Sugar Lake
11-0026-00 CASS COUNTY
Lake Water Quality
Summary
Sugar Lake is located 6 miles northeast of Remer,
MN in Cass County. It is a mostly round lake
covering 702 acres (Table 1).
Sugar Lake has no inlets and one outlet, which
classify it as a drainage lake. The water continues
out the northeast corner of Sugar Lake and carries
water north toward Itasca County.
Water quality data exist for just two years, 1973
and 2004 (Tables 2-3). These data show that the
lake is mesotrophic (TSI = 43) with moderately
clear water conditions most of the summer.
Sugar Lake does not currently have an organized lake association.
Table 1. Sugar Lake location and key physical characteristics.
Location Data
Physical Characteristics
MN Lake ID:
11-0026-00
Surface area (acres):
702
County:
Cass
Littoral area (acres):
473
Ecoregion:
Northern Lakes and Forests
% Littoral area:
67%
Major Drainage Basin:
Upper Mississippi River
Max depth (ft)
44
Latitude/Longitude:
47.1595993/-93.83840179
Inlets:
0
Invasive Species:
Curly-leaf pondweed
Outlets:
1
Public Accesses:
1
Table 2. Availability of primary data types for Sugar Lake.
Data Availability
Transparency data
One year of data in the past decade, which is not enough
for a trend analysis.
Chemical data
One year of data in the past decade, which is not enough
for a trend analysis.
Inlet/Outlet data
Recommendations
RMB Environmental Laboratories, Inc.
--
Not necessary, since there is no inlet.
For recommendations refer to page 19.
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2012 Sugar Lake
Lake Map
Figure 1. Map of Sugar Lake with 2010 aerial imagery and illustrations of lake depth contour lines, sample
site locations, inlets and outlets, and public access points. The light green 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. Monitoring programs include the Citizen Lake
Monitoring Program (CLMP) and Lake Trend Monitoring (LTM).
Lake Site
100
101* Primary Site
Depth (ft)
25
44
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Monitoring Programs
CLMP: 1973
LTM: 2004
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Average Water Quality Statistics
The information below describes available chemical data for Sugar Lake through 2011 (Table 4).
Data for total phosphorus, chlorophyll a, and secchi depth are from the primary site 101. All
additional chemical data is from site 101 and reflects mean values from 2004.
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 11.
Table 4. Water quality means compared to ecoregion ranges and impaired waters standard.
Impaired
Waters
Standard2
Parameter
Mean
Ecoregion
Range1
Total phosphorus (ug/L)
18
14 - 27
> 30
3
5
4 - 10
>9
Chlorophyll a max (ug/L)
8
<15
Secchi depth (ft)
15
7.5 - 15
Dissolved oxygen
Polymictic
Chlorophyll a (ug/L)
Interpretation
Results are within the expected
range for the ecoregion.
< 6.5
Dissolved oxygen depth profiles
show that the lake weakly
stratifies and may mix
occasionally in the summer.
see page 8
0.47
0.4 - 0.75
Indicates insufficient nitrogen to
support summer nitrogeninduced algae blooms.
Alkalinity (mg/L)
81
40 - 140
Indicates a low sensitivity to
acid rain and a good buffering
capacity.
Color (Pt-Co Units)
9
10 - 35
Indicates clear water with little
to no tannins (brown stain).
pH
8.3
7.2 - 8.3
Indicates a hard water lake.
Lake water pH less than 6.5
can affect fish spawning and
the solubility of metals in the
water.
Chloride (mg/L)
1
0.6 - 1.2
Within the expected range for
the ecoregion.
Total Suspended Solids
2.2
<1 - 2
Slightly above the expected
range for the ecoregion, but still
considered low level.
166
50 - 250
Within the expected range for
the ecoregion.
26:1
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.
Total Kjeldahl Nitrogen
(mg/L)
(mg/L)
Specific Conductance
(umhos/cm)
Total Nitrogen : Total
Phosphorus
1
th
th
The ecoregion range is the 25 -75 percentile of summer means from ecoregion reference lakes
For further information regarding the Impaired Waters Assessment program, refer to http://www.pca.state.mn.us/water/tmdl/index.html
3
Chlorophyll a measurements have been corrected for pheophytin
Units: 1 mg/L (ppm) = 1,000 ug/L (ppb)
2
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Water Quality Characteristics - Historical Means and Ranges
Table 5. Water quality means and ranges for primary sites. Years monitored for chemical data: 2004. Years
monitored for secchi data: 1973, 2004.
