Upper Hay Lake CROW WING COUNTY

Transcription

1 Upper Hay Lake CROW WING COUNTY Lake Water Quality Summary Upper Hay Lake is located 1 mile east of Jenkins, MN in Crow Wing County. It is a round lake with a total surface area of 596 acres. Upper Hay Lake has one inlet and one outlet, which classify it as a drainage lake. Hay Creek drains approximately 9,485 acres of land upstream and enters the lake on the northwest shore. The outlet is located near the middle of the east shore, where Hay Creek flows north into Lower Hay Lake and then into Upper Whitefish Lake. Water quality data have been collected on Upper Hay Lake in 1981 and (Table 3). These data show that the lake is at the mesotrophic/eutrophic border (TSI 49-51), which is characteristic of moderately clear water throughout the summer. The Upper Hay Lake Association formed on July 4 th, With the MN DNR, the association created an aquatic vegetation management plan in They started a lake management plan in 2006 and monitor the lake s water quality. Table 1. Upper Hay Lake location and key physical characteristics. Location Data MN Lake ID: County: CROW WING Ecoregion: Northern Lakes & Forests Major Drainage Basin: Pine River Watershed Latitude/Longitude: , Invasive Species: None as of 2011 Physical Characteristics Surface area (acres): 596 acres Littoral area (acres): 269 acres % Littoral area: 45% Max depth (ft), (m): 42, 12.8 Inlets: 1 Outlets: 1 Public Accesses: 1 Table 2: Availability of data and an observation of the quantity of sample points. Data Availability Transparency data Chemical data Inlet/Outlet data Excellent data set from by the Citizen Lake Monitoring Program. Fair data set from 1981, 1997, , and Data is spread out over two sites (100 and 101). Volunteer observation data from After a couple years of data an assessment can be completed. Recommendations For recommendations refer to page 18. RMB Environmental Laboratories, Inc. 1 of Upper Hay Lake

2 Lake Map Figure 1. Map of Upper Hay Lake illustrating bathymetry, lake sample site locations, stream inlets and outlets and 2010 aerial land use. The light green shaded areas in the lake illustrate the littoral zone, where the sunlight can usually reach the lake bottom allowing aquatic plants to grow. Table 3. Monitoring programs and associated monitoring sites. Program includes White Fish Area Property Owners Association (WAPOA), Minnesota Pollution Control Agency (MPCA), and Citizens Lake Monitoring Program (CLMP). Lake Site Depth Monitoring Programs (ft) WAPOA: ; MPCA: 1981, *primary site 42 CLMP: , ; MPCA: 1981, 1997; WAPOA: , CLMP: ; WAPOA: 1981, RMB Environmental Laboratories, Inc. 2 of Upper Hay Lake

3 Average Water Quality Statistics The information below describes available chemical data for the primary site (101) of Upper Hay Lake through 2010 (Table 4). The data set is limited, and all parameters with the exception of total phosphorus, chlorophyll a and secchi depth, are means for just 1997 data. Minnesota is divided into 7 ecoregions based on land use, vegetation, precipitation and geology. The MPCA has developed a way to determine the "average range" of water quality expected for lakes in each ecoregion. For more information on ecoregions and expected water quality ranges, see page 9. Table 4. Water quality means compared to ecoregion ranges and impaired waters standard. Impaired Waters Standard 2 Ecoregion Parameter Mean Range 1 Interpretation Total phosphorus (ug/l) > 30 The chlorophyll a is within the 3 Chlorophyll a (ug/l) > 9 Chlorophyll a max (ug/l) 25 <15 Secchi depth (ft) < 6.5 Dissolved oxygen Polymictic See page 8 expected ecoregion ranges. Total phosphorus and secchi depths are poorer than the ecoregion ranges. Dissolved oxygen depth profiles show that the lake weakly stratifies periodically in the summer. Total Kieldahl Nitrogen Indicates insufficient nitrogen to support summer nitrogeninduced algae blooms. (mg/l) Alkalinity (mg/l) Indicates a low sensitivity to acid rain and a good buffering capacity. Color (Pt-Co Units) Indicates cloudy or tanninstained water. ph Indicates a hardwater lake. Lake water ph less than 6.5 can affect fish spawning and the solubility of metals in the water. Chloride (mg/l) Higher than the expected range for the ecoregion, but still low. Total Suspended Solids (mg/l) 2.5 <1-2 Indicates low suspended solids and clear water. Conductivity (umhos/cm) Within the expected range for the ecoregion. Total Nitrogen :Total Phosphorus 18:1 25:1 35:1 Indicates the lake is phosphorus limited, which means that algae growth is limited by the amount of phosphorus in the lake. 1 The ecoregion range is the 25 th -75 th percentile of summer means from ecoregion reference lakes 2 For further information regarding the Impaired Waters Assessment program, refer to 3 Chlorophyll a measurements have been corrected for pheophytin Units: 1 mg/l (ppm) = 1,000 ug/l (ppb) RMB Environmental Laboratories, Inc. 3 of Upper Hay Lake

