Where do you live relative to official flood plains?

During Harvey tens of thousands of people in the Houston area outside of 100-year and 500-year flood plains flooded. Do you really know your home’s location relative to official flood plains? It could be important during lesser floods and affect the cost of flood insurance.

This FEMA web site shows interactive flood plain maps that can give you a wealth of information about the risk to your property.

Feature-rich, Interactive Flood-Plain Map by FEMA

Access FEMA’s Flood Zone map for this area by going to this web page: http://maps.riskmap6.com/TX/Harris/

Then follow these steps:

  1. When you get to the entry page, agree to terms and conditions
  2. Type in  your address to get a detailed view of risk for yourself and your neighborhood. Or you can also type in something more general, such as Kingwood TX, to see the contour of flood plains in the entire community.
  3. On the left-hand panel, check both boxes under “Effective Flood Insurance Rate Map.”
  4. The legend is on the right. Some explanations:
    1. Anything in solid purple is in the FLOODWAY. Expect frequent flooding and major damage.
    2. Anything under the fuchsia diagonal stripes is in the 100-year plain. People there have a 1% probability of flooding every year – and a 26% chance of flooding during the life of a 30-year mortgage.
    3. Anything under grey diagonal stripes is in the 500-year flood plain. People there have a 0.2% probability of flooding every year – and a 5.8% chance of flooding during the life of a 30-year mortgage.
    4. Properties outside those zones are in an area of overall lower risk. Lower-cost, preferred-rate, flood insurance policies (known as Preferred Risk Policies) are often an option in these areas. See your local insurance agent or visit floodsmart.gov for more information.
  5. If you entered your specific address, click the info button above the map, then click the star on your property to learn more about your risk. After the box pops up, you can click “View Detailed Flood Report” for even more information.
  6. You can hide both the legend and check box panels by clicking on the >> double arrows at the top of each panel.
  7. Zoom and move about, as you would Google Maps.
  8. Use the measuring tool above the map to check your distance from flood zones and hazards such as streams, ditches and rivers.

Guide to Terminology

If you need help interpreting all the acronyms and technical language in the check boxes and legend, consult this PDF: How to read a FEMA Map

The PDF above is definitely worth a read. It explains the “language” of flooding and flood insurance. It also explains how to protest a designation if you think the map has misclassified your property, for instance, if your slab has been elevated relative to the average level around you.

Experiment with the different tools and views in the map. Zoom out to see the risk in surrounding areas. The interactive exploration is fascinating.

Regardless of how far you are from flood plains or how high you are above them, if you live in Harris County, seriously consider flood insurance. During Harvey, more homes flooded outside the 500-year flood plain than inside.

A Less Powerful, but Easier-to-Understand Alternative

Harris County Flood Control offers a web site similar to FEMA’s; it has fewer options and less information, but is easier to understand and navigate. It’s actually called a “flood education mapping tool.” See: http://www.harriscountyfemt.org/Index.aspx.

The flood education mapping tool from Harris County Flood Control District has fewer options but is easier to understand.

How to Find the Elevation of Your Home

If you don’t already know the elevation of your home from surveys, deeds or insurance docs, try this web site: https://elevationmap.net/.

My thanks to Paul Margaritis, a long-time Kingwood resident. Paul forwarded this information to RefuceFlooding.com.

Posted 5/29/2018 by Bob Rehak

273 days since Hurricane Harvey