Minnehaha Creek Watershed District 2004 Hydrologic Data Report

Home , Brownie Lake, Minnehaha

March 2005

Prepared by:

Lorin K. Hatch, PhD MCWD Water Quality Specialist

TABLE OF CONTENTS

List of Tables and Figures………………………………………………………… ii

List of Appendices………………………………………………………………… iv

Acronyms…………………………………………………………………………… iv

Preface……………………………………………………………………………… v

Executive Summary………………………………………………………………… vi

1. Introduction……………………………………………………………………… 1

2. Precipitation……………………………………………………………………… 5

3. Lake Minnetonka………………………………………………………………… 8

4. Lower Watershed Lakes………………………………………………………… 15

5. Upper Watershed Lakes………………………………………………………... 18

6. Minnehaha Creek………………………………………………………………. 21

7. Upper Watershed Streams……………………………………………………… 31

8. Groundwater Levels……………………………………………………….…… 43

9. Literature Cited………………………………………………………..………… 49

10. Proposed Minnesota Rule Changes…………………………………………… 51

11. 2005 Initiatives………………………………………………………………… 56

12. Long-Term Initiatives……………………………………………………….… 67

LIST OF TABLES AND FIGURES

Table 3.1 Lake report card grades for Lake Minnetonka bays, 1998-2004 Table 3.2 Mean 2004 summer surface Secchi disk transparency, chlorophyll a concentration, total phosphorus concentration, and trophic state index means for Lake Minnetonka bays Table 3.3 Statistically-significant changes in mean annual water quality in Lake Minnetonka bays over the period of record Table 4.1 Lake report card grades for Lower Watershed lakes, 1998-2004 Table 4.2 Mean 2004 summer surface Secchi disk transparency, chlorophyll a concentration, total phosphorus concentration, and trophic state index means for Lower Watershed lakes Table 4.3 Statistically-significant changes in mean annual water quality in Lower Watershed lakes over the period of record Table 5.1 Lake report card grades for Upper Watershed lakes, 1998-2004 Table 5.2 Mean 2004 summer surface Secchi disk transparency, chlorophyll a concentration, total phosphorus concentration, and trophic state index means for Upper Watershed lakes Table 5.3 Statistically-significant changes in mean annual water quality in Upper Watershed lakes over the period of record Table 6.1 MPCA Ecoregion vs. Minnehaha Creek 2004: Median, Mean, and Maximum Concentrations (Summer) Table 6.2 Mid-September 2004 E. coli (CFU/100mL) in Minnehaha Creek Table 6.3 2004 Late-Summer Dry-Weather DO Profiles in Minnehaha Creek Table 6.4 Aerial Export of Nutrients, Sediments, and Chloride Export to Minnehaha Creek Table 7.1 MPCA Ecoregion vs. Upper Watershed Streams 2004: Median, Mean, and Maximum Concentrations (Summer) Table 7.2 Upper Watershed Stream Samples below 5mg/L DO Table 8.1 Long-term groundwater monitoring in and near the MCWD Table 10.1 Proposed Nutrient Criteria for Minnesota Lakes Table 10.2 Proposed E. coli Standards Shown with the Current Fecal Coliform Standard for Class 2 and Class 7 Waters Table 11.1 Factors Effecting the Effectiveness of Alum on Lake Rehabilitation Table 11.2 Lakes and Lake Minnetonka Bays Proposed for the 2005 Diatom P Study

Figure 1.1 Minnehaha Creek Watershed District Figure 2.1 Annual 2004 precipitation (inches) at all continuous recording sites located in or near the MCWD Figure 2.2 Long-term and 2004 precipitation at the Maple Plain monitoring site Figure 2.3 Long-term and 2004 precipitation at the Minneapolis-St. Paul International Airport monitoring site Figure 2.4 Year 2004 monthly precipitation at all continuous recording sites in or near the MCWD Figure 3.1 Lake Minnetonka elevation (above mean sea level) and Grays Bay Dam discharge during 2004 open-water conditions

ii Figure 3.2 Upper watershed runoff calculated from Grays Bay dam discharge setting, 1987 to 2004 Figure 3.3 Lake Minnetonka elevation time-series Figure 6.1 Stream Monitoring Locations on Minnehaha Creek Figure 6.2 Average Annual Flow at the Browndale Dam (Site CMH03) Figure 6.3 2004 Daily Precipitation at Maple Plain and Measured Flow at Browndale Dam, Edina Figure 6.4 E. Coli Grab Samples in Minnehaha Creek, 2004 Figure 6.5 E. Coli 30-Day Geometric Means in Minnehaha Creek, 2004 Figure 6.6 2004 Nutrient Loading Profile for Minnehaha Creek Figure 6.7 2004 Chloride and Sediment Loading Profile for Minnehaha Creek Figure 7.1 Stream Monitoring Stations in the Upper Watershed Figure 7.2 Painter Creek Sub-watershed Automated Monitoring Figure 7.3 2004 Discharge in Painter Creek at West Branch Road Figure 7.4 2004 Discharge at the Long Lake Outlet Figure 7.5 In-stream TP Loading and Flow-Weighted Mean TP Concentration and for Upper Watershed Streams Figure 7.6 1997-2004 TP Load to Lake Minnetonka from Gauged Sub-Watersheds Figure 7.7 Areal Watershed TP Loading Figure 7.8 In-stream TSS Loading and Flow-Weighted Mean TSS Concentration and for Upper Watershed Streams Figure 7.9 Areal Watershed TSS Loading Figure 7.10 In-stream Chloride Loading and Flow-Weighted Mean Chloride Concentration and for Upper Watershed Streams Figure 7.11 Areal Watershed Chloride Loading Figure 7.11 E. Coli Grab Samples in Six Mile and Painter Creeks, 2004 Figure 7.12 Geometric Mean Fecal Coliform Data in Upper Watershed Streams, 2004 Figure 8.1 Groundwater well elevations near the Minneapolis Chain of Lakes Figure 8.2 Groundwater well elevation for DNR Well Number 27036 (Minneapolis) Figure 8.3 Groundwater well elevation for DNR Well Number 27004 (Minneapolis) Figure 8.4 Groundwater well elevation for DNR Well Number 27012 (Golden Valley). Figure 8.5 Groundwater well elevation for DNR Well Number 27041 (St. Louis Park) Figure 8.6 Groundwater well elevation for DNR Well Number 27044 (St. Bonifacius) Figure 8.7 Groundwater well elevation for DNR Well Number 27043 (Mound) Figure 8.8 Groundwater well elevation for DNR Well Number 27010 (Orono) Figure 11.1 An auto-sampler and a sampling site (solar-powered) on Painter Creek Figure 11.2 A specialized boat designed for injecting alum into lake water Figure 11.3 A Solarbee recirculation unit Figure 11.4 Drs. Edlund and Engstrom taking a sample core Figure 11.5 Total phosphorus concentrations according to ecoregion Figure 11.6 A microscope photograph of E. coli; a caffeine-dispensing device Figure 12.1 The Humber River Watershed

iii LIST OF APPENDICES

Appendix A Lake Report Cards Appendix B Stream Report Cards Appendix C Hydrologic Data Monitoring Plan Appendix D Precipitation and Groundwater Data Appendix E Stream Flow, Loading, and Water Quality Appendix F Glossary of Water Quality Terms

Acronymns

303 (d) List Minnesota Pollution Control Agencies List of Impaired Waters under the Clean Water Act AMSL above mean sea level BMPs best management practices CFU/100 mL colony forming units per 100 milliliters DO dissolved oxygen lbs pounds MCWD Minnehaha Creek Watershed District mg/L milligrams per liter, parts per million µg/L micrograms per liter, parts per billion

MN 7050 Minnesota State Statutes MPCA Minnesota Pollution Control Agency MPRB Minneapolis Park and Recreation Board NCHF North Central Hardwood Forest (Ecoregion) NGVD National Geodesic Vertical Datum NOHW normal ordinary high water (level) NWS National Weather Service SRP soluble reactive phosphorus STORET short for STOrage and RETrieval, a repository for water quality, biological, and physical data TN total nitrogen TP total phosphorus TRPD Three Rivers Park District (formerly SHRPD, Suburban Hennepin Park District) TSI Trophic Status Index TSS total suspended solids

iv Preface

The purpose of the Hydrodata Program is to provide hydrologic, hydraulic, and water quality data to:

1. Identify long-term trends in water quality 2. Assess designated use impairment of lakes and streams, and determine whether lakes are meeting their established water quality goals as determined by MCWD 3. Identify opportunities to design, maintain, and assess performance of capital improvement projects 4. Use as a resource to establish performance-based rules 5. Provide calibration data for the Hydrologic, Hydraulic, and Pollutant Loading Model (HHPL, a.k.a. the H&H Model)

The purpose of the Hydrodata Monitoring Report is to:

1. Record data for posterity (reports and the database) 2. Present the data to the MCWD Board and District Staff in a way that is useful to them when making decisions, providing them with the information they need for other programs and projects (e.g., stream assessment, HHPL calibration, Minnehaha Creek restoration) 3. Provide information in an understandable format to stimulate public interest and involvement in water quality and other watershed issues 4. Add value to the program each year by providing new insight into water quality through creative and intensive data analysis

The main elements of the Hydrodata Monitoring Report are:

1. Precipitation data (daily data graphed) 2. Lake Report Cards which generally show the following: a. Lake level graph b. Long-term average summer surface TP graphs c. Seasonal surface and bottom TP, chlorophyll a, and Secchi depth graphs d. Calculation of the Trophic State Index (TSI) for each lake e. Long-term average TP, chlorophyll a, and Secchi depth graphs f. Assignment of a water quality letter grade (A through F) g. Comparison of water quality to Northern Hardwood Forest Ecoregion averages 3. Stream Report Cards which generally show the following: a. Flow record graph b. Annual loading and flow-weighted mean concentrations of TSS, TP, and SRP c. Seasonal graphs of dissolved oxygen (and bacteria, where monitored) d. Comparison to standards and Northern Hardwood Forest Ecoregion averages e. Stream loading calculations (where possible) f. Long-term average TSS, TP, and SRP graphs 4. Groundwater levels

v Executive Summary

The Minnehaha Creek Watershed District’s (MCWD) annual Hydrologic Data Program is designed for the collection of background water quality and quantity data. The program is a collaboration between the Three Rivers park District (TRPD), the Minneapolis Park and Recreation Board (MPRB), the Metropolitan Council (Met Council), the Minnesota Pollution Control Agency (MPCA), the Lake Minnetonka Conservation District (LMCD), and the Minnesota Department of Natural Resources (MN DNR). Data collected is entered into a database, which is used to identify water quality trends, track progress, and analyze water related problems. The program began in 1968. The District undertook an expanded monitoring program in 1997 to provide a comprehensive view of water quality and to focus improvement projects in the areas with the most need. Findings based on the 2004 monitoring results are presented in this report and summarized below.

Precipitation Precipitation was monitored at several locations in and near the MCWD. The MCWD maintains five automated stations in cooperation with the Cities of St. Louis Park, Long Lake, and the Carver Park Reserve. Precipitation over the watershed was generally above normal during 2004, due in large part to a very wet May and a very wet September. Precipitation measured at the MCWD’s Maple Plain station was 41.1 inches, 27% above the Maple Plain average. Precipitation during 2004 at the Minneapolis-St. Paul Airport was 25.3 inches, 4.1 inches below the 30-year average of 29.4 inches.

Lake Minnetonka The discharge at Grays Bay Dam averaged 36 cfs during 2004, or 4.0 inches of runoff from the 122-square mile upper watershed. Lake elevation fluctuated 1.71 feet over the year, which is typical for Lake Minnetonka.

Each year, water quality in principal lakes is graded based on parameters that indicate the lake’s suitability for recreational use. These parameters include water clarity, chlorophyll a (which estimates algal abundance), and phosphorus (the algal limiting nutrient). The grades do not

vi consider the presence or abundance of non-native aquatic plants such as Eurasian water milfoil. Water quality grades ranged from A’s in several bays to a D- on Forest Lake. Sixteen of the 26 bays monitored in 2004 had average summer TP concentrations below 40 ppb, indicating full use for lakes in the North Central Hardwood Forest ecoregion. Restricted use bays include Black Lake, Peavey Lake, Forest Lake, West Arm, Stubbs Bay, Harrisons Bay, Priests Bay, Jennings Bay, Halsted Bay, and Tanager Lake. These systems are located near major polluting stream outlets (Classen Creek, Six Mile Creek, Painter Creek, Peavey Creek, and Long Lake Creek).

Water quality in Lake Minnetonka is far better today than it was in the 1970s: 1970s TP concentrations were generally more than 3 times the concentrations measured today. Many bays that were impaired for recreational use based on their TP concentrations in the 1970s, today are classified as full use. This improvement in water quality is due mainly to the 50,780-pound reduction in TP load to the lake that resulted from the diversion of wastewater from seven surrounding municipalities to treatment facilities outside the watershed. By comparison, the annual TP load from gauged sub-watersheds (73% of the upper watershed is gauged) between 1997 and 2004 ranged from 684 pounds in 2000 to 18,482 pounds in 2001. The total phosphorus (TP) load to Lake Minnetonka from gauged tributaries was 8,409 pounds in 2004.

While water quality has improved significantly in the long-term, data collected under the District’s expanded monitoring program (1997-2004) is in need of a thorough statistical analysis to determine whether our lake’s water quality is improving, declining, or remaining the same. Such an analysis will also provide insight as to the necessary frequency of sampling required to statistically detect changes in water quality. Any short-term changes in water quality (1997- 2004) may be the result of precipitation and runoff fluctuations. During seven of the past eight years, annual watershed precipitation has exceeded the 30-year average. Increased precipitation causes increased runoff, and increased phosphorus loads from the sub-watersheds to Lake Minnetonka.

Lower Watershed Lakes Water quality grades in lower watershed lakes generally remained the same from 2003 to 2004. Water quality grades ranged from A’s in Lake Calhoun and Lake Harriet to a D- in Windsor

vii Lake. Only 3 of the 12 lower watershed lakes monitored in 2004 had average summer TP concentrations below 40 ppb, indicating full use for lakes in the North Central Hardwood Forest ecoregion. Restricted use lakes include Brownie Lake, Lake of the Isles, Lake Hiawatha, Grass Lake, Lake Nokomis, Powderhorn Lake, Diamond Lake, Twin Lake (St. Louis Park), and Windsor Lake (Minnetonka).

Upper Watershed Lakes Water quality grades in upper watershed lakes showed no clear trend from 2003 to 2004: 5 lakes improved, 6 lakes declined, and 2 lakes remained the same. Water quality grades ranged from an A- in Christmas Lake to an F in Langdon Lake. Relatively high upper watershed loads measured during the past four years (2001-2004) are caused in part by above normal precipitation in 7 of the past 8 years. Only 3 of the 13 upper watershed lakes monitored in 2004 had average summer TP concentrations below 40 ppb, indicating full use for lakes in the North Central Hardwood Forest ecoregion. Restricted use lakes include West Auburn Lake, Stone Lake, Steiger Lake, Schutz Lake, Tamarack Lake, Gleason Lake, Long Lake, Dutch Lake, Lake Wasserman, and Langdon Lake.

Minnehaha Creek Flow and water quality were measured weekly at eight locations on Minnehaha Creek (March through November 2004). Average flow at Browndale Dam in Edina was 37 cubic feet per second (cfs) over the year. The maximum 2004 flow recorded at Browndale Dam was 216 cfs (July 7th and 13th). Water quality in Minnehaha Creek is generally good when compared to MPCA’s Ecoregion guidelines for the North Central Hardwood Forest Ecoregion (in which Minnehaha Creek is located). Dissolved oxygen (DO) concentrations in Minnehaha Creek were generally above the Minnesota State Standards (MN 7050) of 5mg/L. June 17th saw low DO levels in the lower part of the creek (2.4 to 4.6 mg/L), but values returned above 5 mg/L by the next week. Other violations occurred later in the year in the upper sections of the creek during low-flow conditions, but recovered by the following week. Bacteria are a problem in Minnehaha Creek during late August and September; several monitoring sites violated the MPCA 30-day geometric mean standard during this period.

viii Sediment, nutrient, and chloride loading generally increases downstream in Minnehaha Creek, although the reservoirs of Browndale Dam and Lake Hiawatha tend to reduce these loads. The contributing sub-watershed between the Browndale Dam and the Upton Avenue station was by far the greatest contributor of sediment, nutrient, and chloride areal loads in 2004.

Minnehaha Creek in its entirety was included on the MPCA’s draft 2004 303d list of impaired waters for impaired biota. The MCWD’s Stream Assessment (MCWD 2004) should be evaluated with respect to the listing, and comments on the listing provided to the MPCA prior to finalization of the 303d list.

Upper Watershed Streams Flow and water quality were measured weekly at 15 locations on 10 major tributaries in the upper watershed that drain about 73% of sub-watersheds tributary to Lake Minnetonka. Runoff over the upper-watershed (122 square miles) was 4.0 inches as measured at Grays Bay, 10.7 inches from the Painter Creek sub-watershed (14.2 square miles), and 7.2 inches from the Long Lake sub-watershed (12.5 square miles).

The TP loading to Lake Minnetonka from gauged tributary watersheds was 8,409 lbs in 2004; Painter Creek comprised 51% of the load but is only 21% of the sub-watershed area. Therefore, the Painter Creek sub-watershed exported twice the phosphorus per unit area than the rest of the area draining into Lake Minnetonka in 2004. From year to year, it generally exports the largest external TP, chloride, and TSS load to Lake Minnetonka of any of the gauged sub-watersheds draining to the lake.

In-stream DO concentrations in upper watershed streams were consistently below the MN 7050 Standard (5mg/L) during 2004. Low DO in the upper watershed is likely due to a combination of natural and anthropogenic influences.

The MPCA 303d listing criteria for DO states that if 10% or more of DO measurements during the past 10 years are less than 5 mg/L, and there are more than 10 measurements, the water body is included on the MPCA’s 303d List of Impaired Waters. Based on the above criteria, and the

ix most recent 10 years of DO data, most upper watershed streams could be included on the MCPA’s 303d List of Impaired Waters. The exceptions in 2004 were Christmas Creek, Classen Creek, and the Long Lake Outlet.

Recommendations for 2005 • Continue the monitoring program as in 2004, minor changes are recommended which are discussed in the sections of this report. • Intensive workup of dissolved oxygen and phosphorus data to assess the spatial and temporal variation of internal P loading in Lake Minnetonka. • Focus watershed monitoring and rehabilitation efforts in areas that contribute to poor Lake Minnetonka water quality: Six Mile Creek, Painter Creek, Classen Creek, Long Lake Creek, and Gleason Lake Creek. • Conduct a more intensive study of bacterial sources in Minnehaha Creek. Use of tracers such as caffeine will help us further refine bacterial spatial and temporal variation. • Install additional pressure transducers along the creek to better assess discharge dynamics. • Focus BMP efforts in the Upton Ave. subwatershed to address high loading in Minnehaha Creek. • Assess spatial and temporal extent of DO violations in upper watershed streams through continuous monitoring. Priority should be given to Painter Creek. • Address the high nutrient loading to Lake Minnetonka from Painter Creek. Add a station at Painter Creek Drive, including an auto-sampler. • Add stations at the inlet of both Long Lake and Gleason Lake to develop a comprehensive nutrient budget for these waterbodies. • Encourage volunteer monitoring efforts of upper watershed lakes.

x 1. Introduction

The Minnehaha Creek Watershed District (MCWD) was established in 1967 to protect the drainage basin’s water resources, which include Lake Minnetonka, the Minneapolis Chain of Lakes, and Minnehaha Creek (Figure 1.1).

Figure 1.1 Minnehaha Creek Watershed District

The District seeks to conserve the natural resources of Minnehaha Creek watershed through public information and education, regulation of land use, regulation of the use of water bodies and their beds, and capital improvement projects. The MCWD encompasses approximately 181 square miles and includes all or part of 27 cities and three townships in two counties.

The watershed of Minnehaha Creek includes approximately 151 square miles in Hennepin County and 30 square miles in Carver County. The upper watershed, with a total area of 122 square miles, includes Lake Minnetonka and the 100 square miles of land that drains into the lake. The lower watershed includes Minnehaha Creek and the 59 square miles of land that drain into the creek below Lake Minnetonka. The Lake Minnetonka outlet is located at Gray’s Bay Dam, the headwaters of Minnehaha Creek.

1 The major hydrologic features of the watershed include Lake Minnetonka, Minnehaha Creek, the Minneapolis Chain of Lakes, and Minnehaha Falls. Each watershed feature provides unique recreational opportunities and aesthetic resources. Through monitoring and analysis of its streams and lakes, the District has identified areas of water quality degradation and flooding. The District has then used this knowledge to develop and implement solutions that improve or maintain the water quality in the watershed.

Since 1968, the district has collected hydrologic data, generally publishing the results annually. Beginning in 1997, the District undertook an expanded monitoring program to provide a comprehensive view of water quality throughout the watershed and to focus improvement projects in areas with the most need. This report presents hydrologic data collected and compiled during 2004. Data can be categorized into four main types: precipitation, lakes, streams, and groundwater: v Precipitation: The District maintains tipping bucket precipitation stations at five locations in the watershed. Precipitation data from five locations in and near the watershed are compiled from the State Climatologist’s web site. Six Citizen Precipitation Recorders at locations in and near the watershed, record precipitation data and submit it to the MCWD. This data provides an account of the varying precipitation

amounts over the watershed. v Lakes: Lake water quality samples and elevations collected from Lake Minnetonka, the Minneapolis Chain of Lakes and other lakes throughout the watershed provide data for

the Annual Lake Report Cards, first developed in 1998 (Appendix A).

v Streams: ª Stream discharge was measured and water quality samples were collected at 8 locations along Minnehaha Creek and at 15 sites along major tributaries to Lake

Minnetonka. Data collected for each stream is presented in the Annual Stream

Report Cards, first developed in 2002 (Appendix B).

2 ª Continuous water level monitoring was conducted on Minnehaha Creek at Grays Bay Dam (Lake Minnetonka Outlet) in Minnetonka, at the I-494 crossing, and

Browndale Dam in Edina. ª The Metropolitan Council conducts continuous water level monitoring and

flow-weighted sampling at one location near the mouth of Minnehaha Creek. ª Continuous water level monitoring was conducted on Painter Creek and Long Lake Creek in the upper watershed. Flow-weighted water quality samples are collected in Minnehaha Creek at I-494 in Minnetonka and at Browndale Dam in Edina. Flow-weighted water quality samples are also collected in Long Lake

Creek, Six Mile Creek, and Painter Creek in the upper watershed. v Groundwater: Groundwater elevations in the bedrock aquifers recorded by the DNR at three wells with long-term records are compiled for this report. The wells are located in Minneapolis, Orono, and Golden Valley. Groundwater elevations in the surficial aquifers near the Minneapolis Chain of Lakes are monitored by the Minneapolis Park and Recreation Board (MPRB), this data is also compiled for this report.

The 2004 Hydrologic Data Monitoring Program work plan is presented in Appendix C. Also included is a description of quality assurance/quality control procedures to help ensure data quality.

Lake Water Quality Analysis Water quality grades are based on standards established by the Metropolitan Council. The standards give a range to each letter grade for the May through September averages of surface total phosphorus (TP) concentration, surface chlorophyll-a concentration, and Secchi depth. The overall lake water quality grade is the average of the grades for each parameter. Other indicators of lake condition such as aquatic plant growth or invasive species are not factored into these grades. The Trophic State Index (TSI), which measures the productivity level of a lake or degree of eutrophication, is also calculated. High TSI values correspond with poorer water quality.

3 Lakes are additionally classified as full-use, partial-use, and restricted-use based on user perceptions for the local ecoregion (MCWD falls within the North Central Hardwood Forest Ecoregion). The user perceptions are based on summer surface TP concentration observed between May and September. The classifications are based on MPCA data for the North Central Hardwood Forest Ecoregion. For the purpose of this report, lakes with average summer surface TP concentrations below 40 mg/L are classified as full use. Lakes with concentrations between 40 and 60 mg/L are classified as partial use. Lakes with concentrations above 60 mg/L are classified as restricted use.

Additionally some lakes within MCWD are included on the MPCA’s 303 (d) List of Impaired Waters. Not all lakes that are considered partial or restricted use are on the MPCA’s 303 (d) List of Impaired Waters. This is primarily because only a portion of the MCWD’s database has been uploaded to the EPA’s national data warehouse, STORET (short for STOrage and RETrieval).

Stream Water Quality Analysis The MPCA (McCollor and Heiskary, 1993) collected and summarized water quality data from minimally impacted streams within Minnesota’s seven ecoregions. These data may be used to establish water quality guidelines on ecoregion basis. North Central Hardwood Forest Ecoregion median data are compared to data collected in MCWD streams.

Stream data is also compared to: ª water quality standards listed in Chapter 7050 of Minnesota State Rules for the

MPCA (MN 7050), and ª criteria listed in the MPCA’s Guidance Manual for Assessing the Quality of Minnesota Surface Waters for the Determination of Impairment 305(b) Report

and 303(d) List are also used.

4 2. Precipitation

The MCWD and other monitoring entities have continuous precipitation monitoring equipment located in or near the MCWD. The MCWD also has several citizen monitors, who record daily information on data sheets for submittal. All of this data is used to help determine long-term trends and to provide information for calibration of the HHPLS computer model. The data presented in this report consists of continuous data collected by government agencies; summary data is detailed in Appendix D.

Annual precipitation (January to December) varied across the MCWD in 2004, ranging from 25.3 inches at the Minneapolis-St. Paul International Airport to 41.1 inches at both the Maple Plain and Deephaven stations (Figure 2.1). Long-term data has been collected at Maple Plain and the Minneapolis-St. Paul International Airport. The annual mean (1951-1980) for the Maple Plain station is 29.9 inches, which is considerably lower (27%) than precipitation seen in 2004 (41.1 inches). The annual mean (1971-2000) for the Minneapolis-St. Paul International Airport is 29.4 inches, which is higher (16%) that precipitation seen in 2004 (25.3 inches).

Figure 2.1 Annual 2004 precipitation (inches) at all continuous recording sites located in or near the MCWD. Top row of 4 stations: Maple Plain, Long Lake, New Hope, and Minneapolis. Middle row of 4 stations: Mound, Deephaven, St. Louis Park, and Minneapolis-St. Paul International Airport. Bottom row of 2 stations: Carver Park Reserve and Chanhassen

41.1 35.0 29.9 34.9

41.1 36.2 30.6

27.1 25.3 31.0

5 Examination of precipitation data on a monthly scale is also possible for the Maple Plain and Minneapolis-St. Paul International Airport stations. In 2004, Maple Plain received an unusually large amount of precipitation in both May and September, nearly 11 inches over the long-term means (Figure 2.2). These two months make up the majority of the difference between the 2004 annual total and the 1951-1980 annual total (discussed above).

Figure 2.2 Long-term and 2004 precipitation at the Maple Plain monitoring site

12 Maple Plain 2004 10

8 Maple Plain Long- Term Average 6 (1951-1980) 4

2 Precipitation (inches) 0 J F M A M J J A S O N D Month of 2004

In 2004 the Minneapolis-St. Paul International Airport received an unusually large amount of precipitation in May, but not in September (Figure 2.3). This station also received much less precipitation in June and August, compared with the long-term average.

Examination of all continuous data collected by government agencies on a monthly basis is depicted in Figure 2.4. Here we can see that many stations in and around the MCWD received high levels of precipitation in May and September, but that many stations experienced a very dry August, November, and December.

6 Figure 2.3 Long-term and 2004 precipitation at the Minneapolis International Airport monitoring site

7 MSP Airport 2004 MSP Airport Long-Term 6 Average (1971-2000) 5 4 3 2 1 Precipitation (inches) 0 J F M A M J J A S O N D Month of 2004

Figure 2.4 Year 2004 monthly precipitation at all continuous recording sites in or near the MCWD

12 11 10 Maple Plain 9 Long Lake 8 Carver 7 Deephaven 6 5 Mound 4 New Hope 3 Chanhassen

Precipitation (inches) 2 St. Louis Park 1 0 MSP Airport J F M A M J J A S O N D Minneapolis Month of 2004

Recommendations for Precipitation Monitoring in 2005

• Install 5 additional tipping bucket precipitation gauges at strategic locations in the MCWD to fill in data gaps. The MCWD water quality specialist is working with the U.S. Army Corps of Engineers to determine the optimal locations.

7 3. Lake Minnetonka

Lake Minnetonka Elevation and Grays Bay Discharge The lake elevation at ice-out (April 13th) was 928.19 feet (Figure 3.1), which was nearly a foot below the 30-year ice-out average (929.1 feet; 1971-2000). The lake elevation was 928.71 feet by May 24th, at which time the Grays Bay Dam was opened and discharge began. Lake elevation and dam discharge increased to peaks of 930.17 feet and 300 cubic feet per second (cfs) by June 14th, respectively. Note that at this time the level over-topped the gauge, so discharges were likely higher than 200 cfs. The gauge was moved on August 10th (hence the value of zero on Figure 3.1 at this time). Lake elevation and discharge decreased after June 23rd; the dam was closed by late August when the lake elevation was 928.6 feet. At the last reading on October 22nd the lake elevation was 928.46 feet.

Figure 3.1 Lake Minnetonka elevation (above mean sea level) and Grays Bay Dam discharge during 2004 open-water conditions. Note: runout elevation is 929.75 feet; 100-year flood elevation: 931.5 feet

350 930.5 300 930.0 250 929.5 200 929.0 150 928.5 100 928.0 Discharge (cfs) Lake Elevation (feet) 50 927.5 0 927.0 4/1 4/29 5/27 6/24 7/22 8/19 9/16 10/14

Date

The calculated discharge averaged 36 cfs over the entire year, resulting in a calculated total discharge volume of 26,070 acre-feet. This is equivalent to 4.0 inches of runoff from the 122-

8 square mile watershed (14-year average = 4.9 inches; Figure 3.2). The lake elevation surpassed the normal ordinary high water level (NOHW) of 929.4 feet for approximately 2 months during early summer. During the 2004 period of record, the average lake elevation was 929.13 feet with an overall fluctuation of 1.71 feet. Annual lake evaporation in the vicinity is normally about 31 inches.

The long-term elevation history of Lake Minnetonka indicates that the 2004 lake elevation fluctuations are typical of the past 50 years (Figure 3.3). Values typically fluctuate between 928 and 930 feet on an annual basis. Note that target discharges from Lake Minnetonka are determined according to discharge guidelines set in the MCWD’s Headwaters Control Structure Management Policy and Operating Procedures (MCWD 1999). The outlet gate openings are calculated and set according to the target discharge, the prevailing lake and tail water elevations, and the discharge-rating curve.

Figure 3.2 Upper watershed runoff calculated from Grays Bay dam discharge setting, 1987 to 2004. Average = 4.9 inches

4 Runoff (inches) 2

0 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 Year

9 Figure 3.3 Lake Minnetonka elevation time-series

Year

Lake Minnetonka 2004 Water Quality

Lake report card grades in Lake Minnetonka improved in Forest Lake, Halsted Bay, Harrisons Bay, Jennings Bay, Libbs Lake, Maxwell Bay, North Arm, Stubbs Bay, and West Arm compared to 2003 values (Table 3.1). Water quality grades decreased in Cooks Bay, Crystal Bay, Spring Park Bay, Tanager Lake, and West Upper Lake. Water quality grades ranged from A’s in several bays to a D- for Tanager Lake.

Average summer surface TP concentrations in 16 out of 26 bays monitored are less than 40 µg/L, indicating full use for lakes within the North Central Hardwood Forest Ecoregion. The remaining 10 are classified as restricted (> 60 ppb) or partially restricted (40-60 ppb) use (Table 3.2).

