Reading the Ground: A Developer’s Guide to Early Site Clues
Developers scrutinize land prices and returns down to the dollar, yet one of the biggest variables on a project is often treated like a placeholder: the ground. By the time a geotechnical report identifies a problem, the deal is moving and unexpected conditions become added cost instead of informed risk.
This is the part of my job I call “Sherlocking.” Like Sherlock Holmes, the classic detective who famously solves mysteries, you can connect the clues and start understanding a site before you buy. What was there before? What changed? What patterns show up nearby? A lot of this information is available for free or at a low cost. You just have to know where to look.
You can pull a lot of data together in a short amount of time. Topographic maps, historic aerial imagery, geologic mapping, soil surveys, floodplain maps, and local jurisdiction overlays are just a few resources. When you put these together, they tell you where to focus your attention and can change how you look at a deal.
Start with the maps. Topography is usually the first place I go. You can pick up a lot from subtle elevation changes. You can find maps in the United States, UK, and Canada for free through many libraries. Old stream paths and low areas that were filled over time are often seen on these maps. If you see these patterns, you should think: softer soils, higher groundwater, and potential foundation issues. The need for deep foundations due to soft soils, or a permanent dewatering system because of high groundwater, can significantly increase design and construction costs.
Historic aerials are incredibly easy to access now. There are free online databases for many countries and low-cost databases in the UK, United States, and some areas of Canada like Toronto where you can scroll through decades of imagery in minutes. You can see when land was cleared, when buildings went up, when they came down, and more. A site that looks to be untouched forest today may have been a pond, storage yard, or industrial site decades ago. And underground, that history often remains.
Fire insurance maps such as Sanborn maps in the United States and Goad maps in Canada and the UK provide incredibly detailed information. Building footprints, materials, uses, and more can be found. You might find that a vacant lot used to house a machine shop. The building is gone, but the impact remains.
Geologic Maps from the British Geological Survey, United States Geological Survey, and Geological Survey of Canada give you a broader sense of what you are dealing with. Are you in an area with shallow rock? Soft compressible soils? It is not design-level data but can tell you if a site is more complicated than it looks.
In addition, there are Soil Survey Databases such as those through the United States Department of Agriculture, LANDis in the UK, and Canadian Soil Information Service which can provide drainage characteristics and an initial understanding of infiltration and stormwater considerations for a site.
Many government agencies also publish their own Geographic Information System (GIS) systems including important details like floodplain maps, environmental overlays, karst mapping, and historic mining data.
When these clues are combined, hidden risks on your site can become visible. Finding this out after you have closed on a site can be costly. Identifying issues early makes them easier to plan for. This early review doesn’t replace proper geotechnical investigation. However, it affects how aggressive you are on price, how you carry contingency, and how you manage risk.
While maps provide data, local engineers provide judgment. Two sites can appear similar on paper but carry different risk below grade. Local experience helps connect the geologic and historical clues so you can use them to make practical risk and cost decisions.
Before your next site decision, take a little time to look closer. Do some Sherlocking. Use the information that’s already out there and then bring in your local geotechnical engineer to provide a sanity check on what you are seeing.
The ground leaves clues. The question is whether you look for them before you commit.
Shana Carroll, D.W. Kozera, Inc.
Shana Carroll, PE, LEED AP BD+C, is President and majority owner of D.W. Kozera, Inc., a certified WBE geotechnical engineering firm serving clients throughout the Mid-Atlantic. A licensed Professional Engineer in 10 states with more than 25 years of experience, Shana advises owners, developers, and design teams on geotechnical risks that can affect development, design, and construction.
A CREWBaltimore member since 2007, Shana is the chapter’s Immediate Past President and a recipient of its Beacon Award. She also serves as Communications Director for the National Capital Section Geo-Institute of the American Society of Civil Engineers. Her leadership has been recognized by The Daily Record as a 2026 Influential Marylander, as a Baltimore Business Journal Women Who Mean Business honoree, and as one of The Baltimore Sun’s Women to Watch.
Shana holds bachelor's and master's degrees in Civil and Environmental Engineering from Bucknell University.
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