Using Aerial History for Land Due Diligence Before You Buy
A listing photo shows a parcel on its best day. Ten years of aerial imagery shows what actually happens there — and it is the cheapest diligence you will ever do.
Six things the timeline reveals
1. Standing water that is not on any map
Scrub through spring images across several years. Water that shows up repeatedly in the same low spot is telling you about drainage, and possibly about wetlands, long before a delineation does. A single wet photo is weather; the same wet corner in four different years is a feature of the site.
2. Dumping and disturbance
Piles that appear, sit, and vanish. Bare scraped areas that were not there five years ago. Vehicle tracks worn into a pattern. None of this is proof of contamination, but it tells you where to look and what to ask about — and it is exactly the kind of thing a Phase I environmental assessment will want to know.
3. Grading and fill
Comparing early and late imagery often reveals that a site was reshaped. Fill of unknown origin and compaction is a real cost item, and unrecorded grading can create drainage obligations to a neighbour.
4. Access that is not what it looks like
Watch how vehicles actually reach the parcel over the years. A track that crosses a neighbour's field is a use, not a right. If the only visible access is across someone else's land, you have an easement question before you have anything else.
5. Structures that came and went
A building that appears between two images and does not show up in permit records is a conversation to have. So is a foundation or slab visible in older imagery but gone now — that is a demolition, and possibly a buried one.
6. What the neighbours are becoming
Zoom out. A quarry that has doubled, a subdivision creeping toward the boundary, a solar array going in next door — the trajectory of the surroundings is usually more predictive than their current state.
Pair this with the data layers. Aerial history tells you what happened. It does not tell you the flood zone, the slope, the soil, or whether a septic system is feasible. Run both.
A ten-minute routine
- Open RewindEarth at the parcel, zoomed out enough to see the neighbours.
- Press Play. Watch it once at the wide view, once zoomed to the building envelope.
- Use Compare to put the oldest and newest snapshots side by side.
- Screenshot anything that changed, with the year visible.
- Take that list of dates to the county — permits, code cases, recorded documents.
Everything you find becomes either a question for the seller or a reason to walk. Both are wins.
Common questions
Does aerial imagery show wetlands?
Not authoritatively. It shows standing water and vegetation patterns that often correlate with wetlands, which is useful as an early warning. A formal determination requires the National Wetlands Inventory and, for a transaction, a delineation by a qualified consultant.
Can I see if someone dumped on a property?
Often, yes — surface dumping, piles and disturbed ground are usually visible from the air. Buried material is not. Visible disturbance is a reason to commission a Phase I environmental site assessment.
How many years back should I look?
As far as the archive allows. Ten years is usually enough to see patterns; the full 2014-onward range is better, and worth pairing with older NAIP imagery for a parcel you are serious about.
Is this a substitute for a survey?
No. Aerial imagery cannot establish boundaries, easements or encroachments as a legal matter. It tells you where to point a surveyor.
Try it on your own address
Paste an address or a Google Maps link and scrub through every aerial snapshot on record. Free, no account.