Water quality in Lake Minnetonka is better now than it was in the 1970s. Many Lake Minnetonka Bays that were classified as restricted-use in the 1970s based on their average summer surface TP concentrations are now considered full use (Table 3.2). Average summer surface TP concentrations in the 1970s were between 1.5 and 3.5 times higher than they are today. Long-term average summer surface TP, chlorophyll-a, Secchi depth, and TSI graphs for Lake Minnetonka are presented in Appendix A in the lake report cards.

10 Table 3.1 Lake report card grades for Lake Minnetonka bays, 1998-2004. See Appendix A for lake report cards

11 Table 3.2 Mean 2004 summer surface Secchi disk transparency, chlorophyll a concentration, total phosphorus concentration, and trophic state index means for Lake Minnetonka bays. Blue: full use; Orange: partial use; Red: restricted use

Secchi Total Disk Chlorophyll Phosphorus Waterbody (m) (ppb) (ppb) TSI Grays 3.3 1 21 40 Carsons 3.1 1 21 42 Gideons 3.3 2 22 42 St. Albans 3.9 4 16 43 Wayzata 3.4 6 17 45 Lower Lake South 3.3 6 20 46 Libbs 1.8 2 21 46 Carman 2.7 4 24 46 Spring Park 2.9 7 20 47 East Upper 2.7 4 29 47 Smithtown 2.3 5 23 48 Crystal 3.0 9 26 49 West Upper 2.4 12 27 51 North Arm 2.4 11 31 52 Maxwell 2.4 12 32 52 Cooks 1.9 16 32 54 Black 7.7 10 40 54 Peavey Lake 2.1 17 76 58 Forest Lake 1.7 21 71 59 West Arm 1.6 33 59 60 Stubbs 1.6 30 63 60 Harrisons 1.2 32 58 61 Priests 1.0 28 55 62 Jennings 1.4 39 110 65 Halsted 1.6 41 128 65 Tanager Lake 1.1 80 118 68

Caution must be taken when examining these long-term trends. Data in the 1970s and 1980s for Lake Minnetonka bays often had insufficient numbers of samples taken in a given year. For example, only one sampling for Secchi disk transparency may have been taken in a given bay for

12 the entire year. In addition, the time of year that such data may have been collected is also of crucial importance. For example, a very low Secchi disk transparency reading may have been taken in a bay during an unusual algal bloom event. It might have been the case that the remainder of the year produced great transparency conditions; hence, that single data point would bias our conclusions.

With these caveats, statistical analysis of water quality trends (linear regression) indicates that improvements have occurred primarily in the southern and eastern parts of the lake (Table 3.3). For the bays listed, Secchi transparencies have increased, while chlorophyll and TP concentrations have decreased. The trophic state index (TSI) values decreased, indicating an improvement in overall water quality.

Table 3.3 Statistically-significant changes in mean annual water quality in Lake Minnetonka bays over the period of record. Values are given as probabilities (p-values) and trend direction

Waterbody Secchi Chlorophyll TP TSI Cooks 0.031, + Jennings 0.020, + 0.004, - Lower Lake South < 0.001, + 0.043, - 0.027, - < 0.001, - Peavey Lake 0.001, - 0.024, - Wayzata < 0.001, + < 0.001, - < 0.001, - West Upper 0.001, + 0.039, - 0.027, -

The primary reason for the improvement was the gradual elimination of wastewater discharges to Lake Minnetonka and its tributaries from seven surrounding municipalities. This resulted in an annual TP load reduction of 50,780 lbs (MCWD 1997). By comparison, TP loads to Lake Minnetonka from gauged watersheds ranged from 700 to 18,500 lbs in 2000 and 2001 respectively (these numbers represent about 73% of the sub-watershed area tributary to Lake Minnetonka which have been monitored annually since 1997).

Data quality and quantity have been excellent since 1997 when the MCWD began its intensive monitoring program. Caution in data interpretation is also warranted here because annual

13 variation in external drivers such as precipitation quantities can have a significant impact on water quality. Hence it would be inappropriate to apply simple statistical procedures (e.g., linear regression) to suggest whether water quality is changing in Lake Minnetonka since 1997. Such an in-depth statistical analysis will be undertaken by the MCWD water quality specialist in the near future.

Recommendations for Lake Minnetonka in 2005

• Continue monitoring Lake Minnetonka bays, adding monthly monitoring to representative bays in the lake that have not been monitored frequently in the past. Such information is crucial to the Lake Minnetonka phosphorus model that is being developed (see Long Term Initiatives section of report). • Intensive workup of dissolved oxygen and phosphorus data to assess the spatial and temporal variation of internal P loading in Lake Minnetonka. • Focus watershed monitoring and rehabilitation efforts in areas that contribute to poor Lake Minnetonka water quality: Six Mile Creek, Painter Creek, Classen Creek, Long Lake Creek, and Gleason Lake Creek.

14 4. Lower Watershed Lakes

2004 Water Quality in Lower Watershed Lakes The majority of the 12 lakes monitored are in the city of Minneapolis; the two exceptions include Twin Lake (St. Louis Park) and Windsor (Minnetonka). Lake report card grades in the lower watershed improved in Cedar Lake, Grass Lake, and Lakes of the Isles compared to 2003 values (Table 4.1). Water quality grades decreased in Diamond Lake and Lake Nokomis. Water quality grades ranged from A’s in Lake Calhoun and Lake Harriet to a D- for Windsor Lake.

Table 4.1 Lake report card grades for Lower Watershed lakes, 1998-2004. See Appendix A for lake report cards

Waterbody 1998 1999 2000 2001 2002 2003 2004 Brownie C+ B- B ------C+ Calhoun B+ A A B+ A A A Cedar A A A- B+ B+ B+ A- Diamond ------C- D Grass ------F C+ Harriet A- B+ B+ A A A A Hiawatha C+ C C- C+ C+ C+ C+ Isles C+ C+ B- C C C- C Nokomis C C C C C C+ D+ Powderhorn ------D+ Twin (SLP) ------D+ D D Windsor ------D-

Average summer surface TP concentrations in 3 out of 12 bays monitored are less than 40 µg/L, indicating full use for lakes within the North Central Hardwood Forest Ecoregion. The remaining 9 are classified as restricted (> 60 ppb) or partially restricted (40-60 ppb) use (Table 4.2).

15 Table 4.2 Mean 2004 summer surface Secchi disk transparency, chlorophyll a concentration, total phosphorus concentration, and trophic state index means for Lower Watershed lakes. Blue: full use; Orange: partial use; Red: restricted use

Secchi Total Disk Chlorophyll Phosphorus Waterbody (m) (ppb) (ppb) TSI Calhoun 5.2 3 15 40 Harriet 5.2 3 15 43 Cedar 3.7 7 25 47 Brownie 1.5 19 45 58 Isles 1.8 28 50 58 Hiawatha 1.3 17 68 60 Grass n/a 15 68 61 Nokomis 1.0 28 80 64 Powderhorn 0.7 37 118 68 Diamond 0.8 38 178 69 Twin (SLP) 0.7 51 174 71 Windsor 0.7 49 193 71

Water quality in lower watershed lakes is generally better now than it was in the 1970s. Many lower watershed lakes that were classified as restricted-use in the 1970s based on their average summer surface TP concentrations are now considered full use (Table 4.2). As seen in Lake Minnetonka bays, average summer surface TP concentrations in lower watershed lakes in the 1970s were between 1.5 and 3.5 times higher than they are today. Long-term average summer surface TP, chlorophyll-a, Secchi depth, and TSI graphs for the lower watershed lakes are presented in Appendix A in the lake report cards.

Caution must be taken when examining these long-term trends. As was noted for Lake Minnetonka bays in the 1970s and 1980s, there were instances of insufficient numbers of samples taken in a given year. With these considerations in mind, statistical analysis of water quality trends (linear regression) indicates that improvements have occurred in several lower watershed lakes (Table 4.3). For the lakes listed, Secchi transparencies have increased, while chlorophyll and TP concentrations have decreased. The trophic state index (TSI) values decreased, indicating an improvement in overall water quality.

16 Table 4.3 Statistically-significant changes in mean annual water quality in Lower Watershed lakes over the period of record. Values are given as probabilities (p-values) and trend direction

Waterbody Secchi Chlorophyll TP TSI Brownie 0.014, - 0.047, - Calhoun 0.005, + 0.006, - Harriet 0.023, - Hiawatha 0.025, - Isles 0.04, + Nokomis 0.013, + 0.014, - 0.025, - Powderhorn 0.048, - 0.042, -

The primary influx of nutrients into these lakes comes from stormwater runoff; an effort to reduce this type of pollution is the most likely reason that we have seen improvements in water quality. However, intensive in-lake management has also taken place (e.g., rough fish removal, alum treatments) in some of these lakes to help improve water quality.

Data quality and quantity have been excellent since 1997 when the MCWD began its intensive monitoring program. Caution in data interpretation is also warranted here because annual variation in external drivers such as precipitation quantities can have a significant impact on water quality. Hence it would be inappropriate to apply simple statistical procedures (e.g., linear regression) without consideration of such drivers to suggest whether water quality is changing in lower watershed lakes since 1997. Such an in-depth statistical analysis will be undertaken by the MCWD water quality specialist in the near future.

Recommendations for Lower Watershed Lakes in 2005

• Continue monitoring lower watershed lakes, especially those of high recreational value with long-term data. • Encourage ongoing efforts to curb the influx of stormwater nutrients into these lakes.

17 5. Upper Watershed Lakes

2004 Water Quality in Upper Watershed Lakes Five of the 13 lakes monitored in the upper watershed received improved lake report card grades compared to 2003 values; these include Dutch Lake, Gleason Lake, Steiger Lake, West Auburn Lake, and Lake Zumbra (Table 5.1). Water quality grades decreased in Christmas Lake, Lake Minnewashta, Schutz Lake, Tamarack Lake, and Wasserman Lake. Water quality grades ranged from an A- in Christmas Lake to an F for Langdon Lake. Changes in grades most likely reflect year-to-year variation in precipitation.

Table 5.1 Lake report card grades for Upper Watershed lakes, 1998-2004. See Appendix A for lake report cards

Waterbody 1998 1999 2000 2001 2002 2003 2004 Christmas A A A A A A A- Dutch ------C+ D+ C D D+ Gleason C- C- C- D+ C- D C- Langdon D- D F D- D+ F F Long C+ C C- D+ C C- C- Minnewashta A- A- B+ B+ B+ A B+ Parley ------D D+ D+ D --- Pierson ------B A- --- Schutz ------B C+ C Steiger ------C+ --- C+ C C+ Stone ------C+ --- C --- C+ Tamarack ------C+ C- Virginia ------C C --- Wasserman ------D D C C- D+ West Auburn ------B+ --- B- C- B- Zumbra ------A- --- B+ B B+

Average summer surface TP concentrations in 3 out of 13 lakes monitored are less than 40 µg/L, indicating full use for lakes within the North Central Hardwood Forest Ecoregion. The remaining 9 are classified as restricted (> 60 ppb) or partially restricted (40-60 ppb) use (Table 5.2).

18 Table 5.2 Mean 2004 summer surface Secchi disk transparency, chlorophyll a concentration, total phosphorus concentration, and trophic state index means for Upper Watershed lakes. Blue: full use; Orange: partial use; Red: restricted use

Secchi Total Disk Chlorophyll Phosphorus Waterbody (m) (ppb) (ppb) TSI Christmas 4.9 0.1 29 33 Minnewashta 2.6 3 25 46 Zumbra 3.1 12 32 51 West Auburn 2.8 14 41 53 Stone 1.9 15 47 56 Steiger 1.5 18 41 57 Schutz 1.3 26 49 60 Tamarack 1.3 34 72 62 Gleason 1.4 23 104 62 Long 1.2 40 76 64 Dutch 1.1 44 88 65 Wasserman 1.0 36 88 65 Langdon 0.4 99 138 74

Water quality in upper watershed lakes is generally better now than it was in the 1970s. Some lakes (e.g., Langdon Lake) received waterwater effluent for many years, but there appears to be evidence that the cessation of these activities is in large part responsible for improvements in water quality. Long-term average summer surface TP, chlorophyll-a, Secchi depth, and TSI graphs for the lower watershed lakes are presented in Appendix A in the lake report cards.

Caution must be taken when examining these long-term trends. As was noted for Lake Minnetonka bays and lower watershed lakes in the 1970s and 1980s, there were instances of insufficient numbers of samples taken in a given year. With these considerations in mind, statistical analysis of water quality trends (linear regression) indicates that improvements have occurred in several lower watershed lakes (Table 5.3). For the lakes listed, Secchi transparencies have increased, while chlorophyll and TP concentrations have decreased. The trophic state index (TSI) values decreased, indicating an improvement in overall water quality.

19 Table 5.3 Statistically-significant changes in mean annual water quality in Upper Watershed lakes over the period of record. Values are given as probabilities (p-values) and trend direction

Waterbody Secchi Chlorophyll TP TSI Dutch 0.052, - Gleason < 0.001, + 0.058, - Langdon 0.002, + < 0.001, - < 0.001, - Long 0.03, + 0.003, - Minnewashta 0.013, - Zumbra 0.018, +

Recommendations for Upper Watershed Lakes in 2005

• Continue monitoring upper watershed lakes, with emphasis on lakes with long-term data sets. • Focus watershed monitoring and rehabilitation efforts on the major stream-lake systems in the upper watershed, including Gleason Lake, Long Lake, and the Six Mile Creek system of lakes. • Encourage volunteer monitoring efforts of upper watershed lakes.

20 6. Minnehaha Creek

Water quality grab samples are collected weekly at eight sites along Minnehaha Creek. Stream flow at the time of sampling is either gauged or calculated based on an established stage- discharge relationship for the site. Stream report cards are presented in Appendix B. Flow- weighted mean nutrient, sediment, chloride concentrations, and stream loading are included in Appendix E. Monitoring locations are shown in Figure 6.1.

Figure 6.1 Stream Monitoring Locations on Minnehaha Creek

Discharge at the Browndale Avenue Dam Located under the Browndale Avenue Bridge in Edina, the Browndale Avenue Dam (CMH03) is roughly at the creek’s midpoint between Lake Minnetonka and the Mississippi River. The small impoundment created by the dam is often referred to as the Mill Pond. The dam is an ogee- crested weir, which offers a simple and reliable means for calculating stream discharges based on measured water surface elevations upstream of the dam. In addition to the three weekly manual readings recorded by the City of Edina, the water elevation at this location is recorded automatically every 15 minutes by a transducer operated by MCWD.

21 Automated monitoring was conducted between March 25, 2004 and November 11, 2004. Total discharge was calculated using automated water surface elevation data collected during the monitoring period and manual readings collected by the City of Edina. Linear interpolation was used to calculate flow between ice out and the first recorded water level of 2004. Discharge calculated at Browndale Avenue was approximately 26,794 acre-feet during 2004, which is equivalent to 3.5 inches of runoff from the contributing 142 square mile watershed.

Flow in Minnehaha Creek averaged 36 cfs over the year at the headwaters structure, Grays Bay Dam. Comparatively, average flow at Browndale Dam in Edina 11 miles downstream from Grays Bay Dam averaged 37 cfs. Figure 6.2 depicts the average annual flow at the Browndale Dam from 1997 to 2004.

Figure 6.2 Average Annual Flow at the Browndale Dam (Site CMH03)

120 100 80 60 40 20 Average Flow (cfs) 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

The maximum flow recorded at Browndale Dam during 2004 was 216 cfs on both July 7th and 13th. Figure 6.3 shows measured flow at Browndale Dam and precipitation at Maple Plain, MN.

22 Figure 6.3 2004 Daily Precipitation at Maple Plain and Measured Flow at Browndale Dam, Edina

3.5 250

3.0 200 2.5

2.0 150

1.5

100 Flow (cfs) 1.0 50

Daily Precipitation (inches) 0.5

0.0 0 3/25 4/22 5/20 6/17 7/15 8/12 9/9 10/7 11/4 2004 Date

Water Quality Water quality grab samples were collected weekly at 8 sites along Minnehaha Creek March through September. Flow is measured concurrent with the grab sample either by gauging or through a head measurement and an existing stage discharge relationship. Samples were analyzed for TP, SRP, TN, TSS, and chloride, as well as the in-situ parameters: DO, temperature, conductivity, and pH. A similar annual monitoring program has been in place since 1997. Flow-weighted mean concentrations and in-stream loads for Minnehaha Creek are presented in Appendix E.

The 2004 median TP and TSS concentrations in Minnehaha Creek are low when compared with data (1986-1992) collected from minimally impacted streams in the North Central Hardwood Forest ecoregion (Table 6.1). Mean values for these parameters are similar to the ecoregion means. These findings are similar to findings in other years, indicating that Minnehaha Creek has good water quality when compared to streams without anthropogenic impacts. This is due in part to the large influx of clean water discharged from Lake Minnetonka.

23 Table 6.1 MPCA Ecoregion vs. Minnehaha Creek 2004: Median, Mean, and Maximum Concentrations (Summer)

Minnehaha Ecoregion Creek Median Mean Maximum Median Mean Maximum Conductivity (µmhos) 310 301 840 422 492 1070 pH (S.U.) 8.1 8.2 8.9 7.85 7.89 9.35 Total Suspended Solids (mg/L) 10 9.1 29 7 9 74 Total Phosphorus (µg/L) 170 80 430 71 81 447

Chloride Flow-weighted average chloride concentrations in Minnehaha Creek were below the MN 7050 Class 2B Chronic Standard for chloride (230 mg/L) during 2004. Flow-weighted average chloride concentrations increased from 45 mg/L at the headwaters (Grays Bay Dam) to 75 mg/L at Excesior Blvd., then dropping to 63 mg/L just past the Browndale Dam (Edina). Concentrations then doubled to 131 mg/L at Upton Avenue (SW Minneapolis), dropped to 91 mg/L by Chicago Ave. (just east of Lake Nokomis) and finally to 68 mg/L at the most downstream station, 32nd Ave. in Minneapolis.

Individual grab samples collected in during spring runoff, however, did exceed the 230 mg/L standard at all stations except the Grays Bay site (none exceeded the acute chloride standard of 860 mg/L). The majority of these occurred between March 2nd and April 15th. Maximum values were between 263-273 mg/L for the next three sites downstream (W. 34th St. to Excelsior Blvd.). Maximum values then increased to 371-385 mg/L for the next three sites (Browndale Dam to Chicago Ave.), dropping to a maximum of 320 mg/L at 34th Ave.

Bacteria E. coli concentrations are indicators of the potential for human illness contracted through full body contact with surface water. Eleven E. coli bacteria sampling events took place in Minnehaha Creek from July 27th to October 7th in 2004. Grab samples were analyzed for E. coli at the City of Minneapolis Labs. Samples were collected at seven sites along Minnehaha Creek; the monitoring site at I-494 was not sampled due to the fact that the site is not likely to be used for full body contact given its location and limited accessibility.

24 The MPCA has an acute standard of 1,260 CFU/100 mL for E. coli; this standard applies to individual grab samples. A violation occurs when greater than 10% of the samples exceed the standard. Grab sample data collected in 2004 indicates that this acute standard was not violated in Minnehaha Creek (Figure 6.4). A rainfall runoff event occurred in mid-September 2004, causing E. coli levels to dramatically increase at some sites (Table 6.2). Note how values dropped greatly between the last two stations; this represents dilution in Lake Hiawatha. Values quickly returned to pre-event values as the system flushed out.

Figure 6.4 E. Coli Grab Samples in Minnehaha Creek, 2004

Grays W 34th Excelsior Browndale Upton Chicago 32nd Ave 100000

10000

1000

100

10 E. coli (CFU/100 mL) 1 7/16 7/28 8/9 8/21 9/2 9/14 9/26 10/8 10/20 2004 Date

Table 6.2 Mid-September 2004 E. coli (CFU/100mL) in Minnehaha Creek Browndale Upton Chicago 32nd Ave September 14, 2004 290 31,000 74,000 2,500 September 17, 2004 100 500 2,200 900 September 23, 2004 150 300 220 490

The MPCA also has a 30-day geometric mean standard of 126 CFU/100 mL. This approach helps to dampen the statistical effect of major runoff events (like the one discussed above), giving us a better overall picture of the health of the system over the summer. Application of this technique is portrayed in Figure 6.5. The data from 2004 indicates that the 30-day standard was

25 violated for five sites on Minnehaha Creek during August and September. The Grays Bay Dam and Browndale Dam sites were always in compliance over this time period. The lower values for Grays Bay Dam are due to the relatively clean water draining from Lake Minnetonka; the lower values for below the Browndale Dam are due to the settling effect of the reservoir behind the dam. The spatial and temporal variation of E. coli sources should be examined more closely in 2005 to address this health problem.

Figure 6.5 E. Coli 30-Day Geometric Means in Minnehaha Creek, 2004

Grays W 34th Excelsior Browndale Upton Chicago 32nd Ave

10000

1000

100

(CFU/100 mL) 10 30-Day Geometric Mean 1 8/6 8/11 8/16 8/21 8/26 8/31 9/5 9/10 9/15 9/20 9/25 9/30 2004 Mid-Point Date

Dissolved Oxygen Discrete DO measurements are collected weekly at eight locations along Minnehaha Creek. The measurements are discrete and do not take into account diurnal variation, and do not reflect the minimum daily DO concentrations. During the 2004 sampling season, DO concentrations measured in Minnehaha Creek were generally above the MN 7050 standard of 5 mg/L. Measurements dipped below the standard several times during 2004 (Table 6.3). The first instance occurred on June 17th during which all stations downstream off the I-494 site were in violation. During the first half of July violations occurred only at the W. 34th and Excelsior sites. During early September violations occurred only at the upper two sites. The large wetland complex just below Grays Bay Dam is a likely candidate for the late-summer violations:

26 decomposing plant matter can result in significant oxygen demands, lowering the ambient oxygen concentrations downstream.

Table 6.3 2004 Late-Summer Dry-Weather DO Profiles in Minnehaha Creek 32nd Grays I-494 W 34th Excelsior Browndale Upton Chicago Ave 6/10/04 6.3 5.7 5.9 5.0 7.6 7.6 7.7 5.5 6/17/04 7.6 5.8 4.6 2.4 3.2 4.1 4.5 4.1 6/24/04 9.2 6.6 5.6 6.1 7.7 7.8 8.1 6.9 7/1/04 9.9 7.2 5.6 2.7 7.3 7.6 7.7 6.9 7/7/04 7.2 7.1 5.8 7.0 7.6 7.8 8.0 6.4 7/13/04 8.8 7.3 4.8 5.6 6.8 7.1 7.3 6.9 7/20/04 10.7 6.5 4.8 5.7 6.8 7.2 7.5 6.8 7/29/04 7.4 5.5 6.0 6.2 6.9 7.6 7.7 7.0 8/5/04 8.8 6.6 6.9 6.2 7.2 7.4 7.6 5.9 8/12/04 9.3 7.3 7.4 8.2 8.2 9.5 9.3 9.4 8/19/04 7.8 7.1 7.4 8.5 8.1 8.5 9.1 8.1 9/2/04 n/a 4.6 3.6 6.2 8.4 7.3 7.8 8.6 9/9/04 2.9 6.5 5.3 7.3 8.3 7.8 8.7 6.8

Impaired Waters Listing In December 2003, the MPCA published its 2004 Draft List of Impaired Waters under the Clean Water Act, or 303 (d) list. Minnehaha Creek was listed as impaired with respect to biotic integrity. The listing is based on assessments of the fish communities in the Creek at two locations: the creek crossing at Nicollet Avenue in Minneapolis was assessed by the USGS, and the Creek at Big Willow City Park in Minnetonka was assessed by the MnDNR.

Minnehaha Creek at Nicollet Avenue, located downstream of Browndale Dam, was assessed in 1997 and 1998 and scored 26 and 36 out respectively out of 100, well below listing criteria of 46 (scores must be at or above the listing criteria to be listed). Minnehaha Creek at Big Willow Park located upstream of Browndale Dam however, scored above the listing criteria at 48 in 2000. Because the Creek was considered one section, the entire length of Minnehaha Creek was listed, even though the site in the upstream portion of Minnehaha Creek did not meet the requirements for listing.

27 The presence of physical barriers such as Browndale Dam in Edina may suggest that different expectations with respect to biotic community are appropriate for different sections of the creek.

Stream biotic integrity is generally the result of all factors present in the stream, water quality, flow velocities, water depth, migration opportunities, and channel morphology, all may play a role in the lack of biotic integrity. An analysis of possible stressors on fish communities in Minnehaha Creek may be useful in determining how best to deal with the listing.

In-Stream Loading In-stream nutrient, sediment, and chloride loads to the Mississippi River from Minnehaha Creek in 2004 were calculated as TP: 6654 pounds; SRP: 1783 lbs; TN: 74,918 lbs; TSS: 356 tons; and Cl: 2,541 tons. In general, nutrient loads in Minnehaha Creek increase with distance downstream. From the Grays Bay site to the Excelsior Ave. site one can see a gradual increase in TP, SRP, and TN loads (Figure 6.6). The Browndale site is situated immediately downstream of the Browndale Dam; what we see is that nutrients are being lost in the impoundment. By far the greatest surge of nutrients comes between the Browndale and Upton Ave. sites. Loads are relatively high beyond this point, compared to sites further upstream, but do gradually fall off towards the 32nd Ave. site (Figure 6.6).

Figure 6.6 2004 Nutrient Loading Profile for Minnehaha Creek

TP SRP TN

16,000 70 14,000 60 12,000 50 10,000 40 8,000 30 6,000 4,000 20

10 Nitrogen Load (tons)

Phosphorus Load (lbs) 2,000 0 0

Grays I-494 Upton W. 34th Chicago ExcelsiorBrowndale 32nd Ave

28 The reservoir of Lake Hiawatha increases the residence time for Creek water. Hence one can see sediment concentrations drop as Minnehaha Creek water passes through this waterbody (Figure 6.7). TSS load decreases from 594 to 356 tons between the Chicago Ave. and 32nd Ave. stations.

Figure 6.7 2004 Chloride and Sediment Loading Profile for Minnehaha Creek

Cl TSS

8000 700 7000 600 6000 500 5000 400 4000 300 3000

Cl Load (tons) 200

2000 TSS Load (tons) 1000 100 0 0

Grays I-494 Upton W. 34th Chicago Excelsior 32nd Ave Browndale

In-stream chloride concentrations are well below state standards. In-stream chloride loads increases most dramatically in 2004 between the Browndale Dam and Upton Avenue, as was seen for nutrients and sediments. Chloride is conservative, and therefore Lake Hiawatha does not affect chloride loading and concentrations as it does for other nonconservative pollutants.

In-stream loads calculated for 2004 indicate that the highest areal loads to Minnehaha Creek come from the same sub-watershed: the subwatershed between Browndale Dam and Upton Avenue (Table 6.4). Negative values indicated that there was a net loss through a given stream reach. For example, the Browndale and 32nd Ave. subwatersheds show a consistent loss: this is due to sediments and nutrients dropping out into the Browndale reservoir and Lake Hiawatha, respectively.

29 Table 6.4 Areal Export of Nutrients, Sediments, and Chloride Export to Minnehaha Creek

TP SRP TN Cl TSS Subwatershed lbs/mi2 lbs/mi2 tons/mi2 tons/mi2 tons/mi2 I-494 194 -38 1 88 32 W. 34th 265 100 0 61 -12 Excelsior 638 360 2 202 25 Browndale -794 -379 -3 -353 -34 Upton 3023 1642 11 1628 93 Chicago -197 -123 -1 -133 9 32nd Ave -458 -350 -1 -256 -39

2005 Recommendations for Minnehaha Creek • Conduct a more intensive study of bacterial sources. Use of tracers such as caffeine will help us further refine bacterial spatial and temporal variation. • Continue weekly monitoring, and grab samples along the creek. Add a station just above Minnehaha Falls. • Install additional pressure transducers along the creek to better assess discharge dynamics. • Focus BMP efforts in the Upton Ave. subwatershed to address high loading.

30 7. Upper Watershed Streams

Water quality grab samples were collected weekly at 15 locations on 10 major tributaries to Lake Minnetonka from March through September (Figure 7.1). Water quality and flow were measured at the following sites: Classen Lake Creek (CCL01), Long Lake Creek (CLO01 and CLO03), Painter Creek (CPA01-CPA04, 4 sites), Six Mile Creek (CSI01 and CSI03), Gleason Lake Creek (CGL01), Dutch Lake Creek (CDU01), Langdon Lake Creek (CLA01), Minnewashta Lake Creek (CMW01), Christmas Lake Creek (CCH01), and Stubbs Bay Inlet (CST01).

Figure 7.1 Stream Monitoring Stations in the Upper Watershed

Flow is measured concurrent with the grab sample either by gauging or through a stage measurement and the use of an existing stage discharge relationship. Samples were analyzed for TP, SRP, TN, TSS, and chloride, as well as the in-situ parameters: DO, temperature, conductivity and pH. Since 1997, a similar monitoring program has been implemented, though the number of sites monitored has doubled since 2000.

31 Automated flow records, and flow-weighted samples were collected at locations along Painter Creek at three locations (Figure 7.2), Long Lake Creek at the lake outlet and Brown Street, and Six Mile Creek at Highway 7 during 2004.

Figure 7.2 Painter Creek Sub-watershed Automated Monitoring

Discharge Over the Upper Watershed Discharge over the sub-watersheds tributary to Lake Minnetonka is calculated in two ways: • Flow records are developed from continuous stage recorders and stage-discharge relationships • Flow records are developed from weekly manual measurements and stage-discharge relationships.

At sites along Painter Creek, Long Lake Creek, and Six Mile Creek, both continuous and weekly measurements are collected; generally, the continuous readings offer a more complete picture of the runoff from the sub-watershed. When compared, the calculations based on weekly measurements do not differ significantly from those based on continuous measurements.

32 Discharge from the contributing sub-watersheds during 2004 calculated from manual readings ranged from a time-weighted flow of 0.5 cfs at the Christmas Creek site to 12.1 cfs at the Lunsten Lake Outlet in the Six Mile Creek sub-watershed. Comparatively, the discharge calculated for the entire 122-square mile upper watershed based on measurements at Grays Bay Dam was 35.8 cfs.

Painter Creek Runoff from the 13.1 square mile Painter Creek sub-watershed was 10.7 inches based on continuous water level measurements at West Branch Road, or 7,749 acre-feet over the year. The average flow in Painter Creek at West Branch Road was 10.3 cfs over the year. Figure 7.3 shows measured flow at this station.

Figure 7.3 2004 Discharge in Painter Creek at West Branch Road

120 100 80 60

Flow (cfs) 40 20 0 3/25 4/22 5/20 6/17 7/15 8/12 9/9 10/7 2004 Date

Long Lake Creek Discharge from the 10.9 square-mile Long Lake Creek sub-watershed was 7.2 inches (5,214 acre-feet) during 2004. Measured discharge at the Long Lake outlet is shown in Figure 7.4. In past years, runoff over the watershed, calculated through weekly readings, has ranged from 1.36 inches in 2000 to 14.54 inches in 2002. Average discharge from the Long Lake outlet over the entire year was 7.28 cfs.

33 Figure 7.4 2004 Discharge at the Long Lake Outlet

200

150

100 Flow (cfs) 50

0 4/1 4/29 5/27 6/24 7/22 8/19 9/16 10/14 2004 Date

Water Quality and In-Stream Loading Water quality grab samples were collected weekly from Classen Lake Creek, Long Lake Creek (2 sites), Painter Creek (4 sites), Six Mile Creek (2 sites), Gleason Lake Creek, Dutch Lake Creek, Langdon Lake Creek, Minnewashta Lake Creek, Christmas Lake Creek, and Stubbs Bay Inlet. The streams measured are the major tributaries to Lake Minnetonka.

The 2004 median TP and TSS concentrations in the upper watershed streams are similar to data (1986-1992) collected from minimally impacted streams in the North Central Hardwood Forest ecoregion (Table 7.1). Mean and maximum values for these parameters are much higher than the ecoregion means. This is caused by a few high-runoff events that contribute excessively high levels of sediment and nutrient to the streams. Conductivity and pH values were comparable to ecoregion values (Table 7.1). Flow-weighted mean concentrations and annual loading for upper watershed streams is presented in Appendix E.

