If you don’t know how high the ground is above sea level, these online maps showing elevation measurements across the city are a helpful tool. These are ground measurements taken every 10-feet by aircraft, so they’re approximate. Measurements by a Land Surveyor will be more accurate.
View the Map
There are millions of measurement points on this map, so it may take awhile to load and when zooming-in:
These are very large files (approximately 70 megabytes), so depending upon your Internet access speed, they may take a few minutes to download. Once downloaded, keep these files on your computer for much faster access.
Two sets of elevation data are shown on these maps, for comparison:
Light Detection & Ranging (LiDAR)
These readings were converted from their original 1988 NAVD datum to the 1929 NGVD datum (plus 1.35 feet) to match the current flood maps. The 1988 datum readings were retained, just not displayed.
The readings show every 6th elevation point. Originally these measurements were taken every ten-feet (totaling 1.8 meter points), but unless you’re zoomed-in very close, they overlapped and turned the entire map black. A 1:6 ratio made these readings readable at larger scales (totaling 1.9k points).
Surveyor Site Readings
The survey site readings are the red numbers. The Lowest Adjacent Grade (LAG) taken next to the buildings. These red numbers may be plotted on the street, but they represent readings taken against the buildings at those addresses. An Elevation Certificate from a Land Surveyor will be much more accurate and pertain to a specific building and the land upon which it rests.