4 Water Quality Characteristics - Historical Means and Ranges Table 5. Water quality means and ranges for primary sites. Parameters Primary Site 101 Site 100 Site 201 Total Phosphorus Mean (ug/l): Total Phosphorus Min: Total Phosphorus Max: Number of Observations: Chlorophyll a Mean (ug/l): 7 7 Chlorophyll-a Min: <1 1 Chlorophyll-a Max: Number of Observations: Secchi Depth Mean (ft): Secchi Depth Min: Secchi Depth Max: Number of Observations: Figure 2. Upper Hay Lake total phosphorus, chlorophyll a and transparency historical ranges. The arrow represents the range and the black dot represents the historical mean (Primary Site 101). Figure adapted after Moore and Thornton, [Ed.] Lake and Reservoir Restoration Guidance Manual. (Doc. No. EPA 440/ ) RMB Environmental Laboratories, Inc. 4 of Upper Hay Lake

5 Transparency (Secchi Depth) Transparency is how easily light can pass through a substance. In lakes it is how deep sunlight penetrates through the water. Plants and algae need sunlight to grow, so they are only able to grow in areas of lakes where the sun penetrates. Water transparency depends on the amount of particles in the water. An increase in particulates results in a decrease in transparency. The transparency varies year to year due to changes in weather, precipitation, lake use, flooding, temperature, lake levels, etc. The annual mean transparency for Upper Hay Lake ranges from 5.8 to 9.8 feet. The transparency throughout the lake appears to be relatively uniform, with the means for both sites showing the same year-to-year seasonal variability. Both sites seem to hover pretty tightly around the longterm mean. Transparency monitoring should be continued annually at sites 201 and 101 in order to track water quality changes. 12 Transparency: Annual Means 10 Secchi Depth (ft) Site 101 Site 201 Site 101, Long term mean 0 Figure 3. Annual mean transparency compared to long-term mean transparency. Upper Hay Lake transparency ranges from 3.5 to 19 feet at the primary site (101). Figure 4 shows the seasonal transparency dynamics. The maximum Secchi reading is usually obtained in early summer. Upper Hay Lake transparency is high in May and June, and then declines through August. If Secchi disk readings were taken in October, the transparency would most likely improve after lake turnover. This transparency dynamic is typical of a deep northern Minnesota lake. The dynamics have to do with algae and zooplankton population dynamics, and lake turnover. It is important for lake residents to understand the seasonal transparency dynamics in their lake so that they are not worried about why their transparency is lower in August than it is in June. It is typical for a lake to vary in transparency throughout the summer. RMB Environmental Laboratories, Inc. 5 of Upper Hay Lake

6 Secchi Depth (ft) Seasonal Transparenc Dynamics pattern Poly. (pattern) Figure 4. Seasonal transparency dynamics and year-to-year comparison (Primary Site 101). The black line represents the pattern in the data. User Perceptions When volunteers collect secchi depth readings, they record their perceptions of the water based on the physical appearance and the recreational suitability. These perceptions can be compared to water quality parameters to see how the lake "user" would experience the lake at that time. Looking at transparency data, as the secchi depth decreases the perception of the lake's physical appearance rating decreases. Upper Hay Lake was rated as being "not quite crystal clear" 47% of the time between (site 101). 4% 2% 14% Physical Appearance Rating 14% Crystal clear water 47% Not quite crystal clear a little algae visible 33% 33% Definite algae green, yellow, or brown color apparent 4% High algae levels with limited clarity and/or mild odor apparent 47% 2% Severely high algae levels Figure 5. Physical appearance rating, as rated by the volunteer monitor ( ). RMB Environmental Laboratories, Inc. 6 of Upper Hay Lake

7 As the secchi depth decreases, the perception of recreational suitability of the lake decreases. Upper Hay Lake was rated as having "very minor aesthetic problems" 58% of the time from (site 101). 6% 4% 14% Recreational Suitability Rating 14% Beautiful, could not be better 18% 58% Very minor aesthetic problems; excellent for swimming, boating 18% Swimming and aesthetic enjoyment of the lake slightly impaired because of algae levels 6% Desire to swim and level of enjoyment of the lake substantially reduced because of algae levels 58% 4% Swimming and aesthetic enjoyment of the lake nearly impossible because of algae levels Figure 6. Recreational suitability rating, as rated by the volunteer monitor ( ). Total Phosphorus Upper Hay Lake is phosphorus limited, which means that algae and aquatic plant growth is dependent upon available phosphorus. Total phosphorus was evaluated in Upper Hay Lake in 1997, , The data increase somewhat toward the end of the season. The two sites appear to have similar concentrations (Figure 7). In 2005 and 2008 there were some very high single data points. Phosphorus should continue to be monitored to track any future changes in water quality. Total Phosphorus (ug/l) Total Phosphorus Eutrophic Mesotrophic Oligotrophic Site 100, 2003 Site 100, 2004 Site 100, 2005 Site 101, 2007 Site 101, 2008 Site 101, 2009 Site 101, 2010 Figure 7. Historical total phosphorus concentrations (ug/l) for Upper Hay Lake. RMB Environmental Laboratories, Inc. 7 of Upper Hay Lake

8 Chlorophyll a Chlorophyll a is the pigment that makes plants and algae green. Chlorophyll a is tested in lakes to determine the algae concentration or how "green" the water is. Chlorophyll a concentrations greater than 10 ug/l are perceived as a mild algae bloom, while concentrations greater than 20 ug/l are perceived as a nuisance. Chlorophyll a(ug/l) 16 Chlorophyll a 14 Site 100, Site 100, Site 100, Site 101, Site 101, 2008 Site 101, Site 101, Minor Algae 0 Figure 8. Chlorophyll a concentrations (ug/l) for Upper Hay Lake. Chlorophyll a was evaluated in Upper Hay Lake in , Chlorophyll a concentrations reached 10 ug/l most years, indicating minor algae blooms (Figure 8). There was not much variation between sites over the years monitored, and chlorophyll a concentrations remained relatively steady over the summer. Dissolved Oxygen Dissolved Oxygen (DO) is the amount of oxygen dissolved in lake water. Oxygen is necessary for all living organisms to survive except for some bacteria. Living organisms breathe in oxygen that is dissolved in the water. Dissolved oxygen levels of <5 mg/l are typically avoided by game fisheries. Upper Hay Lake is a moderately deep lake, with a maximum depth of 42 ft. Dissolved oxygen profiles from indicate that both sites 101 and 201 weakly stratify in the summer. At site 201 the lake is only 20 feet deep and near site 101 there are shallower spots. When the profile has stratified at site 101, the thermocline is around 5-6 meters ( ft). Benthic phosphorus samples taken in 1997 at site 101 indicate internal loading (TP= ug/l). Figure 9 illustrates stratification in the summer of 2000 at site 101. This is a representative DO profile for Upper Hay Lake. Figure 9. Dissolved oxygen profile for Upper Hay Lake in 2000 at site 101. RMB Environmental Laboratories, Inc. 8 of Upper Hay Lake

9 Trophic State Index Phosphorus (nutrients), chlorophyll a (algae concentration) and Secchi depth (transparency) are related. As phosphorus increases, there is more food available for algae, resulting in increased algal concentrations. When algal concentrations increase, the water becomes less transparent and the Secchi depth decreases. The results from these three measurements cover Numbers represent the mean TSI for each parameter. different units and ranges and thus cannot be directly compared to each other or averaged. In order to standardize these three measurements to make them 100 directly comparable, we convert them to a trophic state index (TSI). Hypereutrophic The mean for Upper Hay Lake falls on the border between mesotrophic and eutrophic (49-51). There is relatively good agreement between the TSI for phosphorus, chlorophyll a and transparency, indicating that these variables are related. The TSI Upper Hay Lake for total phosphorus is slightly higher, which may be due to zooplankton grazers selectively eliminating the smaller algal cells. Lakes on the mesotrophic/eutrophic border (TSI 39-41) are characteristic of moderately clear water throughout the summer with late summer algal blooms (Table 7). Table 6. Trophic State Index for site 101. Trophic State Index Site 101 TSI Total Phosphorus 53 TSI Chlorophyll-a 50 TSI Secchi 48 TSI Mean 50 Trophic State: Mesotrophic/ Eutrophic Eutrophic Mesotrophic Oligotrophic Figure 10. Trophic state index chart with corresponding trophic status. 0 Table 7. Trophic State Index categories and corresponding lake conditions. TSI Attributes Fisheries & Recreation <30 Oligotrophy: Clear water, oxygen throughout Trout fisheries dominate the year at the bottom of the lake, very deep cold water Bottom of shallower lakes may become anoxic (no oxygen). Trout fisheries in deep lakes only. Walleye, Cisco present Mesotrophy: Water moderately clear most of the summer. May be "greener" in late summer. No oxygen at the bottom of the lake results in loss of trout. Walleye may predominate Eutrophy: Algae and aquatic plant problems possible. "Green" water most of the year. Warm-water fisheries only. Bass may dominate Blue-green algae dominate, algal scums and aquatic plant problems. Dense algae and aquatic plants. Low water clarity may discourage swimming and boating Hypereutrophy: Dense algae and aquatic Water is not suitable for recreation. plants. >80 Algal scums, few aquatic plants Rough fish (carp) dominate; summer fish kills possible Source: Carlson, R.E A trophic state index for lakes. Limnology and Oceanography. 22: RMB Environmental Laboratories, Inc. 9 of Upper Hay Lake

10 Trend Analysis For detecting trends, a minimum of 8-10 years of data with 4 or more readings per season are recommended. Minimum confidence accepted by the MPCA is 90%. This means that there is a 90% chance that the data are showing a true trend and a 10% chance that the trend is a random result of the data. Only short-term trends can be determined with just a few years of data, because there can be different wet years and dry years, water levels, weather, etc, that affect the water quality naturally. There is not enough historical data to perform trend analysis for total phosphorus or chlorophyll a on Upper Hay Lake. Site 101 had over 8 years of transparency data, which was enough data to perform a long-term trend analysis (Table 8). The data was analyzed using the Mann Kendall Trend Analysis. Table 8. Trend analyses for Upper Hay Lake. Lake Site Parameter Date Range Trend 101 Transparency , No trend 101 Total Phosphorus Insufficient data 101 Chlorophyll a Insufficient data Secchi Dpeth (ft) Transparency Trend for Upper Hay Lake 08/01/ /12/ /16/ /18/ /31/ /24/ /27/ /14/ /06/ /06/ /04/ /27/ /20/ /17/ /16/ /17/ /11/ /27/ /24/ /29/ /02/ /21/ /05/ /15/ /03/ /12/ /01/ /20/2011 Figure 11. Transparency (ft) trend for Upper Hay Lake, site 101. No trend was detected in the transparency data at site 101 (Figure 11). There was insufficient data to calculate trends for total phosphorus and chlorophyll a. Transparency monitoring should continue at both sites so that this trend can be tracked in future years. RMB Environmental Laboratories, Inc. 10 of Upper Hay Lake

11 Ecoregion Comparisons Minnesota is divided into 7 ecoregions based on land use, vegetation, precipitation and geology. The MPCA has developed a way to determine the "average range" of water quality expected for lakes in each ecoregion. From , the MPCA evaluated the lake water quality for reference lakes. These reference lakes are not considered pristine, but are considered to have little human impact and therefore are representative of the typical lakes within the ecoregion. The "average range" refers to the 25 th - 75 th percentile range for data within each ecoregion. For the purpose of this graphical representation, the means of the reference lake data sets were used. Upper Hay Lake is in the Northern Lakes and Forests Ecoregion. The mean total chlorophyll a was within the expected ecoregion range; however the phosphorus mean and the transparency (secchi depth) mean were poorer than the expected range (Figure 13). Figure 12. Minnesota Ecoregions Total Phosphorus (ug/l, ppb) Chlorophyll-a (ug/l, ppb) Secchi depth (ft) increased algae crystal clear 0 NLF Upper Hay Ecoregion 0 NLF Upper Hay Ecoregion 25 NLF Ecoregion Upper Hay Figures 13a-c. Upper Hay Lake ranges compared to Northern Lakes and Forest Ecoregion ranges. The Upper Hay Lake total phosphorus and chlorophyll a ranges are from 26 data points collected in May- September of 1997, The Upper Hay Lake secchi depth range is from 254 data points collected in May-September from 1981, RMB Environmental Laboratories, Inc. 11 of Upper Hay Lake

