Mitigation Strategies

Mitigation Strategies for Flood Hazard

There are some mitigation actions that both renters and homeowners can take, while other actions can only be taken by the owner of a home. Below, we have color-coded the actions that both renters and homeowners can take in blue, and the actions for homeowners in orange. The mitigation recommendations and costs in this guideline come from FEMA and other credible sources for natural hazard mitigation information. You can find references and suggestions for further advice at the end of this section.

For Homeowners and Renters

1 Buy flood insurance

While flood insurance will not keep your home or belongings from being damaged, it can help you recover at least some of the costs of damage. Renters can purchase flood insurance for their personal belongings, while homeowners should insure both the building and their belongings.


2 Move your belongings to a higher place during floods

If your home is in danger of flooding, move electronics, important paperwork, and belongings that may be easily damaged or have sentimental value off the ground.


3 Use sandbags or other methods to keep water from entering your home

Single Sandbag Placement
Figure. Single Sandbag Placement

Sandbags are an effective temporary way to reduce flood damage. They can keep floodwaters away from building openings (doors, windows), outside walls, or other vulnerable building components (e.g., outdoor HVAC units). When there is no strong current, waves, or danger from floating debris that could topple the bags, a single row is fine. If flooding involves waves, strong currents, or large debris, you may need to create a wall that is two rows wide. Here are the steps to mitigate flood with sandbags correctly:

  • Make sure that the bag flap is folded under, facing away from potential floodwater. If using a tied bag, flare the tied end out.
  • Place the bag lengthwise, parallel to the direction of the water flow.
  • Tamp down on the top of the sandbags before placing the next row to help create a better seal.
  • When stacking bags two or three layers high, make sure the top layer overlaps the bottom layer, similar to the process for laying bricks. Stacks that are more than three layers high (approximately 1 foot) may topple over, so you may want to add a second row of bags to make the stack wider.
  • Make sure to add a waterproof layer between the sandbags and the building door. A waterproof plastic or canvas should work. Secure the layer by taping it to the door frame.

Estimated cost: The number of sandbags you need determines the cost. Your municipality may provide sandbags to residents for free (though you may have to fill them yourself). If you purchase a 40-bag pallet of sandbags from a home improvement store, cost is about $470 (from HomeDepot.com, 2021).

Sandbag Calculator

This calculator estimates the number of sandbags you will need to build a sandbag wall one row high and one row wide. If you need a wider or taller stack, multiply this by the number of additional rows of sandbags you will need. You should also use your own judgement to estimate the correct number of sandbags.

  • How long does your row of sandbags need to be (feet)?
  • What is the projected flood height (feet)?
  • What is the size of sandbags when laid flat? (The default values here are for one of the common Home Depot flood protection sandbags, 15"x11"x3" when lying flat. If you have different-sized sandbags, you can change the default values.)
    • Sandbag Length (inches):
    • Sandbag Width (inches):
    • Sandbag Height (inches):
  • Total number of sandbags required: 0

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For Homeowners

4 Increase your home’s elevation (add or increase freeboard)

Flood elevation on pilings
Figure. Flood elevation on pilings

One of the most effective ways to mitigate residential buildings against flooding is to raise the first-floor elevation of the buildings above the base flood elevation (BFE, the elevation level required by most building codes) or above the historical high water mark. In inland areas, you can increase the freeboard (feet above BFE) using pier and beams, slab on fill, or stem wall foundations. In coastal areas, buildings must be elevated using pilings.

Estimated cost: Elevating buildings during the construction process only increases the construction cost by a small percentage. For instance, 3 ft. elevation above BFE only increases the construction cost by about 3.56% ($8,000 for a single-family home with 1,500 sq. ft. floor area). However, elevating existing buildings is much more expensive. Cost depends on variables such as the level of elevation, foundation type, and number of stories. For more details on potential costs, contact a certified contractor.


