Flood Prevention


Flood Prevention

Central Texas is prone to flooding and even flash-flooding so it’s important to be prepared. Flash floods happen when rain water doesn’t have enough time to soak into the ground. Urban areas are at the most risk due to more impervious cover, which can include parking lots, driveways, roofs or anything that prevents the Stormwater from being absorbed into the ground. This excess Stormwater runoff can pool in areas causing flooding which in turn causes other significant damages like clogged storm sewer systems, erosion and debris deposits. We cannot control the weather but fortunately, they're some ways to help mitigate the effects of flooding.

The Stormwater Management Division of the Public Works Department has multiple programs in place to help control Stormwater runoff including reducing pollutants being discharged to local water bodies:

  • Channel and storm pipe cleaning
  • Street inlet inspections and maintenance
  • Detention and water quality pond inspections and maintenance
  • Street sweeping 
  • Municipal Separate Storm Sewer System Stormwater Management (MS4) 

How can you help prevent flooding?

  • Never dump or throw anything onto the ground, into channels, inlets/storm drains or waterbodies. Yard wastes (grass clippings, leaves and branches) can clog the stormwater system which may cause flooding in the street.
  • If your property is next to a small channel or stream, please keep the banks clear of debris. The city does not maintain small channels or streams on private property.
  • If you see illegal dumping, pollution or significant debris in channels, inlets or the storm pipe please contact the City of San Marcos either at:  stormwatermgt@sanmarcostx.gov or 512-393-8036.

Flood Safety

  • Never walk through fast rising flowing water. Drowning is the leading cause of flood related deaths. You can lose your balance in only half a foot of water.
  • Never drive through high water or rapidly rising flood waters. It only takes 1-2 feet of water to float most vehicles. Turn Around, Don’t Drown! 
  • Stay away from downed power lines. The second cause of deaths related to floods is electrocution cause by damage power lines touching the floodwater. If you see damaged power lines notify the local electric company as soon as possible.
  • Evacuate if needed. If local officials order an evacuation, leave immediately and go to a safe shelter, hotel or a relatives’ house.
  • Look before you step. After a flood, the ground may be covered with dangerous debris including broken glass, sharp metals, nails and fence planks.

How to prepare for flooding


Build an emergency flood kit

If the power goes out, access to normal utilities will be affected, having an emergency kit with the following will be beneficial:

  • Flashlights
  • Batteries
  • First aid kit
  • Money 
  • Knives
  • Medication
  • Tools (knives, duct tape, hammer etc...)

Keep important documents in your kit

Keep flood insurance, birth certificates, passports, medical history and drivers’ licenses in a waterproof kit. For more information on building a flood kit, visit  ready.gov


Don’t forget about your pets

Build a kit for your pets which include food, water, tags, leashes, medication and medical history.


Have a plan

Talk to your family about where to go and what to do during a flood emergency.


Flood Prevention

The City of San Marcos, like all urban areas faces risks to life and property from natural and man-made hazards, including drought, tornados, wildfires, and floods. Most notably, of all these risks, flooding currently poses the greatest threat to the residents of San Marcos. To find more information regarding San Marcos floodplain information, please visit the City’s Floodplain Management Program 

For more information on flooding, please visit the following sites: