A first look at a Boulder study area.
This illustrative 100 × 100 m area in Colorado was analysed on 6 November 2026. It is a drawn study area, not a verified property boundary or a diagnosed drainage problem.
What would you check on site?
The path continues beyond the selected area and reaches the model edge. Inspect the surrounding slopes, curbs and drainage structures before drawing conclusions about where water actually goes.
- Elevation within the selected area
- 5,288.5–5,292.5 ft NAVD88
1611.948–1613.163 m - Native elevation grid
- 1 m · 90,000 cells including context
- Recorded source acquisition period
- 26 May 2020–13 March 2021
These ground elevations are not water levels. No rainfall or drainage-system capacity was simulated. The data may predate changes on site.
Source: USGS 3DEP, CO_DRCOG_2020_B20, published 10 February 2022. Terraincheck aligned the source to a local NAD83 UTM grid using bilinear resampling and derived the path with D8 routing. USGS source metadata ↗
Start with an official US topographic map
USGS supplies topographic maps through The National Map and topoView. Use the location and map date to find the appropriate sheet or viewer, then read its legend and scale.
A USGS map is useful regional context. Terraincheck adds a drawn-area workflow using usable native project-level 1 m elevation where available, with derived slopes, profiles and possible surface flow. The basemap and the analysis grid are separate sources.
Contours, elevation, slope and profiles answer different questions
Contour lines join equal elevations at the map’s stated interval. More closely spaced contours generally indicate steeper ground at that scale. Check the legend and units rather than assuming an interval.
An elevation map shows ground height; a slope map shows its local rate of change. Shaded relief helps reveal shape, while a profile follows one selected line. None of these alone shows the water depth during a storm.
- Read the map scale and contour interval before estimating small changes.
- Check whether elevations use feet or metres and which vertical reference is stated.
- Compare the source acquisition period with later construction or grading.
- Use a custom profile to inspect the line relevant to your site visit.
A study area is not a boundary survey
In the US pilot you draw and confirm an area. Census address search locates a general street-range position; neither that point nor the outline provides official parcel boundaries or ownership information.
Use the relevant records and qualified surveying services when a legal boundary or certified measurement is required. A topographic sheet and a terrain preview do not establish the location of a property line.
Use topography to prepare a drainage assessment
Inspect the high ground, low points and possible contributing slopes before walking the site. A modeled flow path can help identify where to look for curbs, channels, walls and drainage structures.
Terraincheck does not generate a survey-grade contour plan, calculate earthwork quantities or design a drainage system. Use its bounded local catchment and profiles with source information and field observations.
What you can use today
The supported US preview includes browser terrain layers, an automatic or custom profile, local flow-path and catchment tools, and profile CSV export. Feet/acres or metric display is available.
The $79 individual prelaunch offer includes a US terrain PDF and shareable page. The contractor plan is $199/month including 50 reports per paid month. Live sales are paused; a survey-grade contour-map export is not included. Official map products have their own download options.
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
How do I get a topographic map of my property?
Find the location in an official USGS map resource and check its scale and date. For preliminary local terrain screening, draw a supported study area in Terraincheck and inspect the elevation, slope and profile. Neither workflow is a legal boundary survey.
Can I see an elevation map in Google Maps instead?
Different map products show different terrain information. Check their source, scale, date and available measurements. Terraincheck’s US analysis uses a separate USGS project elevation grid and is not a Google Maps integration.
Does a topographic map show my flood zone?
Topography and flood-zone designation are separate information. Use FEMA’s Flood Map Service Center for its official flood-map products and read the relevant local guidance.
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.