The document summarizes a 2010 study of the Shell Creek and Loseke-Taylor Creek watersheds conducted by researchers from the Lower Platte North Natural Resources District. Water quality was assessed at 6 sites along the creeks through tests of dissolved oxygen, fecal coliform, pH, BOD, temperature, phosphates, nitrates, turbidity, and total solids. Results were used to calculate a Water Quality Index for each site. Overall, water quality was found to be medium to poor, with elevated levels of fecal coliform and total solids observed. Flow rates also varied significantly between sites and sampling dates.

1. 1

2. 2010 Shell Creek
Watershed Study
Advisors – Mark Seier, Suzy Goedeken, &
Karen Malmkar
Researchers –Katie O’Brien, Jake Kaufman, Mark
O’Brien, Aubrey Strong, Audrey Wondercheck, Greg
Roberg, Lila Wondercheck, Kendra Nelson, Ciera
Afrank, Alisha Dunlap, Joan O’Brien, Ashley Potmesil,
Darienne Pokorny, Jason Kaufman, Demi Edgell, Billy
O’Brien, Alex Wiese
2

3. Shell Creek and Loseke-Taylor Creek Watersheds
(with Township-Range Labels)
Lower Platte North Natural Resources District
6
3

4. Site 1
South Branch of the Shell Creek
4

5. 6
5

6. Site 2
North Branch of the Shell Creek
6

7. 6
7

8. Site 3
Above Newman Grove
8

9. 6
9

10. Site 4
Below Newman Grove
10

11. 6
11

12. Site 6
By Lindsay
12

13. 6
13

14. Site 5
Near Platte Center
14

15. 6
15

16. W.Q.I.
• The Water Quality Index was developed by the
National Sanitation Foundation as a standard
system to compare different bodies of water.
• To determine the WQI, a series of nine tests
were performed. These tests were: dissolved
oxygen, fecal coliform, pH, Biological Oxygen
Demand (BOD), temperature, total
phosphate, nitrates, turbidity, and total solids.
We also did a water discharge test which we
use to measure the flow of the creek in cubic
feet per second. 16

17. • After the tests are completed, the WQI for each
section of the creek can be computed.
• To formulate the WQI, we first computed Q-
values.
• We multiply this number by a weighting
factor, which provides a measure of the relative
importance of each test to overall water quality.
• The water quality index ranges from zero to 100.
- 0 - 25 is very bad
- 25 - 50 is bad
- 50 - 70 is medium
- 70 - 90 is good
- 90 - 100 is excellent
• The bio-indicator tests are not part of the
W.Q.I., but do give us a water quality rating.
17

18. Sample W.Q.I. Curve Chart
18

19. Sample W.Q.I. Form
Weighting
Test Results Q-value Factor Total
DO % sat. 0.17
Fecal Coliform col/100 mL 0.16
pH units 0.11
BOD mg/L 0.11
Temperature change in C 0.1
Total Phosphate mg/L 0.1
Nitrates mg/L 0.1
Turbidity JTU 0.08
Total Solids mg/L 0.07
Overall Water Quality Index ___ 19

20. 2010 Precipitation
16
14
12
10
Inches
8
6
4
2
0
May June July August
Rainfall
20

21. pH
8.4
8.1
Site 1
7.8 Site 2
pH Level
7.5 Site 3
Site 4
7.2 Site 6
6.9 Site 5
6.6
6.3
May 25 June 16 July 26- August 5
27 21
Date

22. Change in Water Temperature
3.5
3
2.5
2 Site 1
Degrees Celcius
Site 2
1.5
Site 3
1
Site 4
0.5 Site 6
0 Site 5
-0.5 May25 June 16 July 26-27 August 5
-1
-1.5
Date
The higher the change, the worse the water quality. 22

23. Total Solids
1200
1000
800 Site 1
Site 2
mg/L
600 Site 3
Site 4
400 Site 6
Site 5
200
0
May 25 June 16 July 26-27 August 5
Date
The higher the concentration, the worse the water quality. 23

24. Fecal Coliform
24

25. Fecal Coliform
Site 1- 44,800
2000
1800
1600
1400
colonies/100 mL
Site 1
1200 Site 2
1000 Site 3
800 Site 4
Site 6
600
Site 5
400
200
0
May 25 June 16 July 26-27 August 5
Date
25

26. Fecal Coliform
1600
In 2006 In 2010
Site 1- 21,418 Site 1- 11,387
1400 Site 5- 17,800
Site 6- 2,313
1200
colonies/100 mL
Site 1
1000
Site 2
800 Site 3
Site 4
600 Site 6
Site 5
400
200
0
2003 2004 2005 2006 2007 2008 2009 2010
Date
26

27. *Flow was not
Flow measured in
60 June for sites
3, 4, 5, and 6
due to high
50 waters.
Cubic feet per second
40 Site 1
Site 2
Site 3
30
Site 4
Site 6
20
Site 5
10
0
May 25 June 16 July 26-27 August 5
Date
27

28. Turbidity
400
350
300
Site 1
250
Site 2
JTU's
200 Site 3
Site 4
150 Site 6
Site 5
100
50
0
May 25 June 16 July 26-27 August 5
Date
28

29. Dissolved Oxygen
100
90
80
Site 1
70
% Saturation
Site 2
60
Site 3
50
Site 4
40
Site 6
30 Site 5
20
10
0
May 25 June 16 July 26-27 August 5
Date
29

