Reitz Lake TMDL

Goal Setting for Reitz Lake

Reasonable Expectations1

Phase II Adaptive Management

MPCA WaterQuality Standards

40 µg/L

Natural Background

(Pre-settlement)26 µg/L

Current Conditions102 µg/L

Shallow Lakes = Clear, macrophyte dominatedDeep Lakes = Clear, algae dominated; macrophytes in small littoral areas

1 Based on BMPs and current conditions (internal load; macrophytes)

1988 Conditions

Nondegradation109 µg/L

CONCENTRATION and/or LOAD

65 µg/L ?

Goal Setting for Reitz Lake

Reasonable Expectations1

Phase II Adaptive Management

MPCA WaterQuality Standards

60 µg/L

Natural Background

(Pre-settlement)47 µg/L

Current Conditions102 µg/L

Shallow Lakes = Clear, macrophyte dominatedDeep Lakes = Clear, algae dominated; macrophytes in small littoral areas

1 Based on BMPs and current conditions (internal load; macrophytes)

1988 Conditions

Nondegradation109 µg/L

CONCENTRATION and/or LOAD

90 µg/L ?

Past Data

Historical Precipitation and Summer TP

0

5

10

15

20

25

30

35

40

19

85

19

86

19

87

19

88

19

89

19

90

19

91

19

92

19

93

19

94

19

95

19

96

19

97

19

98

19

99

20

00

20

01

20

02

20

03

20

04

Pre

cip

ita

tio

n (

inc

he

s)

0

20

40

60

80

100

120

140

160

To

tal

Ph

os

ph

oru

s (

ug

/L)

Past Data

Year

Total Phosphorus Concentration (g/L)

Chlorophyll-a Concentration (g/L)

Secchi disk transparency

(meters)Total Kjeldahl Nitrogen

(mg/L)

1985 114 NA 0.9 2.1

1991 104 NA 1.1 2.2

1993 152 NA 1.1 2.2

1999 43 20 1.2 1.7

2000 54 35 1.1 1.7

2001 73 36 0.7 1.8

2002 107 40 1.4 2.1

2003 109 65 2.2 2

2004 90 47 1 2.1

Area’s of Concern

Internal Loading– Carp– Curly Leaf Pondweed

External Loading– Run 0ff– Failing ISTS’s

Internal Loading Sources

Problem– Carp

– Curley Leaf Pondweed

– Shallow “bay” Sediments

Possible Solution– Removal Program

– Harvesting / Herbicides

– Minimize bottom disturbing activity (no wake, dedicated channels, etc.)

Fishery Information

1998 Combined Methods-Biomass

Bluegill42.4%

Green Sunfish0.1%

Hybrid Sunfish0.4% Yellow Bullhead

1.8%Largemouth Bass

0.2%

Black Crappie36.3%

Black Bullhead7.3%

Northern P ike2.4%

Common Carp1.9%

Yellow P erch7.3%

2004 Combined Methods-Biomass

Yellow P erch5.3%Northern P ike

6.4%

White Sucker1.4%

Largemouth Bass0.3%

Freshwater Drum2.0%

Golden Shiner0.1%

Bluegill10.5%

Common Carp59.8%

Black Crappie2.1%

Yellow Bullhead0.3%

Black Bullhead11.8%

Curley Leaf Example

Reitz (TP & Chl-a)

0

20

40

60

80

100

120

140

160

180

Date

Tota

l Pho

spho

rus

or

Chl

orop

hyll-

a (u

g/L)

0

1

2

3

4

5

6

7

8

9

10

Sec

chi D

epth

(m)

TP CHLA Secchi

TP Pulse at Curly Leaf Senesence

External Loading Sources

Problem– Run off

• Rural

• Residential

– ISTS

Possible Solution– BMP’s (buffer strips,

rock inlets, control structures, etc.)

– Lake Buffers, Lakescaping

– Upgrade failing systems (loan program) and maintaining current systems.

Prioritizing the Culprits:

Highest Impacts– Agricultural run off (external)– Internal loading caused by Curley Leaf

pondweed and Carp.– ISTS’s

Lower Impacts– Wetlands, Developed Area’s, Forest,

Atmosphere

Next Steps

Complete TMDL– PCA Process

Acceptance by EPA Seek Funding

Possible Funding Sources

Grants/Loans from MPCA (EPA) County Watershed Dollars Landowners Others?

CONCLUSIONS

Internal loading is an important source to Reitz Lake and must be part of any management or implementation plan.

Carp and curly leaf pondweed likely play a large role in internal recycling of nutrients. Carp do not reproduce naturally in Reitz Lake due to egg predation by the large panfish population and likely migrate in during high water.

The TMDL requires an overall load reduction of approximately 65 to 68% to meet the current State Water Quality Standard.

The likely external or watershed sources are agricultural runoff and septic systems.

Questions?