U.S. Department of the InteriorU.S. Geological Survey

Bee Lake Water Quality Monitor Data Summary

Period of record: 10-1-05 to 2/19/07

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

Bee Lake looking north from bridge at Thornton

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

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

La

ke

Sta

ge

, fe

et

0

2

4

6

8

10

12

Tu

rbid

ity,

FN

U

0

20

40

60

80

100

120

9/1/2005 1/1/2006 5/1/2006 9/1/2006 1/1/2007

Ra

infa

ll,

inc

he

s

0

2

4

6

8

10

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

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

Sta

ge

, fe

et

0

2

4

6

8

10

12

14

16

18

Sp

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ific

co

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uc

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, m

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me

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en

tim

ete

r

0

20

40

60

80

100

120

140

160

180

Te

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era

ture

, d

eg

ree

s C

els

ius

0

20

40

60

80

100

120

9/1/2005 1/1/2006 5/1/2006 9/1/2006 1/1/2007

Ra

infa

ll,

inc

he

s

0

2

4

6

8

10

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

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

  10/1/05 - 2/19/06   10/1/06 - 2/19/07

Data Set

Number of missing

data Minimum Maximum Median Mean  

Number of missing

data Minimum Maximum Median Mean

Stage 0/142 6.1 10.7 6.6 7.0   0/142 5.0 9.3 7.4 7.4

Rainfall 18/142 0.0 2.4 0.0 0.1   2/142 0.0 7.1 0.0 0.2

Temperature 1/142 7.2 27.5 12.6 14.3   0/142 6.8 27.8 12.4 13.5

Specific Conductance 10/142 73.4 88.1 82.6 82.5   0/142 71.1 104.5 76.8 78.6

Turbidity 44/142 12.8 70.0 21.0 22.9   51/142 0.1 49.1 4.1 7.2

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

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

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

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