Parameters
Total Phosphorus Mean (ug/L):
Total Phosphorus Min:
Total Phosphorus Max:
Number of Observations:
Chlorophyll a Mean (ug/L):
Chlorophyll-a Min:
Chlorophyll-a Max:
Number of Observations:
Secchi Depth Mean (ft):
Secchi Depth Min:
Secchi Depth Max:
Number of Observations:
Primary
Site
101
100
18
15
21
4
5
2
8
5
15
10
21
5
11
8
14
17
Figure 2. Sugar 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.]. 1988. Lake and Reservoir Restoration Guidance Manual. (Doc. No. EPA 440/5-88-002)
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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.
Sugar Lake transparency ranges from 8 to 21 feet (Table 5). Figure 3 shows the seasonal
transparency dynamics. The maximum Secchi reading is usually obtained in early summer. Sugar
Lake transparency is high in May and June, and then declines through August. The transparency
most likely rebounds in October after fall turnover. This transparency dynamic is typical of a
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.
Seasonal Transparency Dynamics
25
Site 100, 1973
Site 101, 2004
20
Secchi Depth (ft)
Poly. (Pattern)
15
10
5
0
Figure 3. Seasonal transparency dynamics and year to year comparison. The black line represents the
pattern in the data.
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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. Sugar Lake was rated as being "crystal clear" 60% of the time by
samplers at site 101 in 2004 (Figure 4).
Physical Appearance Rating
20%
20%
60%
60%
Crystal clear water
20%
Not quite crystal clear – a little algae visible
20%
Definite algae – green, yellow, or brown color
apparent
0%
High algae levels with limited clarity and/or mild
odor apparent
0%
Severely high algae levels
Figure 4. Sugar Lake physical appearance ratings by samplers at site 101.
As the secchi depth decreases, the perception of recreational suitability of the lake decreases.
Sugar Lake was rated as being "beautiful" 80% of the time in 2004 (Figure 6).
Recreational Suitability Rating
20%
80%
80%
Beautiful, could not be better
20%
Very minor aesthetic problems; excellent for
swimming, boating
0%
Swimming and aesthetic enjoyment of the lake
slightly impaired because of algae levels
0%
Desire to swim and level of enjoyment of the lake
substantially reduced because of algae levels
0%
Swimming and aesthetic enjoyment of the lake
nearly impossible because of algae levels
Figure 5. Recreational suitability rating, as rated by the volunteer monitor at site 101.
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Total Phosphorus
Total phosphorus was
evaluated in Sugar Lake
in 2004. The data do not
indicate much seasonal
variability. All the data
points fall into the
mesotrophic range
(Figure 6).
Phosphorus should
continue to be monitored
to track any future
changes in water quality.
Total Phosphorus
25
Mesotrophic
Total Phosphorus (ug/L)
Lake Sugar is
phosphorus limited,
which means that algae
and aquatic plant growth
is dependent upon
available phosphorus.
20
15
10
2004
Oligotrophic
5
0
Figure 6. Historical total phosphorus concentrations (ug/L) for Sugar Lake site 101.
Chlorophyll a
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
Chlorophyll a (ug/L)
Chlorophyll a is the
pigment that makes
plants and algae green.
Chlorophyll a is tested in
lakes to deter mine the
algae concentration or
how "green" the water is.
10
9
8
7
6
5
4
3
2
1
0
2004
Chlorophyll a was
evaluated in Sugar Lake
Figure 7. Chlorophyll a concentrations (ug/L) for Sugar Lake at site 101.
in 2004 (Figure 7).
Chlorophyll a
concentrations remained well below 10 ug/L on all sample dates, indicating clear water most of the
summer.
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Dissolved Oxygen
0
Dissolved Oxygen (mg/L)
2
4
6
8
10
0
1
12
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.
Sugar Lake is a moderately deep lake, with a
maximum depth of 44 feet. Dissolved oxygen
profiles from data collected in 2004 show weak
stratification developing mid-summer. Due to its
depth, Sugar Lake most likely stratifies during hot
calm weather, and mixes in the littoral areas after a
few days of windy weather. Figure 8 is a
representative dissolved oxygen profile for Sugar
Lake.
2
3
4
5
Depth (m)
6
7
8
9
10
11
12
12.6
6/2/2004
6/15/2004
7/20/2004
9/16/2004
Figure 8. Dissolved oxygen profile
for Sugar Lake in 2004 at site 101.
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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
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
directly comparable, we convert them to a trophic state
index (TSI).