Comparison of upper watershed streams to Minnehaha Creek (Table 6.1) yields interesting differences. In general, upper watershed streams had lower conductivity values. This is most likely related to the amount of road salt runoff reaching the streams. Upper watershed streams are not as closely linked hydrologically to the road networks compared to Minnehaha Creek; hence we see higher conductivity values in Minnehaha Creek when more chloride from road salt reaches the creek. The values for pH are similar between the two systems, but sediment and

34 phosphorus values are higher for the upper watershed streams. There may be several reasons for this; possible factors include the residual impact of the old wastewater treatment plants and the degree of new construction in the upper watershed.

Table 7.1 MPCA Ecoregion vs. Upper Watershed Streams 2004: Median, Mean, and Maximum Concentrations (Summer)

Upper Watershed Ecoregion Streams Median Mean Maximum Median Mean Maximum Conductivity (µmhos) 310 301 840 361 411 789 pH (S.U.) 8.1 8.2 8.9 7.72 7.76 9.55 Total Suspended Solids (mg/L) 10 9.1 29 10 16 245 Total Phosphorus (µg/L) 170 80 430 185 214 1000

Total Phosphorus Classen Lake Creek and the four Painter Creek sites have TP concentrations that exceed the MPCA’s Ecoregion guideline of 170 ppb (Figure 7.5). Figure 7.5 shows in-stream TP loading and flow-weighted mean TP concentrations for upper watershed streams, for streams on which more than one site is monitored the sites are placed in order from upstream to downstream, left to right. The highest TP loads to Lake Minnetonka are from the Painter-Creek sub-watershed.

Figure 7.5 In-stream TP Loading and Flow-Weighted Mean TP Concentration and for Uppe r Watershed Streams

8000 500 7000 450 400 6000 350 5000 300 4000 250 3000 200 2000 150 TP Load (lbs) 100 1000 50 0 0 Flow-Weighted TP (ppb)

Dutch Classen GleasonLangdon Christmas Painter CR 6 Painter CR 26 Painter Deb Dr Six Mile Hwy 7 Painter W Br RdSix Mile Lunsten Long LakeLong Outlet at Brown Rd Station

35 Through the Hydrodata monitoring program, watershed loads from 73% of the sub-watersheds tributary to Lake Minnetonka are measured. Measured TP loads to Lake Minnetonka from upper watershed streams have ranged from 684 lbs in 2000 to 18,482 lbs in 2002 (Figure 7.6).

Figure 7.6 1997-2004 TP Load to Lake Minnetonka from Gauged Sub-Watersheds

20000 17500 15000 12500 10000 7500

TP Load (lbs) 5000 2500 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

During 2004 the measured TP load to Lake Minnetonka was 8,409 lbs. Painter Creek comprised 51% of the load, but only 21% of the sub-watershed area. In past years, Painter Creek has comprised between 38 and 65% of the load to Lake Minnetonka. Six Mile Creek, which has comprised a major portion of the load in previous years, has comprised up to 34% of the load to Lake Minnetonka, accounted for only 24% of the load during 2004. The data show that the Classen Lake Creek sub-watershed delivers the highest areal TP load; the Painter Creek sub- watershed delivers the second highest areal TP load (Figure 7.7).

Total Suspended Solids Median TSS concentrations measured during 2004 in Christmas Lake Creek, Classen Creek, Langdon Lake Creek, Long Lake Creek, Painter Creek, and Six Mile Creek exceeded the MPCA’s Ecoregion guideline of 10 mg/L (Figure 7.8). The highest TSS load is from the Six Mile Creek sub-watershed, followed closely by loads in the Classen Creek and Painter Creek sub-watersheds.

36 Figure 7.7 Areal Watershed TP Loading

700 600 500 400 300

(lbs/sq mi) 200 Areal TP Load 100 0

Dutch Long Painter Classen Gleason Langdon Six Mile Christmas Station

Figure 7.8 In-stream TSS Loading and Flow-Weighted Mean TSS Concentration and for Upper Watershed Streams

500 140 450 120 400 350 100 300 80 250 200 60

150 40 TSS (ppm) Flow-Weighted

TSS Load (tons) 100 50 20 0 0

Dutch Classen GleasonLangdon Christmas Painter CR 6 Painter CR 26 Painter Deb Dr Six Mile Hwy 7 Painter W Br Rd Long LakeLong Outlet at Brown Rd Six Mile Lunsten Station

37 Areal watershed TSS loading is shown in Figure 7.9; the highest load comes from the Classen Creek sub-watershed.

Figure 7.9 Areal Watershed TSS Loading

200 150 100

(tons/sq mi) 50 Areal TSS Load 0

Dutch Long Painter Classen Gleason Langdon Six Mile Christmas Station

Chloride Chloride concentrations in the upper watershed streams are consistently below the MN 7050 chronic standard for chloride, 230 mg/L (Figure 7.10). Flow-weighted mean chloride concentrations in upper watershed streams during 2004 ranged from 25 mg/L in Six Mile Creek at Hwy 7 to 90 mg/L in Gleason Creek. Chloride loads from the upper watershed to Lake Minnetonka from gauged sub-watersheds have ranged from 90 to 2,640 tons in 2000 and 2004, respectively. In 2004 the highest Cl loads came from Painter Creek, Six Mile Creek, Long Creek, and Gleason Creek (Figure 7.10).

Areal watershed chloride loading is shown in Figure 7.11; the highest areal chloride loading came from the Painter Creek sub-watershed in 2004.

38 Figure 7.10 In-stream Chloride Loading and Flow-Weighted Mean Chloride Concentration and for Upper Watershed Streams

800 100 700 90 600 80 70 500 60 400 50 40

300 Cl (ppm) 30 200 Cl Load (tons) 20 Flow-Weighted 100 10 0 0

Dutch Classen GleasonLangdon Christmas Painter CR 6 Painter CR 26 Painter Deb Dr Six Mile Hwy 7 Painter W Br Rd Long LakeLong Outlet at Brown Rd Six Mile Lunsten Station

Figure 7.11 Areal Watershed Chloride Loading

600 500 400 300 200 (tons/sq mi)

Areal Cl Load 100 0

Dutch Long Painter Classen Gleason Langdon Six Mile Christmas Station

Bacteria E. coli concentrations are indicators of the potential for human illness contracted through full body contact with surface water. Eleven E. coli bacteria sampling events took place at the Painter Creek at West Branch Road and Six Mile Creek at Highway 7 stations in upper watershed streams from July 27th to October 7th in 2004. Grab samples were analyzed for E. coli at the City of Minneapolis Labs.

39 The MPCA has an acute standard of 1,260 CFU/100 mL for E. coli; this standard applies to individual grab samples. A violation occurs when greater than 10% of the samples exceed the standard. Six Mile Creek values ranged from 27 to 82 CFU/100 mL over the summer of 2004 (Figure 7.11). Painter Creek values ranged from 28 to 530 CFU/100 mL over the summer of 2004, except for a value of 2400 on September 14th (values dropped to 290 on September 23rd). This event also resulted in the excessively high values seen in Minnehaha Creek (Figure 6.4).

Figure 7.11 E. Coli Grab Samples in Six Mile and Painter Creeks, 2004

Six Mile Painter

3000 2500 2000 1500

(CFU/100 mL) 1000 500

E. coli 0 7/27 8/10 8/24 9/7 9/21 10/5 2004 Date

The MPCA also has a 30-day geometric mean standard of 126 CFU/100 mL. Application of this technique is portrayed in Figure 7.12. The data from 2004 indicates that the 30-day standard was violated at Painter Creek during late August and September. The spatial and temporal variation of E. coli sources should be examined more closely in 2005 to address this health problem.

Dissolved Oxygen Dissolved oxygen concentrations in the upper watershed are generally lower than those observed in Minnehaha Creek (Table 7.2). Mid to late summer DO measurements in upper watershed streams most frequently violate the MN 7050 Standard for DO of 5mg/L (no violations occurred in 2004 in Christmas Creek, Classen Creek, or the Long Lake Outlet).

Based on the criteria for inclusion on the MPCA’s 303 (d) list of impaired waters: if more than 10% of the readings collected within the past 10 years do not meet the standard for DO, the

40 Figure 7.12 Geometric Mean Fecal Coliform Data in Upper Watershed Streams, 2004

Six Mile Painter

600 500 400 300 200 (CFU/100 mL) 100

30-Day Geometric Mean 0 8/6 8/16 8/26 9/5 9/15 9/25 10/5

Table 7.2 Upper Watershed Stream Samples below 5mg/L DO

Hwy 6 Deb Dr. - W Brnch - - Dutch Gleason Langdon Stubbs Bay Minnewashta Long (Brown) Painter Cty 26 Painter Painter Six Mile Hwy 7 Painter Date Six Mile Lunsten 5/5/04 10.48 10.65 10.10 4.14 9.89 12.19 11.60 7.61 7.26 9.01 5/12/04 5.93 8.98 2.75 4.96 6.39 3.65 4.62 2.99 7.40 1.45 5/19/04 8.90 7.40 0.29 6.67 6.28 6.06 7.77 6.73 6.32 10.57 5/26/04 7.54 11.06 6.60 6.89 10.95 9.50 3.32 5.47 8.57 6.30 3.33 10.96 6/2/04 5.56 9.39 9.81 4.37 8.75 5.90 1.70 2.50 8.03 3.72 0.54 10.68 6/9/04 5.02 4.53 6.28 3.24 6.98 4.19 1.39 0.60 4.41 2.54 2.39 8.30 6/16/04 3.06 6.32 10.05 1.94 9.69 8.10 0.44 0.43 4.51 2.62 8.85 6/21/04 4.47 7.12 9.74 3.49 9.24 8.26 1.43 0.41 3.41 3.71 1.70 10.54 6/29/04 6.52 7.88 8.23 3.00 11.86 10.66 0.94 0.52 4.72 4.83 11.45 7/8/04 6.98 6.05 8.67 3.63 9.69 10.04 1.16 0.43 3.76 4.09 3.02 8.94 7/14/04 4.85 6.50 7.85 4.70 7.26 7.74 0.24 0.48 1.98 2.55 9.09 7/21/04 4.30 3.84 8.52 2.21 7.02 4.69 0.11 0.48 1.49 1.90 8.00 7/27/04 6.15 9.01 6.50 2.38 7.29 4.54 2.54 9.34 8/4/04 6.89 6.42 4.03 0.42 1.06 2.18 2.66 5.12 8/11/04 8.33 3.60 1.02 2.21 6.03 3.37 3.15 2.36 3.15 4.48 4.96 8/18/04 5.44 6.70 3.30 3.41 4.66 1.26 1.10 2.86 8/25/04 13.82 10.99 3.49 1.82 2.02 3.08 9/1/04 8.84 3.76 2.86 3.92 3.12 2.56 4.06 9/8/04 1.93 2.04 7.48 2.39 4.56 4.91 9/16/04 8.39 2.51 6.03 2.69 4.47 4.46 9/24/04 4.53 5.24 5.21 1.59 4.18 3.85 10/6/04 5.16 1.62 1.37 3.48

41 stream is included on the MPCA’s 303(d) list. The water body is considered partially supporting if 10 to 25% of readings do not meet the standard, and fully impaired if greater than 25% of samples are less than 5mg/L. A minimum of 10 samples is necessary to consider the stream assessed.

Low DO is widespread in upper watershed streams. The occurrence of low DO in upper watershed streams is not surprising based on several factors including hydrology, riparian wetlands, topography, and historic anthropogenic affects. Measured DO concentrations in these streams make it possible for the MPCA to include them on their 303(d) list. Given the magnitude of this problem, the MCWD water quality specialist will undertake a thorough evaluation of the factors contributing to these low levels in the near future.

2005 Recommendations for Upper Watershed Streams

• Assess spatial and temporal extent of DO violations in upper watershed streams through continuous monitoring. Priority should be given to Painter Creek. • Address the high nutrient loading to Lake Minnetonka from Painter Creek. Add a station at Painter Creek Drive, including an auto-sampler. • Add stations at the inlet of both Long Lake and Gleason Lake to develop a comprehensive nutrient budget for these waterbodies.

42 8. Groundwater Levels

Shallow Minneapolis Wells The MPRB monitors groundwater elevations in Minneapolis at three sets of well nests wells semi- monthly. The well nests are located on the west side of Lake Calhoun, the east side of Lake Calhoun, and the north end of Lake of the Isles. Data for these wells is presented in Figure 8.1.

Figure 8.1 Groundwater well elevations near the Minneapolis Chain of Lakes

864

862 GMP04 MPRB 860 Well W-A-03

858 GMP05 MPRB Well M-A-50 856 GMP06 MPRB Well E-A-114 854 GMP07 MPRB 852 Well N-B-30

850 GMP08 MPRB Well M-B-50 848 GMP09 MPRB Well S-B-96 846

GMP10 MPRB 844

Groundwater Elevation (ft, NGVD) Well W-C-30

842 GMP11 MPRB Well M-C-100 840

838

836 Jan-98 Jul-98 Jan-99 Jul-99 Jan-00 Jul-00 Jan-01 Jul-01 Jan-02 Jul-02 Jan-03 Jul-03 Jan-04 Date

Deep Aquifer Wells Groundwater elevations are recorded at several deep wells within the watershed. Data for these wells was recorded by: the Hennepin Conservation District (HCD), the Minnesota Department of Natural Resources (MDNR), the MPRB, and the United States Geological Survey (USGS). The Prairie du Chien-Jordan formations serve as major sources of municipal water in the western suburbs and as a major industrial water source in Minneapolis.

43 Many wells are monitored for a period of time, then monitoring ceases. Long-term monitoring wells in or near the MCWD are listed in Table 8.1. The remaining figures in this section depict the wells that have been monitored up to the present time (with the exception of well 27004, which ended in 1999).

Table 8.1 Long-term groundwater monitoring in and near the MCWD

DNR Well Years Number Location Monitored 10000 Chanhassen 1975-1986 10001 Christmas Lake 1952-1968 27004* Minneapolis 1970-1999 27009 Grays Bay 1972-1976 27010* Orono 1945-2004 27012* Golden Valley 1971-2004 27013 Plymouth 1972-1981 27015 Edina 1961-1989 27020 Minneapolis 1945-1973 27022 St. Louis Park 1961-1964 27023 Wayzata 1953-1966 27024 Wayzata 1945-1958 27025 Deephaven 1952-1954 27026 Galpin Lake 1953-1968 27027 Minnetrista 1954-1956 27030 Long Lake 1952-1966 27031 Long Lake 1945-1985 27032 Maple Plain 1954-1964 27036* Minneapolis 1979-2004 27037 Minnetonka 1979-1983 27038 Hopkins 1979-1995 27041* St. Louis Park 1980-2004 27043* Mound 1985-2004 27044* St. Bonifacius 1991-2004 *groundwater data presented in this report.

44 Figure 8.2 Groundwater well elevation for DNR Well Number 27036 (Minneapolis). Ground elevation: 830 feet AMSL. Bedrock aquifer

810 805 800 795 790 785 780 775 770 Well Elevation (feet) 765 Apr-79 Apr-81 Apr-83 Apr-85 Apr-87 Apr-89 Apr-91 Apr-93 Apr-95 Apr-97 Apr-99 Apr-01 Apr-03 Date

Figure 8.3 Groundwater well elevation for DNR Well Number 27004 (Minneapolis). Ground elevation: 850 feet AMSL. Bedrock aquifer

700 680 660 640 620 600 580

Well Elevation (feet) 560 540 520 Jul-70 Jul-72 Jul-74 Jul-76 Jul-78 Jul-80 Jul-82 Jul-84 Jul-86 Jul-88 Jul-90 Jul-92 Jul-94 Jul-96 Jul-98

Date

45 Figure 8.4 Groundwater well elevation for DNR Well Number 27012 (Golden Valley). Ground elevation: 890 feet AMSL. Bedrock aquifer

860 858 856 854 852 850 848 846 Well Elevation (feet) 844 Feb-71 Feb-74 Feb-77 Feb-80 Feb-83 Feb-86 Feb-89 Feb-92 Feb-95 Feb-98 Feb-01 Feb-04 Date

Figure 8.5 Groundwater well elevation for DNR Well Number 27041 (St. Louis Park). Ground elevation: 917 feet AMSL. Bedrock aquifer

800 790 780 770 760 750 Well Elevation (feet) 740 Apr-80 Apr-82 Apr-84 Apr-86 Apr-88 Apr-90 Apr-92 Apr-94 Apr-96 Apr-98 Apr-00 Apr-02 Apr-04 Date

Figure 8.6 Groundwater well elevation for DNR Well Number 27044 (St. Bonifacius). Ground elevation: 950 feet AMSL. Bedrock aquifer

900 890 880 870 860

Well Elevation (feet) 850 Sep-91 Sep-93 Sep-95 Sep-97 Sep-99 Sep-01 Sep-03 Date

Figure 8.7 Groundwater well elevation for DNR Well Number 27043 (Mound). Ground elevation: 957 feet AMSL. Bedrock aquifer

900 895 890 885 880

Well Elevation (feet) 875 Nov-85 Nov-87 Nov-89 Nov-91 Nov-93 Nov-95 Nov-97 Nov-99 Nov-01 Nov-03 Date

47 Figure 8.8 Groundwater well elevation for DNR Well Number 27010 (Orono). Ground elevation: 931 feet AMSL. Bedrock aquifer

920 910 900 890 880 870

Well Elevation (feet) 860 Mar-45 Mar-50 Mar-55 Mar-60 Mar-65 Mar-70 Mar-75 Mar-80 Mar-85 Mar-90 Mar-95 Mar-00 Date

48 9. Literature Cited

Heiskary, S.A., and C. B. Wilson, 1990. Minnesota Lake Water Quality Assessment Report, 2nd edition. Minnesota Pollution Control Agency.

McCollor and Heiskary. 1993. Selected Water Quality Characteristics of Minimally Impacted Streams from Minnesota’s Seven Ecoregions. Minnesota Pollution Control Agency Water Quality Division.

Minnehaha Creek Watershed District, 2004. Minnehaha Creek Stream Assessment.

Minnehaha Creek Watershed District, December 2003. Fluvial Geomorphic Assessment Report Prepared by Wenck Associates, Inc. and Interfluv.

Minnehaha Creek Watershed District, July 2003. MCWD Pathogen Report Prepared by Wenck Associates, Inc.

Minnehaha Creek Watershed District, May 2003. 2003 Water Quality Monitoring Program. Prepared by Wenck Associates, Inc.

Minnehaha Creek Watershed District, 1999. Headwaters Control Structure Management Policy and Operating Procedures, March 1, 2000 - March 1, 2001.

Minnehaha Creek Watershed District, 1997. Water Resources Management Plan Prepared by Wenck Associates, Inc.

Minnesota Pollution Control Agency, January 2004. Guidance Manual for Assessing the Quality of Minnesota Surface Waters for the Determination of Impairment, Prepared by the Minnesota Pollution Control Agency.

Minnesota Pollution Control Agency, December 2003. Draft MPCA 2004 303(d) List of Impaired Waters, Prepared by the Minnesota Pollution Control Agency.

United States Department of Agriculture, Soil Conservation Service. Hydrology Guide for Minnesota.

50 10. Proposed Minnesota Rules Changes

The Minnesota Pollution Control Agency (MPCA) is currently circulating preliminary draft amendments (November 1, 2004) to Minnesota Rules Chapter 7050. Areas of interest include the addition of eutrophication standards for lakes, expanded application of the 1 mg/L phosphorus (P) effluent limit, an updated mercury standard, an update of human health-based standards and protection of children, the addition of standards for acetochlor and metolachlor, changing the bacteriological standard from fecal coliform to E. Coli, changing the classification for industrial use protection for most waters from Class 3B to 3C, proposing several new limited resource value waters, and other miscellaneous changes. It is anticipated that a final will come into effect in October 2005. The MPCA has developed a website that gives further details http://www.pca.state.mn.us/water/standards/rulechange.html. Although several of these changes may apply to MCWD activities, the lake eutrophication standards and E. coli standard are directly relevant to the Hydrodata Program at the MCWD.

Eutrophication Standards for Lakes The MPCA is proposing numeric standards for P and two indicators that measure the response of lakes to excess P. The two indicators are chlorophyll a and Secchi disk transparency. Proposed lake standards will be different for the four major ecoregions in the state. The MCWD lies entirely in the North Central Hardwood Forest ecoregion. The MPCA is also proposing separate standards for trout lakes and lakes less than 15 feet deep (“shallow lakes”). In the proposed rule changes, a shallow lake is defined as “a lake with a maximum depth of 15 feet or less, or with 80 percent or more of the lake area shallow enough to support emergent and submerged rooted aquatic plants (the littoral zone). Shallow lakes typically do not thermally stratify during the summer. The quality of shallow lakes will permit the propagation and maintenance of a healthy indigenous plant community, and they will be suitable for boating and other forms of aquatic recreation for which they may be usable. Shallow lakes are generally not wetlands, which are defined in part 7050.0186. Shallow lakes will be differentiated from lakes and reservoirs for purposes of this chapter on a case-by-case basis”.

51 Even within an ecoregion lakes vary greatly in size, depth, natural levels of nutrients, and many other characteristics. For this reason the proposed numeric standards will be supplemented by language in the rule that: 1) protects lakes with water quality better than standards from being degraded, and 2) recognizes that some lakes will not meet standards due to “natural causes”. In the proposed rule changes, natural causes are defined as “the multiplicity of factors in nature that determine the physical, chemical or biological conditions that would exist in a water body in the absence of measurable impacts from human activity or influence”.

The MPCA wants to be very clear that the adoption of eutrophication standards does not mean that it is acceptable to degrade a high quality lake “down to” the level of the standards. Once adopted, implementation of the eutrophication standards will be important if they are to be effective in protecting lakes. The most effective way to implement the new standards, in the MPCA’s view, is through a combination of state and local governmental regulatory programs that reduce nutrient loading to lakes; and by their use as an educational tool. Adopted numeric standards, as opposed to MPCA guidance which currently exists, will have greater legal authority, greater visibility and accessibility because they will be in legally adopted rules. This will enhance their use by other state agencies, consultants, local governments and lake associations. For example, having the standards in rules can help county commissioners and zoning officers make decisions which will better protect lake resources. Also, the standards can serve as a benchmark to help lake associations assess the condition of “their” lake; and they can be used to reinforce educational efforts to help lake associations, lakeshore property owners and individual lake users make good decisions to protect lakes.

The MPCA is finding that rivers and wetlands can be negatively impacted by excess nutrients as well. At this time the MPCA is proposing eutrophication standards only for lakes but standards for rivers and wetlands may be proposed in the future. The U.S. Environmental Protection Agency (EPA) is requiring states to adopt nutrient standards for lakes and to gather data on the impacts of nutrients on rivers and wetlands.

52 What Does this Mean for the MCWD? All lakes in the MCWD are classified as Class 2B waterbodies in the North Central Hardwood Forest ecoregion, so there are two sets of standards we need to address: shallow lakes and deeper lakes. Mean summer values are to be calculated using data collected between June 1st and September 30th each year. A lake is considered out of compliance when the following occurs: 1) the TP standard is exceeded and 2) either the chlorophyll a or the Secchi disk transparency standards are exceeded (Table 9.1).

Table 10.1 Proposed Nutrient Criteria for Minnesota Lakes

TP Chlorophyll a Secchi Lakes 40 ppb 13 ppb 1.5 m Shallow Lakes 60 ppb 20 ppb 1.0 m

The only lake recently monitored by the MCWD that fits the shallow lake definition based on the 15 foot depth definition is Libbs Lake (maximum depth 8 feet); recent data has shown this lake to be in compliance with the proposed eutrophication standards. Other lakes may fall into the shallow lakes category based on the “80% littoral zone” basis (e.g., Gleason Lake); lakes in the MCWD will be evaluated in 2005 to determine if they fit into this definition. The remaining monitored lakes in the MCWD fall into the “Lakes” category above. Their long-term trends pertaining to the proposed eutrophication standards are presented in Appendices F, G, and H.

Change the Bacteriological Standard from Fecal Coliform to E. Coli Water contaminated with bacteria from human or animal fecal material can cause illness in humans if ingested. Bacteriological standards are designed to protect swimmers from getting sick that might ingest small quantities of water. The EPA is urging all states to update their bacteriological standards. The MPCA is proposing to replace the current fecal coliform standard with an E. coli standard, based on an EPA criterion. MPCA’s goal is to adopt the E. coli standard with as little disruption as possible to ongoing programs, specifically to: keep the protection level for swimmers the same, keep the number of waters considered impaired for swimming about the same, retain current assessment methods for determination of impairment, and minimize impact

53 on ongoing bacteriological total maximum daily load studies, and NOT impact the BEACH program on Lake Superior beaches.

The MPCA is recommending the E. coli standards shown in the table below. The current fecal coliform standard is included for comparison.

Table 10.2 Proposed E. coli Standards Shown with the Current Fecal Coliform Standard for Class 2 and Class 7 Waters

*126 E. coli cfu per 100 ml is the 30-day geometric mean EPA criterion (1986).

The analysis of paired E. coli and fecal coliform measurements from Minnesota rivers suggests that the recommended E. coli 30-day geometric mean standard may be slightly more stringent than the current standard. However, because of the variability in bacteriological data, the analysis does not support proposing a geometric mean standard different from the EPA criterion of 126 colony forming units (cfu) per 100 ml.

EPA allows some flexibility to states to determine the appropriate maximum standard. The MPCA is proposing a maximum standard of 1260 cfu/100 ml. Again, the analysis of the paired fecal coliform/E. coli data indicates this value may be slightly more stringent than the current maximum fecal coliform standard of 2000 cfu/100 ml, but well within the variability of the data. The bacteriological standard applicable to limited resource value (Class 7) waters is designed to protect forms of water recreation where emersion in the water is unlikely, such as wading and

54 boating. The MPCA proposes to replace the current Class 7 standard with an E. coli standard that provides the same protection (see table above).

It is important to emphasize that the standards being proposed for change are the ambient standards applicable to lakes, rivers and streams in Minnesota. The current fecal coliform effluent limit of 200 fecal coliform cfu/100 ml as a monthly mean is not proposed for change (Minn. R. 7050.0211).

What Does this Mean for the MCWD? The MCWD switched from the fecal coliform technique to the E. coli technique in summer 2003 at the urging of the MPCA. The Three Rivers Parks District and the Minneapolis Park and Recreation Board currently monitor their major public beaches for E. coli, while the MCWD currently monitor several stream sites for E. coli. Long-term trends pertaining to the proposed standards are presented in the sections “Minnehaha Creek” and “Upper Watershed Streams”.

55 11. Initiatives in 2005

Expanded Monitoring The HHPLS Study (2003) recommended that 1) additional water quality monitoring stations should be established for minor watersheds outletting to Lake Minnetonka. In particular, monitoring should be expanded to some of the minor watersheds that encompass lake/stream systems such as Classen Creek. 2) The District should incorporate into its monitoring program the collection of flow data in Minnehaha Creek that would better define the relationship of the creek to groundwater. 3) The identification of runoff monitoring sites should become an integral part of the District’s overall monitoring program, with watershed-wide coverage occurring as a result of rotating stations based on priority loading and representative site selection. Evaluation of the success of these stations in filling the need should occur after at least two years of monitoring is complete. 4) The flow modeling and groundwater assessment both noted the importance of the role of infiltration in the behavior of Minnehaha Creek, but uncertainty remains over how and where this occurs. It was found that the creek runs dry in certain areas, and that a loss or gain of 5 to 10 cfs could take place along the creek. This could become a very important factor in considering the role of baseflow for ecological integrity. The collection of better data in specific locations of suspected creek infiltration or exfiltration would be very beneficial to overall understanding of creek behavior. Figure 11.1 An auto-sampler and a sampling site (solar-powered) on Painter Creek

56 In 2005 the number of stream monitoring sites will be expanded to include 3 new sites on Six Mile Creek, an additional site on Minnehaha Creek, as well as several other small tributaries to Lake Minnetonka. Additional pressure transducers will deployed in select upper watershed streams and Minnehaha Creek, as will an additional auto-sampler. It is anticipated that a suite of auto-samplers will be rotated from Painter Creek to other major streams in the future (e.g., Six Mile, Long, Gleason). Precipitation monitoring will also be expanded with the purchase of four new tipping-bucket precipitation collectors. These devices will fill in gaps in our monitoring effort, allowing us to further refine the H&H model.

Alum Effectiveness Index Since the 1970s, aluminum sulfate (a.k.a. alum) has been used around the United States as a lake management tool to improve lake water quality. It has been demonstrated that the application of alum can inactivate phosphate anions in lake sediments. Because of this action, phosphorus (P) release from lake sediments can be curtailed with the resulting potential for lake water clarity to be improved. Use of alum can be used to improve water quality in a lake has been used in Minnesota since the 1980s and used in MCWD lakes since the mid 1990s. Several lakes within the MCWD have responded in a positive way with Lake Calhoun being a good example. However, other lakes treated with alum have had minimal or short-term improvements with Long Lake being an example. What are the root factors for these results?

It is well known that there are a variety of limitations that effect alum effectiveness but there has never been a systematic evaluation tool produced that can predict the potential effectiveness of an alum treatment. Because the use of alum is expensive and its effectiveness is variable, it would be advantageous for lake managers to have a firm idea of the potential for an alum treatment to improve water quality in a given lake.

The MCWD has contracted with Blue Water Science (St. Paul, MN) to develop an alum effectiveness index. To do this, a list of factors that influence the effectiveness of an alum treatment will be compiled and reviewed and ranked. Based on these findings we will then prepare an alum effectiveness index that will aid in determining the potential success of an alum treatment.

57 Figure 11.2 A specialized boat designed for injecting alum into lake water

For the purposes of this project, a successful alum project is defined as a one-time alum lake sediment treatment that results in improved lake transparency, through the summer growing season for a minimum of five years. Improved transparency is defined as an increase in transparency of more than one standard deviation based on the pre-treatment data set (this definition could be modified based on lake manager input).

Based on case studies from both the peer reviewed and the gray literature, a list of factors that influence alum effectiveness will be evaluated for lakes that have had alum applications in the past. Some factors that have been shown to influence the effectiveness of alum treatments are listed in the table below. Additional parameters could be added, but the most important variables appear to be watershed loading, water column pH, aquatic plants, and fish.

To evaluate the effectiveness of an alum application, data will be collected from alum projects that have been conducted in Minnesota and Wisconsin since the 1980s. A minimum of 20 lake projects will be evaluated using approximately 16 parameters for each lake. The degree of lake improvement will then be correlated with the parameters that have been monitored. From these

58 data, an index will be developed and analyzed for its ability to rate the potential effectiveness of an alum treatment on a quantitative scale from low to high.

Table 11.1 Factors Effecting the Effectiveness of Alum on Lake Rehabilitation Factors Influencing Alum Effectiveness Potential Influence on Alum Effectiveness Watershed loading high Lake retention time low Lake stratification (dimictic or polymictic) moderate Lake temperature/oxygen profiles moderate Lake bathymetry (% littoral, shallow or deep lake) moderate Lake sediment chemistry Fe:P ratio moderate Redox moderate PH moderate organic matter moderate Lake water column chemistry summer phosphorus concentration high Alkalinity moderate pH (including the influence of algae) high Bioturbation by invertebrates unknown Aquatic plants (influence of curlyleaf pondweed dieback) high Fish (influence of fish excretion and uprooting plants on phosphorus high levels. Also disrupts alum floc layer.)

For each factor included in the Index, a preliminary multiplier assigns a relative weight to each contributing factor while a rating variable, ranging from 1 to 20, is assigned to each factor depending on the conditions found for the lake in question. The rating system will be determined based on the data set used to build the index.

