 | This posting continues some of the common terms and definitions* found in the wetlands regulatory world. Navigable waters - “Those waters that are subject to the ebb and flow of the tide and/or are presently used, or have been used in the past, or may be susceptible for use to transport interstate or foreign commerce” (33 CFR 329(4)). No Net Loss - Goal that the nation's wetlands resource base be maintained, as provided for in the |
Water Resources Development Act and in numerous state laws. Individual actions may result in a loss of wetland functions when it is not practicable to replace them, but overall the stated goal is to maintain, and in the long run increase, the size and quantity of the resource base.
Obligate wetland plants (OBL) - For purposes of jurisdictional delineation, the 1987 Corps Manual identifies obligate wetland plants (OBL) as plants that occur almost always (estimated probability >99 percent) in wetlands, but which may also occur rarely (estimated probability <1 percent) in non-wetlands.
Off-site mitigation - Compensatory mitigation on a different parcel of land than that on which the impacted wetland was located.
On-site mitigation - Compensatory mitigation on the parcel of land where the impacted wetland is located.
Ordinary high-water mark - “The line on the shore established by the fluctuations of water and indicated by physical characteristics such as a clear, natural line impressed on the bank; shelving; changes in the character of soil; destruction of terrestrial vegetation; the presence of litter and debris; or other appropriate means that consider the characteristics of the surrounding area” (33 CFR 328.3(e)).
Out-of-kind mitigation - Compensatory mitigation that replaces an impacted wetland by restoring, enhancing, or creating a wetland of a different kind.
Oxidation - Chemical loss of an electron; often indicates presence of oxygen, as when ferrous iron (Fe2+) is transformed to ferric iron (Fe3+).
Oxidized root channel - Channels and soil surrounding living roots and rhizomes of hydrophytic plants in which iron oxidation occurs due to oxygen transport via the root system to the otherwise reduced soil matrix.
Palustrine System - All non-tidal wetlands dominated by trees, shrubs, persistent emergents, emergent mosses or lichens, and all such wetlands that occur in tidal areas where salinity due to ocean-derived salts is below 0.5 ppt. It also includes wetlands lacking such vegetation, but with all of the following four characteristics: (1) area less than 8 ha (20 acres); (2) active wave-formed or bedrock shoreline features lacking; (3) water depth in the deepest part of basin less than 2 m at low water; and (4) salinity due to ocean-derived salts less than 0.5 ppt (Cowardin et al. 1979).
Persistent vegetation - Vegetation that remains erect in a wetland until the next growing season (Cowardin et al. 1979).
Plant community - A vegetative complex unique in its combinations of plants, usually determined by combinations of environmental influences.
Ponded - Referring to the condition in which free water covers the soil surface and is removed only by percolation, evaporation, or transpiration. No surface outlet is available for ponded water.
Practicable (alternatives) - For the purposes of Section 404 mitigation, “...available and capable of being done after taking into consideration cost, existing technology, and logistics in light of overall project purposes” (40 CFR 230.3(q)).
- JMB
*Source: Wetlands Management Book, Environmental Laboratory (ERDC/EL SR-00-16) by Carolyn B. Schneider and Steven W. Sprecher, December 2000.
Obligate wetland plants (OBL) - For purposes of jurisdictional delineation, the 1987 Corps Manual identifies obligate wetland plants (OBL) as plants that occur almost always (estimated probability >99 percent) in wetlands, but which may also occur rarely (estimated probability <1 percent) in non-wetlands.
Off-site mitigation - Compensatory mitigation on a different parcel of land than that on which the impacted wetland was located.
On-site mitigation - Compensatory mitigation on the parcel of land where the impacted wetland is located.
Ordinary high-water mark - “The line on the shore established by the fluctuations of water and indicated by physical characteristics such as a clear, natural line impressed on the bank; shelving; changes in the character of soil; destruction of terrestrial vegetation; the presence of litter and debris; or other appropriate means that consider the characteristics of the surrounding area” (33 CFR 328.3(e)).
Out-of-kind mitigation - Compensatory mitigation that replaces an impacted wetland by restoring, enhancing, or creating a wetland of a different kind.
Oxidation - Chemical loss of an electron; often indicates presence of oxygen, as when ferrous iron (Fe2+) is transformed to ferric iron (Fe3+).
Oxidized root channel - Channels and soil surrounding living roots and rhizomes of hydrophytic plants in which iron oxidation occurs due to oxygen transport via the root system to the otherwise reduced soil matrix.
Palustrine System - All non-tidal wetlands dominated by trees, shrubs, persistent emergents, emergent mosses or lichens, and all such wetlands that occur in tidal areas where salinity due to ocean-derived salts is below 0.5 ppt. It also includes wetlands lacking such vegetation, but with all of the following four characteristics: (1) area less than 8 ha (20 acres); (2) active wave-formed or bedrock shoreline features lacking; (3) water depth in the deepest part of basin less than 2 m at low water; and (4) salinity due to ocean-derived salts less than 0.5 ppt (Cowardin et al. 1979).
Persistent vegetation - Vegetation that remains erect in a wetland until the next growing season (Cowardin et al. 1979).
Plant community - A vegetative complex unique in its combinations of plants, usually determined by combinations of environmental influences.
Ponded - Referring to the condition in which free water covers the soil surface and is removed only by percolation, evaporation, or transpiration. No surface outlet is available for ponded water.
Practicable (alternatives) - For the purposes of Section 404 mitigation, “...available and capable of being done after taking into consideration cost, existing technology, and logistics in light of overall project purposes” (40 CFR 230.3(q)).
- JMB
*Source: Wetlands Management Book, Environmental Laboratory (ERDC/EL SR-00-16) by Carolyn B. Schneider and Steven W. Sprecher, December 2000.
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