powerpoint presentation - kegonsakegonsa.org/myhtml/pics.pdfmap: dane co. lwr dept. mendota mendota...

1/18/2015

1

What it will take to improve the ecology

and water quality of Lake Kegonsa

Richard Lathrop

Jan. 17, 2015

Photo: R. Lathrop, Sept. 1985

1 pound of phosphorus (P) can

produce 500 pounds of algae! (Source: Vallentyne, 1974)

Photo: Bryce Richter,UW-Madison

Lake Kegonsa, June 2012

Photo: Dane Co. LWR Dept.

Blue-green algal blooms have been a problem in the

Yahara lakes since the early 1900s

Blue-green algae, which typically “bloom” during the

summer and early fall in nutrient-rich waters, create

serious water quality problems:

• Blooms can pile up as noxious scums on downwind shorelines

• Blooms consume oxygen causing fish kills

• Blue-green algae are generally inedible and not part of a lake’s

food chain supporting desirable fish

• Blue-green algae can produce toxins of concern to humans &

wildlife • Seizures & respiratory problems can result from neuro-toxins

• Liver & kidney lesions can result from hepato-toxins

Lake Kegonsa, June 2012

Photo: Dane Co. LWR Dept.

The Capital Times, Sept. 6-7, 2003

First recorded death in U.S. due to blue-green algal toxins! Madison, Wisconsin – July 2002

[The local teenager] …

[ …

…]

Yahara lakes &

watershed

Map: Dane Co. LWR Dept.

Mendota

Kegonsa

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Lake Mendota

Lake Area = 39.6 km2

Max depth = 25.3 m

Mean depth = 12.7 m

Flushing rate (ave.) = 0.23 yr -1 (23% of lake’s volume flushed per year)


Mendota

Mendota Drainage Basin Land Use Total Area = 553 km2

59.7% 22.9%

12.0%

5.4%

Agriculture

Urban

Forest & Grasslands

Wetlands & Open Water(excludes lake area)

Lake Monona

Area = 13.7 km2

Max depth = 22.6 m

Mean depth = 8.3 m



Monona

8.1%

62.6%

23.8%

5.6%

Agriculture

Urban

Forest & Grasslands


Monona Drainage Basin Land Use Total Area = 119 km2

Lake Waubesa

Area = 8.5 km2

Max depth = 11.3 m

Mean depth = 4.7 m



Waubesa

24.6%

38.8%

23.1%

13.5% Agriculture

Urban

Forest & Grasslands


Waubesa Drainage Basin Land Use Total Area = 124 km2

Lake Kegonsa

Area = 13.0 km2

Max depth = 9.8 m

Mean depth = 5.1 m



Kegonsa

54.6%

18.6%

16.9%

9.8%

Agriculture

Urban

Forest & Grasslands


Kegonsa Drainage Basin Land Use Total Area = 155 km2

Burke sewage treatment plant in 1920’s

Early pollution to the Yahara lakes was from Madison’s

poorly treated sewage effluent discharges!

Photo: Wisconsin State Historical Soc. archives

Dissolved Inorganic Phosphorus

Yahara Lakes, July-August 1925-2005

1925 30 35 40 45 50 55 60 65 70 75 80 85 90 95 2000 05

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

DR

P

(mg

/ L

)

Mendota

Monona

Waubesa

Kegonsa

Monona

Waubesa

Mendota

Sewage effluents:

The lower Yahara lakes had very

high inorganic P conc. when the

lakes were receiving sewage

effluent discharges

Source: Lathrop (2007)

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The Chemical Treatment Era 1925-1954

Lake Monona, 1930s

Photo: Madison Dept. Public Health

Copper Sulfate Used in the Madison Lakes

1925-1984

0

100

200

300

400

Me

tric

To

ns

Kegonsa

Waubesa

Monona

Mendota

Madison Sewage Input:

Monona Waubesa 1936 1958

Source: Lathrop (2007)

Blue-green algal blooms in Lake Mendota

first became a problem in mid-1940’s

Photo: UW-Madison Center for Limnology

Dissolved Inorganic Phosphorus in Lake Mendota Yearly Mean Conc., 1926-2012 (Oct-Sep)

P increase from

upstream

community

sewage effluents

~1945

Sewage

effluent

diversion

in 1971

High and variable P levels linked

to ag and urban runoff pollution!

Source: Updated from Lathrop et al. (1996)

Barnyards Streambanks

Uplands Urban construction sites

Sources of non-point P loadings

Photos: Dane Co. Land & Water Resources Dept.

