Laserfiche WebLink
-7- <br />Steven's Gulch, East Roatcap Creek, and Coal Gulch are intermittent to <br />ephemeral drainages. Localized deposits of colluvial material reworked by <br />fluvial processess are present within the general area, primarily within the <br />Steven's Gulch, West Fork Terror Creek, and Roatcap Creek drainages. These <br />deposits are generally 20 to 30 acres in size and provide industrial (Steven's <br />Gulch), domestic (Long Draw), and agricultural (Morrell Cow Camp) water <br />sources (page 39, Section 2.04.7 of Volume lA). Several smaller occurrances <br />of saturated alluvial/colluvial deposits are associated with the streams in <br />the permit areaa; however, none of these are currently supporting agricultural <br />use. <br />The flow of water in Terror Creek and in the North Fork of the Gunnison River <br />are strongly influenced by irrigation structures along these stream courses. <br />The Overland Ditch intercepts and distributes water from the upper reaches of <br />Terror Creek. The flow in the North Fork is controlled by Paonia Reservoir <br />and water withdrawals by several irrigation ditches: the Fire Mountain Canal, <br />Stewart Ditch, Farmers Ditch, and Paonia Ditch. In addition, there are two <br />pipelines that will withdraw water from the Steven's Gulch well field. The <br />first is in operation and is operated by the Pitkin Mesa Pipeline Company. <br />The second pipeline is proposed by the Orchard Valley Mine and will carry <br />water from the Steven's Gulch well field to the site of the proposed Roatcap <br />Creek portal facility. <br />There are many springs and ponds within the permit area and hydrologically <br />adjacent area. It appears that, based on available data, that most of these <br />springs and ponds depend upon seasonal precipitation and recharge from shallow <br />colluvial/alluvial sources. <br />The Orchard Yalley Mine lies on the southeast margin of the Piceance Basin. <br />Sedimentary rocks ranging from late Cretaceous to early Tertiary age, and <br />dipping 5 degrees North, are exposed in the mine areas. <br />Structural-stratigraphic cross-sections and isopach maps are presented in <br />Volume l0A (Confidential Appendices), and the mine area geology is presented <br />on Map 2-2. <br />Coat is to be produced from the Mesaverde Formation, a 2,500-foot-thick <br />sequence of sedimentary beds overlain by the Ohio Creek Congolomerate and <br />underlain by the Mancos Shale. The Mesaverde Formation is composed of four <br />members; the Rollins sandstone, the Upper and Lower Coal members, and the <br />"Barren" member. <br />The lowermost member of the Mesaverde Formation, the Rollins sandstone, is a <br />white to buff-colored, well-sorted, medium-grained sandstone, ranging from 150 <br />feet to 200 feet thick in the permit area. The Lower Coal member overlies the <br />Rollins sandstone and consists of interbedded sandstones, siltstones, coals, <br />and shale. The unit averages 265 feet thick in the permit area and bears <br />three significant coal seams--the "A", "B", and "C" seams. <br />