To run the Index, the multiplier is first multiplied by the rating score for each factor to get a score for each factor. Note that the primary factors are weighted more than the secondary factors. Next, the scores for the factors within the primary and secondary factor groups are totaled and averaged. Finally, the primary score is added to the secondary score to determine a combined average score. The lower the score, the better the probability of a successful alum treatment. At this time, early in the process, the breakpoint that would separate a good candidate lake from a poor candidate lake has been set at 100.

59 The end product of the project will be an Alum Effectiveness Index, which is intended to be an easy-to-use tool to help MCWD managers gage the ecological and economic value of a potential lake alum sediment treatment. A technical document that supports the criteria used in the Alum Effectiveness Index will also be provided. The index will be prepared, in spreadsheet form, so lake managers or others could plug in lake and watershed data for a candidate lake to get a numerical result that relates to the potential for a successful alum treatment. A draft report will be completed by March 2005 for review and comment by the MCWD; a final report will be prepared within 21 days of receiving the draft report comments. Dr. Hatch (MCWD Water Quality Specialist) is coordinating this project; he has also enlisted the free help of a University of Minnesota graduate student who is working on alum-treated lakes in Eagan, MN. A peer- reviewed publication is also anticipated.

Stubbs Bay Algal Management In 2005 the MCWD will rent five Solarbee lake water circulators to assess whether nuisance algal growth can be controlled in Stubbs Bay. The Solarbee is solar-powered and draws water up from a set depth, spreading out the water over the lake surface. The units are efficient enough to utilize energy collected during daylight hours to operate all night. The theory behind their use is that they take away the advantage blue-green algae have with regards to buoyancy regulation: they may not be able to out-compete other algae very well, hence algal levels may be reduced.

MCWD staff will develop a water quality sampling strategy for 2005 in Stubbs Bay to determine whether Solarbee units perform effectively enough to justify purchase and/or use elsewhere in the MCWD. Realize that if these units perform adequately, they are not a permanent solution. Significant reduction of external nutrient loads (from the watershed) is of crucial importance with respect to lake rehabilitation. Then internal loading should be addressed. The Solarbees may create short-term conditions in which algal nuisance blooms are diminished, allowing recreational users of Stubbs Bay to enjoy better water quality conditions right away.

60 Figure 11.3 A Solarbee recirculation unit. Note the three floats, solar panels, and uplifted water beneath the unit

Diatom-Inferred Pre-Development Lake TP Concentrations The MPCA recently used diatom fossils preserved in the sediments of 79 lakes across Minnesota to reconstruct historical total phosphorus (TP) concentrations, which can be found at http://www.pca.state.mn.us/publications/environmentalbulletin/. Prior to these studies, people could only speculate about eutrophication trends since European settlement, including the nature of pre-settlement conditions and the magnitude of change. Reconstruction was accomplished using diatoms in sediment cores by first developing a calibrated mathematical model between water chemistry and diatom species that have grown over the past few years, and then calculating what the water quality must have been in the past by applying the model to diatoms found deep in sediment cores from the study lakes. Hence we are able to get a reasonably accurate TP concentration value for lakes in Minnesota as they were prior to the arrival of European settlers in the mid-1800s. The final 79 Minnesota lakes training set has already been used by the MPCA for the development of nutrient criteria in Minnesota lakes.

The MCWD will contract with the researchers who worked with the MPCA on the aforementioned study. All work will be completed under the direction of Drs. Mark Edlund and Daniel Engstrom at the St. Croix Watershed Research Station. Dr. Edlund is an internationally-

61 recognized expert in diatom taxonomy and paleoecology, and Dr. Engstrom is Director of the SCWRS.

Figure 11.4 Drs. Edlund and Engstrom taking a sample core. Fossil diatom microscope pictures

The primary aims of this project are to perform top-bottom reconstructions of historical total phosphorus annually on 10 sediment cores collected from lakes in the MCWD and to append diatom assemblages from surficial sediments and modern environmental data onto the existing Minnesota training set to increase its applicability and predictive power in the MCWD. From these analyses, the MCWD will be able to determine the background variability and natural levels of phosphorus in watershed lakes from before European settlement. Modern assemblages and data appended onto the existing MN training set will improve performance of the model in MCWD lakes and/or permit subsampling of the training set to specifically address MCWD lakes.

62 Figure 11.5 Total phosphorus concentrations according to ecoregion. “Pre-E” represents the values determined by the diatom-inferred TP technique, while “Modern” represents in-lake water measurements from recent monitoring program data

MCWD staff has chosen the 10 lakes for this study based on two comparisons: “unimpaired” vs. “impaired” Lake Minnetonka bays and “shallow” vs. “deep” upper watershed lakes. Comparing lakes in this manner will allow us to draw some interesting conclusions. For example, did the Lake Minnetonka bays above have similar pre-development water quality? Did upper watershed lakes, which have similar water quality today, have similar water quality prior to development?

MCWD staff will coordinate water quality collection on five dates per annum during the ice-free season. Mean TP, TN, chlorophyll a, chloride, pH, sulfate, alkalinity (or ANC), dissolved silicate, color, and physical and basin characteristics should be determined from these monitoring data. On one of these trips a surface sediment sample for training set development will be collected using a short gravity corer.

63 Table 11.2 Lakes and Lake Minnetonka Bays Proposed for the 2005 Diatom P Study

Maximum TP CHLA SECC Depth Range Range Range Lake/Bay Treatment Range (ft) (ppb) (ppb) (ft) St. Albans Bay unimpaired 29-44 22-23 4-6 2.9-3.7 Spring Park Bay unimpaired Carsons Bay unimpaired

Stubbs Bay impaired 26-37 59-107 27-43 1.1-1.4 Jennings Bay impaired Halsted Bay impaired

Parley Lake shallow 16-18 81-83 38-58 1.0-1.2 Gleason Lake shallow

Wasserman Lake deep 38-41 77-81 42-63 0.6-1.0 Langdon Lake deep

Long cores (2 meters +) for top-bottom reconstructions will be taken in April or May 2005 from 10 lakes determined by MCWD personnel. The top 20-30 cm of long cores will be sectioned in the field in 2-cm increments until the core reaches a stiff consistency. The remaining core section will be capped and transported to either SCWRS or directly to The Limnological Research Center (U of MN) for cold storage prior to magnetics analysis. This process allows us to measure ferromagnetic particles without damaging the sediment core. We can identify the settlement horizon, which will be characterized by an increase in the magnetic signature due to increased erosion following initial land clearance in the region (representing c. 1850-1880). We then can take sediments from below that point and be confident that we have sediments that existed in the lake bottom prior to European settler arrival. Dates will be extrapolated to approximately 1800AD and 1750AD for recovery of two presettlement sample intervals.

For diatom analysis, a small sample will be taken of the 0-1 cm interval and two downcore depths roughly corresponding to 1800AD and 1750AD. Diatom species relative abundance will be calculated for surface sediments and the top sample and two bottom samples in each long core. Using harmonized taxonomy, the counts from the MCWD lakes' surface sediments will be appended onto the 79 Minnesota lake data set and reanalyzed as a pooled data set. Canonical correspondence analysis (CCA), a multivariate ordination technique for direct gradient analysis

64 (ter Braak & Prentice, 1988), will be used to determine the relationship between water quality variables and diatom distributions on the combined training set.

Water chemistry will be completed during the ice-free season (May-September 2005); surface sediment recovery would be done in conjunction with water quality sampling. Sediment core collection will likely take place in April or May 2005. Magnetics, core processing and subsampling, and diatom preparation will be completed in June 2005. Diatom analysis will take place between July and December 2005. Data analysis and reconstructions will be done during January-February 2006 and an annual project report completed by April 2006. The annual report will document project objectives and design, methods, results including combined training set results (if applicable) from canonincal correspondence analysis, taxonomic harmonization, and downcore nutrient reconstructions. Interim reports will be generated in conjunction with invoicing for research tasks completed.

A strong education component will also be developed as part of this project. A new MCWD education and communications staff member will be coming aboard in 2005; an education plan will be assembled soon afterwards.

Minnehaha Creek Caffeine Study Weekly monitoring of seven sites along Minnehaha Creek has indicated a large increase of E. coli bacterial concentrations from Lake Minnetonka to Minnehaha Falls. There is also evidence of these concentrations decreasing due to dilution in both Meadowbrook Lake and Lake Hiawatha. E. coli concentrations begin to rise again after passing through these lakes. During a September 2004 rainfall runoff event, concentrations increased to levels that approach those seen for sewage. Due to the extensive number of stormwater outfalls along Minnehaha Creek, it was not possible to determine the source of these high numbers of E. coli. Possible sources include i) improper sanitary sewer connections with the stormwater sewer, ii) sanitary sewer leaks, iii) surface sources of human/animal fecal matter draining into the stormwater sewer system.

The first step to determine sources of this problem is to narrow down the three source possibilities. Caffeine has been used as a tracer to determine the source of sewer inputs in

65 several studies across the nation; the source is from human urine originating in the sanitary sewer system. If caffeine is detected in a stream water sample, it suggests that factor (iii) above can be eliminated for the creek stretch immediately upstream from the sampling site. It also suggests that factors (i) and (ii) may be occurring. If caffeine is not detected in a stream water sample, it would suggest that any fecal matter (i.e., E. coli) entering the stream is originating from surface sources, supporting factor (iii). In this case, any E. coli entering the stream immediately above the sampling point would most likely be originating from animal feces (e.g., dogs, geese).

Figure 11.6 A microscope photograph of E. coli; a caffeine-dispensing device.

In 2005, District staff will expand Minnehaha Creek sampling to total 16 sites for four different stream conditions: a spring snowmelt runoff event, a spring rainfall runoff event, a summer low flow condition, and a summer rain event. For these four sampling surveys these sites will be sampled for both E. coli and caffeine. The results of this study will allow us to narrow down the locations of fecal inputs into Minnehaha Creek. Local municipalities will be informed of the results, allowing them to track down and address the source of contamination. Costs for this study have been incorporated into the 2005 Hydrodata Program budget; the Minneapolis Department of Health has been contacted for E. coli analyses, and the Minnesota Department of Health can conduct the caffeine analyses.

66 12. Long-Term Initiatives

Lake Internal Phosphorus Loading Assessment and a Lake-Wide Lake Minnetonka Phosphorus Model (recommended by the HHPLS Report: The District should begin a long-term effort to integrate data collection on watershed loading, internal Lake Minnetonka loading and in-lake circulation for development of a whole-lake model A comprehensive lake wide model should be completed for Lake Minnetonka.)

Understanding the sources, sinks, and cycling rates of phosphorus in lakes is crucial to understanding where our management efforts should take place. Our regular water quality monitoring of lakes and streams in the District provides us with important data, but internal loading (most lakes) and intra-lake circulation (for Lake Minnetonka) data needs have not been adequately addressed.

Some attention is being paid to internal load reduction on Jennings Bay through the Jennings Bay Feasibility Study funded by the District for 2003. However, the relationship of Jennings Bay internal load dynamics to the other bays has not been determined, and a need continues for additional data from other locations around the lake. For the other monitored lakes in the District, collection of data to determine the contribution of internal P loading to overall lake P budgets is also lacking.

Recommendation: During the coming few years, lake bottom sediments will be sampled and laboratory analyses will be conducted (e.g., P content, organic matter content, sediment density). This information, along with ongoing monitoring of P and DO in our lakes, will allow us to effectively assess the contribution of internal P loading to our lakes’ P cycles. Analytical costs will be incorporated into the 2006 Hydrodata Program budget.

There are several bays (for example Crystal, Wayzata, and Spring Park) in Lake Minnetonka that are of exceptional quality. The preservation of these bays was identified as a high priority by many study participants. Similarly, there are at least two bays (Jennings and Halsteds) with very poor water quality. The range of water quality conditions within bays of Lake Minnetonka is

67 governed by a number of different factors, including basin morphometry, watershed input, internal loading, and intra-lake circulation. A lake-wide model would take the guesswork out of defining the true source of phosphorus and help to better target Lake Minnetonka Management efforts. The need for intra-lake circulation knowledge in Lake Minnetonka is paramount, since the movement of water from the upper portion of the lake to the outlet at Gray’s Bay seems to be a key factor in lake quality determination. For bays experiencing poor water quality (e.g., Jennings, Halsteds), water quality inputs including tributaries and direct runoff from the contributing watershed have been modeled. Outputs out of these bays, however, are poorly understood. The BATHTUB computer model has been constructed for Lake Minnetonka by Bruce Wilson (MPCA). Intra-lake circulation data and internal P load data are the missing elements to the completion of the Lake Minnetonka Phosphorus Model.

Recommendation: The Saint Anthony Falls Laboratory (University of Minnesota) is uniquely qualified to assist in the assessment of intra-lake circulation in Lake Minnetonka. Respected researchers such as Heinz Stefan and Miki Hondzo have years of experience modeling water movements in lakes, reservoirs, and rivers. District staff will meet with these researchers in early 2005 to determine monitoring and equipment needs to determine intra-lake circulation patterns and incorporate this information into the BATHTUB model. A Scope of Work report will be generated and presented to the Board of Managers soon afterward. It is optimistic to expect such a project to commence in 2005; most likely funding will be requested for 2006.

Use of Remote Sensing to Assess Water Quality Many of the lakes and ponds in the District presently lack water quality goals; regular water quality monitoring would be cost-prohibitive. A promising approach to address this need is the use of remote sensing (satellite or airplane) data. Such data may consist of photography and/or sensing of various radiation wavelengths. Models are developed using this information in conjunction with data collected on the Earth surface (a process known as ground truthing).

First, the University of Minnesota and the MPCA have developed techniques to estimate water transparency in all Minnesota lakes that are greater than 20 acres in size. Images can be purchased (http://resac.gis.umn.edu/water/regional_water_clarity/regional_water_clarity.htm)

68 relatively inexpensively each year and processed for water clarity information. Second, a Lake Minnetonka QuickBird image has been used by UMN researchers to do some aquatic plant research on Christmas, Auburn, and Schutz Lakes. This research could be expanded to the entire image. In that research they were able to distinguish eurasian water milfoil from other submersed plant due to its growing characteristics. Third, there will soon be a new assessment of impervious surface available for the District. This GIS layer will be of great use for modeling efforts.

Recommendation: District staff will present a workshop to the Board of Managers in 2005 to determine which (if any) of these techniques would be of interest with respect to District watershed management objectives. UMN researchers will be invited to speak.

Development of a Watershed Report Card Currently the MCWD issues “report card grades” for the nearly fifty monitored lakes and bays, focusing on water clarity, chlorophyll a and total phosphorus concentrations. There have been efforts in other watershed districts to generate much broader assessments of their watersheds. The Humber River Watershed (http://www.trca.on.ca/water_protection/strategies/humber/) is one example, flowing through Toronto, Canada.

The Humber Watershed Alliance produced A Report Card on the Health of the Humber River Watershed, July 2000. The report card assesses the current health of the watershed using 28 indicators: significant landforms, forest cover, wetlands, vegetation communities, wildlife, groundwater quantity, groundwater quality, stormwater management, bacteria, conventional pollutants, heavy metals and organic contaminants, river flow, benthic invertebrates, fish communities, riparian vegetation, air quality, heritage resources, heritage events, public greenspace, outdoor recreation, trails, agricultural land, sustainable use of resources, community stewardship, outdoor environmental education, aesthetics, business stewardship, and municipal stewardship. Overall, the Humber River watershed was given a "C" or fair grade. This is an average of the grades given to all 28 indicators. There is a wide range of health, from "A" for outdoor recreation - to "F" for stormwater management. Grades also differ depending on which part of the watershed is being evaluated. The report card set targets for 5, 15 and 25 years from now, and it proposes how to get there.

This broader approach would give a much more comprehensive view of resources in the District. It represents a holistic integration of plants, animals, land, air, water, and people that really touches on how our resources and our interactions with them affect our quality of life.

Recommendation: District staff will present a workshop to the Board of Managers in 2005 to determine which of these 28 indicators above (if any) and/or others would be of interest with respect to District watershed management objectives.

Figure 12.1 The Humber River Watershed

70 Expansion of Biotic Assessment Water quality means many things to many people. In lakes, water quality has often been defined by parameters such as water clarity, chlorophyll a, and nutrients. While such measures have been and will continue to be useful, other factors affect the quality of the recreational user of our waterbodies. Aquatic macrophytes (especially nuisance invaders like Eurasian Water Milfoil and Curly-Leaf Pondweed), fisheries (especially nuisance species like the common carp), and stream macroinvertebrates are all integral parts of aquatic ecosystems.

Recommendation: A significant amount of monitoring and research has been conducted on these and other relevant aquatic biota. District staff will assemble the most recent information and data for this monitoring and research.

71 Appendix A

Lake Report Cards

Waterbody 1998 1999 2000 2001 2002 2003 2004 Black ------C+ Browns A- B+ ------Carman ------B+ Carsons ------A Cooks B B- B+ B+ C+ B B- Crystal B+ C+ A- B+ C+ A- B+ East Upper ------B+ Forest Lake C- C- C- D+ D+ D C Gideons ------A Grays ------A Halsted D+ C- D+ C- C- D+ C- Harrisons C- C- C+ C- C D+ C Jennings D+ D+ C- D+ C- D+ C- Lafayette A- A------Libbs ------B- B+ Lower Lake North A A------Lower Lake South A A- A- A A A A Maxwell B- C+ B C+ C+ C+ B North Arm B+ C+ B C+ B- B- B Peavey Lake ------C+ C+ C+ C C Priests ------C- Smithtown ------B+ Spring Park A- A- B+ A- B+ A A- St. Albans A B+ A- B+ A- A A Stubbs C C- C- C C- C- C Tanager Lake ------D- D+ C- D D- Wayzata A A- A- A A- A A West Arm C- C C+ D+ C- D+ C West Upper B+ B B+ B+ B+ B+ B Christmas A A A A A A A- Dutch ------C+ D+ C D D+ Gleason C- C- C- D+ C- D C- Langdon D- D F D- D+ F F Long C+ C C- D+ C C- C- Minnewashta A- A- B+ B+ B+ A B+ Parley ------D D+ D+ D --- Pierson ------B A- --- Schutz ------B C+ C Steiger ------C+ --- C+ C C+ Stone ------C+ --- C --- C+ Tamarack ------C+ C- Virginia ------C C --- Wasserman ------D D C C- D+ West Auburn ------B+ --- B- C- B- Zumbra ------A- --- B+ B B+ Brownie C+ B- B ------C+ Calhoun B+ A A B+ A A A Cedar A A A- B+ B+ B+ A- Diamond ------C- D Grass ------F C+ Harriet A- B+ B+ A A A A Hiawatha C+ C C- C+ C+ C+ C+ Isles C+ C+ B- C C C- C Nokomis C C C C C C+ D+ Powderhorn ------D+ Twin (SLP) ------D+ D D Windsor ------D-

1 Appendix A

Black Lake (Lake Minnetonka) 2004 Grade: C+ Surface Area: 25 acres Total Phosphorus (TP): 40 ppb (57 TSIP) Mean Depth: Soluble Reactive P (SRP): 1 ppb Maximum Depth: 25 feet Chlorophyll a: 10 ppb (53 TSIC) Secchi Depth: 1.7 m (52 TSIS) Overall TSI: 54

2004 Lake Minnetonka Elevation and Gray's Bay Dam Discharge 350 930.5 discharge 300 930 lake level 250 929.5

200 929

150 928.5 Elevation (feet) 100 928 Discharge (cfs) 50 927.5

0 927

6/8 7/6 8/3 4/13 4/27 5/11 5/25 6/22 7/20Date 8/17 8/31 9/14 9/28 10/12

Lake Minnetonka Elevation History

Year

2 Appendix A

Black Lake (Lake Minnetonka) 2004 Values

2004 Date 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 0.0

0.5

1.0

1.5

2.0 Secchi Depth (m) 2.5

16 14 12 10 8 6 4 2 Chlorophyll a (ppb) 0 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 2004 Date

Surface TP Surface SRP Deep TP Deep SRP

60 600 500 40 400 300 20 200

Phosphorus (ppb) 100 0 0 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 2004 Date 2004 Date

3 Appendix A

Carman Bay (Lake Minnetonka) 2004 Grade: B+ Surface Area: Total Phosphorus (TP): 24 ppb (50 TSIP) Mean Depth: Soluble Reactive P (SRP): 1 ppb Maximum Depth: 20 feet Chlorophyll a: 4 ppb (43 TSIC) Secchi Depth: 2.7 m (46 TSIS) Overall TSI: 46

2004 Lake Minnetonka Elevation and Gray's Bay Dam Discharge 350 930.5 discharge 300 930 lake level 250 929.5

200 929

150 928.5 Elevation (feet) 100 928 Discharge (cfs) 50 927.5

0 927

6/8 7/6 8/3 4/13 4/27 5/11 5/25 6/22 7/20Date 8/17 8/31 9/14 9/28 10/12

Lake Minnetonka Elevation History

Year

4 Appendix A

Carman Bay (Lake Minnetonka) 2004 Values

2004 Date 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 0.0

1.0

2.0

3.0 Secchi Depth (m) 4.0

10 8

6 4 2 Chlorophyll a (ppb) 0 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 2004 Date

Surface TP Surface SRP Deep TP Deep SRP

40 400

300

20 200

100 Phosphorus (ppb) 0 0 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 2004 Date 2004 Date

5 Appendix A

Carsons Bay (Lake Minnetonka) 2004 Grade: A Surface Area: Total Phosphorus (TP): 21 ppb (48 TSIP) Mean Depth: Soluble Reactive P (SRP): 4 ppb Maximum Depth: 29 feet Chlorophyll a: 1 ppb (34 TSIC) Secchi Depth: 3.1 m (44 TSIS) Overall TSI: 42

2004 Lake Minnetonka Elevation and Gray's Bay Dam Discharge 350 930.5 discharge 300 930 lake level 250 929.5

200 929

150 928.5 Elevation (feet) 100 928 Discharge (cfs) 50 927.5

0 927

6/8 7/6 8/3 4/13 4/27 5/11 5/25 6/22 7/20Date 8/17 8/31 9/14 9/28 10/12

Lake Minnetonka Elevation History

Year

6 Appendix A

Carsons Bay (Lake Minnetonka) 2004 Values

2004 Date 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 0.0 1.0 2.0 3.0 4.0 Secchi Depth (m) 5.0

6 5 4 3 2 1 Chlorophyll a (ppb) 0 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 2004 Date

Surface TP Surface SRP Deep TP Deep SRP

40 250 200 150 20 100 50 Phosphorus (ppb) 0 0 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 2004 Date 2004 Date

7 Appendix A

Cooks Bay (Lake Minnetonka) 2004 Grade: B- Surface Area: 362 acres Total Phosphorus (TP): 32 ppb (54 TSIP) Mean Depth: Soluble Reactive P (SRP): 2 ppb Maximum Depth: 43 feet Chlorophyll a: 16 ppb (58 TSIC) Secchi Depth: 1.9 m (51 TSIS) Overall TSI: 54

2004 Lake Minnetonka Elevation and Gray's Bay Dam Discharge 350 930.5 discharge 300 930 lake level 250 929.5

200 929

150 928.5 Elevation (feet) 100 928 Discharge (cfs) 50 927.5

0 927

6/8 7/6 8/3 4/13 4/27 5/11 5/25 6/22 7/20Date 8/17 8/31 9/14 9/28 10/12

Lake Minnetonka Elevation History

Year

8 Appendix A

Cooks Bay (Lake Minnetonka) 2004 Values

2004 Date 4/20 5/20 6/20 7/20 8/20 9/20 0.0

1.0

2.0 3.0

4.0

Secchi Depth (m) 5.0

6.0

Chlorophyll a (ppb) 5

0 4/20 5/20 6/20 7/20 8/20 9/20 2004 Date

Surface TP Surface SRP Deep TP Deep SRP 100 100

80 80

60 60

40 40

Phosphorus (ppb) 20 20

0 0 4/20 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 10/5 4/20 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 10/5 2004 Date 2004 Date

9 Appendix A

Cooks Bay (Lake Minnetonka) Summer Mean Values

2.5 2

1.5

Secchi Depth (m) 0.5

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

18 16 14 12 10 8 6 4

Chlorophyll a (ppb) 2 0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

50 45 40 35 30 25 20 15 10 5 Total Phosphorus (ppb) 0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Trophic State Index 30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

10 Appendix A

Crystal Bay (Lake Minnetonka) 2004 Grade: B+ Surface Area: 900 acres Total Phosphorus (TP): 26 ppb (51 TSIP) Mean Depth: 28 feet Soluble Reactive P (SRP): 2 ppb Maximum Depth: 113 feet Chlorophyll a: 9 ppb (52 TSIC) Secchi Depth: 3.0 m (44 TSIS) Overall TSI: 49

2004 Lake Minnetonka Elevation and Gray's Bay Dam Discharge 350 930.5 discharge 300 930 lake level 250 929.5

200 929

150 928.5 Elevation (feet) 100 928 Discharge (cfs) 50 927.5

0 927

6/8 7/6 8/3 4/13 4/27 5/11 5/25 6/22 7/20Date 8/17 8/31 9/14 9/28 10/12

Lake Minnetonka Elevation History

Year

11 Appendix A

Crystal Bay (Lake Minnetonka) 2004 Values

2004 Date 4/21 5/5 5/19 6/2 6/16 6/30 7/14 7/28 8/11 8/25 9/8 9/22 10/6 0.0 1.0 2.0 3.0 4.0 5.0 6.0 Secchi Depth (m) 7.0 8.0 9.0

10 Chlorophyll a (ppb) 5

0 4/21 5/5 5/19 6/2 6/16 6/30 7/14 7/28 8/11 8/25 9/8 9/22 10/6 2004 Date

Surface TP Surface SRP Deep TP Deep SRP 80 400

60 300

40 200

20 100 Phosphorus (ppb)

0 0 4/21 5/5 5/19 6/2 6/16 6/30 7/14 7/28 8/11 8/25 9/8 9/22 10/6 4/21 5/5 5/19 6/2 6/16 6/30 7/14 7/28 8/11 8/25 9/8 9/22 10/6 2004 Date 2004 Date

12 Appendix A

Crystal Bay (Lake Minnetonka) Summer Mean Values

2.5

1.5

1 Secchi Depth (m)

0.5

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Chlorophyll a (ppb) 4

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

10 Total Phosphorus (ppb)

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Trophic State Index 30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

13 Appendix A

East Upper (Lake Minnetonka) 2004 Grade: B+ Surface Area: 1956 acres Total Phosphorus (TP): 29 ppb (52 TSIP) Mean Depth: Soluble Reactive P (SRP): 1 ppb Maximum Depth: 48 feet Chlorophyll a: 4 ppb (44 TSIC) Secchi Depth: 2.7 m (46 TSIS) Overall TSI: 47

2004 Lake Minnetonka Elevation and Gray's Bay Dam Discharge 350 930.5 discharge 300 930 lake level 250 929.5

200 929

150 928.5 Elevation (feet) 100 928 Discharge (cfs) 50 927.5

0 927

6/8 7/6 8/3 4/13 4/27 5/11 5/25 6/22 7/20Date 8/17 8/31 9/14 9/28 10/12

Lake Minnetonka Elevation History

Year

14 Appendix A

East Upper (Lake Minnetonka) 2004 Values

2004 Date 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 0.0

1.0

2.0

3.0 Secchi Depth (m) 4.0

12 10 8 6 4 2

Chlorophyll a (ppb) 0 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 2004 Date

Surface TP Surface SRP Deep TP Deep SRP

40 250 200 30 150 20 100 10 50 Phosphorus (ppb) 0 0 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 2004 Date 2004 Date

15 Appendix A

Forest Lake (Lake Minnetonka) 2004 Grade: C Surface Area: 84 acres Total Phosphorus (TP): 71 ppb (66 TSIP) Mean Depth: Soluble Reactive P (SRP): 17 ppb Maximum Depth: 42 feet Chlorophyll a: 21 ppb (60 TSIC) Secchi Depth: 1.7 m (52 TSIS) Overall TSI: 59

2004 Lake Minnetonka Elevation and Gray's Bay Dam Discharge 350 930.5 discharge 300 930 lake level 250 929.5

200 929

150 928.5 Elevation (feet) 100 928 Discharge (cfs) 50 927.5

0 927

6/8 7/6 8/3 4/13 4/27 5/11 5/25 6/22 7/20Date 8/17 8/31 9/14 9/28 10/12

Lake Minnetonka Elevation History

Year

16 Appendix A

Forest Lake (Lake Minnetonka) 2004 Values

2004 Date 4/20 5/20 6/20 7/20 8/20 9/20 0.0

1.0

2.0

3.0

Secchi Depth (m) 4.0

5.0

Chlorophyll a (ppb) 10

0 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 10/5 2004 Date

Surface TP Surface SRP Deep TP Deep SRP 350 1500

300 1250 250 1000 200 750 150 500 100

Phosphorus (ppb) 50 250 0 0 4/20 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 10/5 4/20 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 10/5 2004 Date 2004 Date

17 Appendix A

Forest Lake (Lake Minnetonka) Summer Mean Values

2 1.8 1.6 1.4 1.2 1 0.8

Secchi Depth (m) 0.6 0.4 0.2 0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Chlorophyll a (ppb) 20

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

100 90 80 70 60 50 40 30

Total Phosphorus (ppb) 20 10 0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Trophic State Index 30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

18 Appendix A

Gideons Bay (Lake Minnetonka) 2004 Grade: A Surface Area: Total Phosphorus (TP): 22 ppb (49 TSIP) Mean Depth: Soluble Reactive P (SRP): 2 ppb Maximum Depth: 57 feet Chlorophyll a: 2 ppb (36 TSIC) Secchi Depth: 3.3 m (43 TSIS) Overall TSI: 42

2004 Lake Minnetonka Elevation and Gray's Bay Dam Discharge 350 930.5 discharge 300 930 lake level 250 929.5

200 929

150 928.5 Elevation (feet) 100 928 Discharge (cfs) 50 927.5

0 927

6/8 7/6 8/3 4/13 4/27 5/11 5/25 6/22 7/20Date 8/17 8/31 9/14 9/28 10/12

Lake Minnetonka Elevation History

Year

19 Appendix A

Gideons Bay (Lake Minnetonka) 2004 Values

2004 Date 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 0.0

1.0

2.0

3.0 Secchi Depth (m) 4.0

6 5 4 3 2 1 Chlorophyll a (ppb) 0 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 2004 Date

Surface TP Surface SRP Deep TP Deep SRP

40 60

40 20 20 Phosphorus (ppb) 0 0 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 2004 Date 2004 Date

20 Appendix A

Grays Bay (Lake Minnetonka) 2004 Grade: A Surface Area: 207 acres Total Phosphorus (TP): 21 ppb (48 TSIP) Mean Depth: Soluble Reactive P (SRP): 4 ppb Maximum Depth: 28 feet Chlorophyll a: 1 ppb (29 TSIC) Secchi Depth: 3.3 m (43 TSIS) Overall TSI: 40

2004 Lake Minnetonka Elevation and Gray's Bay Dam Discharge 350 930.5 discharge 300 930 lake level 250 929.5

200 929

150 928.5 Elevation (feet) 100 928 Discharge (cfs) 50 927.5

0 927

6/8 7/6 8/3 4/13 4/27 5/11 5/25 6/22 7/20Date 8/17 8/31 9/14 9/28 10/12

Lake Minnetonka Elevation History

Year

21 Appendix A

Grays Bay (Lake Minnetonka) 2004 Values

2004 Date 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 0.0 1.0 2.0 3.0 4.0 Secchi Depth (m) 5.0

3.0 2.5 2.0 1.5 1.0 0.5 Chlorophyll a (ppb) 0.0 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 2004 Date