Runoff laden with

sediment and phosphorus

P transported to lakes

during runoff events

Photos: R. Lathrop, WDNR

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Lake Mendota

Priority Watershed Project

Inventory Phase 1994-1997

Implementation Phase 1998-2008

Photo: R. Lathrop, WDNR

Many conservation

practices were

installed during the

Mendota Priority

Watershed Project

(1998-2008).

Upper: Conservation tillage

with crop residue &

sedimentation basin

Left: Grassed buffer strip

installed between cropland

and drainage ditch


Left: Barynard water runoff

diversion system installation

Right: Animal lot barynard roof

installed for total confinement

feeding operation


Left: Stormwater detention

pond

In urban areas…

Right: Bioretention basin with

native vegetation installed to

infiltrate stormwater

Photos: Carolyn Betz, WDNR (above); Dane Co. Land &

Water Resources Dept. (right)

Erosion control practices

were installed as a result

of Dane County’s erosion

control ordinance

Left: Construction site mulching &

erosion control fabric

Lower: Rock weeper installations


Rain events >3 inches per dayMadison, Wisconsin, 1950-2009

0

1

2

3

4

5

6

7

8

9

10

1950s 1960s 1970s 1980s 1990s 2000s

Nu

mb

er

per

decad

e

Increase in large runoff events has

likely offset P load reductions from

best management practices installed

in watershed

Source: Rainfall statistics from Steve Vavrus, UW-Madison

1/18/2015

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Sixmile Creek inlet

Pheasant Branch inlet

Yahara River inlet

Extreme runoff events

deliver massive loads of

sediment and P Lake Mendota tributary

inflows, July 9, 1993

Photos: Skot Weidemann Photography

for Dane Co. LWR Dept.

Sixmile Creek … and manure management in an

urbanizing watershed is a big problem!

Photo: Dane Co. Land & Water Resources Dept.

Some soils have very high P concentrations

• 48,700 Animal Units (AU = 1,000 lb animal) ~54% “Liquid Storage” operation AU’s

(Note: Some manure is handled as solid)

~46% “Daily Haul” solid manure operation AU’s

• 889,000 tons of livestock manure produced annually

• 1,940,000 lbs of manure P generated annually

(881,000 kg P / yr)

Manure P in Lake Mendota Watershed:

Information source (2009): Dane Co. Land and Water Resources Dept.

Photo: Carolyn Betz, WDNR

Winter manure spreading

Photo: Kurt Welke,

WDNR

March 2008

Major pollution during late winter

runoff events when ground is frozen Mendota Watershed, March 11, 2007

Photo & Data: Herb Garn, USGS

Total Phosphorus = 9.7 mg/L

Ammonium Nitrogen = 19.0 mg/L

Late winter runoff event

with high P loads… Pheasant Branch, 10 March 2013

Photo: R. Lathrop

1/18/2015

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Percent Phosphorus Loads by Season Total for 1990-2013 (24 yrs)

Yahara River Pheasant Branch

• Late winter runoff events contributed largest seasonal P loads (44-45%)

• Spring runoff events contributed second largest seasonal loads (32-33%)

Source: R. Lathrop, UW Center for Limnology; USGS monitoring data

44.8%

31.6%

16.9%

6.6%

43.8%

32.9%

16.4%

6.9%

Jan-Mar Jan-Mar

Apr-Jun

Jul-Sep Jul-Sep

Oct-Dec Oct-Dec

Goal: “Mesotrophic” (moderately fertile) water quality

during July-August

Carlson’s (1977) Trophic State Index (TSI) for mesotrophy:

Total P <0.024 mg/L

Secchi disc >2.0 m

Mesotrophic Eutrophic

Source: Lathrop and Carpenter, 2013

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

TP

(m

g/L

) Mendota & Monona Median Total P

July-August, 1980-2012

Mendota

Monona

Mesotrophic boundary

1987-88 drought

Eutrophic

Mesotrophic

(TP = 0.024 mg/L)

Source: Lathrop and Carpenter 2013

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

TP

(m

g/L

)

Waubesa & Kegonsa Median Total P July-August, 1980-2012

Waubesa

Kegonsa

Mesotrophic

1987-88 drought

(Effect in 1988-89) Eutrophic

Mesotrophic

boundary


Hypereutrophic

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

Secch

i (m

)

4 Yahara Lakes Median Secchi July-August, 1976-2012

Mendota

Monona

Waubesa

Kegonsa

Mesotrophy boundary(Secchi = 2.0 m)

1987-88 drought

Eutrophic

Mesotrophic


1/18/2015

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Photo: Mike Kakuska

How much P loading reduction is needed for the

Yahara lakes to provide better water quality?