Table 6. Trophic State Index for site 101.
Trophic State Index Site 101
TSI Total Phosphorus 46
TSI Chlorophyll-a
46
TSI Secchi
38
TSI Mean
43
Mesotrophic
Trophic State:
Numbers represent the mean TSI for each
parameter.
The mean TSI for Sugar Lake falls into the mesotrophic
range (Figure 9). There is good agreement between the
TSI for phosphorus and chlorophyll a, indicating that
these variables are strongly related (Table
6). The TSI for transparency is lower than
Sugar Lake
the other two parameters, which could be
due to zooplankton selectively grazing on
the larger algal cells, large particulates dominating the
algal community, or loss of rooted vegetation.
Mesotrophic lakes (TSI 40-50) are characterized by
moderately clear water most of the summer. "Meso"
means middle or mid; therefore, mesotrophic means a
medium amount of productivity. Mesotrophic lakes are
commonly found in central Minnesota and have clear
water with algal blooms in late summer (Table 7). They
are also good for walleye fishing.
100
Hypereutrophic
70
Eutrophic
50
Mesotrophic
40
Oligotrophic
0
Figure 9. Trophic state index chart with
corresponding trophic status.
Table 7. Trophic state index attributes and their corresponding fisheries and recreation characteristics.
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.
30-40
Bottom of shallower lakes may become anoxic
Trout fisheries in deep lakes only. Walleye,
(no oxygen).
Cisco present.
40-50
Mesotrophy: Water moderately clear most of
No oxygen at the bottom of the lake results in
the summer. May be "greener" in late summer.
loss of trout. Walleye may predominate.
50-60
Eutrophy: Algae and aquatic plant problems
Warm-water fisheries only. Bass may
possible. "Green" water most of the year.
dominate.
60-70
Blue-green algae dominate, algal scums and
Dense algae and aquatic plants. Low water
aquatic plant problems.
clarity may discourage swimming and boating.
70-80
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. 1997. A trophic state index for lakes. Limnology and Oceanography. 22:361-369.
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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 1985-1988, 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 25th
- 75th percentile range for data within each ecoregion.
For the purpose of this graphical representation, the
means of the reference lake data sets were used.
Figure 10. Minnesota Ecoregions.
30
50
25
40
30
20
10
0
5
Secchi depth (ft)
60
Chlorophyll-a (ug/L, ppb)
Total Phosphorus (ug/L, ppb)
Sugar Lake is in the
Northern Lakes and Forests
Ecoregion (Figure 10). The
mean total phosphorus,
chlorophyll a and
transparency (secchi depth)
for Sugar are within the
ecoregion ranges (Figure
11).
20
15
Sugar
15
20
crystal
clear
25
0
NLF
Ecoregion
10
10
5
0
increased
algae
NLF
Ecoregion
Sugar
NLF
Ecoregion
Sugar
Figure 11. Sugar Lake ranges compared to Northern Lakes and Forest Ecoregion ranges. The Sugar Lake
total phosphorus and chlorophyll a ranges are from 5 data points collected in May-September of 2004. The
Sugar Lake secchi depth range is from 5 data points collected in May-September from 2004.
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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 Mississippi Headwaters Major Watershed is one of the watersheds that make up the Upper
Mississippi River Basin, which drains south to the Gulf of Mexico (Figure 12). This major
watershed is made up of 121 minor watersheds. Sugar Lake is located in minor watershed 7126
(Figure 13).
Figure 12. Mississippi Headwaters Major Watershed.
Figure 13. Minor Watershed 7126
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.
Sugar Lake falls within
lakeshed 712601 (Figure 14).
Though very useful for
displaying the land and water
that contribute directly to a
lake, lakesheds are not
always true watersheds
because they may not show
the water flowing into a lake
from upstream streams or
rivers. While some lakes may
Figure 14. Sugar Lake lakeshed (712601) with land ownership, lakes,
have only one or two upstream
wetlands, and rivers illustrated.
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 Sugar Lake’s full watershed, containing all the lakesheds upstream of the
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Sugar Lake lakeshed, see page 16. The data interpretation of the Sugar Lake lakeshed includes
only the immediate lakeshed as this area is the land surface that flows directly into Sugar Lake.
The lakeshed vitals table identifies where to focus organizational and management efforts for each
lake (Table 8). 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 8. Sugar Lake lakeshed vitals table.
