Laserfiche WebLink
results of the gauging stations along Trout Creek indicate that the monitoring program is being placed on-line early enough in <br />the year to record flow prior to the peak runoff period for each year. The individual data points show [he monthly average <br />Flows and give some indication of the variability between mild winters (winters of less snow accumulation) and harsh winters. <br />The graph showing 1999-2001 data indicates a decrease in [he total s[reamflow in 2001 from 1999 and 2000 levels. The <br />1991-2001 graph suggests that 2001 was the driest winter over the past decade and 1993 was the wettest for [he watershed. <br />The continuous recorder a[ TR-b was down for repairs for much of 2001; therefore, s[reamflow data was only recorded for [he <br />months of June, July and August. <br />The flow record for 2001 shows the peak flow to have occurred in May as it did during 1991, 1992, 1994, and 1996. <br />The runoff from the mine site was much lower in 2001 than in previous years due to less snowpack on the mine site and [he <br />on-se[ of warmer temperatures occurring earlier in [he spring. The flow data presented in Figure 1 consists only of <br />information derived from continuous flow records. Instantaneous flow measurements obtained between 1989 and June 1994 <br />for this location are provided in Appendix A. Prior to that time, instability of [he stream channel caused by a 1984 flood <br />precluded the installation of any type of monitoring station in [he vicinity. <br />The bridge located immediately downstream of TR-a was replaced in the fall of 2000 potentially altering [he current <br />stage rating curve. Therefore, the decision was made [o update the stage/discharge curves for TR-a and TR-b. Over the 2001 <br />season, a total of nine cross-sections and associated velocities were measured a[ each cross section location. This data was <br />used [o compute a stage rating curve at each location. <br />The stage rating curve for TR-a was developed from flows ranging from 1 I cfs to 145 cfs. The curve equation and r2 <br />for [he curve aze as follows: y = 44.469x3~28~, where y =flow in cfs and x =depth of flow; rZ = 0.98. <br />The stage racing curve for TR-b was developed from flows ranging from 13 cfs to 144 cfs. The curve equation and rZ <br />for the curve are as follows: y = 65.049x2.431, where y =flow in cfs and x =depth of flow; r2 = 0.99. This appears to <br />indicate a good correlation between the upstream and downstream flows. <br />Additional measurements will be collected during the spring and early summer of 2002 to further refine the stage <br />rating curve for these locations. <br />2 <br />