Lurid X Aerial Inspections

Drainage Channel Site Model

A graded site with 1,150 ft of open channel through the middle of it. One flight produced the plan and profile sheets, twenty-two cross-sections, the CAD files — and this model, where the channel can be cut at any station and every number on the sheets can be traced back to the ground it came from.

Client: Withheld
Site: Graded site with drainage channel, southwestern U.S.
Extent: 12.4 acres · 1,036 × 1,083 ft
Channel: 1,150 ft · sections every 50 ft
Source: RTK aerial survey · 71 M-point cloud · 1 ft surface model
Datum: Local — lowest section invert = 100.00 ft

The site in three dimensions

Drag to orbit · scroll to zoom · shift-drag to pan · click a station label to cut that section

Surface Vertical exaggeration 2.5× Centreline, stations & section lines

Plan workbench

Click anywhere on the surface to query it · click a section line to cut it · drag to pan · scroll to zoom

Base Layers Centreline Section lines Stations

Station: —
Offset from centreline: —
Surface elevation: —
Surface slope: —
Height above invert here: —
Where: Click the model

Cut a section anywhere along the channel

The station you choose drives the section, the profile cursor and the 3D highlight

Station 6+00 Section vertical exaggeration 3×

Cross-section at Sta 6+00

Looking downstream (north): west bank on the left, east bank on the right. Cut live from the 1 ft surface; at the 50 ft stations the raw-point section from the drawings is drawn over it.

Channel profile — invert and top of bank

Elevation along the flow line, both bank tops, and the best-fit grade. 10:1 vertical exaggeration, as on the sheet.

What the model already knows

Every figure below came out of this surface. The sheets were written from the model, not the other way round.

▤

A uniform trapezoidal channel falling 7.39 ft over 1,150 ft

The invert drops steadily to the north at a best-fit grade of 0.67%, with no reach flatter than 0.2% or steeper than 1.6% between sections. Depth to the lower bank runs 4.1 to 5.8 ft, bottom width 10 to 16 ft, and the side slopes sit between 1.6:1 and 3.2:1. The one irregularity is a ~3 ft object standing in the channel near 4+50 — the model keeps it, the bank pick ignores it.

The twenty-two sections

Cut from the raw point cloud at 50 ft stations — all points within 0.6 ft of the section line, median elevation per 0.25 ft of offset. Depth is to the lower of the two bank tops. Use view to jump the model to that station.

Station	Invert	L bank top	R bank top	Depth	Top width	Bottom width	Side slopes L / R	Area below bank

What the engineer receives

The model is the working copy. The drawings and CAD files are what goes into the project — drawn to the conventions a civil engineer expects: profile at 10:1, sections every 50 ft read bottom-to-top with stations increasing, left-to-right looking downstream.

Plan & profile, cross-section sheetsThree 11×17 sheets, PDF — title block with datum, flight and accuracy statement
Plan DXF, State Plane feet3D centreline at invert elevation, section lines, station labels, invert points — NCS-style layers
Profile & sections DXF, true scaleStation/elevation and offset/elevation geometry, plus a 10:1 plotting copy
Corridor surface for Civil 3D3D-face DXF on a 2 ft grid (Create Surface → 3D faces) and a 1 ft GeoTIFF DSM
CSV tablesSection summary, every section point with coordinates, and the invert profile
This modelOne file, opens in any browser, no login — hosted for the client or delivered as a file

Why this is a model and not a map

A section sheet answers the questions you thought to ask when it was drawn. A site model answers the ones that come up on Thursday.

Any station, any section. The cross-section above is cut live from the surface at whatever station you pick — the 22 drawn sections are a starting set, not a limit. Every foot of the 1,150 ft is already in here.
Every number has a place. The stations and section lines are drawn on the 3D surface, so a depth or a bank elevation in the table can be walked back to the exact ground it was measured from.
Every point carries its own number. Click anywhere on the plan and the model returns the station, the offset from the centreline, the elevation and the slope. A low spot in the pad cannot hide inside an average.
It stays useful after the question changes. Sections at 25 ft, a different alignment, a cut/fill against a design surface, a re-fly after the next storm — the flight does not have to be repeated for the first three.
One flight, many deliverables. The sheets, the CAD package, the surface and this model are four views of a single visit to the site.

This is a photogrammetric model derived from aerial imagery. It is not a topographic survey and does not constitute the practice of land surveying. Elevations follow the visible surface — vegetation, vehicles and equipment are included as ground, and the model is not bare earth. Elevations are on a local datum for publication. Stationing begins at the south edge of the flight and increases downstream; a hydraulic model would number it the other way.

Want your site kept as a model?

Channel and pad sections, stockpile volumes, contour mapping and progress documentation — RTK-flown, referenced to surveyor-established control, with the accuracy stated on every drawing. Southwestern US.

bill@luridx.com · 602-639-1700