30. 5 Day Biological Oxygen Demand
4
3.5
3
Site 1
2.5
Site 2
ppm
2 Site 3
Site 4
1.5 Site 6
Site 5
1
0.5
0
May 25 June 16 July 26-27 August 5
Date
The higher the change, the worse the water quality. 30

31. Nitrates
50
45
40
35 Site 1
30 Site 2
ppm
25 Site 3
Site 4
20
Site 6
15 Site 5
10
5
0
May 25 June 16 July 26-27 August 5
Date
31

32. Nitrates
60
50
40 Site 1
Site 2
ppm
30 Site 3
Site 4
20 Site 5
Site 6
10
0
2002 2003 2004 2005 2006 2007 2008 2009 2010
Date
32

33. Phosphates
4.5
4
3.5
3 Site 1
2.5 Site 2
ppm
Site 3
2
Site 4
1.5 Site 6
1 Site 5
0.5
0
May 25 June 16 July 26-27 August 5
Date
33

34. WQI Averages by Site
70
Good
65
60
Medium
WQI
55
50
Bad
45
Site 1 Site 2 Site 3 Site 4 Site 6 Site 5
2003 Averages 2004 Averages 2005 Averages 2006 Averages
2007 Averages 2008 Averages 2009 Averages 2010 Average
34

35. Total WQI Averages by Year
Good
70
65
60 Medium
WQI
55
50
Bad
45
2003 2004 2005 2006 2007 2008 2009 2010
WQI
35

36. WQI Averages by Date
70 Good
65
60
Medium
WQI
55
50 Bad
45
May June July August
Month
2003 Averages 2004 Averages 2005 Averages
2006 Averages 2007 Averages 2008 Averages
2009 Averages 2010 Average
36

37. 2003 - 2010 Chemical Test Average Comparisons
30
2003 Averages
2004 Averages
25
2005 Averages
2006 Averages
20 2007 Averages
2008 Averages
2009 Averages
15
2010 Average
10
5
0
Total Rainfall Discharge CFS Nitrates ppm pH
Inches
37

38. 2003 - 2010 Chemical Test Average Comparisons
3
2003 Averages
2.5
2004 Averages
2005 Averages
2 2006 Averages
2007 Averages
1.5 2008 Averages
2009 Averages
2010 Average
1
0.5
0
Phosphates ppm B.O.D. ppm Change in Temp.
Celcius
38

39. 2003 - 2010 Chemical Test Average Comparisons
1200
*2006 Fecal Coliform Average 2003 Averages
8,058 col/100 mL
1000 2004 Averages
2005 Averages
800 2006 Averages
*2010 Fecal Coliform 2007 Averages
Average 3,648 col/100 mL 2008 Averages
600
2009 Averages
2010 Average
400
200
0
D.O. % Sat. Turbidity JTU Fecal Coliform Total Solids
Colonies/100 mg/L
mL
39

40. Chemical Test Conclusions
• Phosphates were high in June.
• Fecal Coliform was a problem at certain
times.
• Nitrates seem to have peaked in 2008
and have since dropped down.
• Some of the results may be due to high
rainfall.
• The flow, nitrates levels, and rainfall are
continuing to correlate. 40

41. Macro Invertebrates
Sensitive Somewhat Sensitive Tolerant
41

42. Sample Bio-Indicator Data Form
42

43. Beaver-Shell Creek
WQI Comparison
Good
70
Medium 60 Beaver Creek
Average WQI
50
Bad
40
WQI Shell Creek
Average WQI
30
20
10
0
May-10 Jun-10 Jul-10 Aug-10 Summer Summer Summer
Average Average Average
10 09 08 43

44. Beaver-Shell Creek Comparison
2010
18
16
14
12 Beaver Creek
10 Shell Creek
8
6
4
2
0
pH Nitrates Phosphates B.O.D
44

45. Beaver-Shell Creek Comparison
2010
4000
3500
3000
2500
2000 Beaver Creek
1500 Shell Creek
1000
500
0
Turbidity Fecal Total Solids D.O. % Sat.
Coliform
45

46. 2010 Flood Study
46

47. Flood Study
Avg. Total Solid Solid
Date and Width Flow Nitrates
Depth Solids Discharge Discharge
Time (ft) (cfs) (ppm)
(ft) (mg/L) (lbs/min) (tons/hr)
5/30/07 110 8.42 2243 9300 78145 2344
6/8/08 130 8.98 4328 8950 145138 4354
110 7.6 1430 7210 18.04 38611.9 1158.4
6/10/10 125 9.6 3996 6410 10.34 95959.4 2878.8
6/12/10 130 11.1 4416 2510 3.3 41517.9 1245.5
X cu ft 60 sec 28.32 L X mg 1g 1 lb 1 ton 60 min
1 sec 1 min 1 cu ft 1L 100 mg 453.6 g 2000 lb 1 hr
47

48. Water
Testing
48

49. 49

50. 50

51. 51

52. Website
• http://www.newman.esu8.org/
• Click “Activities”
• Click “Watershed Project”
• Click “Watershed Homepage”
• You can see our data and further
information concerning this project,
including pictures.
52

53. 53

54. Thank You To:
• Lower Platte North Natural
Resource District
• PrairieLand RC&D
• Natural Resource Conservation
Service
• Nebraska Department of
Environmental Quality
• Shell Creek Watershed 54
Improvement Group