Burandt Lake Burandt Lake TMDLTMDL

(Total Maximum Daily Load)(Total Maximum Daily Load)Water quality in an urban Water quality in an urban

lakelake

2/7/20082/7/2008

Objectives of this Objectives of this presentationpresentation

Why Burandt Lake is listed as impairedWhy Burandt Lake is listed as impaired Water Quality in Burandt LakeWater Quality in Burandt Lake

Watershed characteristicsWatershed characteristics Quality of waterQuality of water Plant communitiesPlant communities

Sources of pollution and SolutionsSources of pollution and Solutions Who will do what?Who will do what?

Local governmentLocal government YOU!YOU!

Impaired Water ListingImpaired Water Listing

Burandt Lake was added to the Burandt Lake was added to the impaired waters list in 2004impaired waters list in 2004

Designated use= Aquatic Recreation Designated use= Aquatic Recreation (swimming)(swimming)

Impaired for Excess Nutrients= too Impaired for Excess Nutrients= too much phosphorusmuch phosphorus

Why the lake is impairedWhy the lake is impaired

Average Total Phosphorus (ug/L)

0.0

20.0

40.0

60.0

80.0

100.0

1999 2000 2001 2004 2005

To

tal P

ho

sph

oru

s (u

g/L

)

Total phosphorus standard= 40 ug/L

32-66% Reduction in phosphorus needed to meet the standard

Sources of phosphorusSources of phosphorus“When it rains, it pollutes”“When it rains, it pollutes”

THINK WATERSHEDS!THINK WATERSHEDS!Source: Ron Struss, BWSR. “Lawns, Lakes, and Laws. 2002

Diagram not to scale

Epilimnion (Mixed Layer) warm, light water

Hypolimnion(cool, heavy water)

Thermocline(prevents mixing)

Metalimnion

0-4 meters

4-17 meters

Generalized Lake Ecosystem(Summertime Average Conditions)

Watershed Watershed Characteristics Characteristics Lake Waconia

7,147 Acres

Agriculture= 28%

Developed= 9%

Open Space= 63%

Scheuble Lake

430 Acres

Agriculture= 52%

Developed= 12%

Open Space= 40%

Burandt Lake

246 Acres

Agriculture= 1%

Developed= 55%

Open Space= 44%

Water QualityWater Quality

2005 Total Phosphorus

0

20

40

60

80

100

120

Tota

l Ph

osph

oru

s (u

g/L)

TP

High flow from Lake Waconia

Impacts from surrounding watershed and in-lake

In- lake and

Scheuble Lake

watershed

Trends in Water QualityTrends in Water Quality

Average Total Phosphorus (ug/L)

0.0

20.0

40.0

60.0

80.0

100.0

1999 2000 2001 2004 2005

To

tal P

ho

sph

oru

s (u

g/L

)

Aquatic Plant SurveysAquatic Plant Surveys

2005 Survey conducted by County staff2005 Survey conducted by County staff

Exotic Invasive Plants:Exotic Invasive Plants: Dense stands of eurasian watermilfoilDense stands of eurasian watermilfoil Moderate stands of curly leaf Moderate stands of curly leaf

pondweedpondweed

Native Plants:Native Plants:6 species6 species

ConclusionsConclusions

Must keep Lake Waconia healthy!Must keep Lake Waconia healthy! Focus on reducing storm water Focus on reducing storm water

runoff in Burandt Lake watershedrunoff in Burandt Lake watershed Ensure that spring flow from Ensure that spring flow from

Scheuble Lake has reduced Scheuble Lake has reduced phosphorus.phosphorus.

In-Lake Phosphorus must be In-Lake Phosphorus must be reduced!reduced!

External Phosphorus External Phosphorus SourcesSources

The PollutionThe Pollution Stormwater runoffStormwater runoff

ResidentialResidential Impervious surfaceImpervious surface AgricultureAgriculture

Failing/direct Failing/direct discharge septic discharge septic systemssystems

Degraded wetlandsDegraded wetlands

The SolutionThe Solution Buffers, shoreline Buffers, shoreline

restoration, infiltration restoration, infiltration ponds, rain gardens, ponds, rain gardens, rock inletsrock inlets

Upgrade you septic Upgrade you septic system and/or make system and/or make sure it is compliantsure it is compliant

Restore and protect Restore and protect wetlandswetlands

In-lake Phosphorus In-lake Phosphorus SourcesSources

The PollutionThe Pollution Anoxic sedimentAnoxic sediment Seasonal Seasonal

turnoverturnover Wind and boat Wind and boat

propeller mixingpropeller mixing Curly leaf Curly leaf

pondweedpondweed

The SolutionsThe Solutions Minimize boat Minimize boat

propeller action in propeller action in shallow areas of shallow areas of lakelake

Aquatic plant Aquatic plant managementmanagement

Chemical Chemical treatmentstreatments

What Local Government What Local Government Can DoCan Do

Help to coordinate local volunteers Help to coordinate local volunteers and effortsand efforts

Seek and/or provide funding for Seek and/or provide funding for projectsprojects

Make technical assistance availableMake technical assistance available EducationEducation Provide suppliesProvide supplies Offer project ideasOffer project ideas Provide media exposure/promotionProvide media exposure/promotion

What you can doWhat you can do Use zero phosphorus fertilizerUse zero phosphorus fertilizer - it’s the law! - it’s the law! Don’t sweep or blow leaves into the street- Don’t sweep or blow leaves into the street- they they

will end up in the storm sewer and then the lake.will end up in the storm sewer and then the lake. Install a Rain GardenInstall a Rain Garden – they catch runoff from – they catch runoff from

you yard and filter it.you yard and filter it. Use a Rain Barrel Use a Rain Barrel – they catch runoff from your – they catch runoff from your

roof and you can use the water to your gardenroof and you can use the water to your garden Install buffers- Install buffers- they reduce runoff of fertilizer they reduce runoff of fertilizer

from lawns and ag fields.from lawns and ag fields. Upgrade failing or direct discharge septic Upgrade failing or direct discharge septic

systemssystems Educate your neighbors!Educate your neighbors! Restore your shorelineRestore your shoreline -plant a native vegetation -plant a native vegetation

buffer.buffer.

Next Steps…Next Steps…

MPCA approval of TMDLMPCA approval of TMDL EPA approval of TMDLEPA approval of TMDL Design and implementation strategyDesign and implementation strategy Seek additional funding$$Seek additional funding$$

Be proactive!Be proactive! Stay involved!Stay involved!

Websites of InterestWebsites of Interest

http://www.co.carver.mn.us/tmdlshttp://www.co.carver.mn.us/tmdls

http://www.dnr.state.mn.us/lakefindhttp://www.dnr.state.mn.us/lakefind

http://www.pca.state.mn.us/data/http://www.pca.state.mn.us/data/edaWateredaWater

http://www.dnr.state.mn.us/grants/habitat/http://www.dnr.state.mn.us/grants/habitat/shoreland.htmlshoreland.html

Panfish64%Predators

2%

Rough Fish34%

Fish PopulationsFish Populations