, grading concepts, and construction processes enables the surveyor to contribute effectively to project planning and to identify potential problems before they become costly errors.

Key Concepts

The Development Process

Figure PS.2.34 — Six-phase land development process

Land development follows a general sequence in which the surveyor plays a role at each stage:

Phase	Survey Activities
Feasibility	Records research, preliminary boundary survey, topographic survey, environmental constraints mapping
Entitlement	Tentative map preparation, boundary survey, zoning analysis, environmental review support
Design	Design survey, utility survey, grading design support, easement planning
Permitting	Final map preparation, improvement plans, legal descriptions for dedications
Construction	Construction staking (rough grade, fine grade, buildings, utilities), progress surveys
Completion	As-built survey, monument setting, final map recordation, lot corner staking

Regulatory Framework

Land development is governed by overlapping layers of regulation at federal, state, and local levels.

Federal Regulations

Regulation	Application
Clean Water Act	Wetlands protection, stormwater management
Endangered Species Act	Habitat preservation, species surveys
FEMA flood regulations	Floodplain management, base flood elevation
ADA requirements	Accessible routes, grades, cross-slopes

State Requirements

State subdivision laws typically regulate:

Map requirements -- tentative and final map content, format, and filing procedures
Dedications -- streets, utilities, drainage, open space
Improvement standards -- road widths, grades, curve radii
Environmental review -- state environmental protection acts (NEPA at the federal level)
Monument requirements -- what must be set and when

Local Regulations

Cities and counties impose additional requirements through:

Zoning ordinances -- use restrictions, density limits, setbacks, height limits, lot coverage
Subdivision ordinances -- design standards, improvement requirements
Grading ordinances -- cut/fill limitations, erosion control, slope stability
Building codes -- setback verification, grade requirements
Design standards -- road cross-sections, utility specifications, drainage requirements

Subdivision Design

Figure PS.2.35 — Subdivision design with setbacks and easements

Lot Layout Considerations

The surveyor and engineer must balance multiple factors in subdivision design:

Factor	Considerations
Zoning compliance	Minimum lot size, frontage, width, depth requirements
Topography	Street grades, lot drainage, buildable pad areas
Access	Street connectivity, emergency access, circulation
Utilities	Water, sewer, storm drain, electric, gas, communication
Environmental	Setbacks from sensitive areas, tree preservation, habitat
Marketability	Lot shapes, views, orientation, desirable lot sizes
Phasing	Logical construction sequence, temporary access, interim conditions

Street Design

Street design in subdivisions must comply with local standards for:

Element	Typical Requirements
Right-of-way width	50-80 feet for local streets (varies by jurisdiction)
Pavement width	32-40 feet for local streets
Minimum centerline radius	100-300 feet for local streets
Maximum grade	6-15% depending on street classification
Minimum grade	0.5% for drainage
Cul-de-sac radius	40-50 foot right-of-way radius
Intersection spacing	Minimum distance between intersections
Sight distance	Adequate stopping sight distance at intersections

Cul-de-Sac and Turnaround Design

Cul-de-sacs require careful geometric design:

The bulb must accommodate emergency vehicle turning radii
Lot frontage on the arc must meet minimum requirements
Side lot lines typically radiate from the center of the bulb or are perpendicular to the arc
Utility easements within the bulb must be coordinated with lot lines

Grading Plans

Cut and Fill

Grading plans show the proposed modification of existing terrain. Key concepts include:

Cut -- excavation of earth to lower the existing grade to the design grade.

Fill -- placement of earth to raise the existing grade to the design grade.

Balance -- the goal of balancing cut and fill quantities so that material removed from cut areas can be used in fill areas, minimizing import or export of earth.

Volume Computation Methods

Method	Description	Best Application
Average end area	Compute area of cut/fill at each cross-section, average adjacent sections, multiply by distance	Linear features (roads, channels)
Prismoidal formula	More accurate than average end area, accounts for variation between sections	When higher accuracy is needed
Grid method	Compare existing and proposed elevations at grid points	Area grading, building pads
Surface-to-surface	Compare TIN or grid surfaces digitally	Modern software-based computation

The average end area method tends to overestimate volumes, particularly where the cross-sections change significantly between stations. The prismoidal correction adjusts for this overestimation.

Drainage Design Principles

Proper drainage is essential in any development:

Minimum grades for drainage (typically 1-2% for paved surfaces, 2-5% for unpaved)
Lot drainage -- each lot must drain to a street, storm drain, or approved facility
Concentration points -- avoid directing drainage from one lot across another
Drainage easements -- required where drainage crosses private property
Retention/detention -- facilities to manage increased runoff from development

Utility Layout

Common Utilities and Easement Requirements

Utility	Typical Easement Width	Location
Sanitary sewer	10-20 feet	Typically in street or rear easement
Storm drain	10-20 feet	Street, drainage channels, or easements
Water main	10-15 feet	Typically in street
Gas	5-10 feet	Street or front easement
Electric	5-10 feet	Street, front or rear easement
Telephone/cable	5-10 feet	Often shared with electric

Utility Coordination

The surveyor's role in utility coordination includes:

