2018-01-23_GENERAL DOCUMENTS - C1981041

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12 C1981-041 RN7 findings On the east side of the river, the Roadside Mine undermined two additional canyons: Rapid Creek and Cottonwood Creek. Both creeks are intermittent during most years, but do flow continuously during wet years. Flows in these creeks occur primarily in response to annual snowmelt and seasonal precipitation events. Intake structures are present in both Rapid Creek and Cottonwood Creek to divert water from those drainages into reservoirs for later release which, along with water from other storage structures, can artificially increase the duration of stream flows. Several small unnamed drainages (washes) on the east side of the river will also be impacted by mining, either through surface disturbance or through undermining. The only other major surface water body within the permit area is the federally owned Highline Canal. This canal carries river water down the west side of DeBeque Canyon of the Colorado River, with siphons under the channels of Coal and Jerry Creeks. The Highline Canal is primarily used for agricultural purposes in the Grand Valley. Upon approval of TR-70, the Highline Canal is no longer immediately adjacent to the permit area. Soils Permit Section 2.04.12: The limited surface disturbance area associated with the North and South Portals facilities areas are considered “Rock Outcrop” areas, as defined by the NRCS. No prime farmland exists in the areas associated mining activity disturbances. The operator states, “None of the existing areas of land disturbed by surface facilities is considered prime farmland since, historically none of the disturbed areas are used as cropland. (Permit Tab 9 p. 9-6) The Soil Survey of the area shows no map units with designations of Prime Farmland by the NRCS. Soils in the general area are commonly high in sodium and, occasionally, saline. Soil mapping units identified within and adjacent to surface disturbed areas are Torriorthents-Warm Rock Outcrop Complex, Wrayha-Veatch-Rabbitex Complex, Barx-Clapper Complex, Cameo, Fluvaquents, and Uffens Loam. These consist primarily of gravelly to stony loams, often calcareous, with slight to moderate alkalinity. All tend to have low available water capacity, due to the stony to cobbly textures. Occasional clay loams are found with high water capacity. The stoniness limits their successful utilization. Low organic matter content and elevated SAR values also limit vegetative growth on soils in the area. Variability of the characteristics of the soils on the permit area is primarily due to slope and topography. The depth of the soils range from 1 inch to greater than 60 inches, with the shallower soils of 0 to 40 inches along the side slopes of the canyons and the deeper soils located in the valley floors. The deeper soils tend toward the sandy loams while the shallower soils tend to be stony loams. Further information on soils can be found in Tab 9 of the permit application document.