Periods of low P loadings during droughts

can provide useful targets

Lake outlet water is

the major source of P

load to downstream

lakes and river,

especially Waubesa

and Kegonsa.

Lake Mendota Outlet

Lake Kegonsa Outlet Photos: R. Lathrop, WDNR

Outlet P is virtually all

“biologically available”

for growing algae.

Direct drainage

P input = 29,600 kg

Outlet P

= 11,400 kg

Lake Mendota Average Annual P Loads 1976-2008

Mendota

Average Annual P Loads (kg)

Direct drainage sources 29,600

Other (atmospheric,

groundwater, etc.)

3,800

Total input load 33,400

Drought load (ave. 1987-1988)

17,400

Reduction needed to meet

drought target

−16,000

(−48%)

Outlet P load

11,400

Other P sources

= 3,800 kg


Direct drainage

P input = 7,500 kg

P input from

Mendota outlet

= 11,400 kg

Outlet P

= 10,400 kg

Lake Monona Average Annual P Loads 1976-2008

Average Annual

P Loads (kg)

Direct drainage 7,500

Upstream lake outlet 11,400

Other 1,100


Drought load

(ave. 1988-1989)

11,700

Reduction to meet

drought target

−8,300

(−42%)

Outlet P load

10,400

Other P

sources

= 1,100 kg


Lake Waubesa Average Annual P Loads 1980-2008

Direct drainage

P input

= 2,100 kg

P input from

Monona outlet

= 10,400 kg

Outlet P

= 12,500 kg

Average Annual

P Loads (kg)



Other 700


Drought load

(ave. 1988-1989)

6,800

Reduction to meet

drought target

−6,500

(−49%)

Outlet P load

12,500

Other P sources

= 700 kg


Kegonsa

Lake Kegonsa Average Annual P Loads 1980-2008

P input from

Waubesa outlet

= 12,500 kg

Direct drainage

P input = 4,000 kg

Outlet P

= 15,200 kg

Average Annual

P Loads (kg)



Other 1,100


Drought load

(ave. 1988-1989)

7,100

Reduction to meet

drought target

−10,600

(−60%)

Outlet P load

15,200

Other P sources

= 1,100 kg


1/18/2015

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Photo: Mike Kakuska

Goal: Reduce average annual P loads

from direct drainage sources in each of

the Yahara lakes by 50%.

(Yahara CLEAN Strategic Action Plan, November 2012)

P reductions in upstream drainage basins will produce

substantial P loading reductions to downstream lakes.

2009 SWAT modeling results by Montgomery Associates:

Resource Solutions, LLC, Cottage Grove, WI

While much work needs to

be done to reduce P loads

from agricultural lands in

Mendota’s direct drainage

basin, reducing P loads

from “hotspots” in

Kegonsa’s direct drainage

basin would also benefit

Lake Kegonsa.

Door Creek wetland 1970’s

Can Door Creek wetland’s hydrology be restored to

increase the removal of P and sediment to Lake Kegonsa?

Photo: Harvey Harper, Environmental Research and Design, Inc.

Alum treatments of lakes

• Alum treatments are done to reduce high internal P loading

from a lake’s bottom sediments when external P loading is low.

• Alum is typically applied in smaller lakes without strong water

currents that can prevent an even layer of Al floc from settling

uniformly across a lake’s bottom sediments.

Cost:

~$3-5 million

for Kegonsa?

Copper and Phosphorus Concentrations in Yahara Lake Sediments

Data source: Lathrop 2007

Little P is retained in Kegonsa’s sediments

An expensive alum

treatment would not

work in Lake Kegonsa

as little P is stored in

its deep-water

sediments and

external P loads are

very high.

Recycling is rapid in

the shallow lake with

the P rapidly flushing

downstream.

Cartoon: Bill Feeny, UW-Madison

1/18/2015

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Massive carp hatch

Lake Waubesa, 1936 (same year as sewage

effluent into Waubesa)

Carp removal by

long seines

“Jumbo” carp Lake

Kegonsa, 1930s

Carp holding pen

Yahara River

inlet to Lake

Kegonsa, 1930s

Large carp went to

market in trucks…

… and trains

Small carp were

canned…

… or plowed under

Rough Fish Removal in the Madison Lakes

1934-1984

0

1,000

2,000

3,000

4,000

5,000

Me

tric

To

ns

Kegonsa

Waubesa

Monona

Mendota

State Removal Program (1934-1969)

Photo: E. Sievers 5 Sept. 2007

Lake Wingra restoration project A Collaboration between: Wisconsin DNR

UW Center for Limnology (LTER)

Friends of Lake Wingra

Dane County

Madison Fishing Expo

Edgewood College

UW Arboretum

City of Madison

1/18/2015

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Alternative States in Shallow Lakes:

Clear-Water, Aquatic Plant State Turbid Algal State

Clear water

Carp absent/sparse

Aquatic plants abundant

(with high biodiversity?)

