Our flood model can’t account for personal flood reduction measures like raised homes. Therefore, these features aren’t considered in Flood Factor scores.
First Street Foundation works to include as many public and community adaptation features as possible into our model. However, because no comprehensive national inventory of adaptation features presently exists, our model may not take into account personal mitigation features.
What are personal flood protection measures?
Solutions to protect your home vary in terms of cost, effort, time to implement, and effectiveness. Structural options can help flood-proof a home to mitigate physical damage, or make a property more absorbent to reduce runoff and prevent flooding.
Elevating your home
Houses can be raised above flood levels with six-foot tall wooden stilts or concrete blocks. Even if a house doesn’t flood, the driveway and the roads around it still may. It is easier for a new home to be built higher, but existing homes can also be raised. Rebuilding typically occurs when FEMA grants money after a disaster like Hurricane Harvey. These grants can cover the majority of the cost of rebuilding. The median price of elevating a home is $130,000. An important first step is to contact the local zoning and building departments prior to making any improvements.
Rain garden installation
A rain garden is a garden in a depressed area of a landscape that is designed to temporarily hold and soak in rainwater. Rain gardens reduce runoff from roofs, streets, and/or driveways. The amount of gallons of rainwater that a rain garden can hold depends on the square footage of the catchment area and the depth of the rain garden. In general, rain gardens are typically built to hold 1 inch of rainwater. The cost of rain gardens varies depending on whether you do it yourself or hire a contractor; costs can range from $5 - $45 per square foot. Some communities offer incentives to support the installation of rain gardens. Check your local government website to learn more.
Rain garden in front of someone’s home (photo courtesy of Candace Stoughton, August 2010)
Install a water removal system in any area (sump) that water collects to be moved (pumped) off of your property. Sump pumps keep basements dry by pumping out water away from a house to a higher ground level or a municipal storm drain. This can reduce humidity and prevent mold and mildew. For larger floods, heavy-duty flood mitigation pumps that meet ANSI 2510 standards can be used with perimeter flood barriers.
Adaptation features included on Risk Factor
In an effort to create as accurate a flood model as possible, the First Street Foundation’s data team created the nation’s first flood adaptation database. By researching and locating green and grey infrastructure, scientists are able to mark an area as either protected or semi-protected from flooding. Close attention is paid to whether a structure is designed to protect against pluvial, fluvial, tidal flooding or a combination of the three.
Insights on local histories of flooding and the construction of flood-protection infrastructure can be found in a variety of ways including news reports, public meeting minutes, and foundation funded studies. It is possible to find all kinds of information in these reports such as information on when projects were built, how much they cost, who paid for them, the community or area they serve, and what type of scenario they were created for. A great deal is learned about what types of flooding is most intrusive to a place within this research stream in addition to what has been done to address it. Adaptation data is sourced from State-level GIS databases, Coastal Zone Management Authorities, the Georgetown Climate Adaptation Clearinghouse, Army Corps of Engineers, and groups such as the American Society of Adaptation Professionals (ASAP).
Use Risk Factor to find the only property-specific flood risk assessments that consider community-level flood mitigation structures.
Why we cannot account for personal flood control features
Information on community level flood control features are well documented and publicly available. However, personal adaptation features are just that -- personal!
Our flood model cannot account for personal adaptations you may have installed at this time. Personal adaptation features such as sump pumps are not designed to protect against a certain source of flooding. Without publicly available information we cannot determine the size of the geographic area or the exact depth of flooding the feature protects against. While property-specific flood reduction measures may reduce the risk to its structure, they are not included in Flood Factor scores due to the aforementioned reasons.