Laserfiche WebLink
Site Description <br />(a) Two soil types were mapped by the Natural Resources Conservation Service (NRCS) <br />in the vicinity of the proposed Red Mesa Pit: <br />Fluvaquents. sandy. frequently flooded- This is a deep, somewhat poorly drained and <br />poorly drained, nearly level soils that formed in recent alluvial deposits bordering <br />major drainageways on alluvial valley floors. Average annual precipitation is 15 to <br />20 inches. <br />The soils in this unit are extremely variable. The surface layer ranges from gravelly <br />or cobbly loam to sandy loam. Stratified sandy loam, sand, and gravel are at a depth <br />of 5 to 20 inches. Included in this unit are small areas of Pescar fine sandy loam, <br />Tefton loam, Riverwash, gravel, and sand bars. <br />Permeability of this soil is moderately rapid or rapid. Effective rooting depth is 12 to <br />40 inches or more because of the presence of a fluctuating water table. Available <br />water capacity is very low to low, runoff is slow, and the hazard of erosion is slight. <br />The soils have a fluctuating water table between the depths of 12 to 40 inches year <br />round. <br />The native vegetation of this unit is mainly cottonwood, willows, sedges, rushes, <br />tufted hairgrass, yarrow, and iris. For the most part, the vegetation in the proposed <br />Red Mesa Pit is undisturbed. <br />• Svcle fine sandv loam- This soil unit is deep, well drained soil on terraces of major <br />drainageways. This soil is formed in alluvium overlying river-deposited cobbles and <br />gravel, and has a slope of 1 to 3 percent. The average annual precipitation ranges <br />from 15 to 19 inches. <br />Typically the surface is brown fine sandy loam about ten inches thick. The subsoil is <br />reddish brown sandy clay loam about 12 inches thick, and the underlying material is <br />calcareous, light reddish brown gravelly sandy loam about 4 inches thick over sand, <br />cobbles, and gravel that extend to a depth of 60 inches or more. Inclusions in this <br />unit are 5 percent Harlan cobbly loam, 10 percent Sedillo gravelly loam, and small <br />areas of Tefton loam. <br />Permeability of this soil is moderate. Effective rooting depth is 30 to 40 inches <br />because of the presence of extremely cobbly material. Available water capacity is <br />low, runoff is slow, and the hazard of erosion is slight. <br />The native vegetation on this unit is mainly Indian ricegrass, needleandthread, <br />western wheatgrass, and sagebrush. Seeding facilitates revegetation of areas <br />depleted by disturbances.