2007 Lake Assessment of Fountain Lake (86-0086) Wright County, Minnesota Environmental Analysis and Outcomes Division Water Assessment and Environmental Information Section December 2008

Minnesota Pollution Control Agency 520 Lafayette Road North Saint Paul, MN 55155-4194 http://www.pca.state.mn.us 651-296-6300 or 800-657-3864 toll free TTY 651-282-5332 or 800-657-3864 toll free Available in alternative formats

Author Kelly O’Hara Lake Assessment Program 2008 2007 Lake Assessment of Fountain Lake (86-0086) Wright County, Minnesota Minnesota Pollution Control Agency Environmental Analysis and Outcomes Division Water Assessment and Environmental Information Section

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The MPCA is reducing printing and mailing costs by using the Internet to distribute reports and information to wider audience. For additional information, see the Web site: www.pca.state.mn.us/water/lakereport.html This report was printed on recycled paper manufactured without the use of elemental chlorine (cover: 100% post-consumer; body: 100% post-consumer)

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Table of Contents Introduction................................................................................................................................... 1 Background ................................................................................................................................... 3 Lake Morphometric and Watershed Characteristics................................................................. 3 Lake Level Trends .................................................................................................................... 4 Precipitation .............................................................................................................................. 4 Fisheries .................................................................................................................................... 6 Methods.......................................................................................................................................... 6 Results and Discussion.................................................................................................................. 6 Trophic State Index (TSI) ............................................................................................................ 8 Trophic Status Trend Data .......................................................................................................... 8 Modeling ........................................................................................................................................ 9 Toxic Algae .................................................................................................................................. 10 303(d) Assessment and Goal Setting ......................................................................................... 11 Appendix A .................................................................................................................................. 14 Glossary .................................................................................................................................. 14 Appendix B .................................................................................................................................. 16 Water Quality Data: Abbreviations and Units ....................................................................... 16 Appendix C .................................................................................................................................. 17 References............................................................................................................................... 17 Appendix D .................................................................................................................................. 18 Fountain Lake Surface Water Results..................................................................................... 18

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List of Tables Table 1. Fountain Lake ecoregion land use comparison................................................................. 4 Table 2. Fountain Lake summer mean water quality..................................................................... 6 Table 3. MINLEAP model results for Fountain Lake ................................................................... 9 Table 4. Fountain Lake algal toxin data....................................................................................... 10 Table 5. Eutrophication standard by ecoregion and lake type ...................................................... 12

List of Figures Figure 1. Minnesota’s seven ecoregions as mapped by U.S. Environmental Protection Agency .. 2 Figure 2. Fountain Lake minor watershed land use....................................................................... 4 Figure 3. Summer 2007 rainfall based on records for Delano, Minnesota .................................... 5 Figure 4. 2007 Minnesota Water Year Precipitation and Departure from Normal ....................... 5 Figure 5. Fountain Lake dissolved oxygen and temperature profiles............................................ 7 Figure 6. Fountain Lake total phosphorus and chlorophyll-a concentrations and secchi depth.... 8 Figure 7. Fountain Lake microcystin results................................................................................ 11 Figure 8. Carlson’s Trophic State Index for Fountain Lake ........................................................ 13

