Survey, Design & Verification
Drainage Grade Design
Drainage grade design must connect the contributing area to a suitable outlet. Selecting a numerical fall before checking the outlet can produce a surface that cannot discharge as intended.
Plan the surface handover
BeforeSurvey entry points, structures and the receiving level.
Work stageDevelop the profile with appropriate hydraulic and erosion considerations, then calculate the required movement.
AfterInspect the constructed route and its transitions.
What to verify
Check invert continuity and controls at crossings.
Keep the design reference and survey evidence traceable. State units, coordinate system, vertical datum and revision, then compare independent checks with the issued target. Surface measurements establish geometry; they do not establish the material quality of a buried layer.
Scope and limits
This guide does not size drains or establish discharge permissions.
Continue the job brief
Include the location, existing condition, intended surface, material, available tractor and proposed dates.