Corridor surveys and spot-height plans
Relief, boundaries and boundary markers, existing roads with their kerbs and levels, ditches, buildings, fences, over the footprint of a road, a network or a subdivision.
Expertise
Surveying for roads and utility networks.
A road, sewerage or water supply project is designed on a plan and built on reference marks. We provide project owners, engineering consultancies and contractors with the topographic data for each phase, from the first survey to the as-built plan.
The role of surveying
One reference system, from the initial survey to the as-built survey.
Roads and utility networks (VRD, voirie et réseaux divers) cover carriageways, wastewater and stormwater sewerage, drinking water, electricity, street lighting and telecommunications. The design of these networks is the remit of specialist engineers; the surveyor's part is to measure the land, then to transfer the design onto the ground and to survey what has been built.
A surveying error is rarely visible on the plan: it shows up on site, as a reverse gradient, a network discovered during excavation or a connection to the public sewer that cannot be made. That is why the whole project must be based on a survey tied to Lambert coordinates and to elevation, and the same reference system must be used up to the last check.
The details of the stages, the deliverables to require and common mistakes are explained in our guide Roads and utilities studies: the role of surveying. For a subdivision, the legal framework (authorisation, provisional acceptance, transfer of roads and networks to the municipality) is presented in the Subdivision guide.
Our roads and utilities services
What we measure, phase by phase.
Survey of existing networks and structures
Visible features (manholes, valve boxes, poles), invert levels and manhole levels, bridges and culverts and connection points. For each section, the plan states how it was obtained.
Detecting existing networks →Sections, terrain model and earthwork volumes
Longitudinal and cross sections, digital terrain model (DTM), cut and fill volumes by section to compare options and cost the earthworks.
Setting-out of alignments and monitoring
Transfer onto the ground of centrelines, kerbs, manholes and service connections, with levelling benchmarks; check of trench bottoms, invert levels and finished levels.
Setting-out and site monitoring →As-built survey of completed networks
Survey of the structures actually built and georeferenced as-built plan, by network, with invert levels, depths and manhole levels.
Control points and traverses
For long routes, a network of control points observed by GNSS and precision traverses give all parties a common reference system.
Geodesy and GNSS →How the assignment works
How we work on a roads and utilities project.
The main stages of our method, adapted to network contracts and works.
Understanding the need
Technical specifications, footprint, scale, density of points, planimetric and altimetric tolerances, formats expected by the engineering consultancy or the network operator. If these requirements are not written down, we help you define them.
Quote or tender
Services by phase (survey, sections, setting-out, as-built survey), deliverables and estimated time for our work.
Tie-in and survey
Planimetric tie-in to points of the geodetic network in Lambert, altimetric tie-in to an identified levelling benchmark, then survey with GNSS and total station. Site reference marks are set out.
Computations, checks and plans
Computations at the office, independent checks (points surveyed twice, closed traverses), plans, sections and DTM. A report states the equipment, the tie-in points and the discrepancies observed.
Works and as-built survey
Setting-out and checks at key moments, then survey of the completed works and handover of the as-built plan in the requested format.
Deliverables
What you receive.
The deliverables are set in the contract according to the phase and the use. Always require the digital files in addition to the prints.
- Spot-height topographic plan
- Scale suited to the project, Lambert coordinates, tied elevations
- Sections
- Longitudinal sections (natural ground, invert levels, manholes) and cross sections (widths, crossfalls, slopes)
- DTM and earthwork volumes
- Digital terrain model; cut and fill volumes by section
- Setting-out
- Setting-out plans, staking-out books, levelling benchmarks
- As-built survey
- Georeferenced plans by network, invert levels, depths, manhole levels
- Formats
- Signed PDFs, CAD files (DWG/DXF), lists of points with coordinates
- To provide
- Project footprint, specifications, plans of known networks, project alignment for setting-out
Equipment, precision, timescales and cost
Precision is defined before the survey.
We work with GNSS for tie-ins and large areas, and with the total station for detail, sections and setting-out. For an extensive corridor or one with difficult access, a drone survey can supplement ground measurements when the project warrants it.
The expected precision depends on the use: a gravity sewerage network is more demanding in elevation than a pressurised water pipe. It must be written into the contract; we do not publish a general figure. The detection of buried networks has its limits: no non-destructive method guarantees completeness, and only a trial pit gives the position and depth of a pipe with certainty.
The timescale and cost depend on the length and width of the footprint, the density of detail and networks, the relief, traffic, the precision required and the number of phases entrusted to us. We do not publish rates (why). To check a bearing, a slope or an earthwork volume, our free Surveying calculations tool is at your disposal.
References
Some work related to roads and networks.
Extracts from our references.
Fez roads
Topographic works accompanying the Fez road works, alongside the contractors SINTRAM and Route du Nord.
Survey, spot-height plan and longitudinal section
Topographic survey, spot-height plan and longitudinal section for the Sebou Hydraulic Basin Agency.
Sections of 22 structures
Topographic survey, longitudinal and cross sections of 22 structures.
Frequently asked questions
Questions from engineering consultancies and project owners.
Is the network plan provided by the operator enough?
Not for a detailed design. It shows what exists in principle, not always where or at what depth. The visible features must be surveyed, the networks detected and trial pits dug at critical crossings.
Can the survey made for the subdivision authorisation be reused?
Yes, as a base, if it is tied and recent. It often needs to be supplemented before execution: existing networks, surroundings, connection points and changes that have occurred on the ground.
Can you work on a single phase?
Yes: initial survey, setting-out or as-built survey alone. If we take over a project surveyed by another firm, we first check the tie-in and the existing reference marks before setting out.
Is the as-built plan mandatory?
Requirements vary according to the contract and the operator. For a subdivision, the municipality takes over the roads and networks at provisional acceptance: the as-built plan is the document that describes what it is taking over. Provide for it in the contract from the outset.
Do you work outside the Fez region?
For public contracts and large-scale projects, yes, anywhere in Morocco. For other projects, we work mainly in the Fez-Meknes region.
Your project
A route, a subdivision, a call for tenders?
Send us the footprint, the phase and the project specifications: we will reply with a method and a written quote.
- Address
- 47, avenue des FAR, 3e étage, appartement 5, Ville Nouvelle
30050 Fès - Office
- +212 5 35 64 14 36
- Mobile
- +212 6 61 29 81 75