Stormwater and drainage design lives on the terrain layer. Drone LiDAR provides exactly the bare-earth DTM that catchment delineation, flow-path mapping, overland-flow analysis and culvert sizing depend on — captured at engineering accuracy, validated to control, ready for the GIS and modelling tools your team already runs.
Step through the same site as a DTM, a per-cell flow direction map, a derived stream network, and finally a click-anywhere catchment delineator. The rational-method peak flow estimate at the bottom updates per pour point — the input a hydraulic designer feeds straight into a culvert sizing calculation.
Stream network. Cells with flow accumulation above threshold rendered as a defined channel network. Brighter / thicker = more upstream area contributing.
Drainage and stormwater design routinely assumes catchment boundaries traced from old contour mapping or coarse elevation models. The catchments come out approximately right, the flow paths come out approximately right, and the culvert sizing inherits the error — until a downstream event proves the assumption wrong.
Open elevation models at 5 m or 10 m grid resolution smooth over the small saddles, swales and table drains that determine which way water actually goes — and shift catchment boundaries metres at a time.
Hand-drawn catchment boundaries on contour mapping are an engineering tradition — and a quiet source of inconsistency between hydrologists, modellers and reviewers. Same site, three boundaries.
Stormwater overland flow paths typically follow the natural drainage — except where roads, embankments and dams divert it. Without a captured DTM, the diversion features are easily missed.
Q = C × i × A. The catchment area A is the contributing area upstream — and if A is wrong by 20% because the catchment line drifted, the design flow is wrong by 20% in the same direction.
A bare-earth DTM from drone LiDAR is what drainage analysis actually wants: dense, accurate, current, and continuous across the catchment. Catchment delineation, flow-path mapping, accumulation and Q estimates all drop out as derived deliverables — computed, not assumed.
Per-cell steepest-descent flow direction computed from the LiDAR surface. Catchment boundaries are deterministic outputs, not hand traces — the same DTM produces the same catchment every time.
Per-cell upstream accumulation rendered as the natural creek network. Threshold the accumulation to define the stream-channel layer for downstream modelling.
Roads, embankments, dams and other constructed diverters are part of the captured DTM — so the overland flow path computation honours them automatically.
Existing culverts, headwalls, kerb inlets and pipes captured directly and enforced as breaklines in the DTM — the model routes water through structures it can physically reach.
Manning's n classification from the LiDAR-classified surface plus optional ortho — feeds 2D hydraulic models without manual digitising.
Design surface dropped against captured terrain to evaluate diversion options. Same control every iteration — comparison stays apples-to-apples.
Formatted for direct use in TUFLOW, HEC-RAS, MIKE, XP-SWMM, DRAINS, ICM, RORB, WBNM and the ArcGIS / QGIS workflows that surround them.
Bare-earth surface at 0.5 – 1 m resolution with structure breaklines enforced — the layer every drainage product is computed from.
D8-derived catchment boundaries at any pour point. Hand-drawing eliminated; consistent results across team members.
Per-cell accumulation raster + thresholded stream network polylines, with optional Strahler stream order classification.
Highest-accumulation flow paths from any source point — for stormwater overland flow assessment and outfall scoping.
Per-structure catchment area, Q estimate (rational and any other configured method), and tabulated inputs for hydraulic design.
Manning's n raster classified from the LiDAR + ortho — feeds 2D hydraulic model roughness without manual digitising.
Confirm catchment extent, model framework (1D / 2D, software), hydro-enforcement scope and AHD control with hydrologist and design team.
Single-mobilisation drone flight covering the contributing catchment at multi-return density. Structures and existing drainage features captured in the same pass.
Ground classification, structure breaklines, D8 flow direction, accumulation, catchment delineation, roughness classification. Independent QA pass.
Hydro-DTM, catchment pack, flow paths and culvert sizing inputs landed with the design team in their preferred format.
We work with council drainage teams, stormwater consultants, water utilities and civil designers across Australia. Tell us the catchment, the modelling framework and the deliverable schedule — we'll scope a capture programme that lands inside the design window.