5 Raise or floodproof HVAC equipment

Raise or floodproof HVAC equipment (FEMA 2008)
Figure. Raise or floodproof HVAC equipment (FEMA 2008)

Heating, ventilation, and cooling (HVAC) equipment, such as a furnace or hot water heater, can be damaged extensively if it is inundated by flood waters. A good way to protect HVAC equipment is to move it from the basement or lower level of the structure to an upper floor or even to the attic. Another option is to construct a concrete floodwall around the HVAC components

Estimated cost: Having your furnace and hot water heater moved to a higher floor or to the attic will cost about $1,500. The cost of a floodwall will depend partly on its height and length. A 3-foot-high wall with a perimeter length of 35 feet would cost approximately $2,500 (based on a 2008 FEMA estimate).


6 Build with flood damage resistant materials

Practices for building with flood damage resistant materials (FEMA 2008)
Figure. Practices for building with flood damage resistant materials (FEMA 2008)

Constructing a building with materials that are more resistant to flood damage like polyester epoxy paint or decay resistant wood can provide some protection.


7 Wet floodproofing

Wet floodproofing flood mitigation (FEMA 2008)
Figure. Wet floodproofing flood mitigation (FEMA 2008)

Wet floodproofing is a technique to allow flood waters easily enter and exit the enclosed areas of a house during flood events. Flood waters inside the house can rise and fall quickly at the same rate as flood waters outside. This decreases the effects of hydrostatic pressure, including buoyancy (when flood waters make a building float). As a result, the likelihood of structural damage may be greatly reduced. Wet floodproofing is generally used to limit damages to enclosures below elevated buildings, walkout-on-grade basements, below-grade basements, crawlspaces, or attached garages. It is not practical for areas that are to be used as living space. In wet floodproofing you need to make sure to:

  • protect the areas of the house that are below the flood level from damage caused by contact with flood waters
  • protect service equipment inside and outside the house
  • relocate any materials stored below the Flood Protection Elevation (FPE)

Estimated cost: The cost can be obtained by contacting building contractors.


8 Install sewer backflow valves

Sewer backflow valves (FEMA 2008)
Figure. Sewer backflow valves (FEMA 2008)

In some flood-prone areas, flooding can cause sewage from sanitary sewer lines to back up through drain-pipes. A good way to protect your property from sewage backups is to install backflow valves, which are designed to block drain-pipes temporarily and prevent return flow.

Estimated cost: Having a plumber or contractor install one backflow valve will cost approximately $1,400 for a combined gate/flap valve or about $600 for a flap valve. These figures include the cost of excavation and backfilling (based on a 2008 FEMA estimate).


9 Raise electrical system components like outlets and switches above potential flood waters

Raise electrical system components (FEMA 2008)
Figure. Raise electrical system components (FEMA 2008)

Electrical system components, including service panels (fuse and circuit breaker boxes), meters, switches, and outlets, are easily damaged by flood water. If they are inundated for even short periods, they will probably have to be replaced. Another serious problem is the potential for fires caused by short circuits in flooded systems. Raising electrical system components helps you avoid those problems.

Estimated cost: Raising the electrical service panel, meter, and all of the outlets, switches, and wiring in a 1,000-square-foot, single-floor structure will cost about $1,500 to $2,000. If this work is performed during the repair of a damaged structure or construction of a new structure, the cost may be much lower (based on a 2008 FEMA estimate).


10 Anchor fuel tank securely

If you have an external fuel tank, it can tip over or float away in a flood, causing fuel to spill or catch fire. Cleaning up a house that has been inundated with flood waters containing fuel oil can be extremely difficult and costly. Fuel tanks should be securely anchored to the ground. Make sure vents and fill-line openings are above projected flood levels. Propane tanks are the property of the propane company. You’ll need written permission to anchor them. Be sure all work conforms to state and local building codes.


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Mitigation Strategies for Wind Hazard

There are some mitigation actions that both renters and homeowners can take, while other actions can only be taken by the owner of a home. Below, we have color-coded the actions that both renters and homeowners can take in blue, and the actions for homeowners in orange. The mitigation recommendations and costs in this guideline come from FEMA and other credible sources for natural hazard mitigation information. You can find references and suggestions for further advice at the end of this section.

For Homeowners and Renters

1 Get insurance for wind hazard

Make sure your insurance policy covers wind damage.


2 Keep doors and windows closed

During a tropical storm, hurricane, thunderstorm, or tornado, be sure to keep all your doors and windows closed.