Surface TP Surface SRP Deep TP Deep SRP

40 80

20 40

20 Phosphorus (ppb) 0 0 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 2004 Date 2004 Date

22 Appendix A

Grays Bay (Lake Minnetonka) Summer Mean Values

3.5

3.0

2.5

2.0

1.5

1.0 Secchi Depth (m)

0.5

0.0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

4.5

4.0

3.5

3.0

2.5

2.0

1.5

Chlorophyll a (ppb) 1.0

0.5

0.0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

No long-term TP data available

40 Trophic State Index

30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

23 Appendix A

Halsted Bay (Lake Minnetonka) 2004 Grade: C- Surface Area: 544 acres Total Phosphorus (TP): 128 ppb (74 TSIP) Mean Depth: 13 feet Soluble Reactive P (SRP): 28 ppb Maximum Depth: 36 feet Chlorophyll a: 41 ppb (67 TSIC) Secchi Depth: 1.6 m (53 TSIS) Overall TSI: 65

2004 Lake Minnetonka Elevation and Gray's Bay Dam Discharge 350 930.5 discharge 300 930 lake level 250 929.5

200 929

150 928.5 Elevation (feet) 100 928 Discharge (cfs) 50 927.5

0 927

6/8 7/6 8/3 4/13 4/27 5/11 5/25 6/22 7/20Date 8/17 8/31 9/14 9/28 10/12

Lake Minnetonka Elevation History

Year

24 Appendix A

Halsted Bay (Lake Minnetonka) 2004 Values

2004 Date 4/20 5/20 6/20 7/20 8/20 9/20 0.0 1.0 2.0 3.0 4.0

Secchi Depth (m) 5.0 6.0

80 70 60 50 40 30 20 Chlorophyll a (ppb) 10 0 4/20 5/20 6/20 7/20 8/20 9/20 2004 Date

Surface TP Surface SRP Deep TP Deep SRP

200 2,250 2,000 150 1,750 1,500 100 1,250 1,000 50 750 Phosphorus (ppb) 500 0 250 4/20 5/4 5/18 6/1 6/156/297/137/278/10 8/24 9/7 9/21 10/5 0 4/20 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 10/5 2004 Date 2004 Date

25 Appendix A

Halsted Bay (Lake Minnetonka) Summer Mean Values

3.5

2.5

1.5

1 Secchi Depth (m) 0.5

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Chlorophyll a (ppb) 10

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

160

140

120

100

0 Total Phosphorus (ppb) 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Trophic State Index 30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

26 Appendix A

Harrison Bay (Lake Minnetonka) 2004 Grade: C Surface Area: 211 acres Total Phosphorus (TP): 58 ppb (63 TSIP) Mean Depth: 9 feet Soluble Reactive P (SRP): 3 ppb Maximum Depth: 46 feet Chlorophyll a: 32 ppb (65 TSIC) Secchi Depth: 1.2 m (57 TSIS) Overall TSI: 61

2004 Lake Minnetonka Elevation and Gray's Bay Dam Discharge 350 930.5 discharge 300 930 lake level 250 929.5

200 929

150 928.5 Elevation (feet) 100 928 Discharge (cfs) 50 927.5

0 927

6/8 7/6 8/3 4/13 4/27 5/11 5/25 6/22 7/20Date 8/17 8/31 9/14 9/28 10/12

Lake Minnetonka Elevation History

Year

27 Appendix A

Harrison Bay (Lake Minnetonka) 2004 Values

2004 Date 4/20 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 10/5 0.0

0.5

1.0

1.5

2.0

2.5 Secchi Depth (m) 3.0

3.5

100

20 Chlorophyll a (ppb)

0 4/20 5/20 6/20 7/20 8/20 9/20 2004 Date

Surface TP Surface SRP Deep TP Deep SRP 100 400

80 300 60 200 40 100 Phosphorus (ppb) 20

0 0 4/20 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 10/5 4/20 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 10/5 2004 Date 2004 Date

28 Appendix A

Harrison Bay (Lake Minnetonka) Summer Mean Values

1.2

0.8

0.6

0.4

Secchi Depth (m) 0.2

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Chlorophyll a (ppb) 10

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

10 Total Phosphorus (ppb) 0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Trophic State Index 30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

29 Appendix A

Jennings Bay (Lake Minnetonka) 2004 Grade: C- Surface Area: 290 acres Total Phosphorus (TP): 110 ppb (72 TSIP) Mean Depth: 11 feet Soluble Reactive P (SRP): 8 ppb Maximum Depth: 26 feet Chlorophyll a: 39 ppb (67 TSIC) Secchi Depth: 1.4 m (55 TSIS) Overall TSI: 65

2004 Lake Minnetonka Elevation and Gray's Bay Dam Discharge 350 930.5 discharge 300 930 lake level 250 929.5

200 929

150 928.5 Elevation (feet) 100 928 Discharge (cfs) 50 927.5

0 927

6/8 7/6 8/3 4/13 4/27 5/11 5/25 6/22 7/20Date 8/17 8/31 9/14 9/28 10/12

Lake Minnetonka Elevation History

Year

30 Appendix A

Jennings Bay (Lake Minnetonka) 2004 Values

2004 Date 4/20 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 10/5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 Secchi Depth (m) 4.0 4.5

80 70 60 50 40 30 20

Chlorophyll a (ppb) 10 0 4/20 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 10/5 2004 Date

Surface TP Surface SRP Deep TP Deep SRP 200

500

150 400 300 100 200 50 Phosphorus (ppb) 100

0 0 4/20 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 10/5 4/20 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 10/5 2004 Date 2004 Date

31 Appendix A

Jennings Bay (Lake Minnetonka) Summer Mean Values

1.4

1.2

0.8

0.6

0.4

Secchi Depth (m) 0.2

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

180 160 140 120 100 80 60 40

Chlorophyll a (ppb) 20 0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

400

350

300

250

200

150

100

50 Total Phosphorus (ppb) 0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Trophic State Index 30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

32 Appendix A Libbs Lake 2004 Grade: B+ Surface Area: 17 acres Total Phosphorus (TP): 21 ppb (48 TSIP) Mean Depth: Chlorophyll a: 2 ppb (37 TSIC) Maximum Depth: 8 feet Secchi Depth: 1.8 m (52 TSIS) Overall TSI: 46

2004 and long-term lake elevation data not available

33 Appendix A Libbs Lake 2004 Values

2004 Date 4/18 5/18 6/18 7/18 8/18 9/18 0.0

0.5

1.0

1.5

Secchi Depth (m) 2.0

2.5

1 Chlorophyll a (ppb)

0 4/18 5/18 6/18 7/18 8/18 9/18 2004 Date

Surface TP 40

20 Phosphorus (ppb)

0 4/18 5/16 6/13 7/11 8/8 9/5 10/3 2004 Date

34 Appendix A

Lower Lake South (Lake Minnetonka) 2004 Grade: A Surface Area: 1069 acres Total Phosphorus (TP): 20 ppb (47 TSIP) Mean Depth: Soluble Reactive P (SRP): 2 ppb Maximum Depth: 77 feet Chlorophyll a: 6 ppb (48 TSIC) Secchi Depth: 3.3 m (43 TSIS) Overall TSI: 46

2004 Lake Minnetonka Elevation and Gray's Bay Dam Discharge 350 930.5 discharge 300 930 lake level 250 929.5

200 929

150 928.5 Elevation (feet) 100 928 Discharge (cfs) 50 927.5

0 927

6/8 7/6 8/3 4/13 4/27 5/11 5/25 6/22 7/20Date 8/17 8/31 9/14 9/28 10/12

Lake Minnetonka Elevation History

Year

35 Appendix A

Lower Lake South (Lake Minnetonka) 2004 Values

2004 Date 4/21 5/5 5/19 6/2 6/16 6/30 7/14 7/28 8/11 8/25 9/8 9/22 10/6 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 Secchi Depth (m) 4.0 4.5

Chlorophyll a (ppb) 2

0 4/21 5/5 5/19 6/2 6/16 6/30 7/14 7/28 8/11 8/25 9/8 9/22 10/6 2004 Date

Surface TP Surface SRP Deep TP Deep SRP 40 400

30 300

20 200

10 100 Phosphorus (ppb) 0 0 4/21 5/5 5/19 6/2 6/16 6/30 7/14 7/28 8/11 8/25 9/8 9/22 10/6 4/21 5/5 5/19 6/2 6/16 6/30 7/14 7/28 8/11 8/25 9/8 9/22 10/6 2004 Date 2004 Date

36 Appendix A

Lower Lake South (Lake Minnetonka) Summer Mean Values

4.5 4 3.5 3 2.5 2 1.5 1 Secchi Depth (m) 0.5 0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

5 Chlorophyll a (ppb)

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

120

100

20 Total Phosphorus (ppb) 0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Trophic State Index 30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

37 Appendix A

Maxwell Bay (Lake Minnetonka) 2004 Grade: B Surface Area: 300 acres Total Phosphorus (TP): 32 ppb (54 TSIP) Mean Depth: 14 feet Soluble Reactive P (SRP): 19 ppb Maximum Depth: 44 feet Chlorophyll a: 12 ppb (55 TSIC) Secchi Depth: 2.4 m (47 TSIS) Overall TSI: 52

2004 Lake Minnetonka Elevation and Gray's Bay Dam Discharge 350 930.5 discharge 300 930 lake level 250 929.5

200 929

150 928.5 Elevation (feet) 100 928 Discharge (cfs) 50 927.5

0 927

6/8 7/6 8/3 4/13 4/27 5/11 5/25 6/22 7/20Date 8/17 8/31 9/14 9/28 10/12

Lake Minnetonka Elevation History

Year

38 Appendix A

Maxwell Bay (Lake Minnetonka) 2004 Values

2004 Date 4/20 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 10/5 0.0

1.0

2.0

3.0

4.0

Secchi Depth (m) 5.0

6.0

20 10 Chlorophyll a (ppb) 0 4/20 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 10/5 2004 Date

Surface TP Surface SRP Deep TP Deep SRP 100 800

600

50 400

200 Phosphorus (ppb) 0 0 4/20 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 10/5 4/20 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 10/5 2004 Date 2004 Date

39 Appendix A

Maxwell Bay (Lake Minnetonka) Summer Mean Values

2.5

1.5

0.5 Secchi Depth (m)

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

18 16 14 12 10 8 6 4

Chlorophyll a (ppb) 2 0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

45 40 35 30 25 20 15 10 5 Total Phosphorus (ppb) 0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Trophic State Index 30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

40 Appendix A

North Arm (Lake Minnetonka) 2004 Grade: B Surface Area: 307 acres Total Phosphorus (TP): 31 ppb (53 TSIP) Mean Depth: 14 feet Soluble Reactive P (SRP): 2 ppb Maximum Depth: 64 feet Chlorophyll a: 11 ppb (54 TSIC) Secchi Depth: 2.4 m (48 TSIS) Overall TSI: 52

2004 Lake Minnetonka Elevation and Gray's Bay Dam Discharge 350 930.5 discharge 300 930 lake level 250 929.5

200 929

150 928.5 Elevation (feet) 100 928 Discharge (cfs) 50 927.5

0 927

6/8 7/6 8/3 4/13 4/27 5/11 5/25 6/22 7/20Date 8/17 8/31 9/14 9/28 10/12

Lake Minnetonka Elevation History

Year

41 Appendix A

North Arm (Lake Minnetonka) 2004 Values

2004 Date 4/20 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 10/5 0.0

1.0

2.0

3.0

4.0

Secchi Depth (m) 5.0

6.0

10 Chlorophyll a (ppb)

0 4/20 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 10/5 2004 Date

Surface TP Surface SRP Deep TP Deep SRP 60 800

600 40 400 20 200 Phosphorus (ppb)

0 0 4/20 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 10/5 4/20 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 10/5 2004 Date 2004 Date

42 Appendix A

North Arm (Lake Minnetonka) Summer Mean Values

2.5

1.5

0.5 Secchi Depth (m)

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Chlorophyll a (ppb) 2

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

5 Total Phosphorus (ppb) 0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Trophic State Index 30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

43 Appendix A

Peavey Lake (Lake Minnetonka) 2004 Grade: C Surface Area: 8 acres Total Phosphorus (TP): 76 ppb (67 TSIP) Mean Depth: feet Soluble Reactive P (SRP): 17 ppb Maximum Depth: 52 feet Chlorophyll a: 17 ppb (59 TSIC) Secchi Depth: 2.1 m (49 TSIS) Overall TSI: 58

2004 Lake Minnetonka Elevation and Gray's Bay Dam Discharge 350 930.5 discharge 300 930 lake level 250 929.5

200 929

150 928.5 Elevation (feet) 100 928 Discharge (cfs) 50 927.5

0 927

6/8 7/6 8/3 4/13 4/27 5/11 5/25 6/22 7/20Date 8/17 8/31 9/14 9/28 10/12

Lake Minnetonka Elevation History

Year

44 Appendix A

Peavey Lake (Lake Minnetonka) 2004 Values

2004 Date 4/21 5/5 5/19 6/2 6/16 6/30 7/14 7/28 8/11 8/25 9/8 9/22 10/6 0.0

0.5

1.0

1.5

2.0

2.5 Secchi Depth (m) 3.0

3.5

80 70 60 50 40 30 20

Chlorophyll a (ppb) 10 0 4/21 5/5 5/19 6/2 6/16 6/30 7/14 7/28 8/11 8/25 9/8 9/22 10/6 2004 Date

Surface TP Surface SRP Deep TP Deep SRP 140 10000 120 8000 100 80 6000 60 4000 40 Phosphorus (ppb) 2000 20 0 0 4/21 5/5 5/19 6/2 6/16 6/307/14 7/28 8/118/25 9/8 9/22 10/6 4/21 5/5 5/19 6/2 6/16 6/30 7/14 7/288/11 8/25 9/8 9/22 10/6 2004 Date 2004 Date

45 Appendix A

Peavey Lake (Lake Minnetonka) Summer Mean Values

2.5

1.5

Secchi Depth (m) 0.5

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Chlorophyll a (ppb) 10

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

500 450 400 350 300 250 200 150 100 50 Total Phosphorus (ppb) 0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Trophic State Index 30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

46 Appendix A

Priests Bay (Lake Minnetonka) 2004 Grade: C- Surface Area: Total Phosphorus (TP): 55 ppb (62 TSIP) Mean Depth: Soluble Reactive P (SRP): 2 ppb Maximum Depth: 46 feet Chlorophyll a: 28 ppb (63 TSIC) Secchi Depth: 1.0 m (60 TSIS) Overall TSI: 62

2004 Lake Minnetonka Elevation and Gray's Bay Dam Discharge 350 930.5 discharge 300 930 lake level 250 929.5

200 929

150 928.5 Elevation (feet) 100 928 Discharge (cfs) 50 927.5

0 927

6/8 7/6 8/3 4/13 4/27 5/11 5/25 6/22 7/20Date 8/17 8/31 9/14 9/28 10/12

Lake Minnetonka Elevation History

Year

47 Appendix A

Priests Bay (Lake Minnetonka) 2004 Values

2004 Date 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 0.0 0.2 0.4 0.6 0.8 1.0 1.2

Secchi Depth (m) 1.4 1.6

50 40 30 20 10

Chlorophyll a (ppb) 0 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 2004 Date

Surface TP Surface SRP Deep TP Deep SRP

80 1400 1200 60 1000 800 rus (ppb) 40 600 20 400

Phospho 200 0 0 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 2004 Date 2004 Date

48 Appendix A

Smithtown Bay (Lake Minnetonka) 2004 Grade: B+ Surface Area: Total Phosphorus (TP): 23 ppb (49 TSIP) Mean Depth: Soluble Reactive P (SRP): 1 ppb Maximum Depth: 80 feet Chlorophyll a: 5 ppb (46 TSIC) Secchi Depth: 2.3 m (48 TSIS) Overall TSI: 48

2004 Lake Minnetonka Elevation and Gray's Bay Dam Discharge 350 930.5 discharge 300 930 lake level 250 929.5

200 929

150 928.5 Elevation (feet) 100 928 Discharge (cfs) 50 927.5

0 927

6/8 7/6 8/3 4/13 4/27 5/11 5/25 6/22 7/20Date 8/17 8/31 9/14 9/28 10/12

Lake Minnetonka Elevation History

Year

49 Appendix A

Smithtown Bay (Lake Minnetonka) 2004 Values

2004 Date 7/15 7/29 8/12 8/26 9/9 9/23 1.5

2.0

2.5 Secchi Depth (m) 3.0

10 8 6 4 2 Chlorophyll a (ppb) 0 7/15 7/29 8/12 8/26 9/9 9/23 2004 Date

Surface TP Surface SRP Deep TP Deep SRP 40 400

300 20 200

100

Phosphorus (ppb) 0 0 7/15 7/29 8/12 8/26 9/9 9/23 7/15 7/29 8/12 8/26 9/9 9/23 2004 Date 2004 Date

50 Appendix A

St. Albans Bay (Lake Minnetonka) 2004 Grade: A Surface Area: 164 acres Total Phosphorus (TP): 16 ppb (44 TSIP) Mean Depth: 14 feet Soluble Reactive P (SRP): 2 ppb Maximum Depth: 44 feet Chlorophyll a: 4 ppb (45 TSIC) Secchi Depth: 3.9 m (40 TSIS) Overall TSI: 43

2004 Lake Minnetonka Elevation and Gray's Bay Dam Discharge 350 930.5 discharge 300 930 lake level 250 929.5

200 929

150 928.5 Elevation (feet) 100 928 Discharge (cfs) 50 927.5

0 927

6/8 7/6 8/3 4/13 4/27 5/11 5/25 6/22 7/20Date 8/17 8/31 9/14 9/28 10/12

Lake Minnetonka Elevation History

Year

51 Appendix A

St. Albans Bay (Lake Minnetonka) 2004 Values

2004 Date 4/21 5/5 5/19 6/2 6/16 6/30 7/14 7/28 8/11 8/25 9/8 9/22 10/6 0.0

1.0

2.0

3.0

4.0

Secchi Depth (m) 5.0

6.0

9 8 7 6 5 4 3 2 Chlorophyll a (ppb) 1 0 4/21 5/5 5/19 6/2 6/16 6/30 7/14 7/28 8/11 8/25 9/8 9/22 10/6 2004 Date

Surface TP Surface SRP Deep TP Deep SRP 30 250

200 20 150 100 10 50 Phosphorus (ppb) 0 0 4/21 5/5 5/19 6/2 6/16 6/30 7/14 7/28 8/11 8/25 9/8 9/22 10/6 4/21 5/5 5/19 6/2 6/16 6/307/14 7/28 8/118/25 9/8 9/22 10/6 2004 Date 2004 Date

52 Appendix A

St. Albans Bay (Lake Minnetonka) Summer Mean Values

3.5

2.5

1.5

1 Secchi Depth (m) 0.5

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Chlorophyll a (ppb) 1

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

5 Total Phosphorus (ppb) 0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Trophic State Index 30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

53 Appendix A

Spring Park Bay (Lake Minnetonka) 2004 Grade: A- Surface Area: 408 acres Total Phosphorus (TP): 20 ppb (47 TSIP) Mean Depth: Soluble Reactive P (SRP): 8 ppb Maximum Depth: 36 feet Chlorophyll a: 7 ppb (50 TSIC) Secchi Depth: 2.9 m (44 TSIS) Overall TSI: 47

2004 Lake Minnetonka Elevation and Gray's Bay Dam Discharge 350 930.5 discharge 300 930 lake level 250 929.5

200 929

150 928.5 Elevation (feet) 100 928 Discharge (cfs) 50 927.5

0 927

6/8 7/6 8/3 4/13 4/27 5/11 5/25 6/22 7/20Date 8/17 8/31 9/14 9/28 10/12

Lake Minnetonka Elevation History

Year

54 Appendix A

Spring Park Bay (Lake Minnetonka) 2004 Values

2004 Date 4/21 5/5 5/19 6/2 6/16 6/30 7/14 7/28 8/11 8/25 9/8 9/22 10/6 0.0 0.5 1.0 1.5 2.0 2.5 3.0 Secchi Depth (m) 3.5 4.0

Chlorophyll a (ppb) 5

0 4/21 5/5 5/19 6/2 6/16 6/30 7/14 7/28 8/11 8/25 9/8 9/22 10/6 2004 Date

Surface TP Surface SRP Deep TP Deep SRP 60 60

40 40

20 20 Phosphorus (ppb) 0 0 4/21 5/5 5/19 6/2 6/16 6/30 7/14 7/28 8/11 8/25 9/8 9/22 10/6 4/21 5/5 5/19 6/2 6/16 6/30 7/14 7/28 8/11 8/25 9/8 9/22 10/6 2004 Date 2004 Date

55 Appendix A

Spring Park Bay (Lake Minnetonka) Summer Mean Values

3.5

2.5

1.5

Secchi Depth (m) 0.5

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

9 8 7 6 5 4 3 2

Chlorophyll a (ppb) 1 0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

5 Total Phosphorus (ppb) 0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Trophic State Index 30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

56 Appendix A

Stubbs Bay (Lake Minnetonka) 2004 Grade: C Surface Area: 195 acres Total Phosphorus (TP): 35 ppb (64 TSIP) Mean Depth: 13 feet Soluble Reactive P (SRP): 4 ppb Maximum Depth: 37 feet Chlorophyll a: 30 ppb (64 TSIC) Secchi Depth: 1.6 m (53 TSIS) Overall TSI: 60

2004 Lake Minnetonka Elevation and Gray's Bay Dam Discharge 350 930.5 discharge 300 930 lake level 250 929.5

200 929

150 928.5 Elevation (feet) 100 928 Discharge (cfs) 50 927.5

0 927

6/8 7/6 8/3 4/13 4/27 5/11 5/25 6/22 7/20Date 8/17 8/31 9/14 9/28 10/12

Lake Minnetonka Elevation History

Year

57 Appendix A

Stubbs Bay (Lake Minnetonka) 2004 Values

2004 Date 4/20 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 10/5 0.0

1.0

2.0

3.0

4.0

Secchi Depth (m) 5.0

6.0

Chlorophyll a (ppb) 10

0 4/20 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 10/5 2004 Date

Surface TP Surface SRP Deep TP Deep SRP 160 2000 140 120 1500 100 80 1000 60 40 500

Phosphorus (ppb) 20 0 0 4/20 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/2110/5 4/20 5/4 5/18 6/1 6/156/297/13 7/27 8/10 8/24 9/7 9/2110/5 2004 Date 2004 Date

58 Appendix A

Stubbs Bay (Lake Minnetonka) Summer Mean Values

1.4

1.2

0.8

0.6

0.4

Secchi Depth (m) 0.2

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

45 40 35 30 25 20 15 10

Chlorophyll a (ppb) 5 0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

10 Total Phosphorus (ppb) 0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Trophic State Index 30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

59 Appendix A Tanager Lake 2004 Grade: D- Surface Area: 74 acres Total Phosphorus (TP): 118 ppb (73 TSIP) Mean Depth: Soluble Reactive P (SRP): 13 ppb Maximum Depth: Chlorophyll a: 80 ppb (74 TSIC) Secchi Depth: 1.1 m (58 TSIS) Overall TSI: 68

2004 Lake Minnetonka Elevation and Gray's Bay Dam Discharge 350 930.5 discharge 300 930 lake level 250 929.5

200 929

150 928.5 Elevation (feet) 100 928 Discharge (cfs) 50 927.5

0 927

6/8 7/6 8/3 4/13 4/27 5/11 5/25 6/22 7/20Date 8/17 8/31 9/14 9/28 10/12

Year

60 Appendix A

Tanager Lake 2004 Values

2004 Date 5/28 6/11 6/25 7/9 7/23 8/6 8/20 9/3 9/17 0.0

0.5

1.0

1.5

2.0 Secchi Depth (m) 2.5

3.0

250

200

150

100

50 Chlorophyll a (ppb) 0 5/28 6/11 6/25 7/9 7/23 8/6 8/20 9/3 9/17 2004 Date

Surface TP Surface SRP Deep TP Deep SRP

250 600 200 500 400 150 300 100 200

Phosphorus (ppb) 50 100 0 0 5/28 6/11 6/25 7/9 7/23 8/6 8/20 9/3 9/17 5/28 6/11 6/25 7/9 7/23 8/6 8/20 9/3 9/17 2004 Date 2004 Date

61 Appendix A

Tanager Lake Summer Mean Values

1.5

1.0

0.5 Secchi Depth (m)

0.0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

120

100

40 Chlorophyll a (ppb) 20

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

140

120

100

Total Phosphorus (ppb) 20

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Trophic State Index 40

30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

62 Appendix A

Wayzata Bay (Lake Minnetonka) 2004 Grade: A Surface Area: 751 acres Total Phosphorus (TP): 17 ppb (45 TSIP) Mean Depth: Soluble Reactive P (SRP): 4 ppb Maximum Depth: 63 feet Chlorophyll a: 6 ppb (47 TSIC) Secchi Depth: 3.4 m (42 TSIS) Overall TSI: 45

2004 Lake Minnetonka Elevation and Gray's Bay Dam Discharge 350 930.5 discharge 300 930 lake level 250 929.5

200 929

150 928.5 Elevation (feet) 100 928 Discharge (cfs) 50 927.5

0 927

6/8 7/6 8/3 4/13 4/27 5/11 5/25 6/22 7/20Date 8/17 8/31 9/14 9/28 10/12

Lake Minnetonka Elevation History

Year

63 Appendix A

Wayzata Bay (Lake Minnetonka) 2004 Values

2004 Date 4/21 5/5 5/19 6/2 6/16 6/30 7/14 7/28 8/11 8/25 9/8 9/22 10/6 0.0

1.0

2.0

3.0

Secchi Depth (m) 4.0

5.0

18 16 14 12 10 8 6 4 Chlorophyll a (ppb) 2 0 4/21 5/5 5/19 6/2 6/16 6/30 7/14 7/28 8/11 8/25 9/8 9/22 10/6 2004 Date

Surface TP Surface SRP Deep TP Deep SRP 30 400

300 20 200 10 100 Phosphorus (ppb) 0 0 4/21 5/5 5/19 6/2 6/16 6/30 7/14 7/28 8/11 8/25 9/8 9/22 10/6 4/21 5/5 5/19 6/2 6/16 6/307/14 7/28 8/118/25 9/8 9/22 10/6 2004 Date 2004 Date

64 Appendix A

Wayzata Bay (Lake Minnetonka) Summer Mean Values

5 4.5 4 3.5 3 2.5 2 1.5 1 Secchi Depth (m) 0.5 0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

5 Chlorophyll a (ppb)

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

90 80 70 60 50 40 30 20 10 Total Phosphorus (ppb) 0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Trophic State Index 30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

65 Appendix A

West Arm (Lake Minnetonka) 2004 Grade: C Surface Area: 580 acres Total Phosphorus (TP): 59 ppb (63 TSIP) Mean Depth: 11 feet Soluble Reactive P (SRP): 4 ppb Maximum Depth: 44 feet Chlorophyll a: 33 ppb (65 TSIC) Secchi Depth: 1.6 m (53 TSIS) Overall TSI: 60

2004 Lake Minnetonka Elevation and Gray's Bay Dam Discharge 350 930.5 discharge 300 930 lake level 250 929.5

200 929

150 928.5 Elevation (feet) 100 928 Discharge (cfs) 50 927.5

0 927

6/8 7/6 8/3 4/13 4/27 5/11 5/25 6/22 7/20Date 8/17 8/31 9/14 9/28 10/12

Lake Minnetonka Elevation History

Year

66 Appendix A

West Arm (Lake Minnetonka) 2004 Values

2004 Date 4/20 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 10/5 0.0

1.0

2.0

3.0

4.0

Secchi Depth (m) 5.0

6.0

Chlorophyll a (ppb) 10

0 4/20 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 10/5 2004 Date

Surface TP Surface SRP Deep TP Deep SRP

140 400 120 100 300 80 200 60 40 100

Phosphorus (ppb) 20 0 0 4/20 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 10/5 4/20 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 10/5 2004 Date 2004 Date

67 Appendix A

West Arm (Lake Minnetonka) Summer Mean Values

1.4

1.2

0.8

0.6

0.4

Secchi Depth (m) 0.2

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Chlorophyll a (ppb) 10

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

120

100

20 Total Phosphorus (ppb) 0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Trophic State Index 30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

68 Appendix A

West Upper (Lake Minnetonka) 2004 Grade: B Surface Area: 879 acres Total Phosphorus (TP): 27 ppb (52 TSIP) Mean Depth: Soluble Reactive P (SRP): 1 ppb Maximum Depth: 84 feet Chlorophyll a: 12 ppb (55 TSIC) Secchi Depth: 2.4 m (47 TSIS) Overall TSI: 51

2004 Lake Minnetonka Elevation and Gray's Bay Dam Discharge 350 930.5 discharge 300 930 lake level 250 929.5

200 929

150 928.5 Elevation (feet) 100 928 Discharge (cfs) 50 927.5

0 927

6/8 7/6 8/3 4/13 4/27 5/11 5/25 6/22 7/20Date 8/17 8/31 9/14 9/28 10/12

Lake Minnetonka Elevation History

Year

69 Appendix A

West Upper (Lake Minnetonka) 2004 Values

2004 Date

4/20 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5

Secchi Depth (m) 4.0 4.5 5.0

18 16 14 12 10 8 6 4 Chlorophyll a (ppb) 2 0 4/20 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 10/5 2004 Date

Surface TP Surface SRP Deep TP Deep SRP 100 500

80 400 60 300 40 200 20 100

Phosphorus (ppb) 0 0 4/20 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 10/5 4/20 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 10/5 2004 Date 2004 Date

70 Appendix A

West Upper (Lake Minnetonka) Summer Mean Values

2.5

1.5

Secchi Depth (m) 0.5

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Chlorophyll a (ppb) 5

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

160

140

120

100

20 Total Phosphorus (ppb) 0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Trophic State Index 30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

71 Appendix A Christmas Lake 2004 Grade: A- Surface Area: 276 acres Total Phosphorus (TP): 29 ppb (52 TSIP) Mean Depth: 33 feet Soluble Reactive P (SRP): 1 ppb Maximum Depth: 87 feet Chlorophyll a: 0.1 ppb (8 TSIC) Secchi Depth: 4.9 m (37 TSIS) Overall TSI: 33

Christmas Lake Elevation History

934

NOHW (932.79)

932 Runout (931.5)

930 Elevation (Feet, NGVD)

928 Jan-80 Jan-82 Jan-84 Jan-86 Jan-88 Jan-90 Jan-92 Jan-94 Jan-96 Jan-98 Jan-00 Jan-02 Jan-04

933

932

931

930

929

928 Lake Elevation (feet AMSL) 4/20 5/20 6/20 7/20 8/20 9/20 10/20 2004 Date

72 Appendix A

Christmas Lake 2004 Values

2004 Date 5/25 6/22 7/20 8/17 9/14 0.0 2.0 4.0 6.0

Secchi Depth (m) 8.0

Chlorophyll a (ppb) 0 5/25 6/22 7/20 8/17 9/14 2004 Date

Surface TP Surface SRP Deep TP Deep SRP

100 150 80 60 100 40 50 20 Phosphorus (ppb) 0 0 5/25 6/22 7/20 8/17 9/14 5/25 6/22 7/20 8/17 9/14 2004 Date 2004 Date

73 Appendix A

Christmas Lake Summer Mean Values

3 Secchi Depth (m) 2

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

50 45 40 35 30 25 20 15 Chlorophyll a (ppb) 10 5 0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

50 40

Total Phosphorus (ppb) 20

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Trophic State Index 40

30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

74 Appendix A Dutch Lake 2004 Grade: D+ Surface Area: 160 acres Total Phosphorus (TP): 88 ppb (69 TSIP) Mean Depth: 15 feet Soluble Reactive P (SRP): 7 ppb Maximum Depth: 45 feet Chlorophyll a: 44 ppb (68 TSIC) Secchi Depth: 1.1 m (58 TSIS) Overall TSI: 65

