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Regional General Permit Notification for Grisenti Farms Gravel Pit Bank Stabilization Project Fremont County,Colorado Corps File No.RGP-37 Soils The Natural Resource Conservation Service(NRCS)has mapped the soils in the project area as Aquic Ustifluvents(U.S.Department of Agriculture(USDA),NRCS 2018a), These soils typically occur on floodplains and stream terraces. The surface layers(to a depth of 14 inches)are typically loam. Wetlands and Other Waters Methods On February 7,2018,Clint Henke and Hidde Snieder with ERO assessed the project area for potential waters of the U.S.,including abutting and adjacent wetlands(2018 site visit). Using methods outlined in the Corps of Engineers Wetlands Delineation Manual(Environmental Laboratory 1987)and Regional Supplement to the Corps of Engineers Wetland Delineation Manual:Great Plains Region(Version 2.0) (U.S.Army Corps of Engineers(Corps)2010),surveys for wetlands were conducted based on the presence or absence of three wetland indicators:hydrophytic vegetation,hydric soils,and wetland hydrology. If present,hydric soils were identified using field observation for hydric soil indicators accepted by the Corps. A Munsell soil color chart was used to determine soil color. The wetland indicator status of plant species was identified using the National Wetland Plant List(Lichvar 2016)and nomenclature was determined using The PLANTS Database(USDA, NRCS 2018b). If present,wetlands were classified according to the U.S.Fish and Wildlife Service's(Service)Cowardin classification system(Cowardin et al. 1979)combined with a hydrogeomorphic approach(Brinson 1993). If present,wetland classifications were supported by U.S.Geological Survey(USGS)topographic maps,aerial photography,and the USGS Soil Survey(USDA,NRCS 2018a). Characteristics of a defined streambed,streambank,ordinary high water mark(OHWM),and other erosional features also were identified. The Corps defines"stream bed"as"the substrate of the stream channel between the OHWMs. The substrate may be bedrock or inorganic particles that range in size from clay to boulders." The Corps defines"ordinary high water mark"as"that line on the shore established by the fluctuations of water and indicated by physical characteristics such as a clear natural line impressed on the bank,shelving,changes in the soil character,destruction of terrestrial vegetation, presence of litter and debris,or other appropriate means that consider the characteristics of the surrounding areas"(33 CFR 328.3(e)). The dimensions of these characteristics within the Arkansas River and the boundaries of identified waters of the U.S.either were drawn onto aerial photographs or mapped using a Global Positioning System(GPS)unit. GPS data were differentially corrected using the CompassCom base station. All differential correction was completed using Trimble Pathfinder Office 5.40 software. GPS data were incorporated onto base mapping using ARC Geographic Information System software. Potential waters of the U.S.,including adjacent wetlands, identified in the project area are shown on Figure 2. Data were collected from various locations in the project area to document the characteristics ERO Project R7141 5 1)