flood·​plain | \ˈfləd-ˌplān \

Definition of floodplain 

1 : level land that may be submerged by floodwaters

2 : a plain built up by stream deposition

Examples of floodplain in a Sentence

Recent Examples on the Web

Millions of tons of sediment polluted with lead, arsenic, cadmium and zinc remain—in the Coeur d’Alene River, groundwater, lakes, floodplains and hillsides. Sena Christian, Newsweek, "Bunker Hill Superfund Site Is Still a Toxic Mess, With Legacy of Suffering," 12 June 2016 Derosier points to the fact that this area is also home to floodplain forests, wetlands and managed wetlands, which are all helpful at absorbing floodwaters. Michigan Wildlife Council, Detroit Free Press, "Polishing a gem: Plan aims for St. Clair-Detroit River system improvements," 10 July 2018 These floodplains are going to be studied for years. Katherine Feser, Houston Chronicle, "Q&A: Land broker Stan Creech says land prices are up with oil," 20 June 2018 Suitable plants are more likely to come from low areas with frequent moisture, such as river floodplains or the edges of wetlands. Beth Botts, chicagotribune.com, "'Plants aren’t sponges': Soil that's too wet, too long can spoil your garden," 6 June 2018 Waters within the 100-year floodplain or within 4,000 feet of the high tide line would be treated similarly under the Obama approach. Ariel Wittenberg, Science | AAAS, "Obama’s wetlands protection rule put ‘too much emphasis’ on science, Trump officials argue," 5 July 2018 That’s putting a premium on properties that did not flood and are not in the floodplain. Katherine Feser, Houston Chronicle, "Q&A: Land broker Stan Creech says land prices are up with oil," 20 June 2018 The fruit bloom coincides with the annual flooding, when fish spend as much as 87 percent of their time in the floodplain. Adam Popescu, National Geographic, "These Fish Keep Forests Alive—And Fishing Threatens Them," 12 June 2018 Mahoney lives about a mile south of Haverstick Woods in the floodplain of the White River. Emily Hopkins, Indianapolis Star, "Nora residents sue the city over controversial zoning decision," 6 June 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'floodplain.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of floodplain

1873, in the meaning defined at sense 1

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Last Updated

10 Oct 2018

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Time Traveler for floodplain

The first known use of floodplain was in 1873

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English Language Learners Definition of floodplain

: an area of low, flat land along a stream or river that may flood

: an area of land built up from soil left by floods


flood·​plain | \ˈfləd-ˌplān \

Kids Definition of floodplain

: low flat land along a stream that is flooded when the stream overflows

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Britannica.com: Encyclopedia article about floodplain

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