2004 and long-term lake elevation data not available

75 Appendix A

Dutch Lake 2004 Values

2004 Date 5/4 6/1 6/29 7/27 8/24 0.0 0.5 1.0 1.5 2.0 Secchi Depth (m) 2.5

120 100 (ppb)

a 80 60 40 20

Chlorophyll 0 5/4 6/1 6/29 7/27 8/24 2004 Date

Surface TP Surface SRP Deep TP Deep SRP

200 2500

150 2000 1500 100 1000 50 500 Phosphorus (ppb) 0 0 5/4 6/1 6/29 7/27 8/24 5/4 6/1 6/29 7/27 8/24 2004 Date 2004 Date

76 Appendix A

Dutch Lake Summer Mean Values

2.5

2.0

1.5

1.0 Secchi Depth (m) 0.5

0.0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

20 Chlorophyll a (ppb)

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

100 90 80 70 60 50 40 30 20 Total Phosphorus (ppb) 10 0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

40 Trophic State Index

30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

77 Appendix A Gleason Lake 2004 Grade: C- Surface Area: 156 acres Total Phosphorus (TP): 104 ppb (71 TSIP) Mean Depth: 8 feet Soluble Reactive P (SRP): 17 ppb Maximum Depth: 16 feet Chlorophyll a: 23 ppb (61 TSIC) Secchi Depth: 1.4 m (55 TSIS) Overall TSI: 62

Gleason Lake Elevation History

948 100 Year Flood (947.0) 947

946

945 Runout (943.85) (Outlet constructed in 1994)

944

943 OHW (943.4)

942 Elevation (Feet, NGVD)

941

940

939 Dec-84 Jan-87 Jan-89 Jan-91 Jan-93 Jan-95 Jan-97 Jan-99 Jan-01 Jan-03

2004 lake elevation data not available

78 Appendix A

Gleason Lake 2004 Values

2004 Date 5/4 6/1 6/29 7/27 8/24 9/21 0.0

0.5

1.0

1.5

2.0 Secchi Depth (m) 2.5

60 50 40 30 20 10 0 Chlorophyll a (ppb) 5/4 6/4 7/4 8/4 9/4 2004 Date

Surface TP Surface SRP Deep TP Deep SRP

200 300 250 150 200 100 150 100

Phosphorus (ppb) 50 50 0 0 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 9/21 2004 Date 2004 Date

79 Appendix A

Gleason Lake Summer Mean Values

2.5

2.0

1.5

1.0 Secchi Depth (m) 0.5

0.0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

180

160

140

120

100

Chlorophyll a (ppb) 40

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

350

300

250

200

150

100

Total Phosphorus (ppb) 50

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Trophic State Index 40

30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

80 Appendix A Langdon Lake 2004 Grade: F Surface Area: 144 acres Total Phosphorus (TP): 138 ppb (75 TSIP) Mean Depth: 8 feet Soluble Reactive P (SRP): 11 ppb Maximum Depth: 38 feet Chlorophyll a: 99 ppb (76 TSIC) Secchi Depth: 0.4 m (72 TSIS) Overall TSI: 74

Langdon Lake Elevation History

935

100 Year (934.5)

934

933

OHW (932.1) 932

Runout (931.3)

931 Elevation (Feet, NGVD)

930

929 Jan-83 Jan-85 Jan-87 Jan-89 Jan-91 Jan-93 Jan-95 Jan-97 Jan-99 Jan-01 Jan-03

2004 lake elevation data not available

81 Appendix A

Langdon Lake 2004 Values

2004 Date 5/28 6/28 7/28 8/28 0.0 0.1 0.2 0.3 0.4 0.5

Secchi Depth (m) 0.6 0.7

160 140 120 100 80 60 40 20

Chlorophyll a (ppb) 0 5/28 6/11 6/25 7/9 7/23 8/6 8/20 9/3 9/17 2004 Date

Surface TP Surface SRP Deep TP Deep SRP

250 2000 200 1500 150 1000 100

Phosphorus (ppb) 50 500

0 0 5/28 6/11 6/25 7/9 7/23 8/6 8/20 9/3 9/17 5/28 6/11 6/25 7/9 7/23 8/6 8/20 9/3 9/17 2004 Date 2004 Date

82 Appendix A

Langdon Lake Summer Mean Values

0.8

0.7

0.6

0.5

0.4

0.3

Secchi Depth (m) 0.2

0.1

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

350

300

250

200

150

100 Chlorophyll a (ppb) 50

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

1800

1600

1400

1200

1000 800

600

400 Total Phosphorus (ppb) 200

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

100

Trophic State Index 40

30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

83 Appendix A Long Lake 2004 Grade: C- Surface Area: 144 acres Total Phosphorus (TP): 76 ppb (67 TSIP) Mean Depth: 8 feet Soluble Reactive P (SRP): 6 ppb Maximum Depth: 38 feet Chlorophyll a: 40 ppb (67 TSIC) Secchi Depth: 1.2 m (58 TSIS) Overall TSI: 64

Long Lake Elevation History

947

946.5

946

945.5

945

944.5 OHW (944.3) Elevation (Feet, NGVD) Runout (944.25) 944 (Runout elevation established in 1990)

943.5

943 Jan-83 Jan-85 Jan-87 Jan-89 Jan-91 Jan-93 Jan-95 Jan-97 Jan-99 Jan-01 Jan-03

2004 lake elevation data not available

84 Appendix A

Long Lake 2004 Values

2004 Date 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 0.0

1.0

2.0

3.0

4.0 Secchi Depth (m)

5.0

80 70 60 50 40 30 20 10 Chlorophyll a (ppb) 0 5/4 6/4 7/4 8/4 9/4 2004 Date

Surface TP Surface SRP Deep TP Deep SRP

120 2500

100 2000 80 1500 60 1000 40

Phosphorus (ppb) 20 500 0 0 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 2004 Date 2004 Date

85 Appendix A

Long Lake Summer Mean Values

3.0

2.0

1.0 Secchi Depth (m)

0.0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

160

140

120

100

40 Chlorophyll a (ppb) 20

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

140

120

100

Total Phosphorus (ppb) 20

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

40 Trophic State Index

30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

86 Appendix A Lake Minnewashta 2004 Grade: B+ Surface Area: 656 acres Total Phosphorus (TP): 25 ppb (51 TSIP) Mean Depth: 15 feet Soluble Reactive P (SRP): 3 ppb Maximum Depth: 70 feet Chlorophyll a: 3 ppb (40 TSIC) Secchi Depth: 2.6 m (46 TSIS) Overall TSI: 46

Lake Minnewashta Elevation History

946

945.5 100 Year Flood (945.6) OHW (944.5) 945 Runout (944.2)

944.5

944

943.5 Elevation (Feet, NGVD)

943

942.5

942 Jan-83 Jan-86 Jan-89 Jan-92 Jan-95 Jan-98 Jan-01 Jan-04

950

948

946

944

942

940 Lake Elevation (feet AMSL) 4/8 5/28 7/17 9/5 10/25 12/14 2004 Date

87 Appendix A

Lake Minnewashta 2004 Values

2004 Date

5/25 6/8 6/22 7/6 7/20 8/3 8/17 8/31 9/14 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 Secchi Depth (m) 4.0 4.5

7 6 5 4 3 2 1 Chlorophyll a (ppb) 0 5/25 6/8 6/22 7/6 7/20 8/3 8/17 8/31 9/14 2004 Date

Surface TP Surface SRP Deep TP Deep SRP

60 600 500

40 400 300 20 200

Phosphorus (ppb) 100 0 0 5/25 6/8 6/22 7/6 7/20 8/3 8/17 8/31 9/14 5/25 6/8 6/22 7/6 7/20 8/3 8/17 8/31 9/14 2004 Date 2004 Date

88 Appendix A

Lake Minnewashta Summer Mean Values

5.0

4.0

3.0

2.0 Secchi Depth (m) 1.0

0.0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

4 Chlorophyll a (ppb) 2

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Total Phosphorus (ppb) 10

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

40 Trophic State Index

30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

89 Appendix A Schutz Lake 2004 Grade: C Surface Area: 105 acres Total Phosphorus (TP): 49 ppb (60 TSIP) Mean Depth: Chlorophyll a: 26 ppb (62 TSIC) Maximum Depth: 49 feet Secchi Depth: 1.3 m (56 TSIS) Overall TSI: 60

2004 and long-term lake elevation data not available

90 Appendix A Schutz Lake 2004 Values

2004 Date 4/12 5/12 6/12 7/12 8/12 9/12 10/12 0.0

0.5

1.0

Secchi Depth (m) 1.5

2.0

80 70 60 50 40 30 20

Chlorophyll a (ppb) 10 0 4/12 5/12 6/12 7/12 8/12 9/12 10/12 2004 Date

Surface TP

160 140 120 100 80 60 phorus (ppb) 40 20 Phos 0 4/12 4/26 5/10 5/24 6/7 6/21 7/5 7/19 8/2 8/16 8/30 9/13 9/2710/11 2004 Date

91 Appendix A Steiger Lake 2004 Grade: C+ Surface Area: 164 acres Total Phosphorus (TP): 41 ppb (58 TSIP) Mean Depth: 11 feet Soluble Reactive P (SRP): 4 ppb Maximum Depth: 37 feet Chlorophyll a: 18 ppb (59 TSIC) Secchi Depth: 1.5 m (55 TSIS) Overall TSI: 57

2004 and long-term lake elevation data not available

92 Appendix A

Steiger Lake 2004 Values

2004 Date 6/14 6/28 7/12 7/26 8/9 8/23 9/6 0.0

0.5

1.0

1.5 Secchi Depth (m)

2.0

30 25 20 15 10 5 Chlorophyll a (ppb) 0 6/14 6/28 7/12 7/26 8/9 8/23 9/6 2004 Date

Surface TP Surface SRP Deep TP Deep SRP

60 800

600 40 400 20 200 Phosphorus (ppb)

0 0 6/14 6/28 7/12 7/26 8/9 8/23 9/6 6/14 6/28 7/12 7/26 8/9 8/23 9/6 2004 Date 2004 Date

93 Appendix A

Steiger Lake Summer Mean Values

2.5

2.0

1.5

1.0 Secchi Depth (m)

0.5

0.0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Chlorophyll a (ppb) 5

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

50 45 40 35 30 25 20 15 10 Total Phosphorus (ppb) 5 0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

40 Trophic State Index

30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

94 Appendix A Stone Lake 2004 Grade: C+ Surface Area: 100 acres Total Phosphorus (TP): 47 ppb (60 TSIP) Mean Depth: 7 feet Soluble Reactive P (SRP): 8 ppb Maximum Depth: 30 feet Chlorophyll a: 15 ppb (57 TSIC) Secchi Depth: 1.9 m (51 TSIS) Overall TSI: 56

Long-term lake elevation data not available

950

949

948

947

946

Lake Elevation (feet AMSL) 945 4/8 5/28 7/17 9/5 10/25 12/14 2004 Date

95 Appendix A

Stone Lake 2004 Values

2004 Date 6/17 7/1 7/15 7/29 8/12 8/26 9/9 9/23 0.0 0.5 1.0 1.5 2.0 2.5 Secchi Depth (m) 3.0 3.5

35 30 25 20 15 10 5 Chlorophyll a (ppb) 0 6/17 7/1 7/15 7/29 8/12 8/26 9/9 9/23 2004 Date

Surface TP Surface SRP Deep TP Deep SRP

80 2500 2000 60 1500 40 1000

Phosphorus (ppb) 20 500

0 0 6/17 7/1 7/15 7/29 8/12 8/26 9/9 9/23 6/17 7/1 7/15 7/29 8/12 8/26 9/9 9/23 2004 Date 2004 Date

96 Appendix A

Stone Lake Summer Mean Values

1.5

Secchi Depth (m) 0.5

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

10 Chlorophyll a (ppb) 5

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Total Phosphorus (ppb) 10

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

40 Trophic State Index

30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

97 Appendix A Tamarack Lake 2004 Grade: C- Surface Area: 24 acres Total Phosphorus (TP): 72 ppb (66 TSIP) Mean Depth: Chlorophyll a: 34 ppb (65 TSIC) Maximum Depth: 82 feet Secchi Depth: 1.3 m (59 TSIS) Overall TSI: 62

Long-term lake elevation data not available

970

969

968

967

966

Lake Elevation (feet AMSL) 965 4/8 5/28 7/17 9/5 10/25 12/14 2004 Date

98 Appendix A Tamarack Lake Surface Values

2004 Date 4/12 5/10 6/7 7/5 8/2 8/30 9/27 0.0

0.5

1.0

1.5

2.0 Secchi Depth (m)

2.5

3.0

100

20 Chlorophyll a (ppb)

0 4/12 5/12 6/12 7/12 8/12 9/12 10/12 2004 Date

Surface TP

200

150

100

Phosphorus (ppb) 50

0 4/12 5/10 6/7 7/5 8/2 8/30 9/27 2004 Date

99 Appendix A Tamarack Lake Summer Mean Values

2.0

1.5

1.0

Secchi Depth (m) 0.5

0.0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

10 Chlorophyll a (ppb)

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

20 Total Phosphorus (ppb)

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Trophic State Index 40

30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

100 Appendix A Wasserman Lake 2004 Grade: D+ Surface Area: 153 acres Total Phosphorus (TP): 88 ppb (69 TSIP) Mean Depth: 7 feet Soluble Reactive P (SRP): 8 ppb Maximum Depth: 41 feet Chlorophyll a: 36 ppb (66 TSIC) Secchi Depth: 1.0 m (60 TSIS) Overall TSI: 65

Long-term lake elevation data not available

948 947 946 945 944 943

Lake Elevation (feet AMSL) 942 4/8 5/28 7/17 9/5 10/25 12/14 2004 Date

101 Appendix A

Wasserman Lake 2004 Values

2004 Date 5/25 6/8 6/22 7/6 7/20 8/3 8/17 8/31 9/14 0.0

0.5

1.0

1.5 Secchi Depth (m) 2.0

70 60 50 40 30 20 10 Chlorophyll a (ppb) 0 5/25 6/8 6/22 7/6 7/20 8/3 8/17 8/31 9/14 2004 Date

Surface TP Surface SRP Deep TP Deep SRP

120 1500 100 80 1000 60 40 500 Phosphorus (ppb) 20 0 0 5/25 6/8 6/22 7/6 7/20 8/3 8/17 8/31 9/14 5/25 6/8 6/22 7/6 7/20 8/3 8/17 8/31 9/14 2004 Date 2004 Date

102 Appendix A

Wasserman Lake Summer Mean Values

1.5

1.0

0.5 Secchi Depth (m)

0.0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

20 Chlorophyll a (ppb)

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

120

100

Total Phosphorus (ppb) 20

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Trophic State Index 40

30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

103 Appendix A West Auburn Lake 2004 Grade: B- Surface Area: 140 acres Total Phosphorus (TP): 41 ppb (54 TSIP) Mean Depth: 17 feet Soluble Reactive P (SRP): 4 ppb Maximum Depth: 84 feet Chlorophyll a: 14 ppb (58 TSIC) Secchi Depth: 2.8 m (47 TSIS) Overall TSI: 53

2004 and long-term lake elevation data not available

104 Appendix A

West Auburn Lake 2004 Values

2004 Date 4/27 5/11 5/25 6/8 6/22 7/6 7/20 8/3 8/17 8/31 9/14 0.0

1.0

2.0

3.0

4.0

Secchi Depth (m) 5.0

6.0

Chlorophyll a (ppb) 5

0 4/27 5/11 5/25 6/8 6/22 7/6 7/20 8/3 8/17 8/31 9/14 2004 Date

Surface TP Surface SRP 140

120 100

Phosphorus (ppb) 20

0 4/27 5/11 5/25 6/8 6/22 7/6 7/20 8/3 8/17 8/31 9/14 2004 Date

105 Appendix A

West Auburn Lake Summer Mean Values

3.5

3.0

2.5

2.0

1.5

1.0 Secchi Depth (m)

0.5

0.0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

10 Chlorophyll a (ppb) 5

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

90 80 70 60 50 40 30 20

Total Phosphorus (ppb) 10 0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

40 Trophic State Index

30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

106 Appendix A Lake Zumbra 2004 Grade: B+ Surface Area: 162 acres Total Phosphorus (TP): 32 ppb (54 TSIP) Mean Depth: 14 feet Soluble Reactive P (SRP): 4 ppb Maximum Depth: 58 feet Chlorophyll a: 12 ppb (55 TSIC) Secchi Depth: 3.1 m (43 TSIS) . Overall TSI: 51

Long-term lake elevation data not available

945

944

943

942

941

Lake Elevation (feet AMSL) 940 4/8 5/28 7/17 9/5 10/25 12/14 2004 Date

107 Appendix A Lake Zumbra 2004 Values

2004 Date 4/27 5/11 5/25 6/8 6/22 7/6 7/20 8/3 8/17 8/31 9/14 0.0 0.5 1.0 1.5 2.0 2.5 3.0

Secchi Depth (m) 3.5 4.0 4.5

5 Chlorophyll a (ppb)

0 4/27 5/11 5/25 6/8 6/22 7/6 7/20 8/3 8/17 8/31 9/14 2004 Date

Surface TP Surface SRP 80

20 Phosphorus (ppb)

0 4/27 5/11 5/25 6/8 6/22 7/6 7/20 8/3 8/17 8/31 9/14 2004 Date

108 Appendix A

Lake Zumbra Summer Mean Values

Secchi Depth (m) 1

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

10 Chlorophyll a (ppb) 5

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Total Phosphorus (ppb) 10

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

40 Trophic State Index

30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

109 Appendix A Brownie Lake 2004 Grade: C+ Surface Area: 12 acres Total Phosphorus (TP): 45 ppb (59 TSIP) Mean Depth: Soluble Reactive P (SRP): 3 ppb Maximum Depth: 20 feet Chlorophyll a: 19 ppb (59 TSIC) Secchi Depth: 1.5 m (54 TSIS) Overall TSI: 58

Lake Calhoun Elevation History

856

854

852 Runout (851.8) Elevation (Feet, NGVD) 850

848 Jan-72 Jan-74 Jan-76 Jan-78 Jan-80 Jan-82 Jan-84 Jan-86 Jan-88 Jan-90 Jan-92 Jan-94 Jan-96 Jan-98 Jan-00 Jan-02 Jan-04

2004 elevation data not available

110 Appendix A

Brownie Lake 2004 Values

2004 Date 4/14 5/12 6/9 7/7 8/4 9/1 9/29 10/27 0.0

0.5

1.0

1.5

Secchi Depth (m) 2.0

2.5

40 30 20 10 0 Chlorophyll a (ppb) 4/14 5/14 6/14 7/14 8/14 9/14 10/14 2004 Date

Surface TP Surface SRP Deep TP Deep SRP 60 6000 5000 40 4000 3000 20 2000 1000 Phosphorus (ppb) 0 0 4/14 5/12 6/9 7/7 8/4 9/1 9/29 10/27 4/14 5/12 6/9 7/7 8/4 9/1 9/29 10/27 2004 Date 2004 Date

111 Appendix A

Brownie Lake Summer Mean Values

3.0

2.5

2.0

1.5

1.0 Secchi Depth (m) 0.5

0.0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

35 30

Chlorophyll a (ppb) 10

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

120

100

Total Phosphorus (ppb) 20

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

40 Trophic State Index

30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

112 Appendix A Lake Calhoun 2004 Grade: A Surface Area: 408 acres Total Phosphorus (TP): 15 ppb (43 TSIP) Mean Depth: 35 feet Soluble Reactive P (SRP): 4 ppb Maximum Depth: 90 feet Chlorophyll a: 3 ppb (42 TSIC) Secchi Depth: 5.2 m (36 TSIS) Overall TSI: 40

Lake Calhoun Elevation History

856

854

852 Runout (851.8) Elevation (Feet, NGVD) 850

848 Jan-72 Jan-74 Jan-76 Jan-78 Jan-80 Jan-82 Jan-84 Jan-86 Jan-88 Jan-90 Jan-92 Jan-94 Jan-96 Jan-98 Jan-00 Jan-02 Jan-04

2004 elevation data not available

113 Appendix A

Lake Calhoun 2004 Surface Values

2004 Date 4/14 5/14 6/14 7/14 8/14 9/14 10/14 0.0

1.0 2.0

3.0

4.0 5.0

Secchi Depth (m) 6.0 7.0

8.0

5 4 3 2 1

Chlorophyll a (ppb) 0 4/14 5/14 6/14 7/14 8/14 9/14 10/14 2004 Date

Surface TP Surface SRP Deep TP Deep SRP

20 100 80 60 10 40 20

Phosphorus (ppb) 0 0 4/14 5/12 6/9 7/7 8/4 9/1 9/29 10/27 4/14 5/12 6/9 7/7 8/4 9/1 9/29 10/27 2004 Date 2004 Date

114 Appendix A

Lake Calhoun Summer Mean Values

2 Secchi Depth (m) 1

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

10 Chlorophyll a (ppb) 5

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

60 50

30 20 Total Phosphorus (ppb) 10

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Trophic State Index 40

30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

115 Appendix A Cedar Lake 2004 Grade: A- Surface Area: 170 acres Total Phosphorus (TP): 25 ppb (51 TSIP) Mean Depth: 20 feet Soluble Reactive P (SRP): 3 ppb Maximum Depth: 51 feet Chlorophyll a: 7 ppb (49 TSIC) Secchi Depth: 3.7 m (41 TSIS) Overall TSI: 47

Lake Calhoun Elevation History

856

854

852 Runout (851.8) Elevation (Feet, NGVD) 850

848 Jan-72 Jan-74 Jan-76 Jan-78 Jan-80 Jan-82 Jan-84 Jan-86 Jan-88 Jan-90 Jan-92 Jan-94 Jan-96 Jan-98 Jan-00 Jan-02 Jan-04

2004 elevation data not available

116 Appendix A

Cedar Lake 2004 Surface Values

2004 Date 4/14 5/14 6/14 7/14 8/14 9/14 10/14 0.0

2.0

4.0

6.0 Secchi Depth (m) 8.0

15.0

10.0

5.0

Chlorophyll a (ppb) 0.0 4/14 5/14 6/14 7/14 8/14 9/14 10/14 2004 Date

Surface TP Surface SRP Deep TP Deep SRP 40 300 250 200 20 150 100

Phosphorus (ppb) 50 0 0 4/14 5/12 6/9 7/7 8/4 9/1 9/29 10/27 4/14 5/12 6/9 7/7 8/4 9/1 9/29 10/27 2004 Date 2004 Date

117 Appendix A

Cedar Lake Summer Mean Values

2 Secchi Depth (m)

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

10 Chlorophyll a (ppb) 5

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

160

140

120

100

40 Total Phosphorus (ppb) 20

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

40 Trophic State Index

30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

118 Appendix A Diamond Lake 2004 Grade: D Surface Area: 54 acres Total Phosphorus (TP): 178 ppb (79 TSIP) Mean Depth: Soluble Reactive P (SRP): 45 ppb Maximum Depth: 6 feet Chlorophyll a: 38 ppb (68 TSIC) Secchi Depth: 0.8 m (63 TSIS) Overall TSI: 69

2004 and long-term lake elevation data not available

119 Appendix A

Diamond Lake 2004 Values

2004 Date 4/9 5/9 6/9 7/9 8/9 9/9 10/9 0.0 0.2 0.4 0.6 0.8 1.0 Secchi Depth (m) 1.2

120 100 80 60 40 20 Chlorophyll a (ppb) 0 4/9 5/9 6/9 7/9 8/9 9/9 10/9 2004 Date

Surface TP Surface SRP 300 250 200 150 100 50

Phosphorus (ppb) 0 4/9 5/7 6/4 7/2 7/30 8/27 9/24 10/22 2004 Date

120 Appendix A

Diamond Lake Summer Mean Values

3.5

3.0

2.5

2.0

1.5

1.0 Secchi Depth (m)

0.5

0.0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

160

140

120

100

40 Chlorophyll a (ppb) 20

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

250

200

150

100

50 Total Phosphorus (ppb)

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

40 Trophic State Index

30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

121 Appendix A Grass Lake 2004 Grade: C+ Surface Area: Total Phosphorus (TP): 68 ppb (65 TSIP) Mean Depth: Soluble Reactive P (SRP): 6 ppb Maximum Depth: Chlorophyll a: 15 ppb (57 TSIC) Secchi Depth: n/a Overall TSI: 61

2004 and long-term lake elevation data not available

122 Appendix A

Grass Lake 2004 Values

No Secchi disk transparency data

25 20 15 10 5

Chlorophyll a (ppb) 0 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 2004 Date

Surface TP Surface SRP 120

100 80 60 40

Phosphorus (ppb) 20 0 5/4 5/18 6/1 6/15 6/29 7/13 7/27 8/10 8/24 9/7 2004 Date

123 Appendix A

Grass Lake Summer Mean Values

0.6

0.5

0.4

0.3

0.2 Secchi Depth (m)

0.1

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

900

800

700

600

500

400

300

Chlorophyll a (ppb) 200

100

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

700

600

500

400

300

200

Total Phosphorus (ppb) 100

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

100

Trophic State Index 40

30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

124 Appendix A Lake Harriet 2004 Grade: A Surface Area: 353 acres Total Phosphorus (TP): 15 ppb (47 TSIP) Mean Depth: 29 feet Soluble Reactive P (SRP): 4 ppb Maximum Depth: 82 feet Chlorophyll a: 3 ppb (45 TSIC) Secchi Depth: 5.2 m (37 TSIS) Overall TSI: 43

Lake Harriet Elevation History

849

848.5

848

847.5

847

846.5 Elevation (Feet, NGVD)

846

845.5

845 Jan-72 Jan-74 Jan-76 Jan-78 Jan-80 Jan-82 Jan-84 Jan-86 Jan-88 Jan-90 Jan-92 Jan-94 Jan-96 Jan-98 Jan-00 Jan-02 Jan-04

2004 elevation levels not available

125 Appendix A

Lake Harriet 2004 Values

2004 Date 4/21 5/21 6/21 7/21 8/21 9/21 10/21 0.0

2.0

4.0

6.0

8.0 Secchi Depth (m) 10.0

9 8 7 6 5 4 3

Chlorophyll a (ppb) 2 1 0 4/21 5/21 6/21 7/21 8/21 9/21 10/21 2004 Date

Surface TP Surface SRP Deep TP Deep SRP 100

20 80 60 10 40 20 Phosphorus (ppb) 0 0 4/14 5/12 6/9 7/7 8/4 9/1 9/29 10/27 4/14 5/12 6/9 7/7 8/4 9/1 9/29 10/27 2004 Date 2004 Date

126 Appendix A

Lake Harriet Summer Mean Values

Secchi Depth (m) 2

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Chlorophyll a (ppb) 4

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

20 Total Phosphorus (ppb) 10

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

40 Trophic State Index

30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

127 Appendix A Lake Hiawatha 2004 Grade: C+ Surface Area: 54 acres Total Phosphorus (TP): 68 ppb (65 TSIP) Mean Depth: 15 feet Soluble Reactive P (SRP): 15 ppb Maximum Depth: 30 feet Chlorophyll a: 17 ppb (58 TSIC) Secchi Depth: 1.3 m (56 TSIS) Overall TSI: 60

Lake Hiawatha Elevation History

817.00

816.00

815.00

814.00

813.00

812.00 Elevation (Feet, NGVD)

811.00

810.00

809.00 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04

2004 elevation data not available

128 Appendix A

Lake Hiawatha 2004 Values

2004 Date 4/22 5/22 6/22 7/22 8/22 9/22 10/22 0.0 0.5 1.0 1.5 2.0 Secchi Depth (m) 2.5

50 40 30 20 10

Chlorophyll a (ppb) 0 4/22 5/22 6/22 7/22 8/22 9/22 10/22 2004 Date

Surface TP Surface SRP Deep TP Deep SRP 120 120

100 100 80 80 60 60 40 40

Phosphorus (ppb) 20 20 0 0 4/22 5/20 6/17 7/15 8/12 9/9 10/7 11/4 4/22 5/20 6/17 7/15 8/12 9/9 10/7 11/4 2004 Date 2004 Date

129 Appendix A

Lake Hiawatha Summer Mean Values

2.5

2.0

1.5

1.0 Secchi Depth (m)

0.5

0.0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

20 Chlorophyll a (ppb)

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

200 180 160 140 120 100 80 60 Total Phosphorus (ppb) 40 20 0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

40 Trophic State Index

30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

130 Appendix A Lake of the Isles 2004 Grade: C Surface Area: 103 acres Total Phosphorus (TP): 50 ppb (61 TSIP) Mean Depth: 9 feet Soluble Reactive P (SRP): 4 ppb Maximum Depth: 31 feet Chlorophyll a: 28 ppb (63 TSIC) Secchi Depth: 1.8 m (51 TSIS) Overall TSI: 58

Lake Calhoun Elevation History

856

854

852 Runout (851.8) Elevation (Feet, NGVD) 850

848 Jan-72 Jan-74 Jan-76 Jan-78 Jan-80 Jan-82 Jan-84 Jan-86 Jan-88 Jan-90 Jan-92 Jan-94 Jan-96 Jan-98 Jan-00 Jan-02 Jan-04

2004 elevation data not available

131 Appendix A

Lake of the Isles 2004 Values

2004 Date 4/14 5/14 6/14 7/14 8/14 9/14 10/14 0.0 1.0 2.0 3.0 4.0

Secchi Depth (m) 5.0 6.0

60 50 40 30 20 10 Chlorophyll a (ppb) 0 4/14 5/14 6/14 7/14 8/14 9/14 10/14 2004 Date

Surface TP Surface SRP Deep TP Deep SRP 80 200

60 150 us (ppb) 40 100

20 50 Phosphor 0 0 4/14 5/12 6/9 7/7 8/4 9/1 9/29 10/27 4/14 5/12 6/9 7/7 8/4 9/1 9/29 10/27 2004 Date 2004 Date

132 Appendix A

Lake of the Isles Summer Mean Values

2.5

2.0

1.5

1.0 Secchi Depth (m)

0.5

0.0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

160

140

120

100

Chlorophyll a (ppb) 40

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

250

200

150

100 Total Phosphorus (ppb) 50

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

40 Trophic State Index

30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

133 Appendix A Lake Nokomis 2004 Grade: D+ Surface Area: 204 acres Total Phosphorus (TP): 80 ppb (67 TSIP) Mean Depth: 14 feet Soluble Reactive P (SRP): 4 ppb Maximum Depth: 33 feet Chlorophyll a: 28 ppb (63 TSIC) Secchi Depth: 1.0 m (60 TSIS) Overall TSI: 64

Lake Nokomis Elevation History

818

817

816

Runout (815.1)

815 Elevation (Feet, NGVD)

814

813 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04

Note: Graph does not include 21 APR 82 @ 815.82 and 2 SEP 82 @ 815.40

2004 elevation data not available

134 Appendix A

Lake Nokomis 2004 Values

2004 Date 4/19 5/19 6/19 7/19 8/19 9/19 10/19 0.0

0.5

1.0

1.5 Secchi Depth (m) 2.0

50 40 30 20 10

Chlorophyll a (ppb) 0 4/19 5/19 6/19 7/19 8/19 9/19 10/19 2004 Date

Surface TP Surface SRP Deep TP Deep SRP 250

160 140 120 200 100 150 80 60 100 40 50 Phosphorus (ppb) 20 0 0 4/19 5/17 6/14 7/12 8/9 9/6 10/4 4/19 5/17 6/14 7/12 8/9 9/6 10/4 2004 Date 2004 Date

135 Appendix A

Lake Nokomis Summer Mean Values

2.5

2.0

1.5

1.0 Secchi Depth (m)

0.5

0.0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

Chlorophyll a (ppb) 20

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

120

100

40 Total Phosphorus (ppb) 20

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

40 Trophic State Index

30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

136 Appendix A Powderhorn Lake 2004 Grade: D+ Surface Area: 11 acres Total Phosphorus (TP): 118 ppb (73 TSIP) Mean Depth: Soluble Reactive P (SRP): 9 ppb Maximum Depth: 20 feet Chlorophyll a: 37 ppb (66 TSIC) Secchi Depth: 0.7 m (66 TSIS) Overall TSI: 68