12 Lakeshed Data and Interpretations Lakeshed Understanding a lakeshed requires an understanding of basic hydrology. A watershed is defined as all land and water surface area that contribute excess water to a defined point. The MN DNR has delineated three basic scales of watersheds (from large to small): 1) basins, 2) major watersheds, and 3) minor watersheds. The Pine River Major Watershed is one of the watersheds that make up the Upper Mississippi River Basin, which eventually drains south to the Gulf of Mexico (Figure 14). This major watershed is made up of 69 minor watersheds. Upper Hay Lake is located in minor watershed (Figure 15). Figure 14. Pine River Watershed. Figure 15. Minor Watershed The MN DNR also has evaluated catchments for each individual lake with greater than 100 acres surface area. These lakesheds (catchments) are the building blocks for the larger scale watersheds. Upper Hay Lake falls within the Upper Hay ( ) lakeshed (Figure 16). Though very useful for displaying the land and water that contribute directly to a lake, lakesheds are not true watersheds because they do not show the water flowing into a lake from upstream streams or rivers. While some lakes may have only one or two upstream lakesheds draining into them, others may be connected to a large number of lakesheds, reflecting a larger drainage area via stream or river networks. For further discussion of Upper Hay Lake s full watershed, containing all the upstream lakesheds, see page 17. The data interpretation of the Upper Hay Lake lakeshed is only the immediate Figure 16. The Upper Hay ( ) Lakeshed. This area is the land and water surface that flow directly into Upper Hay Lake. RMB Environmental Laboratories, Inc. 12 of Upper Hay Lake

13 lakeshed, not including the upstream lakesheds, as this area is the land surface that flows directly into Upper Hay Lake. The lakeshed vitals table identifies where to focus organizational and management efforts for each lake (Table 9). Criteria were developed using limnological concepts to determine the effect to lake water quality. KEY Possibly detrimental to the lake Warrants attention Beneficial to the lake Table 9. Upper Hay Lake lakeshed vitals table. Lakeshed Vitals Rating Lake Area 596 acres descriptive Littoral Zone Area 269 acres descriptive Lake Max Depth 42 ft. descriptive Lake Mean Depth 17 ft. Water Residence Time NA NA Miles of Stream None descriptive Inlets 1 Outlets 1 Major Watershed 11 Pine River descriptive Minor Watershed descriptive Lakeshed descriptive Ecoregion Northern Lakes and Forest descriptive Total Lakeshed to Lake Area Ratio (total lakeshed includes lake area) 4:1 Standard Watershed to Lake Basin Ratio (standard watershed includes lake areas) 25:1 Wetland Coverage 1.7% Aquatic Invasive Species Public Drainage Ditches Public Lake Accesses 1 None None Miles of Shoreline 3.8 descriptive Shoreline Development Index 1.1 Public Land to Private Land Ratio 0.02:1 Development Classification General Development Miles of Road 11.9 descriptive Municipalities in lakeshed Jenkins, Pequot Lakes County Forest Management: Forestry Practices Feedlots 1 Individual Subsurface Sewage Treatment Sewage Management Systems (Inspection and assessment required for all permits and property transfers within the Shoreland Protection Zone) Healthy Lakes & Rivers Partnership program, Lake Management Plan 2006 Lake Vegetation Survey/Plan None RMB Environmental Laboratories, Inc. 13 of Upper Hay Lake

