2010-11-22_REVISION - M2009023 (6)

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The project area has not been recently disturbed except for the low-flow crossing. The boundaries were flagged with pink pin flags marked "wetland delineation." There are a few signs of past cattle ranching, but the majority of the vegetation is undisturbed. WETLANDS The wetland boundaries delineate the edges of riverine wetland systems and other waters of the U.S. Classifications of wetland types are in accordance with the U.S. Fish and Wildlife Service (USFWS) classification system for wetlands and deep water habitats (Cowardin et. al. 1979). Soils The Natural Resource Conservation Service (MRCS) mapped two soil types in the vicinity of the delineated jurisdictional areas in La Plata County, Colorado. The soil types mapped by the NRCS in the Soil Survey of La Plata County Area, Colorado (NRCS 1981) are as follows: • Fluvaquents, sandy, frequently flooded- This is a deep, somewhat poorly drained and poorly drained, nearly level soils that formed in recent alluvial deposits bordering major drainageways on alluvial valley floors. Average annual precipitation is 15 to 20 inches. The soils in this unit are extremely variable. The surface layer ranges from gravelly or cobbly loam to sandy loam. Stratified sandy loam, sand, and gravel are at a depth of 5 to 20 inches. Included in this unit are small areas of Pesear fine sandy loam, Teflon loam, Riverwash, gravel, and sand bars. Permeability of this soil is moderately rapid or rapid. Effective rooting depth is 12 to 40 inches or more because of the presence of a fluctuating water table. Available water capacity is very low to low, runoff is slow, and the hazard of erosion is slight. The soils have a fluctuating water table between the depths of 12 to 40 inches year round. . . The native vegetation of this unit is mainly cottonwood, willows, sedges, rushes, tufted hairgrass, yarrow, and iris. For the most part, the vegetation in the proposed Red Mesa Pit is undisturbed. • Sycle fine sandy loam- This soil unit is deep, well drained soil on terraces of major drainageways. This soil is formed in alluvium overlying river-deposited cobbles and gravel, and has a slope of 1 to 3 percent. The average annual precipitation ranges from 15 to 19 inches. Typically the surface is brown fine sandy loam about ten inches thick. The subsoil is reddish brown sandy clay loam about 12 inches thick, and the underlying material is calcareous, light reddish brown gravelly sandy loam about 4 inches thick over sand, cobbles, and gravel that extend to a depth of 60 inches or more. Inclusions in this unit are 5 percent Harlan cobbly loam, 10 percent Sedillo gravelly loam, and small areas of Teflon loam.