2022-04-04_PERMIT FILE - M2022013 (33)

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Threatened and Endangered Species Habitat Assessment Two Rivers Parcels-Varra Companies Weld County, Colorado Ecological Features of the Project Area The project area is bounded by the South Platte River on the south and east,the Big Thompson River and 54th Street on the north, and County Road 396 on the west (Figure 1). Overall,the project area is characterized as agricultural. Agricultural areas consist of irrigated cropland located on an elevated terrace between the South Platte and Big Thompson Rivers (Photos 1 and 2), and nonnative pasture north of the Big Thompson River(Photo 3). The Big Thompson River flows east through the project area and joins the South Platte River approximately 0.5 mile east. The vegetation in the Big Thompson River riparian area is dominated by an overstory of plains cottonwood (Populus deltoides), narrowleaf cottonwood (Populus angustifolia), Russian olive (Elaeagnus angustifolia), water birch (Betula occidentalis),thinleaf alder(Alnus incana), and box elder (Acer negundo)trees (Photo 4). The riparian corridor supports dense thickets of sandbar willow (Salix exigua) shrubs along the river banks. Upland shrub species including chokecherry(Prunus virginiana) and American plum (Prunus americana) occur in scattered stands. Other dominant herbaceous species in the riparian area include smooth brome (Bromus inermis), reed canarygrass (Phalaris arundinacea), and redtop (Agrostis gigantea). The South Platte River has been scoured by flooding over the last 10 years and is characterized as a wide, sandy floodplain with sparse vegetation dominated by a mixture of native and nonnative grasses with scattered patches of sandbar willow and plains cottonwood (Photo 5). The Evans Town Ditch parallels the Big Thompson River and consists of a concrete-lined channel with vegetated banks of nonnative grasses and Scotch thistle (Onopordum acanthium) (Photo 6). Previous Surveys for Preble's Near the Project Area ERO conducted live-trapping surveys for Preble's in 2017 in suitable habitat along the Little Thompson and South Platte Rivers in the project area, but outside of the mine area (Appendix B; Figure 2). ERO conducted the trapping survey using the methods outlined in the Service's Preble's Meadow Jumping Mouse Survey Guidelines, revised April 2004 (Service 2004). During the 2017 field survey, ERO placed live-traps beginning the afternoon of September 11 and collected traps on the morning of September 15, 2017. A total of 180 traps were checked each morning at sunrise, closed, and reopened each evening at dusk,for a total of 720 trap nights. No Preble's were found during the 2017 field survey. Four different species of small mammals, with 60 individuals, were trapped on-site (Table 1). Deer mice (Peromyscus maniculatus)were the most common species trapped,followed by house mice (Mus musculus), meadow voles (Microtus pennsylvanicus), and a single prairie vole (Microtus ochrogaster). ERO Project#21-266 3 ERO Resources Corporation