Flash Flood Alley Segements

Known Flood Hazards in the Central Texas Area

Storm Summary
& Rescue Efforts

Property Damage
& Relief Efforts

Success Stories
Regional Flood


& Publications

Known Hazards
in Central Texas

City of Austin Known Hazards Map (in PDF form)


  • Wait it out
  • Have alternative routes for home, school, and work. Designate places to wait out a storm since families can be separated when home is inaccessible.
  • Just because your home or workplace is on high ground, doesn't mean it won't be cut off by rising waters.
  • To monitor roadway conditions during floods and storms, listen to the radio or TV, or visit the OEM Road Closures and Emergency Conditions web page.
  • Driving Problem Spots:
  • Low water crossings
    Low Water Crossings In North Austin by OEM
    Low Water Crossings In South Austin by OEM
  • Bridges and overpasses over creeks or rivers. Over 300 bridges in Austin are subject to flooding.
  • Road surface or road supports may be washed out and hidden under water
  • High water on the road from clogged drainage or low areas like underpasses may cause hydroplaning or stalling
  • Clogged drainage on roads may cause unpredictable flooding on roadways
  • Barricades on closed roads; Never drive past barricaded road signs or where there is water over the road -- driving through rushing water is the number one cause of loss of life during floods. If your car stalls in a flooded area, abandon it as soon as possible and walk to safety in the direction you came from.
  • Utility outages like traffic lights compound traffic
  • Even knowledgeable people are affected.
    "Since flooding unexpectedly destroyed my home, I can never look at it again and feel the comfort and safety it once offered. The reality is, if you live in a floodplain, you will be flooded."
    -Roy Sedwick, Texas flood official
    Source: Floods and Your Family brochure, U.S. Army Corps of Engineers.
  • Central Texas' unique meteorology/geology
  • Flash Flood Alley/Texas experiences some of the most violent flooding in the world.
    See magnitude/duration chart from Balcones Escarpment report.
  • Inland flooding from hurricanes
  • Lots of urban creeks that make Austin so livable but also create risk
  • Middle of the Colorado River Watershed
  • Ask your insurance agent how you can buy flood insurance to protect your property. Homeowners' insurance does not cover flood loss, but most homeowners' insurance agents also sell flood insurance. Anyone can get flood insurance, even if you are located in an area not mapped as a floodplain, or even if you have never been flooded before. Apartments flood too-- insure your belongings if you rent.
  • Even with the City's early warning technology and coordination in place, every rainstorm is different and can cause sudden and unpredictable flooding effects. Severe local storms are the most common widespread hazard and they affect large numbers of people throughout the region when they occur. These types of storms can quickly overwhelm city and county resources.
  • Family Emergency Plan
    Flash flooding and localized flooding can sometimes occur faster than citizens can be warned or emergency personnel can respond. This is why every family, especially in flood prone areas, needs to take personal responsibility to prepare in advance for flooding. Family plans should be developed, disaster kits should be put in homes, workplaces, schools and cars and every family member should be taught how to shut off household utilities.
  • Loss of utilities- Because electrical lines are damaged, other utilities such as telephone systems (cell and land lines), natural gas, water and sewer systems can become inoperable.
  • The dangers associated with flooding do not end when the rain stops. Electrocution, structural collapse, hazardous materials leaks, and fire are secondary hazards associated with flooding and flood cleanup. Bank erosion can threaten areas that are not inundated by floods.
  • Around your own home, keep street drains and storm grates free of leaves and other debris. Call the City if you need assistance.
  • Minimize flood damage and pollution:
    Store valuables at higher elevations (second story, if possible)
    Store household chemicals above flood levels
    Ensure that underground storage tanks are fully sealed and secure.
    Close storm shutters and sandbag doorways.
    Have check valves installed in building sewer traps to prevent flood waters from backing up in sewer drains.
    Move vehicles and RVs to higher ground.
    Buy sand and sandbags ahead of time. Learn how to use them; call the U.S. Army Corps of Engineers for a copy of their brochure on sandbagging.
  • Find out if you are in a floodplain. Approximately 7,000 houses in Austin are subject to flooding in FEMA-designated floodplains. There are currently only 4,500 flood insurance policies active in Austin. About 30% of flood insurance claims are from policies for houses outside of floodplains. This leaves almost 4,000 Austin households in the designated floodplains uninsured for the inevitable flooding they will experience!
  • Flooding can occur near rivers, creeks and normally dry ditches. But, "urban flooding" can also happen in subdivisions, parking lots and city streets. You don't have to live on the banks of a creek or in a floodplain to experience significant flooding. Tremendous amounts of rain can fall in randomly concentrated areas overtaxing drainage systems and flooding areas outside of the normal floodplain.
  • Consider the layout and location of your home:

    Is it on a hill or in a low spot?

    Where does your neighborhood's stormwater go? Will it go through your property or house on it's way downhill?

    Where are your neighborhood stormdrains? If they get clogged, where will the water go?

    How far is your house from a stormdrain, creek, river, ditch, drainage basin, drainage tunnel, or bridge? If they get clogged, where will the water go?

    Do you live near a bend in a creek? If raging floodwaters jump the bank and go straight instead of following the curve, will it send floodwaters into your house or neighborhood?

    Water travels downhill and will collect there unless there is someplace else for it to go. Is your driveway or street higher than your house? This may funnel water right into your house.

    Do you have a basement, low windows, or doors that may let flood waters into your home?

    Do you live near a highway, parking lot, underpass, retention pond, or a low road? Where will the water go if their drainage pipes become clogged?

    Do you or your neighbors have fences or sheds that can impair the flow of swollen creeks?

    Are there loose items in your yard that could wash into your neighborhood drainage system or creek and clog it? For example: picnic tables, toys, patio furniture, BBQs, barrels, loose building materials, weak fencing, branches, leaves, trash cans, recycle bins, etc.

    Are there loose items in your yard that could pollute the stormwater or injure someone? For example: gasoline, chemicals, batteries, fertilizers, paint, oil, etc.

    Is there construction or rocky slopes in your neighborhood that won't absorb water very well or could wash out? Could silt clog your neighborhood drainage?

    Is your home near a creek bank that may erode during a heavy storm?

    What kind of soil or landscaping does your neighborhood have? Compacted and/or clay soils will not absorb stormwater fast enough-- even with grass growing on it.

    If your house is vulnerable, how high will the water rise inside your house? If your house is in a floodplain, how deep in the floodplain is it?

    Distance from a creek, lake, or river does not protect you from flooding. It's how high the property is above the water that counts. If you have had a survey, what is the elevation of your house? How does compare to the flood stage elevation of your floodplain?

    Will emergency vehicles be able to reach you during a flood?

  • Talk to neighbors and share information on preparedness and previous experiences. Remember, the next flood can always be bigger and more unpredictable than floods you have seen before. Even if there is no flood history in your neighborhood, the chance of flooding is still there because you live in Central Texas A.K.A. Flash Flood Alley!