3 Bring everything not attached to the ground indoors

Lawn furniture, decorations, and other outdoor objects can easily be picked up by the wind and cause damage to your house or to your neighbors’. Before a storm, be sure to put them inside a securely anchored shed, garage, or your house.


4 Stay away from windows

During a storm, be sure to stay away from windows to avoid being injured by broken glass or other objects that may hit the windows in high winds.

For Homeowners

5 Install shutters

High winds and windblown debris can easily break unprotected windows and cause doors to fail. Once wind enters a structure, the likelihood of severe structural damage increases, and the contents of the building will be exposed to the elements. The most reliable method of protecting windows and doors is installing permanent storm shutters. Alternatives include using temporary plywood covers, mesh, or screen systems, and replacing existing windows and doors with impact-resistant windows and doors. Shutters should be attached to the structural framing of the house surrounding the window and door openings and not directly to the window or door frames.

Estimated cost: Storm shutters can cost $50 to $60 per square foot of window. A set of shutters for a 3-foot by 4-foot window will cost approximately $600 to $720. The cost of a plywood cover will also depend on the size of the window. If you do the work yourself, you can expect plywood to cost about $1.50 per square foot. Screws or lag bolts, including washers, will cost about $0.10 to $0.15 each. This figure covers only the materials you will have to buy and excludes the cost of any tools you use and the value of your time. If you hire a contractor or handyman to do the work, you will have to pay for time as well as materials (based on a 2008 FEMA estimate; the plywood cost updated from HomeAdvisor website in 2021).


6 Use impact-resistant glass products

Hurricane windows or impact-resistant glass products are an alternative to shutters for windows, especially in high-rise buildings.

Estimated cost: Hurricane impact-resistant windows typically cost $2,423 and $13,179, or $7,657 on average. Each window is about $90 to $400 and takes about two hours to install at $30 to $65 per hour. You’ll pay more if you have custom storm windows installed (HomeAdvisor, 2021).


7 Reinforce or replace garage doors

High winds from hurricanes and tornadoes can damage garage doors or even blow them in. If wind enters a garage, it can cause dangerous and expensive structural damage. Reinforcing your garage door helps to protect not only your garage but its contents as well.

Estimated cost: If you hire a contractor to reinforce an existing two-car garage door, you can expect to pay about $300. The cost of replacing a door, including installation, can vary greatly, depending on the size and type of door (based on a 2008 FEMA estimate).


8 Get a Certified FORTIFIED Roof

A FORTIFIED Roof is a construction standard that includes several mitigation strategies for making roofs stronger in high winds and tropical storms. It was specifically designed to prevent damage that commonly occurs during high winds, hurricanes, hailstorms, severe thunderstorms, and even tornadoes. It helps homes better withstand severe weather by keeping the roof on and keeping water out.


9 Maintain exterior insulation finishing system (EIFS) walls

Maintain EIFS walls (FEMA 2008)
Figure. Maintain EIFS walls (FEMA 2008)

An EIFS wall typically consists of several layers of materials sandwiched together into a single panel, which is then attached to a substrate mounted on the wall studs. The exterior of an EIFS wall is water resistant, but the wall can be weakened by moisture that becomes trapped behind the wall. The sources of this moisture are usually leaks around doors and windows and where the wall joins the roof. Once an EIFS wall has been weakened, it is more likely to be torn away or penetrated by high winds and windborne debris. If wind enters a building, the likelihood of severe structural damage increases, and the contents of the building will be exposed to the elements.

Estimated cost: EIFS wall costs vary; however, the cost of a typical EIFS wall is approximately $4 to $6 per square foot (based on a 2008 FEMA estimate).


10 Properly site trees and remove potential windborne missiles

Remove trees and potential windborne missiles (FEMA 2008)
Figure. Remove trees and potential windborne missiles (FEMA 2008)

If the area immediately surrounding your home contains trees, outbuildings, trash cans, yard debris, or other materials that can be moved by the wind, your house will be more likely to be damaged during a hurricane or tornado. You should ensure that all trees on your property are far enough away to prevent them from damaging your home if they should fall. The distance between the structure and any nearby tree should always be greater than the height the tree will reach when it is fully grown. All storage sheds and other outbuildings should be securely anchored.