2004 and long-term lake elevation data not available

137 Appendix A

Powderhorn Lake 2004 Values

2004 Date 4/22 5/22 6/22 7/22 8/22 9/22 10/22 0.0 0.2 0.4 0.6 0.8

Secchi Depth (m) 1.0 1.2

Chlorophyll a (ppb) 0 4/22 5/20 6/17 7/15 8/12 9/9 10/7 2004 Date

Surface TP Surface SRP Deep TP Deep SRP 200 200

150 150

100 100

50 50 Phosphorus (ppb) 0 0 4/22 5/20 6/17 7/15 8/12 9/9 4/22 5/20 6/17 7/15 8/12 9/9 10/7 2004 Date 2004 Date

138 Appendix A

Powderhorn Lake Summer Mean Values

0.8

0.7

0.6

0.5

0.4

0.3 Secchi Depth (m) 0.2

0.1

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

100 90 80 70 60 50 40 30 Chlorophyll a (ppb) 20 10 0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

200 180 160 140 120 100 80 60 Total Phosphorus (ppb) 40 20 0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

40 Trophic State Index

30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

139 Appendix A

Twin Lake (St. Louis Park) 2004 Grade: D Surface Area: 24 acres Total Phosphorus (TP): 174 ppb (79 TSIP) Mean Depth: Chlorophyll a: 51 ppb (69 TSIC) Maximum Depth: Secchi Depth: 0.7 m (65 TSIS) Overall TSI: 71

2004 and long-term lake elevation data not available

140 Appendix A

Twin Lake (St. Louis Park) Surface Values

2004 Date 4/24 5/24 6/24 7/24 8/24 9/24 0 0.2 0.4 0.6 0.8

Secchi Depth (m) 1 1.2

160 140 120 100 80 60 40 Chlorophyll a (ppb) 20 0 4/24 5/24 6/24 7/24 8/24 9/24 2004 Date

Surface TP

400

300 P (ppb)

T 200 100 0 4/24 5/8 5/22 6/5 6/19 7/3 7/17 7/31 8/14 8/28 9/11 9/25 10/9 2004 Date

141 Appendix A

Twin Lake (St. Louis Park) Summer Mean Values

2.5

1.5

Secchi Depth (m) 0.5

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

250

200

150

100

50 Chlorophyll a (ppb)

0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

800

700

600

500

400

300

200

100 Total Phosphorus (ppb) 0 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003

40 Trophic State Index 30 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 Year

142 Appendix A

Windsor Lake 2004 Grade: D- Surface Area: Total Phosphorus (TP): 193 ppb (80 TSIP) Mean Depth: Chlorophyll a: 49 ppb (69 TSIC) Maximum Depth: Secchi Depth: 0.7 m (65 TSIS) Overall TSI: 71

2004 and long-term lake elevation data not available

143 Appendix A Windsor Lake 2004 Values

2004 Date 4/18 5/18 6/18 7/18 8/18 9/18 0.0 0.2 0.4 0.6 0.8

Secchi Depth (m) 1.0 1.2

120 100 80 60 40 20 Chlorophyll a (ppb) 0 4/18 5/18 6/18 7/18 8/18 9/18 2004 Date

Surface TP

300

200

100 Phosphorus (ppb) 0 4/18 5/16 6/13 7/11 8/8 9/5 10/3 2004 Date

144 Appendix B

2004 Stream Report Cards

1 Appendix B Minnehaha Creek Site: CMH07 – Grays Bay Dam, City of Minnetonka Drainage Area: 125 sq. mi.

Land Use

Agricultural 0% Lake 9% Open 21% Residential 51% Wetland 8% Wooded 7%

350 150 300 250 100 200 150

Flow (cfs) 50 100 50 Average Flow (cfs) 0 0 3/4 4/23 6/12 8/1 9/20 11/9 2001 2002 2003 2004 2004 Date Year

12 800 10 700 600 8 500 6 400

(per 100 mL) 300 4 200

2 E. coli 100 Dissolved Oxygen (mg/L) 0 0 4/15 5/15 6/15 7/15 8/15 9/15 10/15 7/27 8/10 8/24 9/7 9/21 10/5 2004 Date 2004 Date

2 Appendix B

Minnehaha Creek (CMH07) 2004 Flow-Weighted Concentrations and Loads

4 700 600 3 500 400 2 300 1 200

Mean TSS (ppm) 100 0 0 TSS Load (1000*lbs) 2001 2002 2003 2004 Year

40 6000 5000 30 4000 20 3000 2000 10 TP Load (lbs)

Mean TP (ppb) 1000 0 0 2001 2002 2003 2004 Year

46 12000 10000 45 8000 44 6000 4000 43

Mean Cl (ppm) 2000 42 0 Cl Load (1000*lbs) 2001 2002 2003 2004 Year

3 Appendix B Minnehaha Creek Site: CMH19 – I-494, City of Minnetonka Drainage Area: 130.43 sq. mi.

Land Use

Agricultural 0% Lake 9% Open 21% Residential 51% Wetland 8% Wooded 7%

250 100 200 80 150 60 100 40 Flow (cfs) 50 20

0 Average Flow (cfs) 0 3/4 4/23 6/12 8/1 9/20 11/9 12/29 1997 1998 1999 2000 2001 2002 2003 2004 2004 Date Year

16 14 12 10 8 No E. Coli 6 sampling 4 2 Dissolved Oxygen (mg/L) 0 3/2 5/2 7/2 9/2 11/2 2004 Date

4 Appendix B

Minnehaha Creek (CMH19) 2004 Flow-Weighted Concentrations and Loads

20 1200 1000 15 800 10 600 400 5 200 Mean TSS (ppm)

0 0 TSS Load (1000*lbs) 1997 1998 1999 2000 2001 2002 2003 2004 Year

150 7000 6000 100 5000 4000 3000 50 2000 TP Load (lbs) Mean TP (ppb) 1000 0 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

250 12000 200 10000 8000 150 6000 100 4000

Mean Cl (ppm) 50 2000 Cl Load (1000*lbs) 0 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

5 Appendix B Minnehaha Creek Site: CMH02 – West 34th Street, City of Minnetonka Drainage Area: 137.95 sq. mi.

Land Use

Agricultural 0% Lake 9% Open 21% Residential 51% Wetland 8% Wooded 7%

120 300 100 250 80 200 150 60 100 40 Flow (cfs) 50 20 Average Flow (cfs) 0 0 3/2 5/2 7/2 9/2 11/2 1997 1998 1999 2000 2001 2002 2003 2004 2004 Date Year

14 600 12 500 10 400 8 300

6 (per 100 mL) 200 4 100 2 E. coli Dissolved Oxygen (mg/L) 0 0 3/2 5/2 7/2 9/2 11/2 7/12 8/1 8/21 9/10 9/30 10/20 2004 Date 2004 Date

6 Appendix B

Minnehaha Creek (CMH02) 2004 Flow-Weighted Concentrations and Loads

12 1200 10 1000 8 800 6 600 4 400 2 200 Mean TSS (ppm)

0 0 TSS Load (1000*lbs) 1997 1998 1999 2000 2001200220032004 Year

120 12000 100 10000 80 8000 60 6000 40 4000 TP Load (lbs)

Mean TP (ppb) 20 2000 0 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

140 12000 120 10000 100 8000 80 6000 60 40 4000

Mean Cl (ppm) 20 2000 Cl Load (1000*lbs) 0 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

7 Appendix B Minnehaha Creek Site: CMH11 – Excelsior Boulevard, City of St. Louis Park Drainage Area: 141.1 sq. mi.

Land Use

Agricultural 0% Lake 9% Open 21% Residential 51% Wetland 8% Wooded 7%

400 100

300 80 60 200 40 Flow (cfs) 100 20

0 Average Flow (cfs) 0 3/2 5/2 7/2 9/2 11/2 1999 2000 2001 2002 2003 2004 2004 Date Year

14 1000 9/14: 6500/100 mL 12 800 10 8 600

6 (per 100 mL) 400 4 200

2 E. coli

Dissolved Oxygen (mg/L) 0 0 3/2 5/2 7/2 9/2 11/2 7/12 8/1 8/21 9/10 9/30 10/20 2004 Date 2004 Date

8 Appendix B

Minnehaha Creek (CMH11) 2004 Flow-Weighted Concentrations and Loads

30 1200 25 1000 20 800 15 600 10 400

Mean TSS (ppm) 5 200 TSS Load (1000*lbs) 0 0 1999 2000 2001 2002 2003 2004 Year

200 14000 12000 150 10000 8000 100 6000 4000 50 TP Load (lbs) Mean TP (ppb) 2000 0 0 1999 2000 2001 2002 2003 2004 Year

100 12000 80 10000 8000 60 6000 40 4000 20

Mean Cl (ppm) 2000 0 0 Cl Load (1000*lbs) 1999 2000 2001 2002 2003 2004 Year

9 Appendix B Minnehaha Creek Site: CMH03 – Browndale Dam, City of Edina Drainage Area: 143.6 sq. mi.

Land Use

Agricultural 0% Lake 9% Open 21% Residential 51% Wetland 8% Wooded 7%

120 250 100 200 80 150 60 100 40 Flow (cfs) 50 20 Average Flow (cfs) 0 0 3/25 5/25 7/25 9/25 1997 1998 1999 2000 2001 2002 2003 2004 2004 Date Year

16 600 14 500 12 400 10 8 300 (per 100 mL) 6 200 4 100 2 E. coli Dissolved Oxygen (mg/L) 0 0 3/25 4/25 5/25 6/25 7/25 8/25 9/25 10/25 7/27 8/10 8/24 9/7 9/21 10/5 2004 Date 2004 Date

10 Appendix B

Minnehaha Creek (CMH03) 2004 Flow-Weighted Concentrations and Loads

16 8000 14 7000 12 6000 10 5000 8 4000 6 3000 4 2000 Mean TSS (ppm)

2 1000 TSS Load (1000*lbs) 0 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

140 14000 120 12000 100 10000 80 8000 60 6000

40 4000 TP Load (lbs) Mean TP (ppb) 20 2000 0 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

120 14000 100 12000 80 10000 8000 60 6000 40 4000 Mean Cl (ppm) 20 2000 Cl Load (1000*lbs) 0 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

11 Appendix B Minnehaha Creek Site: CMH12 – Upton Avenue, City of Minneapolis Drainage Area: 173.1 sq. mi.

Land Use

Agricultural 0% Lake 9% Open 21% Residential 51% Wetland 8% Wooded 7%

400 120 100 300 80 200 60 40 Flow (cfs) 100 20 0 Average Flow (cfs) 0 3/2 5/2 7/2 9/2 11/2 1999 2000 2001 2002 2003 2004 2004 Date Year

18 800 16 700 9/14: 31,000/100 mL 14 600 12 500 10 400

8 (per 100 mL) 300 6 200 4 E. coli 100

Dissolved Oxygen (mg/L) 2 0 0 3/2 5/2 7/2 9/2 11/2 7/12 8/1 8/21 9/10 9/30 10/20 2004 Date 2004 Date

12 Appendix B

Minnehaha Creek (CMH12) 2004 Flow-Weighted Concentrations and Loads

80 3000 2500 60 2000 40 1500 1000 20

Mean TSS (ppm) 500 0 0 TSS Load (1000*lbs) 1999 2000 2001 2002 2003 2004 Year

300 16000 250 14000 12000 200 10000 150 8000 100 6000

4000 TP Load (lbs) Mean TP (ppb) 50 2000 0 0 1999 2000 2001 2002 2003 2004 Year

140 16000 120 14000 100 12000 10000 80 8000 60 6000 40 Mean Cl (ppm) 4000 20 2000 Cl Load (1000*lbs) 0 0 1999 2000 2001 2002 2003 2004 Year

13 Appendix B Minnehaha Creek Site: CMH05 – Chicago Avenue, City of Minneapolis Drainage Area: 166.9 sq. mi.

Land Use

Agricultural 0% Lake 9% Open 21% Residential 51% Wetland 8% Wooded 7%

300 120 250 100 200 80 150 60 100 40 Flow (cfs) 50 20 0 Average Flow (cfs) 0 3/2 5/2 7/2 9/2 11/2 1997 1998 1999 2000 2001 2002 2003 2004 2004 Date Year

16 2500 14 2000 12 9/14: 74,000/100 mL 10 1500 8

6 (per 100 mL) 1000 4 500 2 E. coli Dissolved Oxygen (mg/L) 0 0 3/2 5/2 7/2 9/2 11/2 7/12 8/1 8/21 9/10 9/30 10/20 2004 Date 2004 Date

14 Appendix B

Minnehaha Creek (CMH05) 2004 Flow-Weighted Concentrations and Loads

50 3000

40 2500 2000 30 1500 20 1000

Mean TSS (ppm) 10

500 TSS Load (1000*lbs) 0 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

200 16000 14000 150 12000 10000 100 8000 6000 TP Load (lbs)

Mean TP (ppb) 50 4000 2000 0 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

100 12000

80 10000 8000 60 6000 40 4000

Mean Cl (ppm) 20

2000 Cl Load (1000*lbs) 0 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

15 Appendix B Minnehaha Creek Site: CMH17 – 32nd Avenue, City of Minneapolis Drainage Area: 173.1 sq. mi.

Land Use

Agricultural 0% Lake 9% Open 21% Residential 51% Wetland 8% Wooded 7%

250 120 200 100 80 150 60 100 40 Flow (cfs) 50 20 0 Average Flow (cfs) 0 1/14 4/23 8/1 11/9 1999 2000 2001 2002 2003 2004 2004 Date Year

25 1200 9/14: 2500/100 mL 20 1000 800 15 600

10 (per 100 mL) 400 5 200 E. coli 0 Dissolved Oxygen (mg/L) 0 3/2 5/2 7/2 9/2 11/2 7/12 8/1 8/21 9/10 9/30 10/20 2004 Date 2004 Date

16 Appendix B

Minnehaha Creek (CMH17) 2004 Flow-Weighted Concentrations and Loads

20 1600 1400 15 1200 1000 10 800 600 5 400 Mean TSS (ppm)

200 TSS Load (1000*lbs) 0 0 1999 2000 2001 2002 2003 2004 Year

140 16000 120 14000 100 12000 10000 80 8000 60 6000

40 TP Load (lbs)

Mean TP (ppb) 4000 20 2000 0 0 1999 2000 2001 2002 2003 2004 Year

80 14000 70 12000 60 10000 50 8000 40 6000 30

Mean Cl (ppm) 20 4000 Cl Load (1000*lbs) 10 2000 0 0 1999 2000 2001 2002 2003 2004 Year

17 Appendix B Christmas Creek Site: CCH01 – Christmas Lake Outlet, City of Excelsior Drainage Area: 1.13 sq. mi.

Land Use

Agricultural 27% Lake 6% Open 14% Residential 25% Wetland 12% Wooded 13%

15 1.0 0.8 10 0.6 0.4

Flow (cfs) 5 0.2

0 Average Flow (cfs) 0.0 4/1 5/1 6/1 7/1 8/1 9/1 1997 1998 1999 2000 2001 2002 2003 2004 2004 Date Year

12 10 8 6 No E. Coli 4 sampling 2

Dissolved Oxygen (mg/L) 0 6/2 6/16 6/30 7/14 7/28 8/11 8/25 2004 Date

18 Appendix B

Christmas Creek 2004 Flow-Weighted Concentrations and Loads

30 35 25 30 20 25 20 15 15 (1000*lbs) 10 10 TSS Load

Mean TSS (ppm) 5 5 0 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

90 90 80 80 70 70 60 60 50 50 40 40 30 30 TP Load (lbs) Mean TP (ppb) 20 c 20 10 10 0 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

35 40 30 35 25 30 25 20 20 15

15 Cl Load 10 (1000*lbs) Mean Cl (ppm) 10 5 5 0 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

19 Appendix B Classen Creek Site: CCL01 – Classen Creek, City of Orono Drainage Area: 2.89 sq. mi.

Land Use

Agricultural 19% Lake 9% Open 3% Residential 10% Wetland 17% Wooded 38%

40 2.5

30 2 1.5 20 1 Flow (cfs) 10 0.5

0 Average Flow (cfs) 0 4/23 6/12 8/1 9/20 11/9 1997 1998 1999 2000 2001 2002 2003 2004 2004 Date Year

12 10 8 6 No E. Coli 4 sampling 2 0

Dissolved Oxygen (mg/L) 8/4 8/18 9/1 9/15 9/29 10/13 2004 Date

20 Appendix B

Classen Creek 2004 Flow-Weighted Concentrations and Loads

140 350 120 300 100 250 80 200 60 150 40 100

Mean TSS (ppm) 20 50 TSS Load (1000*lbs) 0 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

500 1200 450 400 1000 350 800 300 250 600 200 400 TP Load (lbs)

Mean TP (ppb) 150 100 200 50 0 0 1997 1998 1999 2000 2001 2002 2003 2004

100 250

80 200

60 150

40 100

Mean Cl (ppm) 20 50 Cl Load (1000*lbs) 0 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

21 Appendix B Dutch Creek Site: CDU01 – Dutch Lake Creek, City of Mound Drainage Area: 2.89 sq. mi.

Land Use

Agricultural 5% Lake 7% Open 10% Residential 58% Wetland 7% Wooded 4%

14 2.5 12 2.0 10 8 1.5 6 1.0 Flow (cfs) 4 2 0.5

0 Average Flow (cfs) 0.0 3/2 4/2 5/2 6/2 7/2 8/2 9/2

10/2 11/2 1997 1998 1999 2000 2001 2002 2003 2004 2004 Date Year

16 14 12 10 8 6 No E. Coli 4 sampling 2 Dissolved Oxygen (mg/L) 0 3/2 4/2 5/2 6/2 7/2 8/2 9/2 10/2 11/2

2004 Date

22 Appendix B

Dutch Creek 2004 Flow-Weighted Concentrations and Loads

70 300

60 250 50 200 40 150 30 100 20 Mean TSS (ppm)

10 50 TSS Load (1000*lbs) 0 0 1997 1998 1999 20002001 2002 2003 2004 Year

250 1000

200 800

150 600

100 400 TP Load (bls) Mean TP (ppb) 50 200

0 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

40 160 35 140 30 120 25 100 20 80 15 60

Mean Cl (ppm) 10 40 Cl Load (1000*lbs) 5 20 0 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

23 Appendix B Gleason Creek Site: CGL01 – Gleason Lake Outlet, City of Wayzata Drainage Area: 3.85 sq. mi.

Land Use

Agricultural 5% Lake 7% Open 10% Residential 58% Wetland 7% Wooded 4%

25 5.0 20 4.0 15 3.0 10 2.0 Flow (cfs) 5 1.0

0 Average Flow (cfs) 0.0 4/8 5/8 6/8 7/8 8/8 9/8 1997 1998 1999 2000 2001 2002 2003 2004 2004 Date Year

12 10 8 6 4 No E. Coli 2 sampling 0 Dissolved Oxygen (mg/L) 5/2 6/2 7/2 8/2 9/2 2004 Date

24 Appendix B

Gleason Creek 2004 Flow-Weighted Concentrations and Loads

35 150 30 25 100 20 15 10 50

Mean TSS (ppm) 5 0 0 TSS Load (1000*lbs) 1997 1998 1999 2000 2001 2002 2003 2004 Year

140 1600 120 1400 100 1200 1000 80 800 60 600

40 TP Load (lbs)

Mean TP (ppb) 400 20 200 0 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

95 2500

90 2000

85 1500

80 1000

Mean Cl (ppm) 75 500 Cl Load (1000*lbs)

70 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

25 Appendix B Langdon Creek Site: CLA01 – Langdon Lake Outlet, City of Mound Drainage Area: 1.68 sq. mi.

Land Use

Agricultural 19% Lake 21% Open 10% Residential 19% Wetland 7% Wooded 24%

6 1.5 5 4 1.0 3 2 0.5 Flow (cfs) 1 0 Average Flow (cfs) 0.0 4/28 5/28 6/28 7/28 8/28 1997 1998 1999 2000 2001 2002 2003 2004 2004 Date Year

12 10 8 6 4 No E. Coli 2 sampling 0 Dissolved Oxygen (mg/L) 4/21 5/19 6/16 7/14 8/11 9/8 2004 Date

26 Appendix B

Langdon Creek 2004 Flow-Weighted Concentrations and Loads

600 50

500 40 400 30 300 20 200

Mean TSS (ppm) 10 100 TSS Load (1000*lbs) 0 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

800 300 700 250 600 200 500 400 150 300 100 TP Load (lbs)

Mean TP (ppb) 200 50 100 0 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

50 90.00 80.00 40 70.00 60.00 30 50.00 40.00 20 30.00 Mean Cl (ppm)

10 20.00 Cl Load (1000*lbs) 10.00 0 0.00 1997 1998 1999 2000 2001 2002 2003 2004 Year

27 Appendix B Long Lake Creek Site: CLO01 – Long Lake Outlet, City of Long Lake Drainage Area: 10.88 sq. mi.

Land Use

Agricultural 37% Lake 9% Open 6% Residential 20% Wetland 9% Wooded 17%

200 15

150 10 100 5 Flow (cfs) 50

0 Average Flow (cfs) 0 4/1 6/1 8/1 10/1 1997 1998 1999 2000 2001 2002 2003 2004 2004 Date Year

5 No E. Coli sampling 0 Dissolved Oxygen (mg/L) 4/1 6/1 8/1 10/1 2004 Date

28 Appendix B

Long Lake Creek (CLO01) 2004 Flow-Weighted Concentrations and Loads

18 200 16 14 150 12 10 100 8 6 50

Mean TSS (ppm) 4

2 TSS Load (1000*lbs) 0 0 1997 199819992000 2001 200220032004 Year

120 2500 100 2000 80 1500 60 1000 40 TP Load (lbs) Mean TP (ppb) 20 500 0 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

60 1200 50 1000 40 800 30 600 20 400

Mean Cl (ppm) 10 200 0 0 Cl Load (1000*lbs) 1997 1998 1999 2000 2001 20022003 2004 Year

29 Appendix B Long Lake Creek Site: CLO02 – Long Lake Creek at Brown Road, City of Orono Drainage Area: 12.39 sq. mi.

Land Use

Agricultural 37% Lake 9% Open 6% Residential 20% Wetland 9% Wooded 17%

12 60 10 50 8 40 6 30 4

Flow (cfs) 20 2 10 Average Flow (cfs) 0 0 3/4 4/23 6/12 8/1 9/20 11/9 1997 1998 1999 2000 2001 2002 2003 2004 2004 Date Year

16 14 12 10 8 6 4 No E. Coli 2 sampling Dissolved Oxygen (mg/L) 0

4/1 5/1 6/1 7/1 8/1 9/1

2004 Date

30 Appendix B

Long Lake Creek (CLO02) 2004 Flow-Weighted Concentrations and Loads

20 500

400 15 300 10 200

Mean TSS (ppm) 5 100 TSS Load (1000*lbs)

0 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

200 3000 2500 150 2000 100 1500 1000 TP Load (lbs)

Mean TP (ppb) 50 500 0 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

60 1200 50 1000

40 800 30 600 20 400 Mean Cl (ppm)

10 200 Cl Load (1000*lbs) 0 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

31 Appendix B Painters Creek Site: CPA01 – West Branch Road, City of Minnestrista Drainage Area: 15.4 sq. mi.

Land Use

Agricultural 34% Lake 3% Open 17% Residential 10% Wetland 22% Wooded 13%

120 20 100 15 80 60 10

Flow (cfs) 40 5

20 Average Flow (cfs) 0 0 3/25 4/22 5/20 6/17 7/15 8/12 9/9 10/7 1997 1998 1999 2000 2001 2002 2003 2004 2004 Date Year

16 600 9/14: 2400/100 mL 14 500 12 400 10 8 300 6 (per 100 mL) 200 4 100 E. coli

Dissolved Oxygen (mg/L) 2 0 0 3/2 3/30 4/27 5/25 6/22 7/20 8/17 9/14 10/12 7/12 8/1 8/21 9/10 9/30 10/20 2004 Date 2004 Date

32 Appendix B

Painters Creek (CPA01) 2004 Flow-Weighted Concentrations and Loads

18 400 16 350 14 300 12 250 10 200 8 6 150

Mean TSS (ppm) 4 100 TSS Load (1000*lbs) 2 50 0 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

450 10000 400 9000 350 8000 300 7000 6000 250 5000 200 4000

150 TP Load (lbs)

Mean TP (ppb) 3000 100 2000 50 1000 0 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

60 1400

50 1200 1000 40 800 30 600 20 Mean Cl (ppm) 400 Cl Load (1000*lbs) 10 200

0 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

33 Appendix B Painters Creek Site: CPA02 – County Road 6, City of Minnestrista Drainage Area: 8.2 sq. mi.

Land Use

Agricultural 34% Lake 3% Open 17% Residential 10% Wetland 22% Wooded 13%

20 6 5 15 4 10 3 2 Flow (cfs) 5 1 0 Average Flow (cfs) 0 3/4 4/23 6/12 8/1 9/20 11/9 12/29 2002 2003 2004 2004 Date Year

14 12 10 8 6 No E. Coli 4 sampling 2 Dissolved Oxygen (mg/L) 0 3/2 5/2 7/2 9/2 11/2 2004 Date

34 Appendix B

Painters Creek (CPA02) 2004 Flow-Weighted Concentrations and Loads

10 120 100 9 80 9 60 40 8 20 Mean TSS (ppm)

8 0 TSS Load (1000*lbs) 2002 2003 2004 Year

400 2500

300 2000 1500 200 1000 100 500 TP Load (lbs) Mean TP (ppb) 0 0 2002 2003 2004 Year

43 500.00 42 400.00 41 300.00 40 200.00 39 100.00 Mean Cl (ppm) 38 37 0.00 Cl Load (1000*lbs) 2002 2003 2004 Year

35 Appendix B Painters Creek Site: CPA03 – County Road 6 at Deborah Drive, City of Minnestrista Drainage Area: 7.11 sq. mi.

Land Use

Agricultural 34% Lake 3% Open 17% Residential 10% Wetland 22% Wooded 13%

20 8

15 6

10 4

Flow (cfs) 5 2

0 Average Flow (cfs) 0 3/4 4/23 6/12 8/1 9/20 11/9 12/29 2001 2002 2003 2004 2004 Date Year

16 14 12 10 8 6 No E. Coli 4 sampling 2 Dissolved Oxygen (mg/L) 0 3/25 4/25 5/25 6/25 7/25 8/25 9/25 10/25 2004 Date

36 Appendix B

Painters Creek (CPA03) 2004 Flow-Weighted Concentrations and Loads

8 100

6 80 60 4 40 2 20 Mean TSS (ppm)

0 0 TSS Load (1000*lbs) 2001 2002 2003 2004 Year

400 3000 2500 300 2000 200 1500 1000 100 TP Load (lbs)

Mean TP (ppb) 500 0 0 2001 2002 2003 2004 Year

41 600 40 500 39 400 38 300 37 200

Mean Cl (ppm) 36 100 35 0 Cl Load (1000*lbs) 2001 2002 2003 2004 Year

37 Appendix B Painters Creek Site: CPA04 – County Road 26, City of Minnestrista Drainage Area: 9.4 sq. mi.

Land Use

Agricultural 34% Lake 3% Open 17% Residential 10% Wetland 22% Wooded 13%

80 20

60 15

40 10

Flow (cfs) 20 5

0 Average Flow (cfs) 0 3/25 4/25 5/25 6/25 7/25 8/25 2002 2003 2004 2004 Date Year

14 12 10 8 6 No E. Coli 4 sampling 2 Dissolved Oxygen (mg/L) 0 3/25 4/25 5/25 6/25 7/25 8/25 2004 Date

38 Appendix B

Painters Creek (CPA04) 2004 Flow-Weighted Concentrations and Loads

10 300 8 250 200 6 150 4 100 2 50 Mean TSS (ppm)

0 0 TSS Load (1000*lbs) 2002 2003 2004 Year

400 10000

300 8000 6000 200 4000 100 2000 TP Load (lbs) Mean TP (ppb) 0 0 2002 2003 2004 Year

50 1500 40 1000 30 20 500 10 Mean Cl (ppm) 0 0 Cl Load (1000*lbs) 2002 2003 2004 Year

39 Appendix B Six Mile Creek Site: CSI01 – Lunsten Lake Outlet, Carver Park Reserve Drainage Area: 17.35 sq. mi.

Land Use

Agricultural 37% Lake 18% Open 16% Residential 5% Wetland 14% Wooded 10%

100 16 14 80 12 60 10 40 8

Flow (cfs) 6 20 4 Average Flow (cfs) 0 2 0 5/1 5/29 6/26 7/24 8/21 9/18 1997 1998 1999 2000 2001 2002 2003 2004 2004 Date Year

14 12 10 8 6 No E. Coli 4 sampling 2 Dissolved Oxygen (mg/L) 0 4/1 5/1 6/1 7/1 8/1 9/1 10/1 2004 Date

40 Appendix B

Six Mile Creek (CSI01) 2004 Flow-Weighted Concentrations and Loads

14 400 12 350 10 300 250 8 963 200 6 150 4 100 Mean TSS (ppm)

2 50 TSS Load (1000*lbs) 0 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

120 3500

100 3000 2500 80 2000 60 1500 40 TP Load (lbs)

Mean TP (ppb) 1000 20 500 0 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

30 1200 25 1000 20 800 15 600 10 400 Mean Cl (ppm)

5 200 Cl Load (1000*lbs) 0 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

41 Appendix B Six Mile Creek Site: CSI02 – Six Mile Creek at Highland Road, City of St. Bonifacius Drainage Area: 23.81 sq. mi.

Land Use

Agricultural 37% Lake 18% Open 16% Residential 5% Wetland 14% Wooded 10%

200 20

150 15

100 10

Flow (cfs) 50 5 Average Flow (cfs) 0 0 4/28 5/28 6/28 7/28 8/28 1997 1998 1999 2000 2001 2002 2003 2004 2004 Date Year

12 100

10 80 8 60 6

(per 100 mL) 40 4 20 2 E. coli

Dissolved Oxygen (mg/L) 0 0 4/8 5/8 6/8 7/8 8/8 9/8 7/27 8/10 8/24 9/7 9/21 10/5 2004 Date 2004 Date

42 Appendix B

Six Mile Creek (CSI02) 2004 Flow-Weighted Concentrations and Loads

25 600 20 500 400 15 300 10 200 5 Mean TSS (ppm) 100 TSS Load (1000*lbs) 0 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

200 7000 6000 150 5000 4000 100 3000

2000 TP Load (lbs)

Mean TP (ppb) 50 1000 0 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

28 1000 27 800 26 25 600 24 400 23 Mean Cl (ppm)

200 Cl Load (1000*lbs) 22 21 0 1997 1998 1999 2000 2001 2002 2003 2004 Year

43 Appendix C

Appendix C – Hydrologic Data Monitoring Plan

The MCWD has an extensive hydrologic data program through which it collects and analyzes precipitation, water level, discharge, water quality, stream flow, and groundwater level data. The District publishes the information in annual hydrologic data reports. In addition, historical hydrologic data that the MCWD has collected since 1968 are maintained in databases and available at the District office.

The program is a cooperative effort by the MCWD, Minneapolis Park and Recreation Board (MPRB), Three Rivers Park District (TRPD, formerly Suburban Hennepin Regional Park District), Lake Minnetonka Conservation District (LMCD), Metropolitan Council (MC), Minnesota Pollution Control Agency (MPCA), and Minnesota Department of Natural Resources (MDNR).

The sampling and analysis program was expanded in 1997 to provide an intensive look at background water quality throughout the watershed, and to better define annual water and nutrient budgets within the watershed. The monitoring program was again expanded in 2003 to provide calibration and validation data for the Hydrologic and Hydraulic Pollutant Loading Study (HHPLS).

The program is presented in the work plan summarized in the tables of this Appendix. The plan lays out the monitoring responsibilities of the various partners and details monitoring locations, frequencies, parameters, and quality assurance measures. Under the expanded program, water quality data from all monitoring partners are combined in a single Access™ database available from the District. The 2004 monitoring data is available on CD from the District.

