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shale dips a few degrees generally northward into the Sand Wash Basin. The shale beds have <br />weathered out to form gently sloping hillsides on either side of the nearly level alluvial valley <br />floors and terraces found along Dry Creek. <br />Surface waters do not appear to be in hydrologic communication with the Twentymile <br />Sandstone, a significant regional aquifer that underlies the Lewis shale. Ground water <br />movement is described below and in Tabs 7, 14 and 15 of the permit application. <br />More detailed geologic information, including geologic maps and a generalized geologic cross - <br />section, can be found in Tab 6 of the permit application. <br />Soils <br />Soils in the Dry Creek area range from clays to loams. The soils are of limited agricultural use <br />due to high concentrations of sodium and salt. information on soils can be found in Tabs 9 and <br />19 of the permit application. Specific findings related to soils are described in Section B, Item <br />IV of this document. • <br />Climate <br />The region is characterized by a semi -arid steppe climatic regime with cold winters and mild to <br />cool summers. The prevailing wind is from the northwest (reversing at night due to <br />southeasterly upslope winds). Average annual precipitation is 16 inches and the growing season <br />in the region is approximately 94 days. Climatic information was collected from Hayden <br />Station, one mile away, and the Seneca II -W Mine, six miles south of the loadout. <br />More detailed climatic information can be found in Tab 8 of the permit application. <br />Surface Water Hydrology <br />Surface water information is found in the following sections of the permit application: Tabs 7, <br />12, 13, 14, 15 and 16 and Exhibits 12 -2, 12 -3, and 12 -4. A summary of this information is <br />included here, below in the Description of the Operations Plan and in Section B, Item III of this <br />document. <br />Most of the permit area associated with the Loadout drains to Dry Creek. A small, northern <br />portion of the railroad loop drains directly into the Yampa River. Three drainages, Stokes Gulch, <br />Dry Creek, and Sage Creek, run through the permit area associated with the TAHR. The. Walker <br />irrigation ditch crosses the northern portion of the permit area. The Yampa River lies about one <br />mile north of the permit area. <br />Precipitation averages approximately 16 inches annually in the permit area and the volume of <br />runoff is limited. Most runoff comes from snowmelt or intense thunderstorm events. Flows in <br />Dry Creek have ranged from 0 to 126 cfs (cubic feet per second) upstream of the loadout to from <br />0 to 225 cfs downstream. Two sediment ponds handle runoff at the loadout: the Truck Loop <br />Pond usually discharges during spring snowmelt; the Rail Loop Pond has rarely discharged. <br />Stream flow in Dry Creek generally increases downstream although some sections are <br />ephemeral. During the growing season, diversions of water from Dry Creek above the permit <br />Hayden Gulch Loadout 9 November 22, 2011 <br />