Estimated cost: If you hire a contractor to remove a large tree, you can expect to pay about $1,000 to $1,500. Having a contractor anchor a storage shed with straps and ground anchors will cost about $100 to $200 (based on a 2008 FEMA estimate).


11 Secure metal siding and metal roofs

Secure metal siding and metal roofs (FEMA 2008)
Figure. Secure metal siding and metal roofs (FEMA 2008)

Metal siding and roofing in high-wind areas should be securely attached to the frame of the building with exposed fasteners such as screws or bolts or with concealed clips. The spacing of the fasteners or clips will depend on their strength and on the design and strength of the siding and roofing panels.


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Mitigation Strategies for Wildfire Hazard

There are some mitigation actions that both renters and homeowners can take, while other actions can only be taken by the owner of a home. Below, we have color-coded the actions that both renters and homeowners can take in blue, and the actions for homeowners in orange. The mitigation recommendations and costs in this guideline come from FEMA and other credible sources for natural hazard mitigation information. You can find references and suggestions for further advice at the end of this section.

For Homeowners and Renters

1 Protect propane tanks and other external fuel sources

Safely using and storing necessary flammable materials, including machine fuels. Approved safety cans should be used for storing gasoline, oily rags, and other flammable materials. Firewood should be stacked at least 100 feet away from homes.


2 Get insurance for fire hazard

Be sure your insurance covers wildfire.

For Homeowners

3 Create defensible space around building

The primary way to mitigate wildfire hazard is to create defensible space around a building that can slow the spread of wildfire. This includes the following tips:

  • The distance from trees to the house should always be greater than the height of the full-grown tree, or at least 10 feet.
  • The distance from an outbuilding or shed to the house should always be greater than the height of the outbuilding.
  • Remove combustible materials, such as shrubs, brush, and woodpiles, out to a radius of 30 feet.
  • Prune and clear dead vegetation and cut high grass all around your home.
  • Increase the space between plants and trees. The spacing between grass, shrubs, and trees is crucial to reduce the spread of wildfires. The spacing needed is determined by the type and size of brush and trees, as well as the slope of the land.
  • Remove all tree branches below 6 feet from the ground.

Estimated cost: If you hire a contractor to remove a large tree, you can expect to pay about $1,000 to $1,500. The charge for removing smaller trees and shrubs would be less (based on a 2008 FEMA estimate).


4 Fire-resistant landscaping

Choose fire-resistant plants and materials for landscaping.

Estimated cost: The cost can be varied based on the kind and number of plants.


5 Replace roofing with fire-resistant materials

Some roofing materials, including asphalt shingles and especially wood shakes, are less resistant to fire than others. You can replace your existing roofing materials with slate, terra cotta (clay), or other types of tile, or standing-seam metal roofing.

Estimated cost: If you hire a contractor to replace your existing roof covering, you can expect to pay about $4 per square foot of roof area for tile or metal roofing and about $7 per square foot of roof area for slate. For example, a structure measuring 60 feet by 30 feet will have about 1,800 square feet of roof area. For this structure, tile or metal roofing would cost approximately $7,200 and slate would cost approximately $12,600 (based on a 2008 FEMA estimate).


6 Use non-combustible materials for construction of new buildings

Use materials such as stone, brick, and stucco for new construction in wildfire hazard areas.

Estimated cost: The cost can be obtained by contacting the building contractors.


7 Install fire mitigation systems such as interior and exterior sprinkler systems

Purchase and install external, structure-specific water hydration systems (sprinklers); dedicated power sources; and dedicated cisterns if no water source (e.g., lake, river, or swimming pool) is available.


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Mitigation Strategies for Tornado Hazard

There are some mitigation actions that both renters and homeowners can take, while other actions can only be taken by the owner of a home. Below, we have color-coded the actions that both renters and homeowners can take in blue, and the actions for homeowners in orange. The mitigation recommendations and costs in this guideline come from FEMA and other credible sources for natural hazard mitigation information. You can find references and suggestions for further advice at the end of this section.