Lakeshed Vitals
Lake Area
Littoral Zone Area
Lake Max Depth
Lake Mean Depth
Water Residence Time
Miles of Stream
Inlets
Outlets
Major Watershed
Minor Watershed
Lakeshed
Ecoregion
Total Lakeshed to Lake Area Ratio (total
lakeshed includes lake area)
Standard Watershed to Lake Basin Ratio
(standard watershed includes lake areas)
Wetland Coverage
Aquatic Invasive Species
Public Drainage Ditches
Public Lake Accesses
Miles of Shoreline
Shoreline Development Index
Public Land to Private Land Ratio
Development Classification
Miles of Road
Municipalities in lakeshed
Forestry Practices
Feedlots
Sewage Management
Lake Management Plan
Lake Vegetation Survey/Plan
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Rating
702 acres
473 acres
44 ft.
15 ft.
NA
0
0
1
7 – Mississippi River Headwaters
7126
712601
Northern Lakes and Forests
descriptive
descriptive
descriptive
NA
descriptive
descriptive
descriptive
descriptive
descriptive
4:1
4:1
10.6%
Curly-leaf pondweed
0
1
6.1
1.8
4.9:1
Recreational Development
1.2
0
Yes, managed by Cass County Forest Plan,
2010-2019
0
Individual Waste Treatment Systems, no
lake-wide survey conducted
None
None
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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 land’s ability to
absorb and store water
Figure 15. Sugar Lake lakeshed (712601) land cover (http://land.umn.edu).
rather than cause it to
flow overland
(gathering nutrients and
sediment as it moves) towards the lowest point, typically the lake. Impervious intensity describes
the land’s 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 15 depicts the land cover in Sugar Lake’s lakeshed.
The University of Minnesota has online records of land cover statistics from years 1990 and 2000
(http://land.umn.edu). Although this data is 11 years old, it is the only data set that is comparable
over a decade’s time. Table 9 describes Sugar Lake’s lakeshed land cover statistics and percent
change from 1990 to 2000. 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 for Sugar Lake is the decrease in
grass/shrub/wetland cover (25%). I
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Table 9. Sugar Lake’s lakeshed land cover statistics and % change from 1990 to 2000 (http://land.umn.edu).
1990
2000
% Change
Land Cover
Acres
Percent
Acres
Percent
1990 to 2000
0
0
0
0
No Change
Agriculture
2085
69.41
2175
72.4
4.3% Increase
Forest
184
6.13
138
4.59
25% Decrease
Grass/Shrub/Wetland
717
23.87
673
22.4
6.1% Decrease
Water
16
0.53
16
0.53
No Change
Urban
Impervious Intensity %
0
1-10
11-25
26-40
41-60
61-80
81-100
Total Area
Total Impervious Area
(Percent Impervious Area
Excludes Water Area)
2996
4
1
0
0
0
0
99.83
0.13
0.03
0
0
0
0
2993
4
5
0
0
0
0
99.73
0.13
0.17
0
0
0
0
0.1% Decrease
No Change
400% Increase
No Change
No Change
No Change
No Change
3004
0
0
3004
1
0.04
.04% Increase
Demographics
Sugar Lake is classified as a recreational development lake. Recreational development lakes
usually have between 60 and 225 acres of water per mile of shoreline, between 3 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 2035. Compared to Cass County as a
whole, Unorganized Township has a lower growth projection, while Torrey Township has a higher
extrapolated growth projection (Figure 16).
(source:http://www.demography.state.mn.us/resource.html?Id=19332)
Population Growth Projection
60%
Percentage of 2006 Population
Torrey Township;2006 population: 129
50%
Unorganized Township; 2006 population: 630
Cass County; 2006 population: 28,949
40%
30%
20%
10%
0%
2006
2010
2015
2020
2025
2030
2035
Extrapolation
Figure 16. Population growth projection for Torrey and Unorganized Townships and Cass County.
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Sugar 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 privately owned land within Sugar Lake’s lakeshed is forested uplands (Table
10). This land can be the focus of development and protection efforts in the lakeshed.
