Flood Barrier and Protection

Flooding is a common natural hazard in Louisiana. Research estimates flooding will cost the state billions of dollars by 2050.

Additional elevation above the base flood elevation, or freeboard, is the best way to protect a home from flooding. Flood barriers are another method to protect a home and may be more cost effective to install on an existing home.

There are many different kinds of flood barriers available to homeowners. Some fixtures are more expensive and permanent while others are quickly set up prior to a flood.

Floodwalls

Floodwalls are permanent barriers around a home that block the flow of water to the home. This option requires a professional to properly install and brace the floodwall. Immediately before a flood event, a temporary wall can be installed on any walkway or opening to secure the floodwall.

• Materials: Most floodwalls are made of reinforced concrete, but other materials like brick, stone or steel can also be used. Decorative materials like bricks or blocks can integrate the wall into the building’s architecture and aesthetic.
• Cost: Floodwalls average $150 per linear foot plus labor to install.
• Advantages: They are more resistant to erosion than levees and can be customized to match your home’s aesthetic.
• Considerations: A floodwall requires a solid foundation, regular maintenance (repair cracks, reapply waterproof sealants) and adherence to local regulations and permits.

Temporary Floodwalls

Temporary flood barriers are portable and ideal for short-term use during flood emergencies. Before a flood event, these can be installed around the perimeter of a property to block water intrusion and then taken down after.

• Uses: Temporary floodwalls are emergency protection for low-lying areas or a supplement to permanent flood barriers.
• Cost: Metal or plastic panel systems are typically $50-$150 per square foot.
• Advantages: They are easy to install and remove and can be stored for future use.
• Limitations: Temporary structures are less durable and protective than permanent floodwalls and require assembly before a flood event.

Water-Inflated Barriers

Water-inflated barriers are additional inexpensive and temporary solutions. These large, cylindrical tubes are placed around a property and filled with water prior to a flood event.

• Installation:
  • Select areas to protect.
  • Level the ground and remove debris.
  • Unroll the barrier and inflate with a garden hose.
  • Anchor in place for stability.
• Cost: $20-$50 for small barriers, $100-$300 for larger ones.
• Advantages: These offer quick deployment and are cost-effective and reusable.
• Materials: The outer layer is made of PVC or polyethylene, and the inner tubing holds water.

Sandbags

Sandbags are a simple, versatile option for temporary flood protection. Sandbags are often distributed by local governments prior to a flood. While they do require more work to make and install, sandbags can effectively protect a property when installed correctly.

• Uses: Sandbags are best for secondary defense or filling gaps in existing barriers.
• Cost: They are low-cost, often free from local authorities during emergencies.
• Placement:
  • Fill bags halfway for easier handling.
  • Stack in a pyramid shape for stability.
  • Stagger the rows of bags so there is not a continuous gap
  • Use plastic sheeting for added water resistance.
• Limitations: Sandbags are labor-intensive and less effective for last-minute protection.

Choosing the Right Flood Barrier

When selecting a flood barrier, consider:

• Flood risk: Assess your area’s flood history and potential water levels.
• Budget: Balance up-front costs with long-term savings on potential flood damage and insurance premiums.
• Purpose: Determine whether you need permanent protection or temporary solutions.
• Regulations: Always adhere to local codes and permitting requirements.

“This work was funded as part of Program Project ID R/CH-12_ELWD through the Louisiana Sea Grant College Program under the National Oceanic and Atmospheric Administration Award NA24OARX417C0149.”