Read potential paths through the terrain
Terraincheck derives flow directions from an elevation model. The D8 method assigns each cell a direction towards one of eight neighbouring cells. Real water can behave differently around buildings, walls, drains and other features absent from that model.
Flow accumulation counts contributing cells within the analysis area. It is not a discharge rate, water volume, flow speed or damage probability.
A depression is a terrain feature
A relative depression depth is derived from the difference between the original and conditioned elevation model. It is not a forecast of standing water.
Whether water collects there depends on rainfall, infiltration, drainage and other conditions not simulated by the screening. An area without a displayed flow line is not confirmed free of water problems.
Prepare observations for a site visit
Compare the model with visible channels, grading changes, retaining walls, driveway edges and drainage structures. Record where water is observed after rain and when the observation was made.
Check whether earthworks or paving occurred after the elevation survey. A dry inspection alone cannot rule out intermittent runoff. Ask an appropriately qualified professional to assess recurring wet areas or proposed construction.
Check the location before starting
The US pilot accepts user-drawn study areas within the contiguous-US pilot extent. The worker checks for usable native USGS project-level 1 m elevation data. Coverage is incomplete and may fail for a selected area; no coarser dataset is silently substituted.
Baden-Württemberg remains a separate established German workflow with official ALKIS parcels. US address points and drawn areas are not official parcel boundaries.
What terrain screening cannot determine
Terrain screening does not simulate rainfall, infiltration, sewer capacity or the hydraulic effects of walls and culverts. It cannot predict flood depth, size a drainage system or confirm that a property is safe to build on.
A local catchment is limited to the analysed area. Contributions from beyond its boundary can be unknown. A modelled boundary crossing is not evidence of a real drain or drainage outlet.
Common questions
Does this predict flooding?
No. The screening describes terrain and potential surface flow paths. It does not simulate a storm or predict water levels.
Are PDF reports free?
No. PDFs are paid products. A free preview or analysis access key is not a purchase. Check the pricing page for current sales availability.
Editorial: Terraincheck · Updated 6 November 2026. See our methodology · data sources.
Terrain screening provides preliminary context. Site assessment, engineering design and construction decisions require appropriately qualified professionals.