Table 10. Land ownership, land use/land cover, estimated phosphorus loading, and ideas for protection and
restoration in Sugar lakeshed (Sources: Cass County parcel data, National Wetlands Inventory, and the
2006 National Land Cover Dataset).
23%
Private (13%)
Land Use (%)
Runoff
Coefficient
Lbs of
phosphorus/acre/year
Estimated
Phosphorus
Loading
Public (64%)
Developed
Agriculture
Forested
Uplands
0.3
0
6.1
0.45 – 1.5
0.26 – 0.9
0.09
0.09
0.09
0.09
0.09
4 – 14
0
16
6
<1
60
113
Cropland
Focus of
development and
protection
efforts
State
Forest
National
Forest
Other
3.6
Wetlands
Open
Water
County
State
Federal
2.1
23.0
0.1
22.0
41.9
Acreage x runoff
coefficient
Description
Potential
Phase 3
Discussion
Items
Focused on
Shoreland
Shoreline
restoration
Restore
wetlands;
CRP
Open,
pasture,
grassland,
shrubland
Forest
stewardship
planning, 3rd
party
certification,
SFIA, local
woodland
cooperatives
Protected
Protected by
Wetland
Conservation
Act
County
Tax Forfeit
Lands
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.
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Table 11. Suggested approaches for watershed protection and restoration of DNR-managed fish lakes in
Minnesota.
Watershed
Disturbance
(%)
Watershed
Protected
(%)
Management
Type
> 75%
Vigilance
Sufficiently protected -- Water quality supports healthy and
diverse native fish communities. Keep public lands protected.
< 75%
Protection
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.
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.
< 25%
25-60%
> 60%
n/a
Comments
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.
Sugar Lake’s lakeshed is classified with having 87.7% of the watershed protected and 1.5% of the
watershed disturbed (Figure 17). Therefore, this lakeshed should have a vigilance focus. Goals for
the lake should be to limit any increase in disturbed land use. Figure 18 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 Sugar Lake, whether through direct overland flow or
through a creek or river. Sugar Lake’s lakeshed is a headwaters catchment, which means no
additional lakesheds contribute water this to area.
Percent of the Watershed Protected
0%
100%
75%
Sugar Lake
(87.7%)
Percent of the Watershed with Disturbed Land Cover
0%
25%
100%
Sugar Lake
(1.5%)
Figure 17. Sugar Lake’s lakeshed percentage of
watershed protected and disturbed.
RMB Environmental Laboratories, Inc.
Figure 18. Upstream lakesheds that contribute water
to the Sugar lakeshed. Color-coded based on
management focus (Table 11).
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Conservation Easement Potential
In an ever-growing society, today’s landscapes are being urbanized more and more to sustain the
ever-growing population and behavior of recreational usage. In Minnesota, the land of ten
thousand lakes, it is only natural to develop properties within the boundaries and beauty of our
lakes and streams. Conservation efforts to limit or slow down the development process can only
assist in the preservation of the lakeshed and inevitably the water quality of water bodies found
within. Figure 19 identifies parcels within the lakeshed that are large enough to warrant the
investigation of parcel conservation practices and purchase.
Figure 19. Lake parcels with conservation potential (developed by John Snyder, LLAWF).
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Status of the Fishery (DNR, as of 06/29/2009)
Sugar Lake (DOW # 11-0026) is a moderately developed lake located eight miles northeast of
Remer, MN. The lake has a surface area of 711 acres and a maximum depth of 44 feet. There is a
US Forest Service-owned public access at the southwest corner of the lake. Sugar Lake is a
relatively fertile lake that often experiences dense summer algae blooms.
Sugar Lake has curly-leaf pondweed, a harmful exotic species. Curly-leaf pondweed grows in thick
beds, displacing native plant species and hampering water-based recreation. To prevent the
spread of exotic species, anglers are reminded to carefully inspect boats and trailers and remove
any plant fragments when leaving the lake. It is unlawful to transport exotic species like curly-leaf
pondweed in Minnesota. Much of the shoreline is undeveloped and in public ownership.
The best angling opportunities in Sugar Lake are largemouth bass, black crappie, bluegill, and
northern pike. Twelve largemouth bass were sampled from standard summer netting. The mean
length of sampled largemouth bass was 14 inches and the lengths ranged from 10 to 18 inches.
Black crappies are a popular species sought after by anglers in Sugar Lake, particularly in the
winter. The quality of the fishery varies depending upon the number of fish 10 inches or greater in
length available in any given year. From the 2009 assessment, 80 percent of the black crappies
sampled were 8 inches or greater in length. Only one black crappie was 10 inches or greater in
length. The average length of black crappies was 8 inches and the lengths ranged from 5 to 11
inches. Angling for larger crappies should improve in the next couple of years. Walleye are not
abundant in Sugar Lake. The walleye in the sample were large with an average length of 22 inches
and the lengths ranged from 16.1 to 28.9 inches. Northern pike are very abundant with an average
length of 20 inches with fish ranging in length up to 34 inches. Bluegills are moderately abundant.
