This document summarizes a 2009 watershed study of Shell Creek. Researchers took water quality measurements at 6 sites along the creek monthly from May to August. Measurements included pH, temperature, dissolved oxygen, turbidity, nutrients, bacteria, and more. A water quality index was calculated for each site and averaged between 25-70 indicating medium quality overall. Some sites had elevated bacteria and nutrients. Comparison to previous years found improving quality but room for further improvement remains.

1. 1

2. 2009 Shell Creek
Watershed Study
Advisors – Mark Seier & Suzy Goedeken
Researchers –Katie O’Brien, Olivia Wiese, Jonathon
Dohmen, Jake Kaufman, Mark O’Brien, April Ramaekers,
Aubrey Strong, Audrey Wondercheck, Greg Roberg, Lila
Wondercheck, Kendra Nelson, Ciera Afrank, Alisha
Dunlap, Joan O’Brien
2

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

4. Site 1
4

5. Site 2
5

6. Site 3
6

7. Site 4
7

8. Site 6
8

9. Site 5
9

10. 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. 10

11. • 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 weren’t part of W.Q.I., but
did give us a water quality rating.
11

12. Sample W.Q.I. Curve Chart
12

13. 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 ___ 13

14. 2009 Precipitation
6
5
4
Inches
3
2
1
0
May June July August
Rainfall
14

15. pH
8.4
8.1
Site 1
7.8 Site 2
pH Level
7.5 Site 3
Site 4
7.2 Site 5
6.9 Site 6
6.6
6.3
May 22 June 23 July 23 August 6
15
Date

16. Change in Water Temperature
1.5
1
0.5
Site 1
Degrees Celcius
0
Site 2
-0.5 May22 June 23 July 23 August 6
Site 3
-1 Site 4
Site 5
-1.5
Site 6
-2
-2.5
-3
Date
The higher the change, the worse the water quality. 16

17. Total Solids
4000
3500
3000
2500 Site 1
Site 2
mg/L
2000 Site 3
Site 4
1500
Site 5
1000 Site 6
500
0
May 22 June 23 July 23 August 6
Date
The higher the concentration, the worse the water quality. 17

18. Fecal Coliform
18

19. Fecal Coliform
1200
1000
colonies/100 mL
800 Site 1
Site 2
600 Site 3
Site 4
400 Site 5
Site 6
200
0
May 22 June 23 July 23 August 6
Date
19

20. Fecal Coliform
1600
In 2006
Site 1- 21,418
1400 Site 5- 17,800
1200
colonies/100 mL
Site 1
1000
Site 2
800 Site 3
Site 4
600 Site 5
Site 6
400
200
0
2003 2004 2005 2006 2007 2008 2009
Date
20

21. Flow
80
70
60
Cubic feet per second
Site 1
50 Site 2
Site 3
40
Site 4
30 Site 5
Site 6
20
10
0
May 22 June 23 July 23 August 6
Date
21

22. Turbidity
2500
2000
Site 1
1500 Site 2
JTU's
Site 3
Site 4
1000
Site 5
Site 6
500
0
May 22 June 23 July 23 August 6
Date
22

23. Turbidity On July 23, 2009
23

24. Dissolved Oxygen
100
90
80
Site 1
70
% Saturation
Site 2
60
Site 3
50
Site 4
40
Site 5
30 Site 6
20
10
0
May 22 June 23 July 23 August 6
Date
24

25. 5 Day Biological Oxygen Demand
8
7
6
Site 1
5
Site 2
ppm
4 Site 3
Site 4
3 Site 5
Site 6
2
1
0
May 22 June 23 July 23 August 6
Date
The higher the change, the worse the water quality. 25

26. Nitrates
50
45
40
35 Site 1
30 Site 2
ppm
25 Site 3
Site 4
20
Site 5
15 Site 6
10
5
0
May 22 June 23 July 23 August 6
Date
26

27. 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
Date
27

28. Phosphates
3
2.5
2 Site 1
Site 2
ppm
1.5 Site 3
Site 4
1 Site 5
Site 6
0.5
0
May 22 June 23 July 23 August 6
Date
28

29. 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
29

30. Total WQI Averages by Year
70
Good
65
60 Medium
WQI
55
50 Bad
45
2003 2004 2005 2006 2007 2008 2009
WQI
30

31. 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 31

32. 2003 - 2009 Chemical Test Average Comparisons
30
25
20
15 2003 Averages
2004 Averages
10 2005 Averages
2006 Averages
2007 Averages
5
2008 Averages
2009 Averages
0
Total Rainfall Discharge Nitrates ppm pH
Inches CFS
32

33. 2003 - 2009 Chemical Test Average Comparisons
3
2.5
2
1.5 2003 Averages
2004 Averages
1 2005 Averages
2006 Averages
0.5 2007 Averages
2008 Averages
2009 Averages
0
Phosphates ppm B.O.D. ppm Change in Temp.
Celcius
33

34. 2003 - 2009 Chemical Test Average Comparisons
1200
*2006 Fecal Coliform
1000 Average 8,058 col/100 mL
800 2003 Averages
2004 Averages
600 2005 Averages
2006 Averages
400
2007 Averages
2008 Averages
200
2009 Averages
0
D.O. % Sat. Turbidity JTU Fecal Coliform Total Solids
Colonies/100 mg/L
mL
34

35. Chemical Test Conclusions
• Fecal Coliform is down, but still erratic
• Less Rainfall seems to effect our data
• Site 1 has significantly higher nitrates
• WQI is increasing downstream
• D.O. is still low
• Very high correlation between nitrates
and flow
35

36. Macro Invertebrates
Sensitive Somewhat Sensitive Tolerant
36

37. Sample Bio-Indicator Data Form
37

38. Beaver-Shell Creek
WQI Comparison
80
70 Beaver Creek
Average WQI
60
50
WQI 40 Shell Creek
Average WQI
30
20
10
0
May-09 Jun-09 Jul-09 Aug-09 Summer Summer
Average Average
09 08 38

39. Beaver-Shell Creek Comparison
14
12
10
Beaver Creek
8 Shell Creek
6
4
2
0
pH Nitrates Phosphates B.O.D
39

40. Beaver-Shell Creek Comparison
800
700
600
500
400 Beaver Creek
300 Shell Creek
200
100
0
Turbidity Fecal Total Solids D.O. % Sat.
Coliform
40

41. Flood Study
41

42. Flood Study
Date Avg. Total Solid Solid
Width Flow Solids
and Depth Discharge Discharge
(ft) (cfs)
Time (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
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
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46. 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.
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48. Thank You To:
• David Rus from USGS
• Lower Platte North Natural
Resource District
• PrairieLand RC&D
• Natural Resource Conservation
Service
• Nebraska Department of
Environmental Quality 48