Abstract:
Derived from WCSOIL, which was derived from the 2006 Westchester County Soil Survey, U.S. Department of Agriculture, Soil Conservation Service.
Hydric Soils
Westchester County, New York
Survey Area Version Date: 07/14/2006
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Percent
Map symbol and Component of map Landform Hydric Hydric
map unit name unit rating criteria
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Ce:
Carlisle muck Carlisle 70 Marshes, Swamps Yes 1, 3
Ff:
Fluvaquents-Udifluvents Fluvaquents 35 Flood plains Yes 2B3, 3, 4
complex, frequently flooded
Fr:
Fredon silt loam Fredon 80 Depressions Yes 2B3
Ip:
Ipswich mucky peat Ipswich 80 Tidal marshes Yes 1, 3, 4
LcA:
Leicester loam, 0 to 3 percent Leicester 70 Depressions Yes 2B3
slopes, stony
Pa:
Palms muck Palms 75 Marshes, Swamps Yes 1, 3
Pc:
Palms and Carlisle soils, Palms 40 Marshes, Swamps Yes 1, 3
Carlisle 35 Depressions Yes 1, 3
Ra:
Raynham silt loam Raynham 75 Depressions Yes 2B3
RdA:
Ridgebury loam, 0 to 3 percent Ridgebury 75 Depressions Yes 2B3
Sh:
Sun loam Sun 80 Depressions Yes 2B3, 3
Sm:
Sun loam, extremely stony Sun 75 Depressions Yes 2B3, 3
This table lists the map unit components that are rated as hydric soils in the survey area. This list can help in
planning land uses; however, onsite investigation is recommended to determine the hydric soils on a specific site
(National Research Council, 1995; Hurt and others, 2002).
The three essential characteristics of wetlands are hydrophytic vegetation, hydric soils, and wetland hydrology
(Cowardin and others, 1979; U.S. Army Corps of Engineers, 1987; National Research Council, 1995; Tiner, 1985).
Criteria for all of the characteristics must be met for areas to be identified as wetlands. Undrained hydric soils that
have natural vegetation should support a dominant population of ecological wetland plant species. Hydric soils that
have been converted to other uses should be capable of being restored to wetlands.
Hydric soils are defined by the National Technical Committee for Hydric Soils (NTCHS) as soils that formed under
conditions of saturation, flooding, or ponding long enough during the growing season to develop anaerobic conditions
in the upper part (Federal Register, 1994). These soils, under natural conditions, are either saturated or inundated
long enough during the growing season to support the growth and reproduction of hydrophytic vegetation.
The NTCHS definition identifies general soil properties that are associated with wetness. In order to determine
whether a specific soil is a hydric soil or nonhydric soil, however, more specific information, such as information about
the depth and duration of the water table, is needed. Thus, criteria that identify those estimated soil properties unique
to hydric soils have been established (Federal Register, 2002). These criteria are used to identify map unit
components that normally are associated with wetlands. The criteria used are selected estimated soil properties that
are described in "Soil Taxonomy" (Soil Survey Staff, 1999) and "Keys to Soil Taxonomy" (Soil Survey Staff, 2003) and
in the "Soil Survey Manual" (Soil Survey Division Staff, 1993).
If soils are wet enough for a long enough period of time to be considered hydric, they should exhibit certain
properties that can be easily observed in the field. These visible properties are indicators of hydric soils. The
indicators used to make onsite determinations of hydric soils are specified in "Field Indicators of Hydric Soils in the
United States" (Hurt and others, 2002).
Hydric soils are identified by examining and describing the soil to a depth of about 20 inches. This depth may be
greater if determination of an appropriate indicator so requires. It is always recommended that soils be excavated and
described to the depth necessary for an understanding of the redoximorphic processes. Then, using the completed
soil descriptions, soil scientists can compare the soil features required by each indicator and specify which indicators
have been matched with the conditions observed in the soil. The soil can be identified as a hydric soil if at least one of
the approved indicators is present.
Map units that are dominantly made up of hydric soils may have small areas, or inclusions, of nonhydric soils in the
higher positions on the landform, and map units dominantly made up of nonhydric soils may have inclusions of hydric
soils in the lower positions on the landform.
The criteria for hydric soils are represented by codes in the table (for example, 2B3). Definitions for the codes are
as follows:
1. All Histels except for Folistels, and Histosols except for Folists.
2. Soils in Aquic suborders, great groups, or subgroups, Albolls suborder, Historthels great group, Histoturbels great
group, Pachic subgroups, or Cumulic subgroups that:
A. are somewhat poorly drained and have a water table at the surface (0.0 feet) during the growing season, or
B. are poorly drained or very poorly drained and have either:
1) a water table at the surface (0.0 feet) during the growing season if textures are
coarse sand, sand, or fine sand in all layers within a depth of 20 inches, or
2) a water table at a depth of 0.5 foot or less during the growing season if
permeability is equal to or greater than 6.0 in/hr in all layers within a depth of 20 inches, or
3) a water table at a depth of 1.0 foot or less during the growing season if
permeability is less than 6.0 in/hr in any layer within a depth of 20 inches.
3. Soils that are frequently ponded for long or very long duration during the growing season.
4. Soils that are frequently flooded for long or very long duration during the growing season.
References:
Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of wetlands and deep-water habitats of
the United States. U.S. Fish and Wildlife Service FWS/OBS-79/31.
Federal Register. September 18, 2002. Hydric soils of the United States.
Federal Register. July 13, 1994. Changes in hydric soils of the United States.
Hurt, G.W., P.M. Whited, and R.F. Pringle, editors. Version 5.0, 2002. Field indicators of hydric soils in the United
States.
National Research Council. 1995. Wetlands: Characteristics and boundaries.
Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service. U.S. Department of Agriculture
Handbook 18.