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Crystal and Keller Lakes Use Attainability Analysis
Diagnostic-Feasibility Study:
Water Quality Issues and Potential Restorative Measures

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Table of Contents

Crystal Lake/Keller Lake Project Synopsis (1.57 MB)

Executive Summary (1.1 MB)

 

Black Dog Watershed Management Organization Water Quality Goals

 

Lake Characteristics and Recreational-Uses

 

 

Crystal Lake

 

 

Keller Lake

 

Water Quality Problem Assessment

 

 

Water Quality

 

 

 

Crystal Lake

 

 

 

Keller Lake

 

 

Watershed Runoff Pollution

 

 

 

Crystal Lake

 

 

 

Keller Lake

 

 

Aquatic Plants

 

 

 

Crystal Lake

 

 

 

Keller Lake

 

Recommended Lake and Watershed Management Practices

  

1.0

Introduction (377 KB)

1.1

Black Dog Water Management Organization Water Quality Policies and Goals

1.1.1

Policies

1.2

Overview of Lake Use

1.2.1

Crystal Lake

1.2.2

Keller Lake

1.3

Report Coverage

  

 

 

 

2.0

General Concepts in Lake Water Quality (104 KB)

2.1

Eutrophication 

2.2

Trophic States

2.3

Limiting Nutrients

2.4

Stratification 

2.5

Nutrient Recycling and Internal Loading

  

     

3.0

Basin and Watershed Characteristics (382 KB)

3.1

Basin Characteristics

3.1.1

Crystal Lake

3.1.2

Keller Lake

3.2

Watershed Characteristics

 

4.0

Methods (237 KB)

4.1

Lake Water Quality Data Collection

4.2

Watershed Stormwater and Total Phosphorus Loadings

4.2.1

Water Quality Model (P8) Calibration 

4.2.1.1

Stormwater Volume Calibration

4.2.1.2

Phosphorus Loading Calibration

 

5.0

Results (1.36 MB)

5.1

Compiled Data

5.2

Trend Analyses of Total Phosphorus, Chlorophyll a and Secchi Disc Transparency Data

5.2.1

Crystal Lake

5.2.2

Keller Lake

5.3

Seasonal Patterns in 2002 Water Quality Conditions

5.3.1

Phosphorus

5.3.1.1

Crystal Lake

5.3.1.2

Keller Lake

5.3.2

Chlorophyll a

5.3.2.1

Crystal Lake

5.3.2.2

Keller Lake

5.3.3

Secchi Disc Transparency

5.3.3.1

Crystal Lake

5.3.3.2

Keller Lake

5.3.4

Temperature, Dissolved Oxygen, and Phosphorus Isopleth Diagrams

5.3.4.1

Crystal Lake

5.3.4.2

Keller Lake

5.3.5

Macrophytes 

5.3.5.1

Crystal Lake

5.3.5.2

Keller Lake

5.3.6

Fisheries

5.3.6.1

Crystal Lake

5.3.6.1

Crystal Lake

5.3.6.2

Keller Lake

5.4

Water Quality Modeling Results

5.4.1

Baseline Lake Water Quality Status 

5.4.2

Modeled Watershed Phosphorus Loadings

5.4.2.1

Existing (2002) Land Use Conditions

5.4.2.1.1

Crystal Lake

5.4.2.1.2

Keller Lake

5.4.2.2

Full-Development Land Use Conditions/No Best Management Practices

5.4.2.2.1

Crystal Lake

5.4.2.2.2

Keller Lake

5.4.3

Internal Phosphorus Load Calculation Results

5.4.3.1

Crystal Lake

5.4.3.2

Keller Lake

5.4.4

In-Lake Modeling Results

5.4.4.1

Existing (2002) Land Use Conditions (Model Calibration)

5.4.4.2

Full-Development Land Use Conditions/No Best Management Practices

 

6.0

Discussion (2.37 MB)

6.1

General Discussion of Improvement Options

6.1.1

Structural BMPs

6.1.1.1

Wet Detention Ponds

6.1.1.2

Infiltration Trenches or Basins

6.1.1.3

Vegetated Buffer Strips

6.1.1.4

Oil and Grit Separators

6.1.1.5

Alum Treatment Plants

6.1.2

Nonstructural BMPs

6.1.2.1

Public Education 

6.1.2.2

Ordinances

6.1.2.3

Street Sweeping

6.1.2.4

Deterrence of Waterfowl

6.1.3

In-Lake BMPs

6.1.3.1

Removal of Benthivorous (Bottom-Feeding) Fish

6.1.3.2

Application of Alum (Aluminum Sulfate) 

6.1.3.3

Application of Alum + Lime (Aluminum Sulfate plus Calcium Hydroxide)

