Bee Lake Water Quality Monitor Data Summary

1. Bee Lake Water Quality Monitor Data Summary Period of record: 10-1-05 to 2/19/07

2. Bee Lake Monitoring Station • Located mid-bridge at Thornton • In service since summer of 2005 • Continuous, real-time monitor • Stage • Temperature • Rainfall • Specific conductance • Turbidity

3. Bee Lake looking north from bridge at Thornton

4. Bee Lake real-time monitor web page: http://waterdata.usgs.gov/ms/nwis/uv/?site_no=330359090194135&PARAmeter_cd=00065,00060

5. Summary Information • Figures and table are based on daily mean data (or daily totals for rainfall) • Figure 1 – Stage, rainfall, turbidity; 10/1/05 to 2/19/07 • Figure 2 – Stage, rainfall, specific conductance, temperature; 10/1/05 to 2/19/07 • Table 1 – Summary statistics comparing data for period 10/1/05-2/19/06 to data for period 10/1/06-2/19/07

6. Figure 1. Stage, turbidity, and rainfall at Bee Lake monitoring station, 10/1/05 to 2/19/07

7. Figure 1 observations • Overall decrease in turbidity for 10/1/05 – 2/19/07: BMPs or weather? • Antecedent stage was lower prior to winter 2006-2007 than winter 2005-2006 • Dry summer 2006; drought conditions • Storm of 10/06 • 7 in. rainfall event • Turbidity and stage lower than previous year’s storms • Storms 10/2006 – 2/2007 • Stage peaks are smaller and have a longer duration than previous year • Lower turbidities than previous year

8. Figure 2. Stage, specific conductance, temperature, and rainfall at Bee Lake monitoring station, 10/1/05 to 2/19/07

9. Figure 2 observations • Interaction between specific conductance and rainfall are typical and expected • Higher specific conductance with lower stage and infrequent rainfall • Rainfall events immediately drop temperature and specific conductance • During drought conditions, specific conductance goes up possibly indicating ground water infiltration

10. Table 1.Summary statistics comparing data for period 10/1/05-2/19/06 to data for period 10/1/06-2/19/07 Rainfall totals for 10/1/05-2/19/06: 17.03 inches Rainfall totals for 10/1/06-2/19/07: 23.25 inches

11. Table 1 observations • Time periods were selected to cover fall and winter months during which intense storms are expected • Summary statistics for stage, temperature, and specific conductance are similar for both time periods • Rainfall maximum and totals are higher for 2006-07 • All turbidity statistics are lower for 2006-07

12. Summary • Stage peaks are smaller and have a longer duration for storms in 2006-07 • Turbidity was lower for 2006-07 in spite of more rainfall and one intense rainfall event during 10/2006 • Possible ground water infiltration during summer drought periods • Data indicate that changes have occurred in Bee Lake basin resulting in lower turbidity in the lake • Still too early to tell if changes were caused by BMPs or by drought conditions during summer 2006

13. Future Activities • Continue monitoring lake conditions • During 2007: • One new sampling sites installed just below large area of BMP-treated land • One new sampling site located at lake outlet • Three to four years of sampling at all locations • Summary report will be completed at the end of sampling period