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<br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />r <br />I <br />I <br />I <br />I <br />I <br />I <br /> <br />..,- <br />nn~9,;) <br />SECTIONTWO <br /> <br />Emnnron01entalSe~ng <br /> <br />PEMA, 10 percent PEMC) on the NWl maps. Individual areas of mapped PEMA or PEMC do <br />not exceed 50 to 200 acres in any other portion of the study area. Some large areas of grassland <br />with interspersed channels of PEMA or PEMC occur in a number of areas on islands and along <br />secondary channels away from the river. <br /> <br />Mapping of wet meadows and bottomland grasslands within the study area is being completed by <br />BOR as part of the GIS database. Maps with this information will be included as an appendix in <br />a later version of this Baseline Report. A preliminary identification of the locations of <br />significant areas of wet meadows was developed, based on review of the NWI and WELUT <br />maps, and is listed below. This list includes both areas of wet meadows and bottomland <br />grasslands with interspersed wet meadows or marsh vegetation. <br /> <br />. Lower Wood River Valley and areas north of the Platte River in Segment I (partly included <br />in WELUT acres) <br /> <br />. Mormon Island and Indian Island (Segment 2-3) <br /> <br />. Some areas immediately south of the South Channel (Segment 3) <br /> <br />. Large parts of Shoemaker Island (Segment 3-4) <br /> <br />. Areas adjacent to the North Channel of the Platte River (1.5 to 4 miles north of the South <br />[main) Channel) in Segments 3 through 6 (not included in WELUT wet meadow acres) <br /> <br />. Areas adjacent to the South Channel of the Platte River on the south side of Elm Island <br />(Segments 5 through 7) <br /> <br />. Portions of Clark Island (Segments 6 and 7) <br /> <br />. Large portions of Fort Farm and Kilgore Islands (Segments 7 to 8) <br /> <br />. Large areas along the North Channel (Segments 9 to 10) (not included in WELUT acres) <br /> <br />. Some areas along the South Channel (0.5 to 1 mile south of main channel) and south of the <br />Platte River (Segments 10 to II) <br /> <br />. Portions of large islands (Segment 11) <br /> <br />. Parts of Jeffrey Island (Segment 12) (partly included in WELUT acres) <br /> <br />2.7.3 Hydrology and Ecology <br /> <br />The Central Platte River Valley is underlain by an unconfined, shallow, alluvial aquifer (Hurr <br />1983). Soils consist of permeable or very permeable sandy and gravelly soils that are poorly <br />drained or very poorly drained. In general, areas within the floodplain are subirrigated, have a <br />shallow ground water table within 2 feet of the surface in depressions and meadow channels, and <br />are 2 to 5 feet below the land surface in grasslands during the spring (SCS soil surveys: Brown <br />et al. 1978; Bowman et al. 1973; Buller et al. 1973; Pollock et al. 1981; Ragon 1974; Vanek et al. <br />1985; Wahl et al. 1984). Common soil series within wet meadows and wet meadow complexes <br />include Platte, AIda loam, Gibbon silt loam, Leshara fine sandy loam, Wann fine sandy loam, <br />and loamy alluvial land. These same soils also occur in many areas up to a mile or more on <br />IIIfS Greiaet ........ /:IjIfe <br />fetIeIII Senfces t\8FOO972e&lC11r\.<<Ie ~,~9".5l NAW~'&G~rS12 2-9 <br />