Friday, September 15, 2017

Jacksonville's GIS Map Needs This Feature

My house did not flood during Hurricane Irma. We were in Evacuation Zone 1, and we got out of the area. However, that's not enough for me. I want to know if my housing investment is safe, and the best way to do it is to have more information about the flooding that did occur, possibly as an added layer on Jacksonville's fairly nice GIS mapping system.


I worked on GIS maps in the early days of the system, back in the 1990s. I know these maps were powerful even then, but they can do so much more today. A simple overlay would be one that shows actual flooding during Irma. Not flood zones or Evacuation Zones, but where the water really went. I know it was about more than storm surge and more than just the river. Some areas were flooded because of poor drainage, possibly due to new development in those areas.

On top of seeing where actual flooding occurred, an overlay should show where flooding was close to happening. For example, my neighbor told me that the pond in our collective backyard got to within six inches of the top. Were we six inches from flooding? Would the pond have drained properly? Would it have drained into another pond and overflowed there? We don't know. There's also a creek tied to the intercoastal about 100 yards from our houses, which is likely the reason we're in the top-tier evacuation zone. How close was that to flooding? At least provide a post-Irma satellite overlay on the GIS map so that folks can determine where the flood waters went near their homes.

I don't know if flood insurance will exist in the future. I don't know if Global Warming will put my front yard under water half the year. What I do know is that we all deserve to have access to the information that could help us to plan not only evacuations but measures to prevent catastrophic effects in the future. Since I own a two-story house, knowing the kind of storm that might flood my house could make a big difference in how I move items in preparation for a storm.

If nothing else, a system that shows where flooding has occurred or almost occurred would be useful in planning future development or drainage systems, including possible deep tunnels, diversion techniques, or even dams or levies or whatever might keep water out of our living rooms.