Case study · building site topography

A North Kona hillside, mapped before anything is built

A landowner in North Kona, planning to build on a terraced hillside, wanted to know what the ground really does. One drone LiDAR flight answered it: 140 ft of fall, every terrace and bank, every tree, in files an architect and a designer can open.

The hillside, in its own data

Every picture here is a product of one flight. Tap any of them to see it large.

Where: North Kona, Hawaiʻi Island
Flown: September 15, 2026
Area: 3.0 acre parcel, 5.1 acres mapped
Client: Private landowner

The question

The lot is about 3 acres of old terraces cut into the slope, with a house, a drive and a ring of big trees. The owner was weighing an extension, a new building, a pool and a septic field, and each of those asks the ground the same thing first: how steep is it here, and where does the water go. A county map and a phone photo cannot answer that on a hillside where the terraces hide under grass and the edges hide under trees.

One flight

On September 15, 2026 we flew the parcel and a 55 ft margin around it with drone LiDAR and a camera together, 5.1 acres in all, with a GNSS base station logging over a mark on the lot. The laser recorded 57,507,170 points inside the mapped area, about 2,800 on every square meter, enough to hold each terrace edge, each step in the drive and each tree crown.

What the landowner received

A classified point cloud: ground, vegetation and buildings
Bare earth, surface and canopy height rasters on a 10 cm grid, heights in feet
Contours every foot, heavier every 5 ft, drawn around the buildings rather than through them
A slope map, the building footprints, 303 tree crowns and 403 treetops
An orthomosaic at 1.5 cm, lined up with the point cloud
Six printed map sheets, an accuracy report and CAD files
A private link to our online viewer, to turn the whole site in 3D from a browser

The map sheets

Every package ships with map sheets a person without GIS software can print or read on a phone. These are the delivered sheets, with only the street address and parcel number taken off for this page.

The delivered topographic contours sheet: 1 ft contours with labels every 20 ft over a shaded relief, building footprints, and small bare earth, surface and slope maps down the right side. — Topographic contours, labelled every 20 ft

The delivered bare earth sheet: the ground under the vegetation shaded green on the low side to clay on the high side. — Bare earth

The delivered tree canopy sheet: every crown drawn and shaded by its height over the photograph. — Tree canopy by height

The delivered orthomosaic sheet: the parcel photographed from the air at 1.5 cm, inside the mapped boundary. — Orthomosaic at 1.5 cm

How it looks from above

The bare earth of the whole parcel colored by elevation from blue on the low west side to red on the high east side, contoured every 10 ft. — Bare earth, about 140 ft of fall

Slope across the whole parcel, green where it is gentle and dark red on the steepest cuts and banks. — Slope: the banks and cuts in red

The whole parcel photographed from the air on the same flight as the LiDAR: lawn, trees, the house and the drive. — The orthomosaic, same flight

The 303 tree crowns found on the parcel, filled by their measured height in pastel colors over the dark ground and contours. — All 303 crowns, filled by height

Checked against USGS lidar

Heights are only useful if they are right. We compared our ground with the public USGS 3DEP lidar that covers this part of Kona. On open ground the two agree to 0.08 m (0.25 ft) root mean square, with a median difference of half a centimeter, and the base station's own tripod turns up in our point cloud 2.1 cm from the mark it stood on. The accuracy report in the package shows the method and every number. It is a comparison with USGS data, which has its own error, not a test against check points measured on the ground; a design that needs that calls for a licensed surveyor.

In the landowner's online viewer

The whole mapped area opens in a browser: point cloud, bare earth, contours and the 2D maps, with measuring tools and downloads. No software, no files to move around.