2019-05-14_PERMIT FILE - M2019025 (16)

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3.0 DELINEATION METHODS Wetlands were delineated by Heather Houston of Birch Ecology, LLC and formerly of Western Ecological Resource, Inc. and David Buscher of Buscher Soil & Environmental Consulting, Inc. in accordance with the U.S. Army Corps of Engineers Wetland Delineation Manual (1987) and the Regional Supplement for the Great Plains Region (2010) on May 15, 2018. In general, wetland boundaries were delineated and flagged based upon the prevalence of hydrophytic vegetation, hydric soils and indicators of a wetland hydrology. Field forms for the 11 test pits with vegetation, soil and hydrology data are included in Appendix A. These test pits are located in both wetland and upland habitats. In general, plant species names follow Weber and Whitmann (1992). The wetland status of plants follows the 2016 National List for the Great Plains Region. Classification of wetlands follows Cowardin et al. (1979). Wetland flagging was located with a survey-grade GPS by Peter Wayland of Weiland, Inc. of Boulder, Colorado. 3.1 Agency Coordination The U.S. Army Corps of Engineers (Corps) has not visited the project site to review the flagged wetland boundary. 4.0 WETLANDS & WATERS OF THE U.S. Approximately 46,306 square feet (1.06 acre) of wetlands were mapped in the project area, as illustrated by the Wetland Map (Figure 3) and summarized in Table 1. 4.1 Wetland A 4.1.1 Location Wetland A is located in a slough just north of the Big Thompson River and just east of Weld County Road 13 (Photos 6 & 7). This swale is a historic channel of the Big Thompson River. Wetland A measures approximately 26,500 square feet (0.61 acre). 4.1.2 Classification Under the Cowardin Classification System for Wetlands and Deepwater Habitats (Cowardin et al., 1979), Wetland A is in the Palustrine System, with Emergent Persistent Class. 4.1.3 Vegetation Wetland A is dominated by threesquare bulrush (Scirpus pungens) in the shallow water and saturated soil habitats, growing with Emory sedge (Carex emoryi), saltgrass (Distichlis spicata), foxtail barley (Hordeum jubatum) saltmeadow rush (Juncus gerardii) and variableseed saltbush (Atriplex heterospermo). In the drier soils near the margin, the noxious weeds quackgrass (Elytrigia repens), broadleaf pepperweed (Lepidium latifolium) and Canada thistle (Cirsium arvense) are also present. Large, mature plains cottonwood (Populus deltoideis) trees border the sides of the slough (Photo 7). Table 2 lists the vascular plant species identified on the Amen Gravel Pit project site during the wetland delineation in May 2018. 4.1.4 Hydrology Wetland A is a slough with seasonally saturated soil supported by high groundwater. Shallow standing water was present at the time of the delineation after a period of heavy rains, but is likely present in most years (Photos 6 & 7). 2