Phosphorus and Sediment Sources and Impacts in the Lower Fox River Subbasin: Whats Next

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Phosphorus and Sediment Sources and Impacts in
the Lower Fox River Subbasin Whats Next?
Bud Harris Kevin Fermanich UW Green Bay April 6,
2005
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How did we get here?

• 80-90s GBMSD Monitoring Program
• 1989 PCB Mass Balance Study
• 1990s Priority Watershed Programs
• 1990 State of Bay Report
• 1992 NEWWT
• 2003 PCB Record of Decision
• 2003 Lower Fox River Watershed Monitoring
  Program

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Target for TP Based on Algal Growth Rates in
Green Bay

• Algal growth begins to decline at 45 ug/l TP
• At gt 100 ug/l, growth rates do not increase

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Secchi Depth Model for Lower Green Bay (by Paul
Sager)

• Light penetration measured by secchi disk and
  light meter
• Secchi depth 0.80 0.174 TSS 0.17 VSS 0.16
  Chlor a
• (r2 .69)
• Sea Grant and Paul Sager currently updating model
  using recent MSD data

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Total P in Green Bay
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TSS in Green Bay
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Secchi Disk in Green Bay
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• Basin Load Partitioning
• Data from GBMSD, DNR,USGS
• Estimates by Dale Robertson USGS

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Loads at Main Branch Sites
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Fox-Wolf Basin Point Source P Loads
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Some conclusions from data set

• 23 of the phosphorus load to Green Bay comes
  from the segment between Wrightstown and the
  mouth of the Fox, which constitutes 3.4 of the
  land areas of the entire Fox/Wolf basin.
• gt60 of P is from nonpoint sources
• 47 of the total suspended solid load at the
  mouth of the river comes from the segment between
  Wrightstown and the mouth. 36 of the total is
  added between DePere and the mouth.

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Average phosphorus yields
(lbs/sq mi) 1995-1999 (inc.
point sources)
Average suspended sediment yields (t/sq mi)
1995-1999
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Cooperative, multi-year program 1.5 million
2003-2007

• Measure WQ and Biotic Integrity -- relate to
  watershed.
• Improve ability to predict future impacts.
• More informed decision making.

July 19, 2003
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Program Partners

• UW-Green Bay
• Natural and Applied Sciences
• Cofrin Center for Biodiversity
• UW-Milwaukee
• US Geological Survey
• GBMSD
• Oneida Tribe
• 5 High Schools
• Arjo Wiggins Appleton, Inc.

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Major Program Elements

• Continuous monitoring
• Sediment P loading (3 WY)
• Real-time sensors
• Source area studies
• Watershed modeling
• Stream biotic integrity monitoring (UWM)
• School-based monitoring program
• hands-on learning, citizen scientists, meaningful
  data
• 5 high schools, gt75 students, 8 teachers
• Annual symposium

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Monitoring Stations

• 3 water years started Oct 03
• Watersheds
• Duck Creek (CTH FF)
• Baird Creek (at Superior Road (I-43))
• Apple Creek (CTH U)
• Ashwaubenon Creek (Creamery Rd)
• East River GBMSD (Monroe St.)

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WY 2004 TSS Conc All Samples
Max 75 Median 25 Min
Number of Samples
2.5 times greater than median from previous
studies.
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WY 2004 Total P Conc. All Samples
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Sediment and P Yields WY 2004

• Sediment 0.75 mt/ha (213 t/sq mi) in clay
  soils watersheds
• P 2.0 kg/ha (1140 lbs/sq mi)
• P 2.5x avg. runoff load contribution to Green
  Bay from LFB.

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Fish Index of Biotic Integrity (IBI)Fox River
Tributary 2003 Summer Sampling
Poor
Very Poor
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Watershed Symposium March 9, 2005FWWA Stormwater
Conf.
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NPS SWAT Modeling

• Performed by Paul Baumgart
• 1998 LF Subbasin sediment only
• 2000 NRDA-RCDP full basin
• 2005 LF Subbasin Funded by OneidaTribe
• Sediment and P
• Land Use and BMP Scenarios
• All based primarily on Bower Creek for
  calibration and validation
• Also concentrations from other LF sites

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Simulated average annual non-point
phosphorus yields, 2000
baseline scenario
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Estimated Sediment P Load Allocation, 2000
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Next Steps?
www.uwgb.edu/watershed
Satellite image May 19, 2000