floodplain
/ˈflʌdˌpleɪn/
noun
- A flat area of land next to a river that is often covered with water when the river overflows.
- Many species of birds nest in the wetlands of the floodplain.
- Farmers grow crops on the fertile floodplain after the waters recede.
- The city built levees to protect the floodplain from seasonal flooding.
Synonyms