14 Land Cover / Land Use The activities that occur on the land within the lakeshed can greatly impact a lake. Land use planning helps ensure the use of land resources in an organized fashion so that the needs of the present and future generations can be best addressed. The basic purpose of land use planning is to ensure that each area of land will be used in a manner that provides maximum social benefits without degradation of the land resource. Changes in land use, and ultimately land cover, impact the hydrology of a lakeshed. Land cover is also directly related to the lands ability to absorb and store water rather than cause it to flow overland (gathering nutrients and sediment as it moves) towards the lowest point, Figure 17. The Upper Hay ( ) lakeshed land cover ( typically the lake. Impervious intensity describes the lands inability to absorb water, the higher the % impervious intensity the more area that water cannot penetrate in to the soils. Monitoring the changes in land use can assist in future planning procedures to address the needs of future generations. Phosphorus export, which is the main cause of lake eutrophication, depends on the type of land cover occurring in the lakeshed. Figure 17 depicts the land cover in Upper Hay Lake s lakeshed. The University of Minnesota has online records of land cover statistics from years 1990 and 2000 ( Table 10 describes Upper Hay Lake s lakeshed land cover statistics and percent change from 1990 to Due to the many factors that influence demographics, one cannot determine with certainty the projected statistics over the next 10, 20, 30+ years, but one can see the transition within the lakeshed from agriculture, grass/shrub/wetland, and water acreages to forest and urban acreages. The largest change in percentage is the increase in urban cover (54%); however, in acreage, forest cover has increased the most (94 acres). In addition, the impervious intensity has increased, which has implications for storm water runoff into the lake. The increase in impervious intensity is consistent with the increase in urban acreage. RMB Environmental Laboratories, Inc. 14 of Upper Hay Lake

15 Table 10. Upper Hay Lake s lakeshed land cover statistics and % change from 1990 to 2000 ( % Change Land Cover Acres Percent Acres Percent 1990 to 2000 Agriculture % Decrease Grass/Shrub/Wetland % Decrease Forest % Increase Water % Decrease Urban % Increase Impervious Intensity % % Decrease % Increase % Increase % Increase % Increase % Increase % Increase Total Area Total Impervious Area (Percent Impervious Area Excludes Water Area) % Increase Demographics Upper Hay Lake is classified as a general development lake. General Development Lakes usually have more than 225 acres of water per mile of shoreline and 25 dwellings per mile of shoreline, and are more than 15 feet deep. The Minnesota Department of Administration Geographic and Demographic Analysis Division extrapolated future population in 5- year increments out to Compared to Crow Wing County as a whole, Jenkins Township has a higher extrapolated growth projection (Figure 18). Figure 18. Population growth projection for Jenkins Township and Crow Wing County. (source: state.mn.us/resource.ht ml?id=19332) RMB Environmental Laboratories, Inc. 15 of Upper Hay Lake

16 Upper Hay Lake Lakeshed Water Quality Protection Strategy Each lakeshed has a different makeup of public and private lands. Looking in more detail at the makeup of these lands can give insight on where to focus protection efforts. The protected lands (easements, wetlands, public land) are the future water quality infrastructure for the lake. Developed land and agriculture have the highest phosphorus runoff coefficients, so this land should be minimized for water quality protection. The majority of the land within Upper Hay Lake s lakeshed is made up of private forested uplands (Table 11). The other classification is mostly made up of shrub, grassland, and barren lands. These areas are not currently development and may receive development pressure. Table 11. Land ownership, land use/land cover, estimated phosphorus loading, and ideas for protection and restoration in the lakeshed (Sources: Crow Wing County parcel data, National Wetlands Inventory, and the 2006 National Land Cover Dataset). Private (73%) 24% Public (3%) Developed Agriculture Forested Uplands Other Wetlands Open Water County State Federal Land Use (%) 2.2% 13.7% 28.6% 27.2% 1.3% 24% 1.4% 1.6% 0% Runoff Coefficient Lbs of phosphorus/acre/ year Estimated Phosphorus Loading Acerage x runoff coefficient Description Focused on Shoreland Cropland Focus of development and protection efforts Open, pasture, grassland, shrubland Protected Potential Phase 3 Discussion Items Shoreline restoration Restore wetlands; CRP Forest stewardship planning, 3 rd party certification, SFIA, local woodland cooperatives Protected by Wetland Conservation Act County Tax Forfeit Lands State Forest National Forest DNR Fisheries approach for lake protection and restoration Credit: Peter Jacobson and Michael Duval, Minnesota DNR Fisheries In an effort to prioritize protection and restoration efforts of fishery lakes, the MN DNR has developed a ranking system by separating lakes into two categories, those needing protection and those needing restoration. Modeling by the DNR Fisheries Research Unit suggests that total phosphorus concentrations increase significantly over natural concentrations in lakes that have watershed with disturbance greater than 25%. Therefore, lakes with watersheds that have less than 25% disturbance need protection and lakes with more than 25% disturbance need restoration (Table 12). Watershed disturbance was defined as having urban, agricultural and mining land uses. Watershed protection is defined as publicly owned land or conservation easement. RMB Environmental Laboratories, Inc. 16 of Upper Hay Lake

