1. U.S. Department of the Interior U.S. Geological Survey 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=33 0359090194135&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. 10/1/05 - 2/19/06 10/1/06 - 2/19/07 Data Set Number of missing dataMinimumMaximumMedianMean Number of missing dataMinimumMaximumMedianMean Stage0/1426.110.76.67.0 0/1425.09.37.4 Rainfall18/1420.02.40.00.1 2/1420.07.10.00.2 Temperature1/1427.227.512.614.3 0/1426.827.812.413.5 Specific Conductance10/14273.488.182.682.5 0/14271.1104.576.878.6 Turbidity44/14212.870.021.022.9 51/1420.149.14.17.2 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