6.1.3.4

Application of Herbicides

6.1.3.5

Application of Copper Sulfate

6.1.3.6

Mechanical Harvesting

6.1.3.7

Hypolimnetic Withdrawal

6.2

Feasibility Analysis

6.2.1

Statement of Problem

6.2.2

Selection and Effectiveness of Alternatives

6.2.2.1

Site-Specific Structural BMPs

6.2.2.1.1

Excavate Additional Storage Volume in Existing Ponds to Meet NURP Standards

6.2.2.1.2

Construct Water Quality Treatment Ponds A7a-1 and A7b 1

6.2.2.1.3

Route Keller Lake Outflows Directly to Crystal Lake Outlet

6.2.2.1.4

Construct a Stormwater Alum Treatment Plant at CL 2b (Design Flow 10 cfs)

6.2.2.1.5

Stormwater Alum Treatment Plant at Keller Lake Outlet (Design Flow 5 cfs)

6.2.2.1.6

Restore Wetland between Crystal and Keller Lakes (South of Crystal Beach)

6.2.2.1.7

Upgrade Existing Pond in Redwood Park, Apple Valley into an Infiltration Basin

6.2.2.1.8

Construction of Regional Infiltration Basins (Valley Middle School - Apple Valley, West Buckhill Park - Burnsville, Rolling Oaks Park- Lakeville)

6.2.2.1.9

Retrofit Watershed with Rainwater Gardens to Promote Infiltration

6.2.2.1.10

Replace Culvert between Mystic and Maple Island Bays

6.2.2.2

In-Lake Treatments

6.2.2.2.1

Application of Copper Sulfate to Crystal Lake

6.2.2.2.2

Application of Alum to the Main Basin of Crystal Lake 

6.2.2.2.3

Application of Alum to Crystal Lake and Alum + Lime Application to the Various percentages of the Lake's Littoral Zone

6.2.2.2.4

Application of Alum to Keller Lake and Alum + Lime to the Various percentages of the Lake's Littoral Zone

6.2.2.2.5

Mechanical Macrophyte Harvesting to Control Curlyleaf Pondweed

6.2.2.2.6

Resume Operation of the Ferric Chloride (FeCl3) Treatment System

6.2.2.3

Nonstructural BMP Alternatives

6.2.2.3.1

Fertilizer P Limitation

6.3

Combination of BMP Options

6.4

Cost Allocation

 

7.0

Conclusions (78 KB)

 

8.0

Recommendations (109 KB)

8.1

Structural BMP Recommendations

8.2

In-Lake BMP Recommendations

8.3

Nonstructural BMP Recommendations

 

References (95 kb)

 

 

List of Tables

Table EX-1 (1.1 MB)

Water Quality Management Goals

Table EX-2 (1.1 MB)

Summary of Select BMP Combinations for Crystal Lake

Table EX-3 (1.1 MB)

Summary of Select BMP Combinations for Keller Lake

Table 1-1 (377 KB)

Water Body Classification Categories

Table 1-2 (377 KB)

Aesthetic and Habitat Indicators and Recommended City Actions-Revised 

Table 3-1 (382 KB)

Crystal Lake Morphometry

Table 3-2 (382 KB)

Keller Lake Morphometry

Table 3a (382 KB)

Crystal Lake-Existing (2002) Land Use Conditions

Table 3b (382 KB)

Crystal Lake-Full Development (Ultimate) Land Use Conditions

Table 3-4 (382 KB)

Watershed Areas within Municipalities

Table 4-1a (237 KB)

Main Crystal Lake Basin Water Quality Parameters

Table 4-1b (237 KB)

Keller Lake and Crystal Lake Bays Water Quality Parameters

Table 4-2 (237 KB)

Procedures for Chemical Analyses Performed on Water Samples

Table 4-3 (237 KB)

Stage-Storage-Discharge for Crystal Lake

Table 4-4 (237 KB)

Constant Flow Comparison for Crystal Lake

Table 4-5 (237 KB)

Selected Basin Retention Terms 

Table 5-1 (1.36 MB)

Comparison of Areal Phosphorus Loadings

Table 6-1 (2.37 MB)

General Effectiveness of Stormwater BMPs at Removing Common Pollutants from Runoff 

Table 6-2 (2.37 MB)

Crystal Lake MPCA/NURP Wet Detention Volumes (Required per MPCA/NURP)

Table 6-3a (2.37 MB)

Comparison of Estimated Total Phosphorus Concentrations for Feasible Lake/Watershed Management Options for Crystal Lake: Main Basin Assuming Existing or Full Development Watershed Land Use

Table 6-3b (2.37 MB)

Comparison of Estimated Chlorophyll a Concentrations for Feasible Lake/Watershed Management Options for Crystal Lake: Main Basin Assuming Existing or Full Development Watershed Land Use

