We just added USGS elevation and slope screening to Groundcheck. Reports now sample public 3D Elevation Program data across the parcel and estimate the steepest and average grades found between those samples.
Terrain affects more than whether a site looks hilly. Slope can change road access, building placement, earthwork, retaining walls, erosion control, utility routes, stormwater design, and the amount of land that works for a project.
How the screening works
Groundcheck takes points from the saved parcel boundary, limits the analysis to a practical sample, adds a parcel center point, and requests elevation values from USGS 3DEP. It then compares the rise and horizontal distance between sampled points.
The finding reports the steepest estimated grade, average sampled grade, elevation range, minimum and maximum elevations, and the number of points that returned data.
How Groundcheck flags slope
An estimated steepest grade below 8 percent receives a low screening result. A grade from 8 percent to under 15 percent receives a moderate result. A grade of 15 percent or more receives a high result.
Those categories help you compare sites and recognize when terrain deserves attention. They do not apply a local steep slope ordinance or calculate the exact grade of every part of the parcel.
- Steeper sites often require more cut and fill.
- Road and driveway grades can limit practical access.
- Retaining walls and stabilization can increase construction cost.
- Slope changes runoff speed, erosion risk, and stormwater design.
- Local ordinances can protect steep slopes or limit disturbance.
Why this is useful early
A listing photo and contour map can hide how much elevation changes across a parcel. Groundcheck turns national elevation data into a quick, consistent signal and shows it with soils, floodplain, wetlands, roads, and other constraints.
If the result looks moderate or high, you have a reason to review topography before assuming the full acreage works for your plan.
This is not a topographic survey
Groundcheck samples a limited number of points. It does not analyze every elevation cell, identify retaining walls or cliffs, model a building pad, or replace surveyed contours.
Confirm decisions about grading, access, earthwork, drainage, and stormwater with a surveyor and civil engineer. The Groundcheck result tells you when that conversation should happen sooner.
Use the new layer
Check the property you are considering
Groundcheck combines this source with parcel details and other available national, state, and local layers.
Start a property check See every Groundcheck data layerGroundcheck provides early public data screening, not a legal, engineering, surveying, environmental, planning, permitting, or buildability determination. Verify important findings with the responsible agencies and qualified professionals.