17 Table 12. Suggested approaches for watershed protection and restoration of DNR-managed fish lakes in Minnesota. Watershed Disturbance (%) Watershed Protected (%) Management Type Comments < 25% > 75% Vigilance < 75% Protection Sufficiently protected -- Water quality supports healthy and diverse native fish communities. Keep public lands protected. Excellent candidates for protection -- Water quality can be maintained in a range that supports healthy and diverse native fish communities. Disturbed lands should be limited to less than 25% % n/a Full Restoration Realistic chance for full restoration of water quality and improve quality of fish communities. Disturbed land percentage should be reduced and BMPs implemented. > 60% n/a Partial Restoration Restoration will be very expensive and probably will not achieve water quality conditions necessary to sustain healthy fish communities. Restoration opportunities must be critically evaluated to assure feasible positive outcomes. The next step was to prioritize lakes within each of these management categories. DNR Fisheries identified high value fishery lakes, such as cisco refuge lakes. Ciscos (Coregonus artedi) can be an early indicator of eutrophication in a lake because they require cold hypolimnetic temperatures and high dissolved oxygen levels. These watersheds with low disturbance and high value fishery lakes are excellent candidates for priority protection measures, especially those that are related to forestry and minimizing the effects of landscape disturbance. Forest stewardship planning, harvest coordination to reduce hydrology impacts and forest conservation easements are some potential tools that can protect these high value resources for the long term. Upper Hay Lake is classified with having 24.6% of the watershed protected and 16.7% of the watershed disturbed (Figure 19). Therefore, Upper Hay Lake should have a protection focus. Unfortunately, Upper Hay Lake s lakeshed is approaching the 25% disturbed threshold. Goals for the lake should be to limit any increase in disturbed land use. Figure 20 displays the upstream lakesheds that contribute water to the lakeshed of interest. All of the land and water area in this figure has the potential to contribute water to Upper Hay Lake, whether through direct overland flow or through a creek or river. One of the 2 upstream lakesheds has the same management focus (protection). Percent of the Watershed Protected 0% 75% 100% Upper Hay Lake (24.6%) Percent of the Watershed with Disturbed Land Cover 0% 100% 25% Upper Hay Lake (16.7%) Figure 19. Upper Hay Lake lakeshed s percentage of watershed protected and disturbed. Figure 20. Upstream lakesheds that contribute water to the Upper Hay lakeshed. Color-coded based on management focus (Table 12). RMB Environmental Laboratories, Inc. 17 of Upper Hay Lake

