2014-07-11_REPORT - C1980007 - Laserfiche WebLink

Home Browse Search

West Elk Mine 2013 Annual Hydrology Report 2.0 HYDROLOGIC SUMMARY OF WATER YEAR 2013 During WY 2013, the total annual precipitation in the vicinity of the West Elk Mine was slightly below average at the Paonia 1 SW (56306) meteorological station, the Overland Reservoir (59853/CO07K14S) SNOTEL station, and the McClure Pass (59743/CO07K09S) SNOTEL station; compared to the historical total annual precipitation data (CCC, 2014; NRCS, 2014a; NRCS 2014b) (Figures 1 -3). During WY 2013, the snow water equivalent (SWE), a measure of the amount of water in the snow pack, data were well below the historical annual averages at the Overland Reservoir and McClure Pass stations (NRCS, 2014c), resulting in below average stream flows in the permit and surrounding areas (Figures 4 and 5). 2.1 Climatological Data Precipitation and SWE data for the permit and surrounding area for WY 2013 were derived from the following meteorological and SNOTEL stations: Paonia 1SW (56306), McClure Pass (59743/CO07K09S), and Overland Reservoir (59853/CO07K14S) (CCC, 2014; NRCS, 2014a; NRCS 2014b; NRCS, 2014c). Figures 1, 2, and 3 depict the WY 2013 total monthly precipitation data compared to the 73 -year historical average monthly precipitation data (1905 -1930 and 1957 -2005) for Paonia 1SW, the 32 -year (WY 1981- 2012) historical average for McClure Pass, and the 22 -year (WY 1991 -2012) historical average for Overland Reservoir. The total accumulated annual precipitation in WY 2013 was 14.49 inches at Paonia 1SW, 31.5 inches at McClure Pass, and 27.4 inches at Overland Reservoir (CCC, 2014; NRCS, 2014a; NRCS 2014b). This corresponds to 92 %, 95% and 87 %, respectively, of the historical average total accumulated annual precipitation values recorded at Paonia 1SW (15.81 inches), McClure Pass (33.1 inches), and Overland Reservoir (31.5 inches) (CCC, 2014; NRCS, 2014a; NRCS 2014b). June 2014 HydroGeo, Inc.