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Introduction The Minnesota Pollution Control Agency’s (MPCA) core lake monitoring programs include Legacy Lake Monitoring, Citizen Lake Monitoring Program (CLMP), and Lake Assessment Program (LAP). In addition to these programs, the MPCA annually monitors numerous lakes to provide baseline water quality data, provide data for potential LAP and Clean Water Partnership lakes, characterize lake condition in different regions of the state, examine year-to-year variability in ecoregion-reference lakes, provide additional trophic status data for lakes exhibiting trends in Secchi transparency and to provide data for the protection, restoration, and preservation of Minnesota surface waters through the Clean Water Legacy Act (CWLA). In the latter case, sampling is conducted to provide data on water quality conditions to achieve and maintain established standards. To make for efficient sampling, geographic clusters of lakes are selected (e.g., focus on a specific county or region) whenever possible. The MPCA prepares lake assessments under section 305(b) and 303(d) of the Clean Water Act. These assessments are done to estimate the extent to which Minnesota water bodies meet the goals of the Clean Water Act. This information is shared with planners, citizens and other partners in basin planning and watershed management activities. In the case of 303(d) assessments lakes are assessed to determine whether they meet “aquatic recreational uses”. This report details the analysis of water quality data on Fountain Lake in Wright County during the 2007 season. Data collected in 2007 were combined with data from previous sample seasons. For data-poor lakes, monitoring establishes a baseline data. In the selection of lakes, a focus is typically placed on large lakes, typically with surface areas of 500 acres or more; however, Fountain Lake did not meet this criteria. Water quality samples were collected monthly from May through September. An additional shoreline sample was collected in June 2007 as a result of a confirmed dog death related to a toxic algae bloom. A summary of data follows (Appendix D). Fountain Lake lies within the North Central Hardwood Forests (NCHF) (Figure 1). NCHF ecoregion values will be used for land use comparisons (Table 1) and lake summer-mean water quality (Table 2). Additionally, the NCHF ecoregion will be used for the Minnesota Lake Eutrophication Analysis Procedures (MINLEAP) model application. This provides a basis for placing data from this lake in perspective relative to other lakes in the same ecoregion.

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Figure 1. Minnesota’s seven ecoregions as mapped by U.S. Environmental Protection Agency (EPA)

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Background Lake Morphometric and Watershed Characteristics Fountain Lake is a 282-acre lake in south-east Wright County within the North Fork Crow River Basin watershed. Fountain Lake is approximately one mile south east of Montrose, MN. One public access is located on the north shore of the lake. Fountain Lake is classified as a shallow polymictic lake that continuously mixes throughout the summer and does not form distinct thermal layers. The lake has a maximum depth of eight feet making it 100 percent littoral. Percent littoral refers to that portion of the lake that is 15 feet or less in depth, which often represents the depth to which rooted plants may grow in the lake. Lakes with a high percentage of littoral area often have extensive rooted plant (macrophyte) beds. These plant beds are a natural part of the ecology of these lakes and are important to protect. The definition for “shallow” lakes applies to those with maximum depths of 15 feet or less or where the littoral area comprises 80 percent or more of the basin (Heiskary and Wilson, 2005). The major watershed for Fountain Lake is the North Fork Crow River watershed and is contributed from the South Fork Crow River watershed. The immediate watershed that Fountain Lake lies within has no drainage points from surrounding minors and has a total area of 1,510 acres. The watershed to lake area ratio is 4:1. “Immediate watershed” refers to that portion of the watershed that drains directly to the lake without flowing first through other lakes; while “total watershed” refers to the entire watershed upstream of the lake. Differentiating between immediate and total is important as lake nutrients and water budgets are determined based on the estimated total watershed; whereas best management practices (BMP) and protection efforts are often focused initially on the immediate watershed. Total watershed-to-lake area ratio also provides an important perspective on the size of the watershed relative to the lake. For Fountain Lake, the total and immediate watersheds are one and the same. Watershed areas were estimated based on data from the University of Minnesota Remote and Geospatial Analysis Lab. United States Geographical Survey (USGS) watershed data was also used that may be found at: http://gisdmnspl.cr.usgs.gov/watershed/index.htm. Since land use affects water quality, it has proven helpful to divide the state into regions where land use and water resources are similar. Land use in the watershed of Fountain Lake is rather typical for this ecoregion with the exception of a large percentage of water and wetlands. Cultivated land use is the highest land use and falls within the expected range for the ecoregion (Figure 2 and Table 1). Fountain Lake soils are defined as medium- to fine-textured prairie border soils of central Minnesota from the Lester-LeSueur-Glencoe series. This area is gently rolling and the soil types are moderately dark to darkcolored and are well-drained with the exception of the Glencoe clay loam. Erosion is a major problem on Lester and drainage is needed on Glencoe (Arneman 1963). Fountain Lake was likely formed by the separation of stagnant ice blocks from the main mass of retreating glacier and their partial or complete burial which led to the formation of the lake basin (Zumberge, 1952).