18 Upper Hay, Status of the Fishery (as of 08/11/2008) Walleyes are currently stocked annually at a rate of 1,000 per littoral acre (acres 15.0 feet or less) for a total of 184,000 fry. The net catch of 3.7/net is within the historical range of 1.5 to 8.0/gill net. The average catch rate has been around 3.2/gill net. Sizes in 2008 ranged from 12.3 to 23.7 inches and averaged 17.1 inches. Fry stocking success has been good. Growth rate is also good. The northern pike catch of 8.3/gill net is on the higher end of historical net catches. The average size was 21.4 inches with fish as large as 31.4 inches. Black crappie were captured in both gear types in moderate numbers, and averaged 8.4 inches. Largest fish was 12.9 inches. Bluegill numbers were moderate with fish as large as 9.3 inches. A total of 17 % were over 7.0 inches. Both black crappie and bluegill receive heavy fishing pressure and anglers have good success. See the link below for specific information on gillnet surveys, stocking information, and fish consumption guidelines. Key Findings / Recommendations Monitoring Recommendations Transparency monitoring at sites 101 and 201 should be continued annually. It is important to continue transparency monitoring weekly or at least bimonthly every year to enable year-to-year comparisons and trend analyses. Phosphorus and chlorophyll a data should be collected, as the budget allows, to track future water quality trends. The most recent phosphorus and chlorophyll a data was collected at site 101. If monitoring continues, collection should occur at this location to maintain site consistency. Overall Conclusions Overall, Upper Hay Lake has fair water quality, and is in fair shape for lakeshed protection. It is a mesotrophic/eutrophic lake (TSI=50) with no trend in transparency over the past decade. Three percent (3%) of the lakeshed is in public ownership, and 24.6% of the watershed is protected, while 16.7% of the watershed is disturbed (Figure 19). The upstream lakeshed to the north of the lakeshed of interest, which contains the City of Jenkins, is even more disturbed (Figure 20). Because there are no water quality trends and the lake is shallow, a TSI of 50 is most likely the natural state of Upper Hay Lake. Priority Impacts to the lake There are several priority impacts to Upper Hay Lake. The first is the surrounding development and any future development. The majority of the shoreline is developed. The land area around the outlet is owned by the MN DNR. Agriculture land cover decreased by 86 acres from 1990 to 2000 and urban land use increased by 67 acres (Table 10). As land is converted from forested uplands to developed land use, the potential to increase phosphorus loading increases dramatically. Hay Creek does run west to east, just north of the City of Jenkins. It is beneficial that the creek runs through a wetland on the west side, prior to flowing into the lake. The second potential impact is the agriculture land use within the watershed (Figure 20). It looks like there is some forest buffer between the agriculture and the lake, so it is unclear how much the agriculture is actually impacting the lake. On the ground inspection would help determine areas where the buffer is not wide enough. Silviculture (timber management) is also a land use in this lakeshed. Proper silviculture best management practices should be followed to maintain quality water (Forest Resource Council Guidelines: RMB Environmental Laboratories, Inc. 18 of Upper Hay Lake

19 Best Management Practices Recommendations The management focus for Upper Hay Lake should be to restore and protect the water quality and the lakeshed. Restoration efforts should be focused on managing and/or decreasing the impact caused by additional development, and impervious surface area. Project ideas include protecting land with conservation easements, enforcing county shoreline ordinances, smart development, shoreline restoration, rain gardens, and septic system maintenance. Additional project ideas for improving the water quality of Upper Hay Lake include assisting area farmers with best management practices such as restoring wetlands, and preserving their land in the conservation reserve program. Future Studies Future studies that would better pinpoint the impacts on the lake include a shoreline inventory, inlet monitoring, and a watershed flow analysis. The shoreline inventory would consist of boating around the lake and rating each parcel as to how much of the frontage has a vegetative buffer. The full watershed area that contributes water to Upper Hay Lake is relatively small in size. Monitoring the inlet and outlet for water quality and velocity would help identify if and/or where the highest nutrient sources to the lake. A watershed flow analysis could also be done using GIS software to see the areas of heaviest runoff into the lake. Not all the water entering Upper Hay Lake will flow through the inlet. Some will flow in smaller ditches or swales. This analysis would also help pinpoint locations to install BMPs to mitigate increases in impervious surfaces. County-wide Recommendation In order to better manage the impact of septic systems on lake water quality, it is recommended that the county implement a lake-wide septic inspection program. In a program such as this, the county would focus on one to three lakes a year, pull septic system records on those lakes, and require old systems to be inspected. This program can rotate through the county doing a few lakes each year. Organizational contacts and reference sites Upper Hay Lake Association DNR Fisheries Office Regional Minnesota Pollution Control Agency Office Crow Wing Soil and Water Conservation District Crow Wing County Environmental Services Department Minnesota Drive, Brainerd, MN brainerd.fisheries@state.mn.us 7678 College Road, Suite 105, Baxter, MN , Laurel St. Suite 13, Brainerd, MN Laurel St. Suite 14, Brainerd, MN Funding This project was funded in part by the Board of Water & Soil Resources and the Initiative Foundation, a regional foundation. RMB Environmental Laboratories, Inc. 19 of Upper Hay Lake