PERMFILE116695 - Laserfiche WebLink

Home Browse Search

Exhibit B Site Description The 9.9 acre site soil information is presented below. The information for these descriptions was found in the Soil Survey of Rifle Area, Colorado: Parts of Garfield and Mesa Counties (Soil Survey) (SCS 1985) and observations made by City staff. This exhibit includes descriptions of the general soil-mapping units, morphology and the physical characteristics of the soil series found on site. Soil Descriptions Ildefonso-Lazear Series These soils are moderately sloping to very steep soils on hillsides and mesa breaks. Elevation ranges from 5,000 to 6,500 feet. The Ildefonso soil formed in very calcareous, mixed, stony alluvium derived mainly from basalt, and the Lazear soil formed in shale and sandstone residuum. The average annual precipitation is about 14 inches, the average annual air temperature is about 48 degrees F, and the annual frost free period is about 125 days. The Ildefonso makes up about 50% of the unit, the Lazear makes up about 30%, and soils of minor extent make up 20%. The Ildefonso soil is deep, and well drained. Typically, the surface layer is brown stony loam about 8 inches thick. The underlying material is white, very strongly calcareous very stony loam to a depth of 60 inches. Permeability of the Ildefonso soil is moderately rapid, and available water capacity is low. Effective rooting depth is more than 60 inches. Surface runoff is medium, and the erosion hazard is moderate. The Lazear soil is shallow over shale bedrock and is well drained. Typically, the surface layer is grayish brown gravelly loam about 4 inches thick. The underlying material is light brownish grey cobbly loam. Calcareous shale and sandstone is at a depth of 16 inches. Permeability of the Lazear soil is moderate, and available water capacity is very low. Effective rooting depth is 10 to 20 inches. Surface runoff is rapid, and the erosion hazard is severe. Included with these soils in mapping are small areas of shale outcrops and Potts soils. The Potts soils are in depressions. These areas make up about 5 to 10 percent of the map unit,