Flood Mitigation Strategies: Protecting Your Property

Home Elevation

Raising a structure above the base flood elevation is the gold standard of flood mitigation. FEMA building science research shows that elevating a home just one foot above the BFE reduces flood damage by approximately 80%. While the upfront cost is significant ($30,000-$100,000+), the long-term savings in avoided damage and reduced insurance premiums often justify the investment for properties in high-risk flood zones.

Flood Barriers and Shields

Temporary and permanent flood barriers protect properties during flood events. Options range from sandbags (the most basic) to engineered flood shields that seal doorways, windows, and other openings. Permanent flood walls around a property can divert water away from structures. These solutions are most effective for properties facing shallow flooding of 1-3 feet.

Flood Vents and Openings

Flood vents (also called hydrostatic openings) allow water to flow through enclosed areas beneath elevated buildings, equalizing pressure and preventing structural damage. FEMA requires a minimum of one square inch of net open area per square foot of enclosed area. Properly installed flood vents can also reduce flood insurance premiums.

Sump Pumps and Drainage

Interior drainage systems with sump pumps remove water that enters a building's foundation. Battery-backup sump pumps provide protection during power outages, a common occurrence during flood events. French drains around a foundation redirect groundwater away from the structure. These systems are particularly effective for preventing basement flooding in areas with high water tables.

Backflow Prevention

Sewer backflow is a common and destructive type of flood damage. Backflow valves prevent sewage from backing up into buildings when municipal sewer systems are overwhelmed. These devices cost $1,000-$5,000 installed and can prevent thousands of dollars in damage from contaminated water entering a home.

Landscape and Grading

Proper grading ensures water flows away from a building's foundation rather than toward it. The ground should slope at least 6 inches over the first 10 feet away from the foundation. Rain gardens, swales, and permeable surfaces can absorb stormwater before it reaches structures. These green infrastructure solutions are cost-effective and provide environmental benefits.

Flood-Resistant Materials

Using flood-resistant materials for construction below the BFE minimizes damage when flooding occurs. Concrete, ceramic tile, pressure-treated wood, and closed-cell foam insulation resist water damage. Replacing carpet with tile, moving electrical panels above the BFE, and using water-resistant drywall can dramatically reduce repair costs after a flood.

FEMA Mitigation Grants

FEMA offers several grant programs that can fund flood mitigation projects:

• Hazard Mitigation Grant Program (HMGP), Available after a presidential disaster declaration, covers up to 75% of eligible mitigation costs
• Flood Mitigation Assistance (FMA), Targets NFIP-insured properties, prioritizes properties with repeated flood claims
• Building Resilient Infrastructure and Communities (BRIC), Annual competitive grant program for large-scale mitigation projects

Getting Started

Start by checking your county's flood risk score on our county rankings page. Review your FEMA flood map to understand your zone designation. Contact your local floodplain manager about available mitigation programs and permits. Visit FloodSmart.gov for additional resources on protecting your property.