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Figure 2. Fountain Lake minor watershed land use

Table 1. Fountain Lake ecoregion land use comparison Land Use (%)

Fountain

NCHF Ecoregion

Developed

4

2–9

Cultivated (Ag)

38

22 - 50

Pasture & Open

14

11 - 25

Forest

12

6 - 25

Water & Wetland

32

14 - 30

Lake Level Trends The Minnesota Department of Natural Resources (DNR) Division of Waters has not measured water levels on Fountain Lake since 1990. During the period of record (1957 – 1990) the lake level has varied by 2.9 feet, based on seven readings. The highest and lowest recorded elevations are 932.01 feet on July 3, 1957 and 929.03 feet on February 28, 1990, respectively. The ordinary high water mark (OHW) for Fountain Lake is 932 feet.

Precipitation Rain gage records from Delano, MN, show eight one-inch plus rain events during summer 2007 (Figure 3). These rain events will increase runoff into the lakes and may influence in-lake water quality and lake levels. This will be considered in the individual discussions of lake water quality for 2007. Precipitation records for the 2007 water year (October 2006 through September 2007) showed average rainfall (0 -2 inches below normal) for the Meeker and Wright study area (Figure 4). 2007 Lake Assessment of Fountain Lake in Wright County

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2 1.75 1.5 1.25 1 0.75 0.5 0.25 0 5/ 1/ 20 07 5/ 16 /2 00 7 5/ 31 /2 00 7 6/ 15 /2 00 7 6/ 30 /2 00 7 7/ 15 /2 00 7 7/ 30 /2 00 7 8/ 14 /2 00 7 8/ 29 /2 00 7 9/ 13 /2 00 7 9/ 28 /2 00 7

Rainfall (inches)

Figure 3. Summer 2007 rainfall based on records for Delano, Minnesota

Figure 4. 2007 Minnesota Water Year Precipitation and Departure from Normal Prepared by State Climatology Office DNR Waters Values are in inches

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Fisheries Department of Natural Resources fisheries managers utilize netting survey information to assess the well-being of fish communities and measure the efficacy of management programs. Presence, absence, abundance, physical condition of captured fishes, and community relationships among fish species within survey catch information also provide good indicators of current habitat conditions and trophic state of a lake (Schupp and Wilson, 1993). This data is stored in a long-term fisheries survey database, which has proven valuable in qualifying and quantifying changes in environmental and fisheries characteristics over time. Fountain Lake is currently not being surveyed by the DNR. Additional information on DNR fisheries management can be found at www.dnr.state.mn.us/fisheries/management/index.html.

Methods Water quality data for the Fountain Lake were collected in May, June, July, and August 2007. Lake surface samples were collected with an integrated sampler, a Poly Vinyl Chloride (PVC) tube 6.6 feet (2 meters) in length with an inside diameter of 1.24 inches (3.2 centimeters). Zooplankton samples were collected with a Wisconsin plankton net. Phytoplankton (algae) samples were taken at the primary site with an integrated sampler. The June shoreline sample was collected by hand. Summer-means were calculated using June August data. Sampling procedures were employed as described in the MPCA Lake Water Quality Sampling Standard Operating Procedures (SOP). Laboratory analyses were performed by the laboratory of the Minnesota Department of Health using EPA-approved methods. Samples were analyzed for nutrients, color, solids, pH, alkalinity, conductivity, chloride and chlorophyll-a. Temperature and dissolved oxygen (DO) profiles and Secchi disk transparency measurements were also taken. Phytoplankton samples were analyzed at the MPCA. Table 2. Fountain Lake summer mean water quality Parameter

Fountain

NCHF

Total Phosphorus (µg/L)

474

23 - 50

Chlorophyll mean (µg/L)

215

5 - 22

Chlorophyll max (µg/L)

255

7 - 37

Secchi Disk (feet) (meters)

0.3 0.1

4.9 – 10.5 1.5 – 3.2

Total Kjeldahl Nitrogen (mg/L)

6.9