Willard Spur: 2011 Hydrology and Nutrient Loads

1. Development of Water Quality
Standards for Willard Spur
2011 Hydrology &
Nutrient Loads
Willard Spur Science Panel
April 5, 2012
Photo:Josh Noble

2. What was our objective for 2011?
• Understand the sources, quantity,
timing, and mechanisms of water and
nutrient loading
• Relative contribution of the POTW
Note: Recognized that 2011 was
potentially a wet year
• April 2011 snowpack: 185% of normal
• April 2012 snowpack: 65% of normal

3. What we did in 2011
• Mapped and measured inflows
• Monitored nutrients in inflows
• Measured outflow
• Monitored weather
• Monitored water surface elevations

5. Something to consider….
• What does the data mean in the
context of our overall objectives?
• How does this influence what we do
in 2012?

6. Bear River
@ Corinne Overall Inflows (2011)
Did Willard Spur
Water level close off in
2011/2012?
BRMBR “weir”
Willard Bay

7. BRMBR
Inflows (2011)

8. Residence Time of Water
Month Full Volume RT 2/3 Volume RT
(days) (days)
June 4 3
August 14 9
September 17 11
October 14 9
Note: Estimate assumes constant pool elevation

9. How did 2011 compare to recent
record?

10. Apparent elevation where GSL
changes salinity of Willard
Spur = 4201.8ft

11. Observations
• 2011 represented a very wet year
– Does not appear to have “closed”, rare
event since floods of 1980’s
• Bear River most significant source of
flow followed by Willard Bay, Harold
Crane WMA
• Residence times increased

12. Nutrient Loads
• Estimated from flow volume and
discrete water quality samples
(~1/mth)
– LOADEST model requires more sample
points than what we have
– Used spreadsheet to estimate preliminary
loads
– Still trying to address discrepancies in flow
data for Harold Crane WMA

13. Trend of Total Nutrient Loads to Willard Spur
600,000
Total Nitrogen
500,000
Total Phosphorus
Nutrient Loads (lbs/month)
400,000
300,000
200,000
100,000
0
June, 2011 July, 2011 August, 2011 September, 2011

14. Trend of Phosphorus Loads to Willard Spur
70,000
60,000 BRMBR
Total Phosphorus Loads (lbs/month)
Willard Bay
50,000
Willard/Perry WWTP
40,000
30,000
20,000
10,000
0
June, 2011 July, 2011 August, 2011 September, 2011

15. Trend of Nitrogen Loads to Willard Spur
450,000
400,000 BRMBR
350,000 Willard Bay
Total Nitrogen Loads (lbs/month)
300,000 Willard/Perry WWTP
250,000
200,000
150,000
100,000
50,000
0
June, 2011 July, 2011 August, 2011 September, 2011

16. June, 2011 - Total Phosphorus Loads June, 2011 - Total Nitrogen Loads to
to Willard Spur Willard Spur
10.35% 13.51%
0.07% 0.16%
0.00% Willard Perry WWTP 0.00% Willard Perry WWTP
Willard Bay Willard Bay
Bear River Refuge 86.33% Bear River Refuge
89.59%
Harold Crane WMA Harold Crane WMA

17. July, 2011 - Total Phosphorus Loads to July, 2011 - Total Nitrogen Loads to
Willard Spur Willard Spur
0.71% 0.96%
0.93% 1.42%
0.00% Willard Perry WWTP 0.00% Willard Perry WWTP
Willard Bay Willard Bay
Bear River Refuge Bear River Refuge
98.35% 97.63%
Harold Crane WMA Harold Crane WMA

18. August, 2011 - Total Phosphorus August, 2011 - Total Nitrogen Loads to
Loads to Willard Spur Willard Spur
0.50% 0.62%
3.20% 2.78%
0.00% Willard Perry WWTP 0.00% Willard Perry WWTP
Willard Bay Willard Bay
Bear River Refuge Bear River Refuge
96.31% 96.60%
Harold Crane WMA Harold Crane WMA