REP47025 - Laserfiche WebLink

Home Browse Search

13.71 inches or greater. "Dry" years were defined as those years in which the "pre- growing season" precipitation total (as recorded by the National Weather Service or their designee) is 8.45 inches or less. "Normal" yeazs were defined as those years with a "pre-growing season" precipitation coral (as recorded by the National Weather Service or their designee) is greater than 8.45 inches and less than 13.71 inches. "Pre-growing season" precipitation is defined as that precipitation which falls in the months of October, November, and December of year "X", and the months of January, February, Mazch, April, and May of year "X+I". Precipitation will be measured from data collected at the Paonia 1 SW station. Revegetation success standards for vegetation cover and herbaceous production from the historic record data will be established by determining the mean value of the three years data ("dry", "normal", and "wet") for a given parameter (total vegetation cover, total herbaceous production). The revegetation success criterion will then be 90 percent of the value of the historic record standazd with 90 percent statistical confidence. Selection of the Historic Record Vegetation Community Selection of the historic record vegetation community at the West Elk Mine was based on the following criteria; topography, elevation, aspect, soils, seral stage, predominant plant species, land use, and management. MCC proposed that the vegetation community reflect a predominantly herbaceous, graminoid dominated meadow or old field. This type of vegetation community would reflect a community suited to the approved post-mining land uses of livestock grazing and wildlife habitat. Additionally, such a graminoid community would be representative of the meadow communities affected by the operation. _ Based on the above criteria for the target historic record vegetation community, MCC and CDMG reviewed four potential historic record vegetation communities. The first area was a clearing, approximately three acres in size, immediately east of the current dry meadow reference area, on a terrace above Sylvester Gulch. The second community was an old field approximately five acres in size, south of the existing surface facilities in an area slated originally for development as the upper refuse disposal area. The third area was a homestead clearing east of the second community, above Sylvester Gulch. The fourth candidate community was the former ski area south of the North Fork of the Gunnison River, approximately three miles east of the mine. Based on visual inspection of each candidate community, as well as analysis of the physical characteristics, historic land use and management of all of the candidate areas, the second area (old field south of existing facilities) was selected by CDMG and MCC as the historic record vegetation community. An area five acres in size within the study area was fenced for management purposes for the duration of historic record vegetation sampling. -4-