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Rifle Gravel Pit #1 March 2021 <br /> • South—Colorado Department of Transportation (CDOT) <br /> • East—Shidelerosa LLP <br /> This information was obtained from the Garfield County Colorado Land Explorer(Garfield <br /> County, March 2021). <br /> 4.2 Topography <br /> The existing surface topography is extremely flat and composed of several feet of fine- <br /> textured alluvial sediment overlying a highly permeable alluvial aquifer of coarse gravel. The <br /> coarse gravel material lies on bedrock, adjacent to the Colorado River(based upon <br /> available boring data). The only topography of note is the artificially excavated tailwater <br /> return channel of the Last Chance Ditch, with runs east to west across the property and <br /> generally bisects the property into northern and southern sections. Figure 1 and Figure 4 <br /> depict these features. <br /> 4.3 Vegetation <br /> Vegetation in the project area is dominated by partially irrigated pasture lands, which are <br /> subjected to an inconsistent and uneven application of irrigation water via flood irrigation <br /> and subsurface seepage. The mixture of mesic and hydric soil conditions supports a mosaic <br /> of upland pasture areas and wet emergent meadows, with the water table so elevated in <br /> some portions that the wet meadows contain areas of open surface water. Some small <br /> areas contain sparse riparian woodland, dominated by non-native Russian olive (Elaeagnus <br /> angustifolia)with a sparse overstory of cottonwood (Populus deltoides). The wetlands that <br /> are on site were created by irrigation activities and will likely disappear in a relatively short <br /> period of time following the onset of dewatering. Figure 5 through Figure 8 depicts the <br /> location and types of vegetation at the mining site <br /> A site visit was conducted in November of 2020 to inventory the vegetation on the Shideler <br /> property for purposes of selecting a dewatering pipeline alignment that avoided wetlands. <br /> Attachment C includes a copy of the photo log and map from this site visit. <br /> 4.4 US Fish &Wildlife Consultation <br /> Seven federally listed species were evaluated for potential impacts resulting from this <br /> project, per the USFWS Threatened and Endangered species list for the project area (IPaC, <br /> September 2020). Based on this analysis, the USFWS identified the following species as <br /> having potential to occur within the vicinity of the project: <br /> • Birds: yellow-billed cuckoo (Coccyzus americanus), Mexican spotted owl (Strix <br /> occidentalis lucida) <br /> • Fishes: bonytail chub (Gila elegans), Colorado pikeminnow(Ptychocheilus lucius), <br /> humpback chub (Gila cypha), razorback sucker(Xyrauchen texanus) <br /> • Flowering Plants: Debeque phacelia (Phacelia submutica), Ute ladies'-tresses orchid <br /> (Spiranthes diluvialis) <br /> Birds: The project area occurs within the range of the yellow-billed cuckoo; however, the <br /> project would not impact any mature cottonwoods or riparian woodland habitats. The <br /> conditions on the property are generally open pasture and wet meadow/emergent marsh, <br /> which are not utilized by the cuckoo, and therefore no nesting or foraging habitat would be <br /> 8 <br />