Laserfiche WebLink
The Colorado River is the only perennial stream in the permit area. On the west side of the river, Coal Creek and <br />Jerry Creek flow through the Roadside North Portal portion of the permit area within deeply incised canyons <br />draining approximately 12 and 70 square miles, respectively. Coal Creek, an ephemeral drainage, passes through <br />surface mine disturbance near the Roadside North Portal where the channel has been diverted. Jerry Creek is an <br />intermittent drainage located in the extreme northern portion of the permit area. Flows in all of these drainages <br />occur primarily during spring snowmelt and in response to sudden, high intensity thunderstorms, the latter of <br />which are characterized by high peak discharges, short flow durations and high sediment loads. <br />On the east side of the river, the Roadside Mine will undermine two additional canyons: Rapid Creek and <br />Cottonwood Creek. Both creeks are intermittent during most years, but do flow continuously during wet years. <br />Flows in these creeks occur primarily in response to annual snowmelt and seasonal precipitation events. Intake <br />structures are present in both Rapid Creek and Cottonwood Creek to divert water from those drainages into <br />reservoirs for later release which, along with water from other storage structures, can artificially increase the <br />duration of stream flows. Several small unnamed drainages (washes) on the east side of the river will also be <br />impacted by mining, either through surface disturbance or through undermining. <br />The only other major surface water body within the permit area is the federally owned Highline Canal. This canal <br />carries river water down the west 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 agricultural purposes in the Grand Valley. <br />Soils <br />Soils in the general area are commonly high in sodium and, occasionally, saline. Soil mapping units identified <br />within and adjacent to surface disturbed areas are Torriorthents -Warm Rock Outcrop Complex, Wrayha- Veatch- <br />Rabbitex Complex, Barx- Clapper Complex, Cameo, Fluvaquents, and Uffens Loam. These consist primarily of <br />gravelly to stony loams, often calcareous, with slight to moderate alkalinity. All tend to have low available water <br />capacity, due to the stony to cobbly textures. Occasional clay loams are found with high water capacity. The <br />stoniness limits their successful utilization. Low organic matter content and elevated SAR values also limit <br />vegetative growth on soils in the area. <br />Variability of the characteristics of the soils on the permit area is primarily due to slope and topography. The <br />depth of the soils range from 1 inch to greater than 60 inches, with the shallower soils of 0 to 40 inches along the <br />side slopes of the canyons and the deeper soils located in the valley floors. The deeper soils tend toward the <br />sandy loams while the shallower soils tend to be stony loams. <br />Further information on soils can be found in Tab 9 of the permit application document. <br />Climatology <br />The permit area receives less than nine inches of precipitation annually and is characterized by moderately cold <br />winters and warm summers. Average temperatures range between 27 deg. F in the winter and 79 deg. F in the <br />summer, with relatively even distribution of precipitation during the year. <br />The average speed and direction of the prevailing winds in the permit area is 8.0 mph from the southwest. <br />Vegetation <br />