The hydrologic data collected by the District and its partners during 2004 can be categorized into four main types: precipitation, lakes, streams, and groundwater monitoring. The monitoring plan is summarized in Tables C1 through C10. Monitoring station locations are shown in Figures C1 through C5.

1 Appendix C

Table C1 2004 Upper Watershed Lakes Sampling Conducted by MCWD (refer to Figure C1 for locations)

Lake Sampling Frequency

Biweekly 7X/year 5X/year Name Site Name Site Name Site Gleason LGL01 Stone LSN01 Black Lake --- Long LLO01 Stieger LST01 Carman Bay --- Dutch LDU01 E. Upper Lake --- Langdon LLA01 Gideon Bay --- Tanager LTG01 Grays Bay --- Wasserman LWA01 Priests Bay --- Minnewashta LMW01 Smithtown Bay --- Christmas LCH01

Parameters (all lakes & bays)

Lake Mid-Depth or One meter Every Surface Thermocline above bottom meter TP TP TP TEMP SRP SRP SRP DO TN FE COND CHLA PH CL ALK LAB PH LAB COND SECC

Biweekly sampling from May through October TP: total phosphorus; SRP: soluble reactive phosphorus; TN: total nitrogen; CHLA: chlorophyll a; CL: chloride; ALK: alkalinity; LAB PH: laboratory pH; LAB COND: laboratory conductivity;SECC: Secchi disk depth; FE: iron; TEMP: temperature; DO: dissolved oxygen; COND: field conductivity; PH: field pH

2 Appendix C

Table C2 2004 Upper Watershed Lakes Sampling Conducted by Three Rivers Park District and Metropolitan Council (refer to Figure C1 for locations)

Biweekly Lake Sampling Frequency Parameters (all lakes)

Three Rivers Met Council Lake Every Name Site Name Site Surface meter Auburn LAU01 Schutz LSC01 TP TEMP Zumbra LZUO1 Tamarack LTA01 TN DO Virginia LVI01 CHLA COND Libbs LLB01 CL PH Windsor --- ALK St. Joe --- SECC

Biweekly sampling from April through October TP: total phosphorus; TN: total nitrogen; CHLA: chlorophyll a; CL: chloride; ALK: alkalinity SECC: Secchi disk depth; TEMP: temperature; DO: dissolved oxygen; COND: field conductivity PH: field pH

Table C3 2004 Citizen's Lake Monitoring Program (refer to Figure C1 for locations)

Lake Name Lake Minnetonka Bay East Auburn Crystal Bay Minnewashta Halsteds Bay Pierson Lower Lake (3 volunteers) Virginia Maxwell Bay Calhoun Stubbs Bay Diamond (2 volunteers) Upper Lake (5 volunteers) Forest Harriet Nokomis Tanager

Biweekly Secchi disk transparency measurement; program directed by the Minnesota Pollution Control Agency

3 Appendix C

Table C4 Upper Watershed Stream Monitoring Conducted by MCWD (refer to Figure C2 for locations)

Water Flow Stage Quality Name Site Automated Gauging Read Automated Manual Six Mile, Lunsten Lk. Outlet CSI01 Mini Troll Yes No Yes Six Mile, Hwy 7* CSI03 Doppler Yes Yes Yes Painter, W. Branch Rd.* CPA01 Mini Troll No Yes ISCO Yes Painter, Hwy 6 & 110 CPA02 Yes No Yes Painter, Hwy 6 & Deborah Dr.* CPA03 ISCO Yes Yes ISCO Yes Painter, Painter Marsh Outlet* CPA04 Mini Troll Yes Yes ISCO Yes Long, Long Lake Outlet CLO01 Mini Troll Yes Yes Yes Long, Brown Rd.* CLO03 Doppler Yes Yes Yes Gleason, Gleason Lake Outlet CGL01 No Yes Yes Minnewashta, Lake Virginia Outlet CMW01 No No No Dutch, Hwy 110 CDU01 Yes Yes No Classen, Bayside Rd. CCL01 Yes** Yes Yes Langdon, Hwy 110 CLA01 Yes No No Christmas, Christmas Lake Outlet CCH01 Yes Yes Yes Stubbs Inlet, Stubbs Bay CST01 Yes Yes Yes

*Automated sampling occurs during and after rainfall events **If stage > 0.70 feet Manual weekly water quality sampling occurs at all sites between March and October Mini Troll: pressure transducers that measure water stage (height above stream bottom) Doppler: doppler devices that can assess discharge in areas where backflow can occur; manual flow gauging occurs at 20% and 80% of stream depth ISCO: automated samplers, equipped with area velocity meters Field parameters sampled: discharge, temperature, dissolved oxygen, pH, conductivity Lab parameters sampled: total phosphorus, soluble reactive phosphorus, total nitrogen, total suspended solids, chloride, conductivity Note: E. coli sampled for sites CSI03 and CPA01 (May to September only)

4 Appendix C

Table C5 Lake Minnetonka Sampling Conducted by Three Rivers Park District (refer to Figure C1 for locations)

Locations Parameters

Lake Mid-Depth or One meter Every Name Site Surface Thermocline above bottom meter Cooks Bay LCO01 TP TP TP TEMP Crystal Bay LCR01 SRP SRP SRP DO Forest Lake LFO01 TN COND Halsteds Bay LHL01 CHLA PH Harrison's Bay LHR01 CL Jennings Bay LJE01 SECC Lower Lake South LGI01 Maxwell Bay LMA01 North Arm LNR01 Peavey Pond LPE01 Spring Park Bay LSP01 St. Alban's Bay LAL01 Stubbs Bay LSU01 Wayzata Bay LWA01 West Arm LWE01 West Upper Lake LCI01

Biweekly sampling from April through October TP: total phosphorus; SRP: soluble reactive phosphorus; TN: total nitrogen; CHLA: chlorophyll a; CL: chloride; SECC: Secchi disk depth; TEMP: temperature; DO: dissolved oxygen; COND: field conductivity; PH: field pH

5 Appendix C

Table C6 Minnehaha Creek Monitoring Conducted by MCWD (refer to Figure C2 for locations)

Water Flow Stage Quality Name Site Automated Gauging Read Automated Manual Grays Bay Dam Outflow CMH07 Mini Troll No No Yes I-494 Ramps CMH19 Mini Troll Yes Yes ISCO Yes West 34th St. CMH02 No Yes Yes Excelsior Blvd. CMH11 No Yes Yes Browndale Dam* CMH03 Mini Troll No Yes ISCO Yes Upton Ave. CMH12 No Yes Yes Xerxes Ave.** CMH18 No Yes No Chicago Ave. CMH05 No Yes Yes 32nd Ave. CMH17 WOMP No Yes ISCO Yes

Automated sampling occurs during and after rainfall events Manual weekly water quality sampling occurs between March and October *Water quality samples collected downstream of dam at 50th Street; continuous flow records are maintained both upstream and downstream of dam **Stream gauging and continuous flow monitoring conducted by MPRB WOMP: automated flow and water quality data collected by MPRB and Met Council Mini Troll: pressure transducers that measure water stage (height above stream bottom) ISCO: automated samplers, equipped with area velocity meters Field parameters sampled: discharge, temperature, dissolved oxygen, pH, conductivity Lab parameters sampled: total phosphorus, soluble reactive phosphorus, total nitrogen, total suspended solids, chloride, conductivity Note: E. coli sampled for all sites except CMH18 and CMH19 (May to September only)

6 Appendix C

Table C7 Minneapolis Lake Sampling Conducted by the MPRB (refer to Figure C1 for locations)

Location Parameters

Lake All Other Every Name Site Depths Sampled (m) Surface Depths meter Brownie LBR01 0, 5, 7, 12 TP TP TEMP Cedar* LCE01 0, 3, 5, 7, 10, 14 TDP*** TDP*** DO Isles* LIS01 0, 3, 5, 7 SRP SRP COND Calhoun* LCA01 0, 3, 6, 9, 12, 18, 22 TN PH Harriet* LHA01 0, 3, 6, 9, 12, 15, 20 CHLA Nokomis** LNK01 0, 4, 6 PHYTO Hiawatha** LHI03 0, 4 ZOOPL Powderhorn** LPO01 0, 4, 6 SECC Diamond** LDI01 Grab Sample

*Biweekly sampling from April through October **Once during January, April, and October, biweekly during summer ***TDP analysis not done for Brownie Lake, Lake Hiawatha, or Diamond Lake

TP: total phosphorus (3 ppb DL); TDP: total dissolved phosphorus (3 ppb DL); SRP: soluble eactive phosphorus (2 ppb DL); TN: total nitrogen (46 ppb DL); CHLA: chlorophyll a (0.2 ppb DL); PHYTO: phytoplankton surface sample (twice annually); ZOOPL: zooplankton vertical column sample (twice annually); SECC: Secchi disk depth; TEMP: temperature; DO: dissolved oxygen; COND: field conductivity; PH: field pH. Surface samples taken quarterly for silica (50 ppb DL), alkalinity (370 ppb DL), chloride (144 ppb DL), and hardness (1 ppm DL) Note: DL = Minimum Detection Limit

7 Appendix C

Table C8 Lake Level Monitoring Site (refer to Figure C3 for locations)

Name Site Monitor Lake Auburn, West LAU04 TRPD Calhoun, Upper Lakes LCA03 MPRB Christmas Lake LCH03 MCWD Church Lake LCU01 MCWD Dutch Lake LDU02 MCWD Galpin Lake LGA02 MCWD Gleason Lake LGL02 Don Patterson Grass Lake LGR02 Mark McHugh Lake Harriet LHA03 MPRB Lake Hiawatha LHI04 MPRB Holy Name Lake LHN01 MCWD Katrina Lake LKA01 TRPD Wenck Long Lake LLO02 Associates Kelser's Pond LKE01 MCWD Langdon Lake LLA02 Mark Fellegy Long Lake LL002 DNR Lunsten Lake LLU01 TRPD Lydiard Lake LLY01 MCWD Mooney Lake LMO01 Karl Pokorney Lake Minnetonka LMT01 MCWD Lake Minnewashta LMW03 MCWD Parley Lake LPR02 MCWD Piersons Lake LPI02 MCWD St. Joe Lake LSJ01 MCWD Schutz Lake LSC01 Lance Fisher Snyder Lake LSN01 MCWD Stieger Lake LST03 TRPD Stone Lake LSO01 MCWD Tamarack Lake LTA01 MCWD Turbid Lake LTU01 Chuck Johnson Lake Virginia LVI02 Renay Leone Wasserman Lake LWS02 MCWD Zumbra Lake LZU03 MCWD

8 Appendix C

Table C9 Precipitation Gauge Network (refer to Figure C4 for locations)

Location Site Monitor Chanhassen PCN02 NOAA(1) Chanhassen PCN03 CPR: Unknown Delano PDL01 NOAA CPR (2): David H. Greenwood PGE01 Cochran Hamel PHM01 CPR: Robert Mealman Mound PMD01 NOAA Minneapolis PMP01 CPR: Unknown Minneapolis PMP02 CPR: John Bullough Minneapolis-St. Paul Int'l Airport PMP03 National Weather Service Minneapolis- Lower St. Anthony Falls PMP04 NOAA Minneapolis PMP05 MCWD New Hope PNW01 NOAA Plymouth PPL01 CPR: Paul D. Josephson Plymouth PPL02 CPR: Don Patterson Richfield PRI02 City Gauge at Wood Lake

NOAA: National Oceanic and Atmospheric Administration; CPR: Citizen Precipitation Recorder

9 Appendix C

Table C10 MCWD Monitoring Program Quality Assurance/Quality Control Summary

Sample Type Description Function Frequency Quality Assurance Used in estimating Equipment Reagent-grade deionized background 10% of sampling Blank water subject to sample due to sampling collection, trips* collection, processing, and processing, and analysis analysis Every sampling Bottle Reagent-grade deionized Used in estimating trip Blank water subject to sample background due to sample processing and analysis processing and analysis Duplicate of lake Every sampling Field samples Used in estimating overall trip or 1 per 10 Duplicate within -batch precision samples) Alternate Laboratory Synthetic sample of Used in estimating overall sampling among-batch precision and Audit natural lake lab trips bias Every sampling Blind Standard solution with Estimates batch precision trip Standard ficticious site I.D.

Quality Control Used in identifying signal Calibration Reagent-grade drift One/lab batch Blank deionized water and contamination of samples

One/lab batch Reagent Reagent-grade deionized Used in identifying (10% Blank water plus reagents contamination of reagents of samples) Quality Standard solution from Used in determining accuracy One/lab batch Control source other than and consistency of instrument calibration standard calibration 4 times per year Split Split of lake sample Used in determining for Samples comparability 10 samples Used in determining One/lab batch Laboratory Split of sample aliquot analytical (10% Duplicate within -batch precision of of samples) analytical lab measurements Matrix One/lab batch Spike/ Known spike of sample Used in determining percent (10% Matrix recovery of parameter Spike analyzed of samples) Duplicate *Sampling trip is defined as a sampling cycle, or one cycle of stream samples or lake samples, and not justone day's sampling

10 Figure C.1 Lake Water Quality Monitoring Stations in the MCWD # 2004 Lake Sampling Sites

LTG01 Streams LSU01 LPE01 LLO01 Lakes Roads LMA01 Municipal Boundaries LCR01 MCWD Legal Boundary ³ LFO01 # LGL01 # LBR01 LCE01 LNR01 LIS01 # LJE01 # # LWE01 # # LCA01 # # # LPO01 LDU01 # # # # # # # LHR01 # # # # # LHI03 # # LWA01 LLA01 # # # # LLB01 # # # LGI01 # LCO01 # # LAL01 LHL01 # # LHA01 LCH01 LCI01 # LSP01 # # LZU01 # # # LMW01 LNK01 LVI01 LDI01 LAU01 LTA01 LSC01 # LST01 # LWS01

0 1.25 2.5 5 Miles

11 Figure C.2 Stream Water Quality Monitoring Stations in the MCWD !. 2004 Stream Sampling Sites CLO03 Streams CCL01 Lakes CLO01 Roads CST01 CGL01 Municipal Boundaries CPA03 County Boundaries CPA02 MCWD Legal Boundary ³

CPA04 !. !. CMH19 CMH11 !. CMH02 CPA01 !. !. !. !. CDU01 !. !.

!. !. CLA01 CMH17 !. !.

!. !. !. !. CMH07 !. !. !. !. !.

CCH01 CMH03 CSI03 !. !. CMH12

CMH05 CSI01 CMH18

CMW01

0 0.5 1 2 Miles

12 Figure C.3 Lake Level Monitoring Stations in the MCWD #* 2004 Lake Level Sampling Sites LKA01 LMO01 Streams LLO02 Lakes Roads #* MCWD Legal Boundary #* LGL02 Municipal Boundaries ³ #* LCA03 #*

LHI04 LDU02 #* #* LLA02 LMT01 #* #*

#* #* LSO01 LCH03 #* #* #* #* #* #* #* #* LHA03 #* #* #* #* LGA02 LPR02 #* #* LMW03 LSJ01 LLU01 #* LGR02 #* LVI02 LTU01 #* LTA01 LSC01 LAU04 LST03 LPI02 LWS02 LZU03

0 1.5 3 6 Miles

13 Figure C.4 Precipitation Gauge Network po 2004 Precipitation Gauges Lakes PLO01 PHM01 po Streams MCWD Legal Boundary PME02 PNW01 County Boundaries po PPL02 po Roads Municipal Boundaries ³

po PPL01 po po PMP04 po

PMD01

Lake Minnetonka PMP02 Lower Lake po po po po Lake Harriet Lake Minnetonka Upper Lake po PDH01

PSL01 PGE01 Lake Minnewashta PMP03 po po

PCN02 po

PCA01

1 0.5 0 1 Miles

14 Figure C.5 Groundwater Level Monitoring Stations in/near the MCWD 27030 27031 27024 Streams Lakes Roads 27013 27023 27032 MCWD Legal Boundary Municipal Boundaries 27041 ³ 27009 27012 27027 27037 27004 27020 27043 27010

27025 27044 27022 10001 27038 27015

27026 27036

0 1.5 3 6 Miles

15 Appendix D

Precipitation and Groundwater Data

2004 Monthly Precipitation Totals

Carver Mound New Hope Long Lake Deephaven Maple Plain Chanhassen Minneapolis MSP Airport Month St. Louis Park Jan 0.32 0.23 0.26 0.25 0.08 0.64 0.56 0.15 0.23 0.52 Feb 0.70 0.50 0.84 0.95 1.11 1.62 1.34 0.93 1.09 1.53 Mar 2.57 1.93 1.98 2.29 2.27 2.27 2.44 2.26 2.11 2.30 Apr 2.10 2.39 3.58 3.96 2.82 2.96 2.61 3.53 2.06 3.34 May 10.30 8.27 4.71 9.68 9.15 6.98 8.28 7.16 6.39 6.79 Jun 5.82 4.31 0.14 8.02 5.98 5.52 1.11 0.52 1.01 2.83 Jul 5.44 3.56 3.81 3.77 3.44 3.29 4.83 5.58 3.36 5.06 Aug 1.52 1.12 1.68 1.49 1.56 1.46 1.53 1.60 1.19 1.38 Sep 7.52 5.18 5.89 5.05 4.35 4.48 4.42 4.13 4.21 5.52 Oct 3.16 1.00 2.71 4.16 3.40 4.18 2.36 3.35 2.32 3.90 Nov 1.03 0.73 0.95 1.03 0.84 1.06 1.05 1.03 0.93 1.15 Dec 0.57 0.68 0.53 0.45 0.24 0.56 0.48 0.36 0.44 0.57 2004 Total 41.05 29.90 27.08 41.10 35.24 35.02 31.01 30.60 25.34 34.89

2004 Well Water Elevations

DNR Well Identifier Date #27043 #27012 #27041 #27010 #27044 #27036 3/19/04 888.00 849.22 794.74 895.03 865.22 803.54 5/8/04 886.91 852.48 795.27 889.06 881.48 800.07 6/11/04 887.58 853.99 793.97 893.72 882.40 801.65 7/17/04 885.22 853.24 791.43 880.90 800.50 7/19/04 889.93 8/19/04 883.10 852.30 787.82 886.29 880.01 799.74 9/2/2004 786.60 9/18/04 883.42 855.30 889.12 881.44 800.41

Elevations in feet above mean sea level

1 Appendix E

2004 Flow, Loading, and Water Quality

Flow- Weighted Mean Load Concentration (pounds)

Contributing Average Watershed Flow TP SRP Cl TSS Station Creek Area (sq. mi.) (cfs) (ppb) (ppb) TN (ppm) (ppm) (ppm) TP SRP TN Cl TSS CCH01 Christmas Creek 1.13 1 80 10 1.0 29 17 81 8 972 29,435 17,110 CCL01 Classen Creek 1.64 1 430 200 1.9 63 125 1,021 474 4,376 148,534 295,857 CDU01 Dutch Creek 2.89 2 150 90 1.4 34 10 479 276 4,297 108,145 30,577 CGL01 Gleason Creek 3.85 2 50 20 0.9 90 3 205 58 3,316 338,150 10,192 CLA01 Langdon Creek 1.68 1 120 20 2.2 35 19 276 55 5,051 80,397 43,766 CLO03 Long Creek, Brown Rd 1.51 6 140 50 1.5 45 19 1,543 614 17,248 514,544 211,636 CLO01 Long Creek, Lake Outlet 10.88 7 80 20 1.7 45 6 1,088 270 23,867 646,129 90,497 CPA04 Painter, CR 26 7 360 250 1.5 35 4 5,037 3484 20,793 497,046 56,337 CPA02 Painter, CR 6 1.09 4 320 190 1.7 42 8 2,368 1425 12,605 316,661 61,840 CPA03 Painter, Deb Dr 7.11 3 300 220 1.6 40 7 1,614 1157 8,654 212,972 36,695 CPA01 Painter, W Br 6.02 10 360 270 1.5 34 16 7,289 5439 30,823 695,689 334,518 CSI03 Six Mile, Hwy 7 6.46 11 160 30 2.0 27 21 3,524 596 43,028 593,971 459,707 CSI01 Six Mile, Lunsten 17.35 12 50 20 1.0 25 7 1,302 375 24,745 592,045 159,146

Flow- Weighted Mean Load Concentration (pounds)

Contributing Average Watershed Flow TP SRP Cl TSS Station Minnehaha Creek Station Area (sq. mi.) (cfs) (ppb) (ppb) TN (ppm) (ppm) (ppm) TP SRP TN Cl TSS CMH17 32nd Ave 6.15 38 90 20 1.0 68 10 6,654 1783 74,918 5,082,188 712,147 CMH02 W 34th St 7.52 40 60 20 0.9 64 4 4,962 1651 67,767 5,015,743 317,701 CMH19 I-494 5.43 36 40 10 0.9 59 7 2,970 899 64,335 4,099,842 492,517 CMH03 Browndale Dam 2.47 37 70 30 0.9 63 4 5,024 1855 62,161 4,553,678 308,613 CMH05 Chicago Ave 2.55 46 110 40 1.0 91 13 9,470 3935 88,286 8,227,649 1,187,231 CMH11 Excelsior Blvd 3.17 43 80 30 0.9 75 6 6,986 2791 78,199 6,295,493 477,661 CMH07 Grays Bay Dam 122 36 30 20 0.8 45 2 1,915 1105 57,458 3,145,320 143,024 CMH12 Upton Ave 2.81 53 130 60 1.2 131 8 13,520 6468 123,489 13,700,528 832,475

1 Appendix E

2004 E. coli Monitoring Data (CFU/100 mL)

CSI03 CPA01 CMH07 CMH02 CMH11 CMH03 CMH12 CMH05 CMH17 Six 32nd Date Mile Painter Grays W 34th Excelsior Browndale Upton Chicago Ave 7/27/04 42 28 2 60 90 76 260 42 42 8/3/04 72 54 15 84 140 88 140 350 170 8/10/04 35 72 12 100 96 94 320 230 46 8/17/04 64 110 3 100 300 150 410 770 620 8/25/04 36 250 2 280 560 27 230 450 290 8/31/04 45 530 670 340 800 550 750 860 1000 9/9/04 27 270 5 540 820 20 270 840 250 9/14/04 64 2400 120 300 6500 290 31000 74000 2500 9/17/04 100 500 2200 900 9/23/04 82 290 100 410 740 150 300 220 490 9/30/04 40 100 110 250 380 62 110 350 110 10/7/04 60 30 130 390 50 130 300 220

2 Appendix F

Appendix F – Glossary of Water Quality Terms

Water quality parameters commonly monitored by the District, either routinely or for special studies, are briefly described in this section. The parameters provide various indicators of water quality at the locations where samples were collected.

Calcium, Magnesium, and Total Hardness Hardness in water is produced by calcium (Ca) and magnesium (Mg) ions. It is primarily of concern in water supplies because excessive levels (greater than 200-300 milligrams per liter) cause high soap consumption and objectionable scale in pipes. Hardness of 60-120 milligrams per liter is considered moderate. Hardness in lakes is also a very broad indicator of algal and fish productivity. "Hard-water lakes" are usually more productive than "soft-water lakes." Hardness values are conventionally reported as CaCO3 concentrations. Total hardness equals the sum of Ca plus Mg hardness.

Chloride Chloride (Cl-) measurements are performed to detect the influx of road salts from winter deicing procedures. Typically, lakes and streams with heavy groundwater inflow would have low chloride concentrations.

Chlorophyll a Chlorophyll a concentration is a proxy for phytoplankton (algae) biomass in the water. All algae contain chlorophyll a, usually at levels that are a few percent of their cellular biomass. Hence high chlorophyll a concentrations indicate high levels of algal biomass. This analysis is much less tedious and costly than algal identification and enumeration methods. The chlorophyll a concentrations can be used to classify the trophic status of a lake. Concentrations less than 7 micrograms per liter (parts per billion) are generally desirable in lakes.

Dissolved Oxygen Dissolved oxygen (DO) is the uncombined molecular oxygen (O2) that is in solution in water. DO concentrations are increased due to algal/macrophyte photosynthesis and exchange with atmospheric oxygen (which is enhanced in the presence of wave action and/or turbulence). DO concentrations can decrease due to biological respiration (both plants and animals) and nitrification (a bacterial process). DO concentrations provide insight on the oxygen demand exerted on the water column, indicate available habitat for fish populations, and indicate what conditions may exist for, as well as what processes are involved in the breakdown of organic material. DO concentrations greater than 5 to 6 milligrams per liter are generally desirable in surface waters. However, nutrient-rich lakes may become DO-depleted in their bottom waters during summer stratification.

Ecoregion Natural differences in lake water quality occur across Minnesota’s widely varied geographical and environmental regions. The geomorphic and chemical properties of lakes vary across these regions. These differences are accounted for by dividing the regions into seven different ecoregions. Each ecoregion contains a geographically distinct collection of plants, animals, natural communities and environmental conditions. The District is located entirely in the North Central Hardwood Forest ecoregion.

Escherichia coli (E. coli) E. coli is a member of the fecal coliform group of bacteria. For Class 2B waters (Fisheries and Direct Contact Recreation), the Minnesota Pollution Control Agency allowable standard for E. coli is 1260 organisms (acute standard) and 126 organisms (30-day standard, geometric mean) per 100 milliliters.

1 Appendix F

Eutrophication This process represents an increase in biological productivity over time. A lake will naturally fill in due to sedimentation of decaying organic matter (plants, animals) and incoming stream sediments. This can take hundreds of years. However, cultural eutrophication can create conditions in which water bodies receive excess nutrients that stimulate excessive algae blooms, attached algae, and nuisance plants on the order of decades. After the plants die, their decay consumes oxygen in the lake causing a lack of oxygen which can impair other in-lake biota. Fertilizers, erosion of soil-containing nutrients; and sewage treatment plant discharges can all add to eutrophication.

Internal Loading Release of phosphorus from lake sediments during oxygen-depleted conditions. Depending on the overall nutrient budget for a lake, internal loading can be a major source of in-lake phosphorus annually and can contribute to eutrophication.

Iron Iron (Fe) is a minor nutrient for algae and other plants, but its major importance in lake waters is in relation to phosphorus and oxygen. In lake sediments, iron combines with phosphorus and tends to prevent the release of phosphorus into the overlying water. However, the release of both iron and phosphorus occurs readily when dissolved oxygen is depleted in the lake bottom water. Therefore, elevated iron concentrations in lakes often signal an "internal source" of phosphorus -- i.e., release from the sediments.

Macrophyte A relatively large aquatic plant. Examples include floating-leaved (e.g., water lilies), submerged (e.g., coontail), and emergent (e.g., cattail).

Nitrogen Nitrogen (N) is a chemical element occurring in several forms. Primary inorganic forms are ammonia and nitrate. Ammonia-N is the total of all N in the form of either dissolved + - gas (NH3) or ammonium ion (NH4 ). Nitrate-N is nitrogen dissolved as nitrate ion (NO3 ). A less - abundant inorganic form is the nitrite ion (NO2 ), which occurs in reducing environments (low DO). Elevated nitrate levels usually indicate bacterial nitrification, which is typical of sewage- contaminated waters. Total Kjeldahl-N (TKN) measures the total of all N in the form of either organic-N or ammonia-N. Organic-N includes particulate forms (such as cell matter from algae or bacteria, and sewage solids) and dissolved forms (such as proteins and peptides). Algae and other plants require N as a primary nutrient. Ammonia and nitrate N are the chief forms susceptible to algal and plant uptake, but certain dissolved organic forms can also be assimilated. Measurement of N provides insight into the total potential for algal and plant growth. pH and Alkalinity pH measures the concentration of hydrogen ion (H+) in water. The negative of the pH value is the common logarithm of the molar concentration of hydrogen ion. Hydrogen ions, always present in water, impart acidity. When the pH value is 7.0, the condition is called neutrality and the concentrations of hydrogen ion and hydroxide ion (OH-) are equal. When the pH value is less than 7.0, the concentration of hydrogen ion exceeds that of hydroxide, and the water is acidic. When the pH is greater than 7.0, the concentration of hydroxide is greater, and the water is basic or alkaline. Surface waters in the metropolitan area are usually basic (pH greater than 7.0), due to plant and algal photosynthesis and geologic characteristics. Alkalinity indirectly measures the concentration of chemicals able to combine with hydrogen ions, called - bases or alkalis. In natural waters, virtually all alkalinity is due to bicarbonate ion (HCO3 ),

2 Appendix F

-2 carbonate ion (CO3 ), and hydroxide ion. Total alkalinity measures all forms and is reported as CaCO3 is typical for surface waters in the metropolitan area.

Phosphorus Phosphorus (P) is a chemical element found in waters most commonly in one of several forms of phosphate (PO4). The inorganic dissolved form is orthophosphate ion. Orthophosphate (estimated analytically as soluble reactive P or SRP) is an essential nutrient for photosynthesis; not only do plants convert this form into organic cell matter, but P is also a crucial component of the energy-transfer molecule ATP. Organic P includes particulate forms such as living or dead cell matter and sewage solids, and several forms derived from them. Mineralization of organic matter by bacteria and fungi converts organic P into orthophosphate. Total P (TP) measures the sum of all forms. Settling of solids and of algal and bacterial cell matter, as well as uptake by rooted plants, removes P from the water. Sediment P can re-enter the water column as a result of chemical, biological, and physical processes. TP measurements show the maximum potential for algal growth and can be used to classify the trophic status of a lake. Orthophosphorus measurements show the amount of P immediately available for plant life. Concentrations of TP less than 0.02 milligram per liter (part per million) are generally desirable in lakes.

Secchi Disk Transparency The Secchi disc provides a physical measurement of water clarity by observation of the disc at the maximum visual depth in the water column. Secchi transparency is an indicator of algal population density and turbidity, and can be utilized to classify the trophic status of the lake. Secchi disc depths greater than three meters (10 feet) are generally desirable in lakes.

Specific Conductance Specific conductance is a measure of the water's ability to act as a conductor. High conductivity is an indicator of low water quality and implies high concentrations of chlorides or other dissolved solids.

Sulfate Sulfate is a minor nutrient required by algae and other plants. Its concentration in lakes varies geographically and correlates with the distribution of rooted aquatic plant species in Minnesota. Sulfate concentrations below 10 milligrams per liter are typical in the metropolitan area.

Temperature Profile In lakes, the temperature profile with depth determines the extent to which surface and bottom waters are mixed. A large difference (stratification) indicates little mixing, while a small difference or no difference generally shows thorough mixing throughout all depths. Water temperature also determines the DO saturation level, the concentration that would occur in the absence of all biological activity.

Trophic State The trophic state of a lake is a qualitative description of biological productivity. Common terms include eutrophic (high productivity, low water clarity, high chlorophyll a and P concentrations), mesotrophic (intermediate productivity, water clarity, chlorophyll a, and P concentrations), and oligotrophic (low productivity, high water clarity, low chlorophyll a and P concentrations). Most lakes in the District fall into the first two categories.

3 Appendix F

Trophic State Index (TSI) The trophic state index (TSI) is a numerical measure of the trophic status, or productivity level, of a lake. Higher concentrations of nutrients in a lake allow increased plant and algae growth, which then decreases the lake transparency. Therefore, Secchi depth, phosphorus concentration, and chlorophyll a concentration are used to categorize lakes for TSI. The TSI scale ranges from 1 to 100, with lower values corresponding to higher lake water quality.

Water Quality Grades (Lake Report Card Grades) Water quality grades are based on standards established by the Metropolitan Council. The standards give a range to each letter grade for the May through September averages of surface total phosphorus concentration, surface chlorophyll a concentration, and Secchi depth. The overall lake water quality grade is the average of the grades for each parameter. Other indicators of lake condition such as aquatic plant growth or invasive species are not factored into these grades. The TSI, which measures the productivity level of a lake or degree of eutrophication, is also calculated. High TSI values correspond with poorer water quality.