Bottom sediment resuspension &

phosphorus recycling low

Blue-green algae densities low

(Algal toxin concentrations low)

Turbid green water

Carp population dense

Aquatic plants sparse

Bottom sediment resuspension

& phosphorus recycling high

Blue-green algae densities high

(Algal toxin concentrations high?)

R. Lathrop, NALMS Symposium, 9 Nov. 2012

Radio transmitters

implanted in 14 carp to

determine location in

lake during 2006-2007

Are there times and

locations that carp

are vulnerable to

removal by seining?

Photo: R. Lathrop, WDNR

Photo: UW Center for Limnology R. Lathrop, NALMS Symposium, 9 Nov. 2012

June 12, 2006 Aug. 9, 2006

Oct. 19, 2006 Nov. 16, 2006 Feb. 20, 2007

May 10, 2006 May 25, 2006

2-Year Tracking Study:

• Carp spend most of the

open water period near

the shoreline; some

carp exhibit fidelity to

same location

• Carp periodically spawn

in Vilas lagoon in late

spring (1 of 2 years)

• Carp congregate in

deeper water in late fall

and under the ice in

winter

Maps: J. Chipman, NTL-LTER Program

Wingra Carp Removal March 2008

Commercial fishers used long

seines to capture carp in the

lake’s deep waters under the ice

Photos: D. Liebl and R. Lathrop

Photos: R. Lathrop

Lake Wingra has been

dramatically clearer

since the carp removal

in March 2008!

Vilas Beach, Lake Wingra

25 July 2008

Vilas Beach, Lake Wingra

29 July 2011

R. Lathrop, NALMS Symposium, 9 Nov. 2012

Increase in Eurasian water mifoil required macrophyte

harvesting in 2012 to afford more recreational

opportunities. This milfoil growth might also impede native

plants from spreading to deeper areas in the lake. (Lake Wingra, July 2012)

Photo: Mike Kakuska

1/18/2015

11

+5 growing seasons Pre-carp removal

+7 growing seasons

Native plants have increased while Eurasian water milfoil has declined

50

60

70

80

90

100

110

Pre Post

Me

an b

lue

gill

len

gth

(m

m)

Control (Monona)

Treatment (Wingra)

100

110

120

130

140

150

160

170

180

190

Pre Post

Me

an y

. pe

rch

le

ngt

h (

mm

)

Control (Monona)

Treatment (Wingra)

160

180

200

220

240

260

Pre Post

Me

an L

. B

ass

Len

gth

(m

m)

Control (Monona)

Treatment (Wingra)

Wingra fish community responses: Pre-carp removal (2003-2007) Post-carp removal (2008-2012) Compared to Lake Monona (control)

Source: NTL-LTER fish data

Yellow perch

Bluegill Largemouth bass

Sediment & Carp Dynamics

in the Yahara River – Cherokee Marsh System

Photo: Chin Wu, UW-Madison

Chin Wu, Richard Lathrop, Nathan Wells, Khurram Khan, Hoi Tsueng, Kurt Welke

Telemetry: Implanting Transmitter

Implanting transmitters in carp September 2010

20 carp implanted with radio transmitters

Success Rate 81%

Spring

SB MB NB 28% 56% 16%

Summer

SB MB NB 18% 61% 21%

Success Rate 75%

Fall

SB MB NB

12% 84% 4%

Success Rate 96%

Winter

SB MB NB

3% 95% 2%

Success Rate 95%

Hotspot

Rarely found

Management Priorities for Lake Kegonsa:

• Support P loading reduction practices in Mendota’s and

Monona’s drainage basins as water quality improvements in

upstream lakes will cascade downstream to Kegonsa.

• Reduce P loads from “hotspots” in Kegonsa’s direct drainage

basin.

• Determine if restoring the hydrology of the Door Creek

wetland will reduce sediment and P loads coming from Door

Creek’s watershed to Lake Kegonsa.

• Fund a DNR carp tracking study (~$20,000) to determine if a

targeted carp removal could significantly reduce carp

densities to promote clearer water and more aquatic plants

that will in turn reduce sediment resuspension, decrease

blue-green algae densities, and improve the fishery.

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