Laserfiche WebLink
Natural Resources Assessment <br />P125 Gravel Mine - Southwest of State Highway 66 and County Road 17 <br />Weld County, Colorado <br /> <br />ERO Project #24-180 4 <br />ERO Resources Corporation <br />Project Background and Environmental Baseline <br />During the 2024 site visit, ERO assessed the project area for natural resources including a delineation of <br />potential wetlands and other WOTUS, identification of suitable habitat for federally listed T&E species, <br />and identification of other natural resources. In addition to the information gathered during the 2024 <br />site visit, natural resource information was obtained from existing databases and sources such as aerial <br />photography, the Colorado Natural Diversity Information Source (NDIS), Colorado Parks and Wildlife <br />(CPW) map databases, the U.S. Fish and Wildlife Service (Service) National Wetlands Inventory (NWI) <br />database, the U.S. Geological Survey (USGS) National Hydrography Dataset (NHD), the Colorado Natural <br />Heritage Program (CNHP), and other sources (Google, Inc. 2024; NDIS 2021; CPW, n.d.-a; Service, n.d.; <br />USGS 2024; CNHP 2024). <br />Project Area Description <br />The U.S. Department of Agriculture (USDA) has mapped the project area within the Central High Plains, <br />Southern Part Major Land Resource Area, which is mainly characterized as elevated piedmont plains <br />abutting the foothills of the Rocky Mountains (USDA, Natural Resources Conservation Service [NRCS] <br />2006). Precipitation is typically low as most of the region is on the leeward side of the mountains. The <br />average annual precipitation in this region is between 13 and 22 inches (USDA NRCS 2006). The <br />topography of the project area is generally flat (Photo 1). <br />The project area is surrounded by agricultural and commercial properties with limited residential <br />development south of State Highway 66, north of Weld County Road 28, and west of Weld County Road <br />17 (Figure 1). The project area consists of flood-irrigated alfalfa fields and an organic dairy cattle pasture <br />(Figure 2; Photo 1, Photo 2, and Photo 3). <br />The vegetation in the project area includes alfalfa (Medicago sativa), western wheatgrass (Pascopyrum <br />smithii), cheatgrass (Bromus tectorum), flixweed (Descurainia sophia), squirreltail (Elymus elymoides), <br />little hogweed (Portulaca oleracea), pigweed (Amaranthus species), and kochia (Bassia scoparia) (Photo <br />1, Photo 2, and Photo 3). The riparian community contains species such as plains cottonwood (Populus <br />deltoides spp. monilifera), peachleaf willow (Salix amygdaloides), smartweed (Persicaria amphibia), curly <br />dock (Rumex crispus), and Pennsylvania bittercress (Cardamine pensylvanica) (Photo 6 and Photo 7). <br />In the project area, 5 wetlands are in the northern portion and 27 agricultural ditches run through the <br />southern portion (AgDitch1 through AgDitch27) (Photo 4 through Photo 9). AgDitch1 through AgDitch27 <br />only flow when flood irrigation occurs to support the alfalfa fields in which they are located. AgDitch1 <br />through AgDitch12 drain southwest back into Last Chance Ditch. AgDitch13 through Ag Ditch26 drain <br />northwest into Wetland 5 and eventually into an unnamed tributary to St. Vrain Creek. Wetland 1 and <br />Wetland 2 drain into an unnamed perennial tributary to St. Vrain Creek and then into St. Vrain Creek. <br />Wetland 3 and Wetland 4 are located in an oxbow channel of St. Vrain Creek and drain to St. Vrain <br />Creek. Wetland 5 drains into an unnamed tributary to St. Vrain Creek.