How do I know if I live in a flood zone? And if I do, what then?

Texas has seen some good, soaking spring rains this year, relieving drought conditions in much of the Brazos River Basin. With some areas still under drought restrictions, the idea of planning for flooding seems unnecessary. However, understanding your property’s flood risk is key for your safety and that of those around you.

Floods occur naturally and can happen almost anywhere. Flooding may not even happen near a body of water, although river and coastal flooding are two of the most common types. Heavy rains, poor drainage, and even nearby construction projects can put you at risk for flood damage.

Federal Emergency Management Agency (FEMA)

FEMA was created in 1979 when President Jimmy Carter gave the agency a dual mission of emergency management and civil defense. When we think of FEMA, we are often reminded of their work during major flood events like Hurricane Katrina in 2005 and Hurricane Harvey in 2017.

But disaster relief is not the agency’s only responsibility. To further alleviate and prevent damage from future flooding, FEMA provides valuable information to property owners and insurance agencies by providing maps indicating areas of probable flooding. Flood maps show a community’s flood zone, floodplain boundaries, and base flood elevation.

Property owners, insurance agents, and lenders can use flood maps to determine flood insurance requirements and policy costs. These maps are available to the public, allowing property owners to know the flood risks associated with their property.

Floods don’t follow city limits or property lines. A flood map shows the relationship between a property and the areas with the highest risk of flooding. There is no such thing as a “no-risk zone,” but some areas have a lower or moderate risk.

A flood zone is an area that holds a high-risk, moderate-risk, or low-risk of flooding. No matter where you live or work, some risk of flooding exists. A flood zone map can detail the likelihood and severity of flooding in your area.

Moderate to low-risk flood zones are designated with the letters B, C and X on FEMA flood maps. The risk of these areas being flooded is reduced, but not completely removed. High-risk flood areas begin with the letters A or V on a FEMA flood map.

These areas face the highest risk of flooding. If you own property in a high-risk zone and have a federally-backed mortgage, you are required to purchase flood insurance as a condition of the loan.

Texas Water Development Board (TWDB)

In addition to the work FEMA is doing to prepare citizens for possible flood risks, TWDB is also contributing to the cause. TWBD recently released their 2023 Regional Flood Plan Approvals for the 15 regions in Texas.

TWDB develops and adopts a comprehensive state flood plan every five years. The most recent plan shows that 2.4 million Texans live in an area that has a 1% chance of flooding each year, known as the 100-year floodplain. Another 3.5 million people live in areas with a 0.2% chance of flooding each year, known as the 500-year floodplain.

“Getting this program up and running is a really big deal,” TWDB Chair Brooke Paup said before the board approved the 15 regional plans, a major step in creating the statewide flood plan. Each region is built around one of the state’s major watersheds.

The Brazos River Basin falls into two regions. Region 7 covers the Upper Brazos, stretching from Parmer County to Eastland County, including the major cities of Lubbock and Abilene. Region 8 covers the Lower Brazos, stretching from Young County to Brazoria County, including the major cities of Waco, Round Rock, Bryan, and Sugar Land.

Both regions combined show flood risks to more than 378 thousand people and more than 161 thousand buildings. Using the maps from FEMA and TWDB gives property owners a greater chance of being prepared when flooding occurs.

FEMA and TWDB go to great lengths to help citizens plan for future flooding events. The key is to be prepared before a flood and know what to do during a flood.

Stay or go?

Sheltering in place will keep you from the dangers of driving in rising water. However, when flooding will potentially threaten your shelter location, early evacuation may be your safest alternative.

Several resources can help determine whether to evacuate.

Begin by closely monitoring local weather reports via radio, television and the Internet. Being aware of potentially threatening weather conditions is most important if you live in a floodplain or near a river or waterbody that has the potential for flooding.

In Texas, the decision to evacuate an area is determined by the local county judge or the mayor of an incorporated city. The local sheriff’s department and/or city law enforcement implements the evacuation; therefore, monitoring county and city government websites for potential updates is also important.

If you feel threatened by rising water, it is better to get out before becoming stranded. Law enforcement and other agencies will do all they can to help everyone stay safe; however, waiting too long to evacuate is dangerous and will place you and emergency responders in danger if rescue is necessary.

There are areas within the Brazos River Basin that are more prone to flooding than others. Flood events may require spillway gates to be opened at a reservoir near you. You can sign up to be notified of gate openings of Brazos River Authority (BRA) reservoirs here. As you sign up, you can choose both the reservoir and the release rate for notification.

Know the streamflow near you

Another resource to help understand the potential for flooding is the United States Geological Survey’s (USGS) gage system. This is the same system used by the BRA and U.S. Army Corps of Engineers hydrologists in determining floodgate operations at reservoirs. The USGS gages measure streamflow or the amount of water moving past a gage, and record the river stage or water depth at the gage’s location. The BRA makes it easy to find streamflow on the BrazosBasinNOW site.

Another resource for monitoring the potential for flooding is offered by the National Weather Service – West Gulf River Forecast Center (WGRFC) who produces forecasts for the river that are then used by the National Weather Services who issues flood warnings based on these forecasts. The NOAA service provides graphics that show the most recent measured streamflow for each USGS gage and if flooding is anticipated, a projection of what is expected at the gage over the next several days. The site also lists flood stages as well as historical and recent river crests at each gage location.

The BRA provides a link to the Advance Hydrologic Prediction Service for the major tributaries in the Brazos River Basin including the Brazos, North and Middle Bosque, San Gabriel, Navasota, Leon and Lampasas Rivers. That information can be found here.

Don’t gamble with safety

Driving during rain events can be extremely frightening, especially as roads begin to flood. Tragedies often occur when people underestimate the effect water can have on a moving vehicle. The Texas Department of Public Safety reports that almost half of the fatalities caused by flash floods nationwide involve vehicles.

According to the National Weather Service,

  • six inches of water will reach the bottom of most passenger cars, causing loss of control and possible stalling.
  • One foot of water will float many vehicles, and
  • two feet of rushing water can carry away most vehicles, including sport utility vehicles (SUVs) and pick-ups.

The phrase “Turn Around, Don’t Drown” is one to remember, and could save your life or the life of someone you care about.

According to the Ready Campaign, they offer tips for before, during and after a flood.


  • Know your risk for floods.
  • Purchase flood insurance.
  • Sign up for emergency notifications.
  • Make a plan for your household.
  • Keep insurance, important documents, and other valuable items in a fire/flood-proof box.
  • Build a disaster supply kit.
  • Know where you can go if ordered to evacuate.
  • Plan with relatives and friends to stay connected.


  • Stay Informed and be sure cell phones are charged or have a battery backup.
  • Get to Higher Ground: If you live in a flood zone area or are camping in a low-lying area, get to higher ground immediately.
  • Obey Evacuation Orders: If told to evacuate, do so immediately. Lock your home and disconnect utilities and appliances if time allows.
  • Do not attempt to drive over a flooded road. STOP! Turn around and go another way.
  • Never try to walk, swim, or drive through swift water.
  • Keep children from playing in floodwaters or near culverts and storm drains.


  • Stay informed for instructions and only return home if authorities say it is safe.
  • Boil drinking water before using it and throw away any spoiled food.
  • Wear proper protective equipment during cleanup.
  • Do not handle live electrical equipment in wet areas. Leave that to the professionals.
  • Be aware that snakes and other animals may be in your house.

Knowing if you live in a floodplain is the first step to being prepared before, during and after a flood event.