PERMFILE129578 - Laserfiche WebLink

Home Browse Search

Rule 2.04 • 2.04 INFORMATION ON ENVIRONMENTAL RESOURCES 2.04.3 Site Description and Land Use Information Detailed descriptions of environmental resources aze contained in Section 2.04 and referenard appendirer of the anginal permit applieatian. Broad summaries of those descriptions and studies are provided here fat general reference purposes. Copies of the baseline study reports or investigations fat vegetation and soils aze included as Appendices B and C, respectively, to this document. An edited and updated version of the hydrology discussion from the original permit application is also included as Appendix D to this document. Additional hydrology information including the most recent hydrologic impact analysis can be found in Exhibit 7 of the Phare II/Phase III Bond Releare Applieation, and the DMG's findings included in the bond release approval. 2.04.3(1 )Environmental Resources Toooeraohv The Hayden Gulch mine is located in the Williams Fork Mountains which serve as a drainage divide between the Yampa and Williams Fork rivets in the mine area. Topography in the immediate mine azea is dominated by anortheast-southwest running ridge which joins the Yampa River-Williams Fork divide north of the mine azea. Surface elevations at the mine site range from 7300 to 7900 feet above MSL. General topography in the area is characterized by Flat to rolling ridge top terrain with steep cliffs or • escarpments on the southern end of the ridges. Natural slopes in the immediate vicinity of the mine range from 1 (one) to 80 degrees. Pre-mining slopes within the mine permit azea varied from 3:1 to 10:1 with predominantly well drained, northern aspects. (See Exhibit B, ProMining Map, of Exhibitr, Volume L) Vegetation Baseline information on the condition of the permit area prior to mining was included in the vegetation smdies found in Volume III, Appendix G, Section 2 of the original permit application. These studies, performed by 3R Corporation and Morrison-Knudsen Company (M-K), included information on plant communities, premining herbaceous biomass, herbaceous cover, woody plant density, and utilization of vegetation by grazing animals. No threatened, endangered or raze plant species were identified within the mine permit azea. The primary plant communities within the mine permit area were the sagebrush-serviceberry community and various other mountain shrub communities. Several aspen groves were also present on north facing slopes. Within the mountain shrub azeas which dominate the ridge tops and upper slopes, the primary species present include scrub oak (Quercus gambelii), snowberry (Symphiocarpis spp.) and serviceberry (Amelanchier alnifolia). The sagebmsh community was interspersed with the mountain shrub type and dominant along lower ridge slopes and the bottom of Hayden Gulch. Dominant species within the sagebrush community include sagebrush (Artemisia spp.) and snowberry. In all plant communities except the scrub oak type, vazious grass species composed the majority of the herbaceous cover. U 2.04-1 Revised - OG/Ol