Laserfiche WebLink
ENVIRONMENTAL ASSESSMENT <br /> Table 3-7. Cowardin Classification of Aquatic Resources within the Survey Area <br /> Waters of the U.S. Square Ft Acres Linear Ft <br /> PSS Wetland 8,492 0.19 N/A <br /> Total 8,492 0.19 N/A <br /> Source:SME 2018 <br /> Table 3-8. Characteristics of Aquatic Resources within the Survey Area <br /> Water Flow Preliminary <br /> Feature Frequency Flows to Jurisdictional Rationale <br /> Name Determination <br /> Area A Intermittent, La Plata Yes Meets all three wetland parameters <br /> seasonally River (i.e., vegetation, soils, and hydrology) <br /> saturated <br /> Source:SME 2018 <br /> As shown in Table 3-7,approximately 0.19 acres of PSS wetlands exist in the survey area.The PSS wetlands <br /> were dominated by narrowleaf willow with an herbaceous layer of Western wheatgrass (Pascopyrum <br /> smithii)and Mountain rush (Juncus balticus).The PSS wetland within the survey area is located within the <br /> Umbarg Loam soil unit (NRCS 2018). Data collected from soil transects during the field investigation <br /> revealed primarily clay loam/silt loam soils. The primary hydric soil indicator observed at the soil boring <br /> locations within the wetland areas was redoximorphic features (i.e., mottles) located within a dark soil <br /> matrix (F6-Redox Dark Surface). The hydrology in the survey area is sourced primarily from stormwater <br /> and snowmelt that is carried from areas of high elevation to The Gulch.The areas of high elevation (both <br /> to the east and west of the survey area) can be viewed on the USGS Thompson Park, Colo. 7.5' <br /> Topographic Quadrangle 1:24,000. The primary form of hydrology found on the site is the presence of <br /> oxidized rhizospheres within the soil. <br /> No other wetlands or WOTUS were found to be present within the survey area.Within the Gulch,wetlands <br /> are discontinuous and patchy and contain large sections of upland swales. Data points were taken <br /> throughout the survey area where the NWI mapped wetland features crossed the access road and at other <br /> points in The Gulch to show representative wetland and upland areas and to show the <br /> discontinuous/patchy nature of the Gulch. It is to be noted that all delineated aquatic resources extend <br /> beyond the limits of the survey area; however, only the portions of aquatic resources within the survey <br /> area were delineated. Approximately 10 acres would be cumulatively disturbed for all other dispersed <br /> surface disturbances of variable sizes that would occur over the life of the mine. The locations of these <br /> disturbances are not known at this time. When additional surface disturbance is proposed by GCCE, the <br /> agencies will determine if additional surveys for wetlands and WOTUS are required. <br /> Dunn Ranch Area Coal Lease by Application COC-78825 and Mine Plan Modification EA 3-27 <br />