2015-08-31_PERMIT FILE - C1981010A (23)

Home Browse Search

because very little of their area will be impacted by mining. These basins include Small Gulch, Ute Gulch, South Gulches #1 and #2, Castor Gulch and Horse Gulch. Water use on the mine plan area has been limited to stock watering from ponds. Location of stock ponds is shown on Map M-31. Trapper submitted PR -07 in May of 2013 with the intent to extend the perimeter boundary of the mine to the Knez Divide road, otherwise known as Moffat County Road 33. This small permit extension adjoins the active mine area and permit boundary as of 2013. Within these expansion area portions of two previously undisturbed drainages will be included in the permit boundary. Deacon Gulch originates in the expansion area with an upland headwaters area and flows northward to the Yampa River. The drainage within the expansion area does not contain any defined channels and consists of a large bowl fed my several small upland swales within the native mountain brush community. Initial baseline monitoring of the area has indicated water flows in this drainage may only occur during intense precipitation or heavy snowmelt events. No perennial or intermittent flows have been recorded in the drainage within the expansion area. Further downstream Deacon Gulch becomes steeper and gains significantly more area. The drainage channel becomes more entrenched exposing areas of ground water influence on the surface drainage. Larger flows are still limited to springtime melts and precipitation events. The flow regime within the expansion area should be characteristic of other upland headwaters in the eastern portion of the current mine permit area. Jeffway Gulch originates opposite of Deacon Gulch in the expansion area and flows southward to the Williams Fork River. Jeffway is characteristic of the drainages on the south slopes of the Williams Fork Mountains. The lower reaches of this drainage are deep canyons with milder gradients than the north flanking drainages. Within the expansion area Jeffway Gulch primarily consists of upland headwaters areas within sagebrush and grass covered meadows and mountain brush community upland swales. At the southern edge of the expansion area a large un -named tributary to Jeffway Gulch joins the main channel. In this area a series of seeps are present within the expansion area, as is intermittent flows from a large seep complex within the tributary from the east. The area becomes very wet at this junction and a defined channel leaves the expansion area at County Road 33. This riparian area is not expected to be disturbed as it is beyond the extent of the coal reserves in this area. The seeps appear to originate from the base of the Twenty Mile Sandstone and shale layers below the sandstone. This is characteristic of this interface as is evident with seeps located within Deal and Horse Gulch. The upland portions of the drainage above the seep complex appear to only flow during intense precipitation or heavy snowmelt events. No perennial or intermittent flows have been recorded in the drainage above the seep complex. The anticipated watershed yield is contained in Table 2.7-12 for Deacon and Jeffway Gulches. The majority of these drainages within the expansion area would be ephemeral. Minimal flows are anticipated from the area. Maximum flows of these drainages would be dictated by the corresponding precipitation event and the area involved. Due to the placement of the drainages within their overall watershed, large flow events are not anticipated. There is no historic evidence of large flows occurring within these drainages within the expansion area. Continued monitoring of these drainages will occur and any further flow data will be analyzed and added. JUI 0 8 2014 Revision: Ipj — D-7 2-4141 /approved: