(requires Google Earth or another KML viewer)
This analysis uses a Lidar Digital Elevation model, and the MICRODEM computer program to produce a KML file you can view in Google Earth. You can see the predicted flooding at a number of water levels, referenced to NAVD of 1988. We also have historic shorelines depicted by the Maryland Geological Survey; perhaps not surprisingly, almost all the area that floods is fill emplaced after the founding the Naval Academy in 1845.
You can see the current tides and refer them to both NAVD and MLLW, as well as several other vertical datums, in either feet or meters.
You can compare the observations with the NOAA prediction. Insure that you understand the tidal datum used in the model, the units (feet or meters), and then determine the matching NAVD1988 level.
|Water level in downtown Annapolis and the Naval Academy from a storm such as Hurricane
Isabel, overlaid on a 1 m resolution LIDAR DEM.
Water levels go from 0.2 m to 2.5 m in 0.1 m steps. This requires that the point be below the water level, and that it have a clear path to the bay. This will be fooled if water can come through the seawall or a storm drain, for instance, but provides a reasonable estimate. It will also have challenges in areas where there has been substantial recent construction, such as around Rickover and Hopper Halls, which at one point provided a major entry point for flooding waters.
There are many caveats to this analysis, and there is no claim that it accurately portrays what happened in Isabel or would happen in a future storm.
This is a low resolution depiction for web delivery, and does not do justice to the quality of the DEM data. You cannot stop it or change the playback speed. You can get much more control over the visualization with the KML model for storm surge in Annapolis created by MICRODEM.
Actual water levels for recent hurricanes and flooding events that I monitored and in some cases waded through:
"All time*" worst flooding events at Annapolis
|Date||Time||Max Feet above MLLW||Hours above 4 ft MLLW||Storm|
|24-Aug-33||2:00 AM||6.181||16||1933 Chesapeake-Potomac Hurricane|
* History starts with the tide gauge in 1929, so the record extends less than 100 years. Compilation by Davies and Guth
last revision 10/15/2019