| Abstract/Description or Keywords |
This report describes the 2006 baseline surface hydrology program in the Schaft Creek Project study area. The Schaft Creek Project is located directly west of Edziza Provincial Park and approximately 140 km southwest of Dease Lake in Northern British Columbia, Canada. The current mine plan has the main pit located within the Schaft Creek watershed, while the camp and the airstrip will be located in the Mess Creek watershed. Currently there are three potential locations for the tailings impoundment; in the Schaft Creek, Hickman Creek and Skeeter Lake watersheds. Hickman Creek is a tributary of Schaft Creek. Both Schaft Creek and Skeeter Lake drain into Mess Creek. Mess Creek drains an upland area to the east of the Coast Mountains in the Tahltan Highlands of the Boundary Mountain Ranges. At Telegraph Creek, Mess Creek discharges into the Stikine River, which eventually discharges into the Pacific Ocean. Rescan Environmental Services Ltd. (Rescan) established eight automated hydrometric stations for the baseline monitoring program in the spring of 2006. Half of the stations monitored flows from small watersheds (less than 40 km2) and half monitored flows from larger watersheds (greater than 40 km2). The hydrometric stations remained active during the open-water season of May through October. However, two of the stations were damaged during the freshet (Sc-1 and Hctr-1). Consequently, these stations only collected quality data during June and July. At each hydrometric monitoring location, several manual flow measurements were conducted. The manual flow measurements and concurrently measured water level (or stage) were used to establish stage-discharge rating curves. The rating curves were subsequently used to convert the continuous water level data recorded at each station to stream flow hydrographs. For most stations, robust rating curves were established. However, for the Mess-1 and Sc-1 stations, the rating curves should be improved upon with additional data in 2007. Using the available flow data a number of key hydrological parameters were obtained including annual runoff, average monthly discharge, watershed unit yield, and peak and low flow estimates. Monthly average flow and annual runoff from watersheds in the Schaft Creek area are summarized in the report and are consistent with those observed in other watersheds gauged by Rescan in the vicinity of the Project area. Extreme high flows observed during the period of observation at each monitoring location range from 2.1m3/s to 86.5m3/s. Minimum daily flows ranged from 0.01m3/s to 2.2m3/s between hydrometric stations. The baseline surface hydrology program will continue in 2007. All existing hydrometric stations will be re-activated in the spring. One additional station will be built to monitoring flows from watershed that has been identified as a potential site of the tailings impoundment but which was not monitored in 2006. Manual flow measurements will continue to be made at each station to improve the existing stage-discharge rating curves. Due to the substantial glacier and ice field coverage and their hydrological importance to the watersheds in the Project area it is recommended that a glacial monitoring program be investigated in 2007. |