Documenting existing utility locations through field survey and utility records research
Ensuring proposed utility routes have adequate easement coverage
Verifying horizontal and vertical clearances between utilities
Identifying conflicts between proposed improvements and existing facilities
Preparing legal descriptions for utility easements

Construction Staking

Construction staking translates design plans into physical marks on the ground that guide construction. The surveyor provides horizontal and vertical control for:

Types of Construction Staking

Staking Type	Description
Rough grading	Cut/fill stakes at grid points or cross-section stations showing existing and design elevations
Fine grading	Precise grade stakes for finished surfaces, building pads, parking lots
Building layout	Building corners, column lines, foundation lines
Street construction	Centerline, curb and gutter, flow line, edge of pavement
Utility installation	Pipe invert elevations, manhole locations, horizontal alignment
Slope staking	Marks where cut or fill slopes intersect existing ground (catch points)
Offset staking	Stakes placed at known offsets from the design feature to avoid disturbance during construction

Stake Marking Conventions

Construction stakes are marked with standardized information:

Marking	Meaning
C 2.5	Cut 2.5 feet (excavate to reach design grade)
F 1.8	Fill 1.8 feet (add material to reach design grade)
FL 98.50	Flow line elevation 98.50
TC 100.25	Top of curb elevation 100.25
INV 95.30	Pipe invert elevation 95.30
5' R/O	5-foot right offset from design feature

Tentative and Final Maps

Tentative Map

The tentative map is the initial submission for subdivision approval. It shows the proposed lot layout, street design, and site features for agency review. The tentative map typically shows:

Proposed lot lines with dimensions and areas
Proposed streets with centerlines, right-of-way widths, and grades
Existing topography and improvements
Proposed grading concept
Utility layout
Environmental features and constraints
Proposed dedications and easements

Final Map

The final map is the recordable document that creates the subdivision as a legal entity. Requirements include:

Precise boundary and lot dimensions based on field survey
Monuments set (or to be set) at all required locations
Certificates from the surveyor, owner, and approving agencies
Dedication statements for streets, easements, and public facilities
Basis of bearings and coordinate references
Compliance with all conditions of tentative map approval

The final map must be based on a field survey and must close mathematically. All lots must meet minimum standards for size, frontage, depth, and width as specified by the governing ordinances.

Common wrong path — assuming tentative-map approval binds the final map in all details. Tentative map approval authorizes the subdivider to proceed with final engineering and final map preparation, subject to the conditions of approval. Students sometimes assume the tentative map controls everything about the final map; in reality, (a) the final map must be based on an accurate field survey, not the tentative map's preliminary layout; (b) minor adjustments in lot lines, dimensions, or easements are permissible if they remain consistent with the tentative map's basic design; (c) any substantive change from the tentative map requires a revised tentative map and new approval; and (d) all conditions of approval must be satisfied before recordation. Exam questions test this by describing a discrepancy between the tentative map and the field-surveyed final map and asking whether the final map can be recorded; the correct answer depends on whether the discrepancy is consistent with the approval conditions, not on whether it exactly matches the tentative map.

Quick retrieval check — try before reading on.

▶A tentative map approved two years ago shows lot dimensions of 60 ft x 120 ft for lot 5. During final survey, the actual field-measured dimensions based on monumentation come out to 60.12 ft x 119.87 ft. Can the final map be recorded with these actual dimensions, or must the dimensions exactly match the tentative map?

The final map can be recorded with the actual field-measured dimensions, assuming the change is minor and consistent with the overall design approved by the tentative map. Field surveys invariably produce dimensions that differ slightly from the preliminary tentative-map dimensions — the tentative map is based on concept-level design, while the final map reflects the actual survey-accurate positions of monuments and lot corners. The approving agency generally understands and accepts small dimensional refinements as part of the final mapping process.

That said, the final map must (a) maintain compliance with the minimum lot size, frontage, and width requirements (still met here: 60.12 x 119.87 ≈ 7,204 sq ft); (b) fit within the overall subdivision geometry approved by the tentative map (street alignment, block layout, easement locations); (c) comply with all conditions of approval; and (d) not create any substantive departure from the approved design. If the changes are larger — a lot that falls below the minimum required dimension, a new street alignment, a repositioned easement — the subdivider may need to submit a revised tentative map or request agency concurrence with the modification. Verify your specific jurisdiction's rules, but in general, small field-based refinements are not only permitted but expected.

As-Built Surveys

After construction is complete, the surveyor documents what was actually built:

Actual positions of improvements compared to design
Final grade elevations
Utility locations and invert elevations
Building positions relative to property lines (setback verification)
Drainage structures and flow lines
Monument positions (set during or after construction)

As-built information becomes the permanent record of the development and is essential for future maintenance, modification, and boundary work.

Exam Tips

The surveyor's role in land development spans from feasibility through final as-built documentation
Cut/fill stakes show the difference between existing grade and design grade
The average end area method tends to overestimate volumes
Every lot in a subdivision must have positive drainage to an approved outlet
Utility easements must be coordinated with lot lines and other improvements
Offset stakes are placed away from the design feature to avoid disturbance during construction
The final map creates the subdivision as a legal entity and must be based on a field survey
Tentative map approval conditions must all be satisfied before a final map can be recorded