Use official flood information alongside the terrain.

Find the appropriate official resource

In the United States, FEMA’s Flood Map Service Center provides official flood hazard information. Review the location-specific map and related information rather than treating a terrain colour as an insurance or regulatory determination.

German municipalities and state services provide separate flood and heavy-rain resources. Coverage, scenarios and interpretation vary by publisher.

Keep hazards and terrain indicators separate

A hazard map may model defined events and scenarios. Terraincheck’s local terrain indicators do not include a rainfall event, sewer network or infiltration model.

A relative depression depth in the terrain model cannot be read as a flood depth. Being outside a mapped area does not establish that every possible source of surface runoff has been excluded.

Take the map context to a professional

Keep the publisher, map date, selected scenario and legend with any screenshot or notes. Compare those assumptions with observed conditions.

Use the appropriate local authority or qualified professional for flood, insurance, permitting and engineering questions. Terraincheck does not issue official hazard determinations.

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