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16 U.S.C. 831 et seq; E.O. 11988, 42 FR 26951; E.O. 11990, 42 FR 26961
91 FR 2485, Jan. 21, 2026, unless otherwise noted.
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The following definitions apply throughout this part.
(a) Floodplain refers to the lowland and relatively flat areas adjoining inland waters and reservoirs. Floodplain generally refers to an area that has a 1 percent or greater chance of flooding in any given year.
(b) Practicable refers to the capability of an action being performed within existing constraints. The test of what is practicable depends on the situation and includes an evaluation of all pertinent factors, such as environmental impact, economic costs, statutory authority, legality, technological achievability, and engineering constraints.
(c) Natural and beneficial floodplain and wetland values refer to such attributes as the capability of floodplains and wetlands to provide natural moderation of floodwaters, water quality maintenance, fish and wildlife habitat, plant habitat, open space, natural beauty, scientific and educational study areas, and recreation.
(d) Wetland refers to an area inundated by surface or ground water with a frequency sufficient to support, and that under normal circumstances does or would support, a prevalence of vegetation or aquatic life that requires saturated or seasonally saturated soil conditions for growth and reproduction. Wetlands do not include temporary human-made ponds associated with active construction projects.