Table 6-3c (2.37 MB)

Comparison of Estimated Total Phosphorus Concentrations for Feasible Lake/Watershed Management Options for Crystal Lake: Main Basin Assuming Existing or Full Development Watershed Land Use

Table 6-4a (2.37 MB)

Comparison of Estimated Total Phosphorus Concentrations for Feasible Lake/Watershed Management Options for Keller Lake Assuming Existing or Full Development Watershed Land Use

Table 6-4b (2.37 MB)

Comparison of Estimated Chlorophyll a Concentrations for Feasible Lake/Watershed Management Options for Keller Lake Assuming Existing or Full Development Watershed Land Use 

Table 6-4c (2.37 MB)

Comparison of Estimated Total Phosphorus Concentrations for Feasible Lake/Watershed Management Options for Keller Lake Assuming Existing or Full Development Watershed Land Use

Table 6-5 (2.37 MB)

Alum + lime Treatment Acreages for Application to 15 percent of the Littoral Zone

Table 6-6 (2.37 MB)

Alum + lime Treatment Acreages for Application to 50 percent of the Littoral Zone

Table 6-7 (2.37 MB)

Estimated Curlyleaf Pondweed Reduction Resulting from Mechanical Harvesting

Table 6-8 (2.37 MB)

Summary of BMP Combinations and Resulting Crystal and Keller Lakes' Summer Average Water Quality

Table 6-9 (2.37 MB)

Allocation of Costs for Lake/Watershed Management Options for Crystal Lake, based on the Joint Powers Agreement

Table 6-10 (2.37 MB)

Allocation of Costs for Lake/Watershed Management Options for Crystal Lake, based on the Source of the Total Phosphorus Loads

List of Figures

Figure 5-11 (1.36 MB)

Figure EX-1 (1.1 MB)

Crystal Lake-Main Basin 2002 Seasonal Changes in Total Phosphorus and Chlorophyll a Concentrations and Secchi Disc Transparencies

Figure EX-2 (1.1 MB)

Crystal Lake Historic Water Transparency

Figure EX-3 (1.1 MB)

Keller Lake-Main Basin 2002 Seasonal Changes in Total Phosphorus and Chlorophyll a Concentrations and Secchi Disc Transparencies

Figure EX-4 (1.1 MB)

Keller Lake Historic Water Transparency

Figure EX-5 (3.5 MB)

Crystal and Keller Lake Watersheds: Existing and Full Development Land Use

Figure EX-6 (1.1 MB)

Crystal Lake Watershed: Existing and Full Development Land Uses

Figure EX-7 (1.1 MB)

Crystal Lake Annual Total and External Phosphorus Budgets for Existing (2002) Land Use

Figure EX-8 (1.1 MB)

Keller Lake Annual Total and External Phosphorus Budgets for Existing (2002) Land Uses

Figure EX-9 (1.1 MB)

Crystal Lake Secchi Disc Transparencies, Total Phosphorus Concentrations and Annualized Costs Estimated for Several Goal Achieving BMP Combination Options-Modeled Full Development

Figure EX-10 (1.1 MB)

Keller Lake Secchi Disc Transparencies, Total Phosphorus Concentrations and Annualized Costs Estimated for Several Goal Achieving BMP Combination Options-Modeled Full Development

Figure EX-11 (3.7 MB)

Recommended BMPs that are Part of Management Option III.14 for Crystal and Keller Lakes

Figure 1-1 (377 KB)

Crystal Lake Historic Water Transparency

Figure 1-2 (377 KB)

Keller Lake Historic Water Transparency

Figure 3-1 (1.8 MB)

Crystal and Keller Lake Watersheds

Figure 3-2 (3.5 MB)

Crystal and Keller Lake Watersheds: Existing and Full Development Land Use

Figure 3-3 (382 KB)

Crystal Lake Watershed: Existing and Full Development Land Uses

Figure 4-1 (2.0 MB)

2002 Water Quality Sample Locations

Figure 4-2 (237 kb)

Stormwater Volume Calibration Results: WATBUD Model assuming No Net Gain or Loss due to Groundwater

Figure 5-1 (1.36 MB)

Crystal Lake: Summer Average Secchi Disc Transparencies Trend Analysis

Figure 5-2 (1.36 MB)

Crystal Lake: Summer Average Surface Chlorophyll a Concentrations Trend Analysis

Figure 5-3 (1.36 MB)

Crystal Lake: Summer Average Surface Total Phosphorus Concentrations Trend Analysis

Figure 5-4 (1.36 MB)

Keller Lake: Summer Average Secchi Disc Transparencies Trend Analysis

Figure 5-5 (1.36 MB)

Keller Lake: Summer Average Surface Total Phosphorus Concentrations Trend Analysis

