Clear, accurate real estate definitions 1,442 terms 6 topics Free A–Z glossary
Property Types & Construction

Flood Plain

Definition and meaning of Flood Plain in real estate.

A flood plain is a flat or low-lying area of land adjacent to a river, stream, or coastal waterway that is naturally susceptible to flooding during periods of high water.

In more detail

Government agencies map these areas to determine flood risk levels, which directly affect local zoning laws and building regulations. Properties located within a one-hundred-year flood plain have a one percent chance of flooding in any given year, which translates to a high cumulative risk over a typical thirty-year mortgage.

Developing land in these zones often requires elevating structures, installing specialized drainage, or using flood-resistant materials. Buyers and investors must research flood plain status before purchasing, as it impacts property value, insurance costs, and future development potential.

Key facts

CategoryProperty Types & Construction
Regulated byLocal zoning and federal guidelines
High-risk designationOne-hundred-year flood plain
Impact on buyersHigher insurance costs and building restrictions
Example

A developer interested in buying a vacant parcel of land reviews local zoning maps and discovers the property lies within a flood plain, meaning any new home built there must be elevated above the base flood level.

Frequently asked questions

What does the term one-hundred-year flood mean?

It refers to a flood event that has a one percent probability of occurring in any single year, not an event that happens exactly once every one hundred years.

Can you build a house in a designated flood plain?

Yes, but local building codes in many states require specialized engineering, elevated foundations, and proper permits to minimize flood risk.

Related terms