1985-06-12_REVISION - C1981012 (2)

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iii iiiiiiiiiiiiiiii 999 Wyoming Fusl Compony 12055 W. Second Place • P.O.Box 15596 • Lakewood. Colorado 80215 • Telephone (303)969-5037 Mr. Jeff Deckler Colorado Mined Land Reclamation Division 1313 Sherman Street Denver, Colorado 80203 June 6, 1985 ~~~~~~ ~~~ ~ ~ N 12 1985 MINED LAND RECLAMATION DIV1310N RE: Santistevan, Apache and Ciruela Canyons Stream Flow Baseline Monitoring - New Elk and Golden Eagle Mines Dear Mr. Deckler: Wyoming Fuel Company has been gathering stream flow and water quality baseline data from the above referenced canyons over the past year. This data has been gathered as per the requirements of stipulations placed on the two mine permits. During the springs of 1984, flume stations were constructed and Stevens Type F continuous recorders were calibrated and placed in operation on Apache and Santistevan • Canyons on April 5 and April 20, respectively. Also, Ciruela Canyon stream flow has been monitored quarterly at two surface stations, one above the Golden Eagle Mine and one at the confluence with the Purgatoire River below the Golden Eagle Mine. All data collected fromt he three canyons is attached. A summary of the data is presented below. Santistevan Canyon Over the past year, Santistevan Canyon has proven to he a perennial stream. Flows ranged from 0.014 to greater than 30.4 cfs with an average 24-hour mean of 0.096 cfs. The attached Tables present the daily record at mean 24-hour and peak discharges recorded during the year while the hydrograph summarizes the mean 24-hour variations. Runoff calculations indicate an annual discharge of 148 acre-feet. The majority of this runoff was recorded during the summer months in the form of heavy localized thunderstorms. These storms produced extreme spikes in the hydrograph, two of which exceeded the recording limits of the flume station. A relatively constant flow was observed during the fall and winter seasons dictated by snow and the freeze-thaw cycle, and limited vegetation growth eliminating evapotranspiration water loss. With exception to extended periods of freezing weather conditions limiting flow during the winter months, late spring/early summer seems to be the low flow season of the year. This is tied to a number of environmental conditions such as snow melt being gone, increased vegetation growth promoting evapotranspiration, and limited precipitation events.