For Homeowners and Renters

1 During a storm, stay away from windows, doors, and outside walls

A windowless basement or interior room on the bottom floor of a building is the safest place during a tornado.


2 Don’t stay in manufactured structures (mobile homes)

Manufactured structures or mobile homes are completely unsafe in a tornado. Identify an alternative shelter before a tornado watch or warning and prepare to evacuate to it quickly if needed.

For Homeowners

3 Build a safe room

A safe room built to FEMA standards, and storm shelter built to ICC 500 standards are among the best protective actions.


4 Make your building wind resistant

Wind mitigation features for hurricanes can also help make your home more resistant to tornadoes.

  • Structural bracing
  • Straps and clips
  • Anchor bolts
  • Laminated or impact-resistant glass
  • Reinforced pedestrian and garage doors
  • Window shutters
  • Waterproof adhesive sealing strips
  • Interlocking roof shingles

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Mitigation Strategies for Hail Hazard

There are some mitigation actions that both renters and homeowners can take, while other actions can only be taken by the owner of a home. Below, we have color-coded the actions that both renters and homeowners can take in blue, and the actions for homeowners in orange. The mitigation recommendations and costs in this guideline come from FEMA and other credible sources for natural hazard mitigation information. You can find references and suggestions for further advice at the end of this section.

Hail can cause substantial damage to roofs, landscaping, and other areas of the built environment. These techniques can minimize hail damage to new construction as well as existing buildings.

For Homeowners and Renters

1 Stay away from windows.

Staying away from windows can protect you from injury if hail breaks a window.

For Homeowners

2 Install hail-resistant roofing and siding materials

Roof sheathing, hail resistant roofing and siding, and impact resistant shingles can all help protect your home from hail damage. You can contact the Insurance Institute for Business and Home Safety (IBHS) to learn more about the most appropriate type of roof covering for your geographic region

Estimated cost: Costs can vary. For example, hail resistant shingles typically reduce a homeowner’s maintenance costs and cost 10-20% more than their non-impact counterparts.


3 Install other structural strengthening features

Construction features such as structural bracing, shutters, laminated glass in window-panes, and hail-resistant roof coverings or flashing in building design can minimize damage from hail.


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Mitigation Strategies for Lightning Hazard

There are some mitigation actions that both renters and homeowners can take, while other actions can only be taken by the owner of a home. Below, we have color-coded the actions that both renters and homeowners can take in blue, and the actions for homeowners in orange. The mitigation recommendations and costs in this guideline come from FEMA and other credible sources for natural hazard mitigation information. You can find references and suggestions for further advice at the end of this section.

For Homeowners and Renters

1 Do not use landline phones during lightning storms


2 Sign up for your community’s storm warning system


3 Unplug appliances during lightning storms

For Homeowners

4 Buy surge protectors, lightning rods, or a lightning protection system to protect your home, appliances, and electronic devices

Estimated cost: The cost to install a whole-home surge protector ranges from $300-$800.


5 Cut down or trim trees that may be in danger of falling on your home


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Mitigation Strategies for Extreme Cold Hazard

There are some mitigation actions that both renters and homeowners can take, while other actions can only be taken by the owner of a home. Below, we have color-coded the actions that both renters and homeowners can take in blue, and the actions for homeowners in orange. The mitigation recommendations and costs in this guideline come from FEMA and other credible sources for natural hazard mitigation information. You can find references and suggestions for further advice at the end of this section.

Extreme cold can range from near freezing temperatures in the southern United States to temperatures well below zero in the northern states. Extreme cold may cause water pipes to freeze and burst, which can cause flooding inside a building.

For Homeowners and Renters

1 Let a faucet drip during extreme cold weather to prevent the buildup of excessive pressure in the pipeline and avoid bursting

For Homeowners

2 Insulate pipes

A frozen pipe can lead to pipe busting and it can cost homeowner more than $5,000 in water damage.

Estimated cost: Pipe insulation can cost as little as 50 cents per linear foot. You can check your local hardware store for a more accurate cost estimate (Based on IBHS estimates).


3 Locating water pipes on the inside of building insulation and keep them out of attics, crawl spaces, and vulnerable outside walls


4 Add building insulation to walls and attics


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