2019-07-10_PERMIT FILE - C2009087

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Riparian and Wetland Characterization As part of the 2008 ESCO vegetation baseline study, a preliminary characterization of wetland and riparian areas potentially affected by surface facilities was conducted on October 10, 2008. The purpose of this preliminary characterization was to generate a general schema of the extent of obligate hydrophytes. These wetland restricted species are indicators of the presence of potential wetland conditions within the baseline vegetation study area. In addition, this characterization program assessed the extent of sub-irrigated adjacent areas that likely do not meet the criteria for wetlands. This characterization effort was reconnaissance in nature. The characterized areas are located along a portion of Little Grassy Creek adjacent to and partially within the PSCM disturbed area (See Map 8 in Exhibit 2.04.10-E1, Vegetation Information). The surveyed area along Little Grassy Creek extended from north to south along a distance of approximately 1.3 miles. Part of this reach lies within a natural channel (Photographs 59 through 61 and 63 through 65 in Exhibit 2.04.10-E1, Vegetation Information), and part within the previously reclaimed mine area in a created channel (Photographs 62 and 66 in Exhibit 2.04.10-E1, Vegetation Information). Another side-drainage extends down and across a reclaimed area from the east then runs parallel to Little Grassy Creek before joining it near the north end of the studied reach (Map 8 in Exhibit 2.04.10-E1, Vegetation Information). The vegetation of this side drainage was also included in this reconnaissance. The characterization program involved pedestrian traverses of the survey areas and recording of the plant species observed. Plants observed as part of this reconnaissance are listed in Table 23 in Exhibit 2.04.10-E1, Vegetation Information. The survey results indicate the wettest portion of the drainage area is characterized by hydrophytes and other moisture-loving species situated in a tight one- to two-foot band on either side of Little Grassy Creek, as well as on occasional broader portions of the channel (Photograph 60 and 61 in Exhibit 2.04.10-E1, Vegetation Information). In these areas, the dominant species encountered were mostly native perennial forbs and native perennial cool season grasses including rabbitfoot grass (Polypogon monspeliensis), woolly sedge (Carex lanuginosa), beaked sedge, meadow barley, foxtail barley, spikerush, slender wheatgrass, manna grass, Baltic rush, rush (Junctts interior), broadleaf cattail (Typha latifolia), redtop, and reed canarygrass (Phalaroides"arundinacea). Woody plants sporadically present included Booth willow, sand bar willow (Salix exigua), and narrowleaf cottonwood (Populus angustifolia). Smooth horsetail(Hippochaete laevigata)was also occasionally present. Adjacent to and slightly upslope from the Little Grassy Creek channel is a zone characterized by a mix of moisture-loving species as well as species from the surrounding native sagebrush upland habitat that are able to tolerate moister conditions. Dominant species encountered were native and introduced annual and biennial forbs, native perennial forbs, introduced perennial cool-season grasses and native shrubs and included bigfruit willowherb (Epilobium brachycarpum), tarweed, western yarrow, aster(Aster lanceolatus ssp. hesperius), willow dock, smooth brome, orchard grass (Dactylis glomerata), gooseberry and Wood's rose. Also included in this characterization program was the low slope portion of the drainage within the reclaimed areas to the east that merges with Little Grassy Creek (Map 8 in Exhibit 2.04.10-E1, Vegetation Information). Within and adjacent to this created drainage (Photographs 62 and 66 in Exhibit 2.04.10-E1, Vegetation Information), the vegetation community is characteristic of a moist environment, similar to the previously undisturbed areas adjacent to the creek channel. The PSCM Permit App. 2.04-146 Revision 04/05/19