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during most years , but do flow continuously during wet years . Intake <br /> structures are present in both Rapid Creek and Cottonwood Creek to divert <br /> water from those drainages into reservoirs for later release which, along with <br /> water from other storage structures , can artificially increase the duration of <br /> stream flows . Several small unnamed drainages (washes) on the east side of <br /> the river will also be impacted by mining, either through surface disturbance <br /> or through undermining. <br /> The only other major surface water body within the permit area is the <br /> federally owned Highline Canal . This canal carries river water down the west <br /> side of DeBeque Canyon of the Colorado River, with siphons under the channels <br /> of Coal and Jerry Creeks . The Highline Canal is primarily used for <br /> agricultural purposes in the Grand Valley. <br /> Soils <br /> Soils in the general area are commonly high in sodium and, occasionally, <br /> saline . Soil mapping units identified within the permit unit are Green River <br /> Series , Utaline Series , and Stonyland . These consist primarily of gravelly to <br /> stony loams , often calcareous , with slight to moderate alkalinity. All tend <br /> to have low available water capacity, due to the stony to cobbly textures . <br /> Occasional clay loams are found with high water capacity. The stoniness <br /> limits their successful utilization . Low organic matter content and elevated <br /> SAR values also limit vegetative growth on soils in the area. <br /> Variability of the characteristics of the soils on the permit area is <br /> primarily due to slope and topography. The depth of the soils range from <br /> 1 inch to greater than 60 inches , with the shallower soils of 0 to 40 inches <br /> along the side slopes of the canyons and the deeper soils located in the <br /> valley floors . The deeper soils tend toward the sandy loams while the <br /> shallower soils tend to be stony loams . <br /> Further information on soils can be found in Section 2.04.9 of the permit, <br /> pages 98-108. <br /> Climatology <br /> The permit area receives less than nine inches of precipitation annually and <br /> is characterized by moderately cold winters and warm summers . Average <br /> temperatures range between 27°F in the winter and 79°F in the summer . The <br /> majority of precipitation occurs between November and April in the form of <br /> snow. <br /> The average speed and direction of the prevailing winds in the permit area is <br /> 8 .0 mph from the southwest. <br /> Vegetation <br /> The mesas and the valley slopes at the canyon base support sparse salt desert <br /> vegetation, including grasses such as galleta (Hilaria 'am,1 esii ) , indian <br /> ricegrass (Oryzopsis hymenoides) and squirrel tail (Sitanion h sy trix) and <br /> shrubs such as winterfat (Ceratoides lanata) , shadscale (Atriplex <br /> confertifolia) , big sagebrush (Artemisia tridentata) and fourwing saltbrush <br /> (Atriplex canescens) . The riparian zone adjacent to the Colorado River <br /> -8- <br />