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Two sediment ponds are located at the base of the facilities area to control runoff and sediment • generated within the disturbed area. Bourtdaries of the area contributing runoff to each pond are delineated on Map C-4 in the permit document. Runoff from undisturbed eastern pottion of the upper basin area is routed around the disturbed area in the east ditch and passes through a straw bale dike before entering Hay Gulch. Runoff from the undisrurbedwestern portions of the upper basin and the disturbed area is discharged to Hay Gulch afrer passing through the sediment ponds. The sediment ponds have been designedto treat the runoff from the 10-year, 24-hour precipitation event. Calculations used in the pond designs indicate the ponds to be in compliance with the requirements of Rule 4.05.6. A small in-line sediment trap will act to capture sediment from high-flow events in the east ditch. The west pond receives drainage from the bench area through a ditch/culvert system and acts as the primary sediment control device for the disturbed area. It also discharges directly to the alluvium of Hay Gulch. Information on surface water hydrology can be found in Sections 2.04.7, 2.05.3 and 2.05.6 and Maps C-4 and C-9 of the permit application. Climate The climatic regime is classified as semi-arid, characterized by hot suttuners, cold winters, and a limited amount of precipitationeach year. The prevailing winds are from the southwest and west with an average annual precipitation rate varying form 15-19 inches. The growing season in the • area varies depending on elevation and exposure with a maximum of 96 frost-free days. Soils Soils found within the permit boundary vary greatly depending on slope, aspect and topographic position. Basically, two soil orders (Entisolls and Aridisols) occupy the site, as well as one rock outcrop complex. Deeper soils are found along the valley bottoms and the plateau top with shallow soils associated with rock outcrops along the side slopes. Both soil orders have an ustic moisture regime. Soils in the disturbed area are non-existent, since all surface disrurbance took place prior to the enactment of any stanaory reclamation requirements for salvaging topsoil. An area at the upper reaches of the east drainage area has been identified as a "topsoil". borrow area with approximately 17,000 cubic yards of available material for reclamation activities. Appendix 9(4)(a) contains the soil analysis performed by CSU soils lab. Vegetation Vegetation is non-existent in the bench area due to past disturbances. Over the undisturbed permit and affected areas, vegetation is distributed in response to micro-climatic influences. The dominant vegetation in the area is a mountain shrub community. Gambles Oak is the most prominent shrub along the side slopes, forming dense stands. On the plateau top, the oak tends to grow in clumps with open stands of grasses interspersed. A juniper pinon community is found • on the more xeric southern slopes with scattered individuals of Douglas Fir-Ponderosa Pine 6