coulee (n.)youdaoicibaDictYouDict
"deep ravine, seasonally flooded," 1804, a North American word, originally in areas explored by French trappers, from French coulée "flow" (17c.), from fem. past participle of couler "to flow," from Latin colare "to filter, strain" (see colander).
flood (v.)youdaoicibaDictYouDict
1660s, "to overflow" (transitive), from flood (n.). Intransitive sense "to rise in a flood" is from 1755. Related: Flooded; flooding.
irrigate (v.)youdaoicibaDictYouDict
"supply land with water," 1610s, from Latin irrigatus, past participle of irrigare "lead water to, refresh, irrigate, flood," from assimilated form of in- "into, in, on, upon" (see in- (2)) + rigare "to water, to moisten," of uncertain origin, perhaps cognate with rain. Related: Irrigated; irrigating. In Middle English it was an adjective, "watered, flooded" (mid-15c.).