Dane CountyWater Body Classification Study

Phase I

A project of the Dane County Department of Planning and Development,

and the Dane County Regional Planning Commission

Water Body Classification Matrix

Current Level of Development

Natural Sensitivity toDevelopment Low Level Medium level High Level

High Sensitivity Protection Protection Protection and Restoration

Medium Sensitivity Protection Protection and Restoration Restoration and Enhancement

Low Sensitivity Protection and Restoration Restoration and Enhancement Restoration and Enhancement

Lake Classification:

Lake Classification

Seepage/Spring lakes Drainage Lakes

Shallow Deep Shallow Deep

Most Sensitive Least SensitiveDecreasing Sensitivity

Lake Classification

Seepage/Spring lakes Drainage Lakes

Shallow Deep Shallow Deep

(A)High Sensitivity

(C)Low Sensitivity

(B)Medium Sensitivity

23 1

Sensitivity Ranking

Additional Factors

• Area -- small lakes more sensitive

• Shoreline Development -- irregular lakes more sensitive

• Stratification -- stratified lakes more sensitive

• Steep Slopes -- high potential for erosion/sedimentation

• Septic Suitability -- high water table/sandy soils

LAKE CLASSIFICATIONSensitivity Rating Factors

Criterion SignificanceCriterionClasses

Units ofMeasure Points Comments

Lake Surface Area(size)

Smaller lakes are generallymore vulnerable to waterquality problems

1 - 1010 - 100100 - 500500+

Acres 1234

Very small lakes/pondsSmall lakesMedium lakesLarge lakes

ShorelineDevelopment Factor

(shape)

Lakes with irregularshorelines are morevulnerable to a higher densityof development

3.0+2.0 - 3.01.5 - 2.01.0 - 1.5

Unitless 1234

Very irregular shoreline

Close to circular shoreline

Stratification Factor(nutrient sensitivity)

Lakes that strongly stratify aremore sensitive to outsidesources of phosphorus

30.0+13.5 - 30.011.5 - 13.50 - 11.5

Unitless 1234

Strongly stratifiedStratifiedWeaklyNot stratified

Soil Erodability(steep slopes)

Lakes with steep slopedshorelines are morevulnerable to erosion andsurface water degradation

75 - 100%50 - 75%25 - 50%0 - 25%

Percent ofshoreline

within 300’

1234

Percent of shoreline withD slope (12% slope orgreater)

Septic Suitability(severe soils)

Lakes having shorelines withhigh groundwater or soilsposing severe limitation forseptic systems are morevulnerable to ground andsurface water contamination

1 - 1.51.5 - 2.52.5 - 3.53.5 - 4.0

Ave. soilfactor within

300’ ofshoreline

1234

Very severe limitationsSevereModerateSlight or sewered

Water Body Classification Matrix

Current Level of Development

Natural Sensitivity toDevelopment Low Level Medium level High Level

High Sensitivity Protection Protection Protection and Restoration

Medium Sensitivity Protection Protection and Restoration Restoration and Enhancement

Low Sensitivity Protection and Restoration Restoration and Enhancement Restoration and Enhancement

Lake Classification:

Impervious Cover Calculations:

– 300-foot buffer

– Determined acres of each land use present within buffer

– Assigned each land use an impervious cover percentage

– Calculated the average percent impervious cover for each named lake/pond

0

5

10

15

20

25

0% 10% 20% 30% 40% 50%

Impervious Cover

Sen

siti

vity

Ran

kin

g

(C)High

DevelopmentLevels

(B)Medium

(C)Low

(A)High

(B)Medium

Development Levels

I

I

I II

II

II

III

IIIIII

(A)Low

DevelopmentLevels

Water Body Classification Matrix

Current Level of Development

Natural Sensitivity toDevelopment Low Level Medium level High Level

High Sensitivity Protection Protection Protection and Restoration

Medium Sensitivity Protection Protection and Restoration Restoration and Enhancement

Low Sensitivity Protection and Restoration Restoration and Enhancement Restoration and Enhancement

