You have likely seen photos of flood water damage, or heard stories from those who have been victims of a natural disaster. You may have even been through a flooding event yourself. However, you may not fully know how to protect your home from flood damage. There are several methods to ensure your home is less susceptible to flooding, a process known as flood mitigation.
Emergency Flood Preparation
In a flash flood situation, there is not much time for preparation, and little can be done to minimize flood damage. However, there are several proactive and immediate actions to consider. For example, turning off the electricity is a necessary step because the risk of electrocution is higher once the water comes into contact with any wiring. It is also imperative that electrical systems are unplugged and raised off the ground to assure these do not come into contact with floodwaters. And remember, cleaning out any gutters attached to a building allows water to flow through.
When a flood warning is issued, the local news stations will often announce a list of locations where sandbags are available. Sandbags are one of the simplest and most cost-effective methods to keep water out of your home. Sandbags divert the water from going into the structure; instead, the water travels around the structure. Unfortunately, sandbags are only meant to withstand up to two feet of water, and if wet for an extended period can break.
Structural Flood Mitigation Techniques
One of the most common flood mitigation techniques is wetproofing, which allows water to flow through a structure by adding flood openings. A flood opening, or flood vent, is a small gap where water can flow through an area of the building below the elevation level, such as a crawlspace or basement. When the water flows through these uninhabited spaces, the hydrostatic pressure created by floodwaters, which often leads to structural damage, is reduced. Buildings constructed in certain FEMA-designated flood zones are required to have these vents.
While flood vents enable water to flow through buildings, dry floodproofing protects your home without letting water inside. This technique is achieved by installing watertight doors and windows to a building or placing waterproof shields over the existing windows and door openings. Additionally, you can apply a waterproof sealant on the exterior of a building to help prevent moisture from becoming trapped and weakening the integrity of a building.
A more extreme dry floodproofing technique is using floodwalls, or temporary barriers constructed around a building to hold back floodwaters. When building a floodwall, remember that water needs an escape route when there is not a flood happening; therefore, creating a proper drainage system for rainwater is essential. Floodwall construction may require permits or specific approvals. If you want to use this method, check with your local code enforcement before building takes place.
Before the Waters Rise, Raise Your House
Elevating buildings is becoming a popular technique to mitigate flood risk. In many flood-prone areas, building codes require new construction to be built at a specific Design Flood Elevation, which signifies the base flood elevation of an area plus an additional height. A building with a higher elevation is more protected from possible flood damage because the water flows through the crawl space or piers used to lift the home. To raise an existing building, this involves lifting the structure from its original foundation and building a new foundation that consists of piers, columns, or pilings.
Flood mitigation can be expensive, but there are methods to make it more affordable. FEMA has a hazard mitigation program, which is a grant-based program available to the public. You can only qualify for this grant after a federal disaster has been declared in your area. If you receive this grant, FEMA will fund 75 percent of the project, leaving you responsible for the remaining costs. FEMA also has a flood mitigation assistance program, which is only available to states and counties. Many states and cities already possess granted funds for flood mitigation. Check with your local government to see if there is a flood mitigation program right for you.