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Management of Lac Courte Oreilles, Wisconsin ORW. January 6, 2010 USEPA, Region V. Lac Courte Oreilles, Oustanding Resource Water. “An antidegradation policy is also issued by each state to maintain and protect existing uses and high quality waters.” (not limited as to sources)
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Management of Lac Courte Oreilles, Wisconsin ORW January 6, 2010 USEPA, Region V
Lac Courte Oreilles, Oustanding Resource Water • “An antidegradation policy is also issued by each state to maintain and protect existing uses and high quality waters.” (not limited as to sources) • Wisconsin lacks lake standards, science well defined • Inconsistent linkage of eutrophication variables in WISCALMS & 303 listings • Without stds, limited watershed management options. • Major Outstanding Resource Water is not being protected • USEPA intervention is requested
Wisconsin Impairments • Proposed WI 2008 List ~21 lakes for eutrophication, not including LCO • WI 2010 list • Faulty linkage TP:CHLa: TSI • Added 12 lakes for eutrophication • By comparison, MN 2008 List (approved) ~429 lakes for eutrophication including lake bays • Lake Standards Approved and Implemented • WI (2008) Lists Lake St. Croix (w/MN) • Mean St. Croix TP = 51 ug P/L, 20 ug/L Chla, 1.2m Secchi • Mean Musky Bay = 71ug P/L (avg. four stations), 10 ug/L Chla, 1.5 m Secchi + associated indicators
Lac Courte Oreilles Area Lakes: Regional Economic Resource • Estimated Fair Market Value* • Area Lakeshore ** = $593 M • 40% Lac Courte Oreilles properties (~$237M) • County Taxes = $ 5.1 M • Regional study underway * June, 2009 tabulation from Sawyer County (Mike Coleson to B. Wilson) ** Lac Courte Oreilles, Grindstone, Whitefish and Little Lac Courte Oreilles Lakeshore
Satellite Whole Lake Averaged Estimates of Clarity Lac Courte Oreilles Lakes.
Lac Courte Oreilles Watershed Flow Network Osprey Lake=11,709 acres Grindstone Creek = 15,495 acres Grindstone Windigo Lake Osprey Creek= 6,743 acres NE BAY Durphee = 510 acres LCO East LCO Center Ring Creek = 213 acres Spring = 3,543 acres LCO West Musky Bay Ghost Creek = 1,152 acres Sand Whitefish = 2,330 acres Sand Creek = 18,006 acres Chippewa Flowage Headwaters Musky Bay LCO West --> LCO Central LCO East Out Sand, Whitefish, Grindstone and Lac Courte Oreilles are ORW
TP:Dissolved Oxygen Linkage • Musky Bay reduce inflow P • LCO Main Bays protection from increasing DO depletion rates
Halstad, Jennings, West Arm, Stubbs Large Lake Bays and Impairments: Example Lake Minnetonka , MN Impaired Segments
Eutrophication: Increased Oxygen Depletion Rates Flow Path : Musky Bay LCO West LCO Central • LCO East Out • Eutrophication • Rapid loss of DO at ~11 m • Internal P Potential • Stress on cool water fisheries (Cisco) • Lost - cold water two story potential
Musky Bay serial eutrophication impacts beyond P and Chla • Filamentous mats • Expanding Curly Leaf Pondweed infestations 2007-2009. • 2009 CLPW found West (N) and NE Bays
Musky Bay USGS Summary • USGS Sediment study : • Increasing eutrophication since ~1940 with shoreline development and cranberry agri-industry; • Last 25 years (up to 1999) increased degradation, incidence of floating mats, • Loss of wild rice since 1920’s (water level and eutrophication). • Fisheries impacts ---------------------------------------------------------------------- • Barr, 1998 P Loading Sources • Cranberry bogs (44 percent) • Atmospheric deposition (17 percent) • Forests and wetlands (25 percent) • Shoreline development (8 percent) • Agriculture (6 percent).
Changing Climate • Net effect:Increase eutrophication potential • Longer growing seasons, ice free time • Intense storms • More variability dry/wet cycles • More winter thaws • Increasing stream flows • Warmer temperatures • Dry-wet periods • Hence, need for watershed P management • ? Basis without lake standards & meaningful antideg
Considerations for EPA • Support LCO Tribal lake standards being advanced. • Require Musky Bay Listed based on 2008 and 2010 data • … at a minimum, list as threatened • Require protection LCO Bays and associated economies via enforceable antideg. • Initiate TMDL or alternative process • COLA will fund TMDL independent study • Otherwise Antidegradation is limited Point Source and planning concept only