In 2009, only two percent of bluegills sampled were 8 inches or greater in length. However, over
half of the sample in 2009 was 7 inches or greater in length, which indicates that good angling
opportunities for bluegills will exist on Sugar Lake over the next few years. Yellow perch are not
very abundant and they average 6 inches in length. No yellow perch were sampled greater than
8.5 inches in length. Other species sampled in 2009 were black bullhead, brown bullhead,
pumpkinseed sunfish, rock bass, and yellow bullhead.
Anglers can help maintain or improve the quality of fishing by practicing selective harvest.
Selective harvest allows for the harvest of smaller fish for table fare, but encourages release of
medium- to large-sized fish. Releasing these fish can help maintain balance in the fish community
in Sugar Lake and provide anglers the opportunity to catch more and larger fish in the future .
Shoreline habitat consists of aquatic plants, woody plants and natural lake bottom soils. Plants in
the water and at the waters edge provide habitat, prevent erosion and absorb excess nutrients.
Shrubs, trees, and woody debris such as fallen trees or limbs provide good habitat both above and
below the water surface and should be left in place. By leaving a buffer strip of natural vegetation
along the shoreline, property owners can reduce erosion, help maintain water quality, and provide
habitat and travel corridors for wildlife.
See the link below for specific information on gillnet surveys, stocking information, and fish
consumption guidelines. http://www.dnr.state.mn.us/lakefind/showreport.html?downum=11002600
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Key Findings / Recommendations
Monitoring Recommendations
Sugar Lake only has one year of data in the past 10 years, which is not enough for MPCA
assessment. At least one more year of data should be collected in the near future to enable
assessment.
Transparency monitoring at site 101 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. Total Phosphorus and chlorophyll a monitoring should continue,
as the budget allows, to track trends in water quality.
Overall Summary
Sugar Lake is in good shape for water quality and excellent shape for lakeshed protection. Sixtyfour percent (64%) of the lakeshed is in public ownership, and 88% of the lakeshed is protected,
while only 1.5% of the lakeshed is disturbed (Figure 17). Sugar Lake is in the Chippewa National
Forest, which provides good protection from development.
Sugar Lake is at an advantage in that it is a headwaters lake, and no other lakesheds flow into it
(Figure 18). In addition, it has no inlets. This means that the main phosphorus inputs to the lake
come from the surrounding shoreline.
Priority Impacts to the lake
Sugar Lake is moderately developed. Some of the developed shoreline is classified as “sensitive
shoreline” by the DNR (Figure 18). These lots should be kept in a natural state to preserve fish
and wildlife habitat.
The urban and impervious acreage had negligible change from 1990-2000, so there doesn’t
appear to be a lot of development pressure around the lake. The large amount of public land limits
the potential for second and third tier development.
There is some forestry occurring in the lakeshed, but it is managed by the Cass County Forest
Plan, 2010-2019. It is important not to clear cut trees right up to the lake, which can increase
runoff and soil erosion.
Best Management Practices Recommendations
The management focus for Sugar Lake should be to protect the current water quality and the
lakeshed. Efforts should be focused on managing and/or decreasing the impact caused by
additional development, including second tier 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.
There are numerous large parcels of land that could be protected with conservation easements.
See Figure 19 for the location of these parcels.
Project Implementation
The best management practices above can be implemented by a variety of entities. Some
possibilities are listed below.
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Individual property owners
 Shoreline restoration
 Rain gardens
 Aquatic plant bed protection (only remove a small area for swimming)
 Conservation easements
Lake Associations
 Lake condition monitoring
 Ground truthing – visual inspection upstream on stream inlets
 Watershed mapping by a consultant
 Shoreline inventory study by a consultant
 Conservation easements
Soil and Water Conservation District (SWCD) and Natural Resources Conservation Service
(NRCS)
 Shoreline restoration
 Stream buffers
 Wetland restoration
Organizational contacts and reference sites
Cass County Soil and Water
Conservation District
Courthouse, 1st Floor, 303 Minnesota Avenue W, PO Box 3000,
Walker, MN, 56484-3000
218-547-7399
http://www.co.cass.mn.us/soil_conservation/soil_water.html
DNR Fisheries Office
07316 State 371 Northwest, Walker, MN, 56484
218-547-1683
[email protected]
Regional Minnesota Pollution
Control Agency Office
7678 College Road, Suite 105, Baxter, MN 56425
218-828-2492, 1-800-657-3864
http://www.pca.state.mn.us/pyri3df
RMB Environmental Laboratories, Inc.
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