Preliminary Flood Map Comparison Tool

Preliminary Flood Hazard Maps and Data

Preliminary flood hazard maps and data are available on the FEMA Flood Map Service Center website.

Let's look at how to use the Preliminary Map Comparison Tool within the Flood Map Changes Viewer on that site. The Preliminary Map Comparison Tool allows customers to compare current effective flood hazard data with preliminary flood hazard data.

Follow the steps below to locate the Preliminary Map Comparison Tool.

  1. Select this link to view the Preliminary Map Comparison Tool Tutorial
  2. Review "How to use the Preliminary Map Comparison Tool"
  3. Select this link to view the Flood Map Changes Viewer
  4. Make a Comparison of Flood Hazard for the address you used in the previous exercise
  5. Save and print the Comparison of Flood Hazard you made*

    *To preserve the scale of the map, save as PDF and remember to change print settings to "actual size."

Reminder: The website will open in a different window. When you finish reviewing the website, close the window to return to the course and select the forward arrow to continue.

Note: Preliminary flood maps can also be accessed at when searching for a specific address. Simply click on the "Show all products for this area" link on the Search Results page. 

Additional mapping resources related to the status of map change requests and mapping product subscriptions are located at: and, respectively. 

A graphic of a FEMA webpage. The FEMA logo U.S. Department of Homeland Security FEMA is in the top left corner of the page.  In the top right corner are the words Map Service Center. The middle of the page has several lines indicating text.  The bottom half of the page has the following text, Search, Use the following selection boxes to find your area of interest.  Below the text are three lines with selection boxes.  The first line reads, Select a State, District, or Territory.  The second line reads, Select a County, Parish, etc, and the third line is blank.