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proceed eastward, they encounter the softer more erodible rocks of the basin, which continue to <br />add to the TSS levels. <br />Climatology <br />The climate of the area is directly influenced by the topography, with heavier rainfall and cooler <br />temperatures in the mountains and less rainfall and warmer temperatures in the basin. <br />Annual precipitation in the area is approximately 12.9 inches, with most of the precipitation <br />occurring during the spring and summer months. Average annual temperature for the area is 54 <br />degrees with extremes of -20 to 100 degrees Fahrenheit. Prevailing wind direction is from the <br />west except during summer months when the wind originates from the southeast. Section 2.04.8 <br />of the PAP provides additional information. <br />Vegetation and Soils <br />Information on vegetation is found in Section 2.04. 10 and Exhibit 11 of the PAP. Map 16 shows <br />the vegetative communities present in the permitted area. The vegetative community consists of <br />three types: riparian woodland, grassland, and ponderosa pine - pinyon - juniper woodland. The <br />Southfield mine area disturbed two vegetation communities: the RDA affected a grassland <br />community, and the portal and facilities area affected a ponderosa pine - pinyon - juniper woodland <br />community. The loadout area affected a grassland community. Oakbrush, skunkbrush, <br />mountain mahogany, and snowberry are the important shrubs within the ponderosa pine- pinyon- <br />juniper woodland vegetation type. Grasses that naturally occur are blue grama, western <br />wheatgrass, needle- and - thread, squirrel tail, mutton grass and red three -awn. Much of the portal <br />area had been disturbed by historic mining prior to the Colorado permanent program. As such, <br />undisturbed baseline vegetation data was difficult to obtain. <br />Three vegetation reference areas have been approved for the Southfield Mine: the refuse area <br />reference area (Plot "A" representing the grassland vegetation type), the mine portal reference <br />area (Plot `B" representing the ponderosa pine - pinyon - juniper woodland vegetation type), and <br />the loadout reference area (representing the grassland vegetation type near the loadout). <br />Reference areas were selected based upon visual similarities and proximity to the disturbed sites. <br />Statistical comparison between the reference areas and pre - disturbance of the portal area was not <br />possible due to pre- existing disturbances (historic mining) in the portal area prior to initial <br />permitting. The loadout was disturbed prior to the initial vegetation inventory as well. The <br />approved reference areas were established in 1980. <br />TR -39 added a second location to the ponderosa pine - pinyon - juniper woodland reference area. <br />The previously approved "Plot B" ponderosa pine - pinyon - juniper woodland reference area was <br />extremely small, 0.3 acres, and did not fully represent the slope aspect and soil types found in the <br />reclaimed portal area. The additional ponderosa pine - pinyon - juniper woodland reference area is <br />located on the northwestern side of the reclaimed portal area. Data from the two ponderosa pine - <br />pinyon- juniper woodland reference areas will be combined to determine the reclamation success <br />criterion of cover, herbaceous productivity, species diversity, and woody plant density (Permit <br />Section 2.05.4). <br />