Figure 5-6 (1.36 MB)

Keller Lake: Summer Average Surface Chlorophyll a Concentrations Trend Analysis

Figure 5-7 (1.36 MB)

Keller Lake Summer Average Secchi Disc Transparency as a Function of Total Phosphorus Concentration

Figure 5-8 (1.36 MB)

Keller Lake Summer Average Chlorophyll a Concentration as a Function of Total Phosphorus Concentration

Figure 5-9 (1.36 MB)

Crystal Lake-Main Basin 2002 Seasonal Changes in Total Phosphorus and Chlorophyll a Concentrations and Secchi Disc Transparencies

Figure 5-10 (1.36 MB)

Observed Seasonal Variation in Crystal Lake 2002 Total Phosphorus Concentration

Keller Lake-Main Basin 2002 Seasonal Changes in Total Phosphorus and Chlorophyll a Concentrations and Secchi Disc Transparencies

Figure 5-12 (1.36 MB)

Keller Lake Recently Observed (1996-2002) Total Phosphorus Concentration

Figure 5-13 (2 MB)

Curlyleaf Pondweed Growth (Source: Blue Water Science)

Figure 5-14 (1.36 MB)

Crystal Lake Annual External Phosphorus Budgets: Existing (2002) and Full Development Land Use

Figure 5-15 (1.36 MB)

Keller Lake Annual External Phosphorus Budgets: Existing (2002) and Full Development Land Use

Figure 5-16 (2.8 MB)

Crystal Lake Watershed: Existing and Full Development Total Phosphorus Export Rates for Each Subwatershed

Figure 5-17 (2.8 MB)

Crystal Lake Watershed: Existing and Full Development Cumulative Total Phosphorus Removal Fraction for Each Subwatershed

Figure 5-18 (2.8 MB)

Crystal Lake Watershed: Existing and Full Development Cumulative Outflow Soluble Phosphorus Fraction for Each Subwatershed

Figure 5-19 (1.36 MB)

Crystal Lake Annual Phosphorus Budget (1,082 lbs) Model Calibration Year (2002) Using Existing Land Use

Figure 5-20 (1.36 MB)

Crystal Lake In Lake Modeling Results for 2002 Climatic Conditions

Figure 5-21 (1.36 MB)

Keller Lake In Lake Modeling Results for 2002 Climatic Conditions

Figure 6-1 (3.7 MB)

Potential BMPs for Crystal and Keller Lakes

Figure 6-2a (2.37 MB)

Crystal Lake Secchi Disc Transparency and Estimated Costs for the Various BMP Management Options-Modeled Full Development Compared to Existing Conditions

Figure 6-2b (2.37 MB)

Keller Lake Secchi Disc Transparency and Estimated Costs for the Various BMP Management Options-Modeled Full Development Compared to Existing Conditions

Figure 6-3 (2.37 MB)

Pond CL 2b Outflows-Percent of Annual Flows Treated as a Function of Alum Treatment Plant Design Flow Rate

Figure 6-4 (2.37 MB)

Keller Lake Outflows-Percent of Annual Flows Treated as a Function of Alum Treatment Plant Design Flow Rate

Figure 6-5 (2.37 MB)

Predicted Summer Average Total Phosphorus Concentrations for Various Amounts of Impervious Area Runoff Infiltration Volumes

Figure 6-6 (2.37 MB)

Crystal Lake Hypolimnetic Withdrawal and Chemical Treatment System Operating Alternatives

Figure 6-7 (2.37 MB)

Impacts of Iron Dosing on Keller Lake Summer Average Total Phosphorus Concentration

Figure 6-8 (2.37 MB)

Crystal Lake Secchi Disc Transparencies, Total Phosphorus Concentrations and Annualized Costs Estimate for BMP Combination Options-Modeled Full Development

Figure 6-9 (2.37 MB)

Keller Lake Secchi Disc Transparencies, Total Phosphorus Concentrations and Annualized Costs Estimated for BMP Combination Options-Modeled Full Development

Figure 8-1 (3.8 MB)

Recommended BMPs that are Part of Management Option III.14 for Crystal and Keller Lakes
 

Appendices

Appendix A (69 kb)

Pond Data

Appendix B (281 kb)

Crystal and Keller Lakes 2002 In-Lake Water Quality Data

Appendix C (72 kb)

2002 Isopleth Diagrams for Crystal and Keller Lakes

Appendix D (148 kb)

P8 Model Parameter Selection

Appendix E (294 kb)

MDNR Crystal and Keller Lakes Latest Fisheries Survey

Appendix F (2.7 MB)

BMP Analysis: Benefits of BMPs on Water Quality in Mystic, Maple Island, Bluebill, and Buckhill Bays

Appendix G (98 kb)

BMP Cost Estimates