Five Free Tools That Map Your Land

Federal agencies and research labs have already surveyed your property. Sun, soil, rainfall, flood exposure, and solar potential are mapped and free to access, and almost no owner pulls any of it. Run these five in the right order and you will know more about your land than most contractors bidding on it.

The five tools

ShadeMap gives animated sun and shadow across your actual terrain and buildings for any date and hour. Pull screenshots at 9am, noon, and 4pm on June 21 and December 21. The USDA Web Soil Survey gives soil series, drainage class, depth to water table, and slope, mapped for over 95 percent of US counties. Pull your soil series name and its drainage class. NOAA Atlas 14 gives rainfall intensity and duration for your exact coordinates, the basis for sizing any water system. Pull the 10-year and 100-year, 24-hour rainfall depths. The FEMA Flood Map gives your official flood zone designation and base flood elevation. Pull your zone letter. PVWatts, from NREL, gives a real annual solar production estimate for a roof or ground array. Pull the estimated annual kWh at your roof pitch and orientation.

The order to run them in

Flood first, because a mapped floodplain constrains siting, insurance, and permitting before any design question is worth asking. Soil second, because drainage class determines what is plantable, what needs amendment, and whether infiltration-based stormwater is viable at all. Sun third, because the shadow study tells you where the productive ground is, and it is frequently not where people assume. Rainfall fourth, because Atlas 14 numbers size your swales, basins, catchment, and drainage, and guessing here is the most common and most expensive error in residential land work. Solar last, because it is only meaningful once you know where the sun actually lands.

What to do with it

Put all five outputs into one folder before you talk to any designer, builder, or solar installer. It changes the conversation from a sales call into a technical one, and it is the fastest way to find out whether the person across the table knows what they are doing.