Lake Classification:

G ood

F air

P oor

Str

eam

Qua

lity

Watershed Impervious C over

10% 25% 40% 60% 100%

Urban Drainage

Degraded or Non-S upporting

Stream Classification

Impervious Cover Calculations

– Determine area of each land use in a subwatershed

– Assign an impervious cover percentage to each land use

– Calculate the average impervious cover percentage for each subwatershed

Management Implications

• Lake or Stream• Protection, Restoration, or Enhancement

– based on classification• Regulatory, Incentive, or Educational

– Updating the County Shoreland Zoning Ordinance– Environmental Corridors, Rural Protection Areas– PDRs, TDRs, DNR grants, CRP, WRP, etc.

• Urban or Rural Design– Maximizing infiltration and natural vegetation– Minimizing impervious cover– Cost-sharing, BMPs, conservation plans– Conservation easements, etc.

Management Programs/Strategies

• Shoreland Vegetation (e.g., Buffer Size and Quality)

• Wetlands Restoration

• Shoreland Development

• Floodplain Management

• Land Disturbance/Construction Site Erosion Control

• Stormwater Management and Urban BMPs

• Rural Runoff and Agricultural BMPs

• Comprehensive Land Use Planning

Potential Management Tools by Classification(examples)

Program Area

ClassificationEducation & Technical

Assistance ProgramsPublic Investment, Incentives

& Acquisition ProgramsPlan Approval & Regulatory

Programs

Class I (Protection)

- Farm conservation plans- Agricultural runoff practices

design- Agricultural performance

standards- Agricultural buffers- Nutrient and pesticide

management- Safe handling / use of

chemicals- Workshops and field

demonstrations- Landowner and citizen

education

- Parks & Open Space Plan andCounty Conservation Fund

- State Stewardship Fund- Lake / River Planning and

Protection Grants- Cost-share programs- Conservation Reserve (CRP) and

other easement programs- Streambank buffer programs- Wetland / habitat restoration- Purchase of Development Rights

(PDRs) and Transfer ofDevelopment Rights (TDRs)

- Shoreland / wetland zoning- Floodplain zoning- Conservancy zoning- Site plan approval- Erosion control and stormwater

management (focus on newdevelopment)

- Open space corridors- Comprehensive planning

Class II (Protection &Restoration)

- Agricultural buffers- Stormwater practices design- Regional stormwater facility

planning- Wetland / habitat restoration

assistance- Watershed group support- Adult conservation volunteers- Workshops and field

demonstrations- Landowner and citizen

education

- Streambank buffer programs- Wetland / habitat restoration- Lake / River Planning and

Protection Grants- Cost-share programs- PDR / TDR programs- Wastewater treatment facilities- Regional stormwater facilities

planning- Water quality monitoring- Public land stewardship- Floodplain hazard mitigation

- Shoreland / wetland zoning- Floodplain zoning- Sewer services planning- Environmental corridor

mapping- Erosion control- Stormwater management (both

new and redevelopment;quality and quantity)

- High capacity well withdrawalsand permiting

- Comprehensive planning

Class III (Restoration &Enhancement)

- Neighborhood / watershedgroup support

- Volunteer clean-up programssuch as “Take a Stake in theLakes”

- Nonpoint runoff education- Citizen monitoring- Pollution prevention- Invasive and exotic species

control- Landowner and citizen

education

- Streambank buffer programs- Wetland / habitat restoration- Lake / River Planning and

Protection Grants- Cost-share programs- Regional stormwater facilities- Recreational access / trails- Floodplain hazard mitigation- Weed harvesting, dredging, lake

level management (YaharaLakes)

- Nutrient / pollution control andremoval

- Shoreland redevelopment- Erosion control- Stormwater management (focus

on redevelopment / retrofit)- Lake use regulations- Boater safety / enforcement

Phase I: - Provide the scientific basis/rationale

- Develop management strategies/alternatives

Phase II: - Develop a water body

management program;

- Including policies, programs and guidelines based on:

Classification

Public input

Water Body Classification: