Illinois Environmental Protection Agency Clean Lakes Program%3A Phase 1 Diagnostic Feasibility Study, Glenn Shoals Lake, City of Hillsboro, Montgomery County, Illinois

              City of Hillsboro
Glenn Shoals Lake
Illinois Environmental Protection Agency
CLEAN LAKES PROGRAM
Phase 1 Diagnostic Feasibility Study
GLENN SHOALS LAKE
CITY OF HILLSBORO, MONTGOMERY COUNTY, ILLINOIS
Prepared by:
Eric Ahern, James Lang, Jake Hartter, Matthew Shively, Rachel
Petrucha, Adam Vrabec, & William Ahern
Zahniser Institute For Environmental Studies, Greenville College
For the City of Hillsboro
In Cooperation with the Illinois Environmental Protection Agency
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Table of Contents
Part 1: Diagnostic Study
PAGE
A.1. Lake Identification and Location 1
A.2.. Geological and Soil Description 2
A.2.a Geological Description 4
A.2.b. Groundwater Hydrology 4
A.2.c Topography 4
A.2.d Soils 9
A.3. Description of Public Access 12
A.3.a Description of Public Access 12
A.3.b Description of Access Points 13
A.3.c Routes and distances to Access Points 15
A.3.d Public transportation availability 15
A.4.. Description of Size and Economic Structure 16
A.4.a Size of resident population 16
A.4.b Size of any significant seasonal user 16
A.4.c Distribution of population 16
A.4.d Pertinent economic characteristics 18
A.5. Summary of Historical Lake Uses 21
A.5.a Inventory of present and past lake uses 21
A.5.b Statistics on present and historical usage 21
A.5.c Analysis of relationship between historical
trends in lake water quality 21
A.6 Population Segments Adversely Affected by
Lake Degradation 22
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A.7. Comparison of Lake Uses 23
A.7.a Summary of statistics on other
publicly-owned lakes within 80 km 23
A.7.b Discussion of relationship
of lake under study to other lakes 24
A.8. Inventory of Point Source Pollution Discharge 26
A.9. Land Uses and Nonpoint Pollutant Loading 27
A.9.a Land uses in the watershed 29
A.9.b The area of each land use as a percentage
of the total drainage area 29
A.9.c Land use map 30
A.9.d Nonpoint source pollutant loading
by land use category 31
A.10. Baseline and Current Limnological Data 33
A.10.a Summary analysis and discussion
of historical baseline limnological data 33
A.10.b Presentation, analysis, and discussion
of one year of current baseline limnological data 36
A.10.c Trophic Condition of the Lake 81
A 10.d Limiting Algae Nutrients 82
A.10.e Hydraulic budget 83
A. 10. f Phosphorus budget 86
A.11. Biological Resources and Ecological Relationships 89
A.11.a Composition of lake fish fauna 89
A.11.b Identification and approximate numbers of waterfowl
supported by the lake 95
A.11.c Identification of other wildlife 103
A.11.d Discussion of the relationships of the
organisms identified in a, b & c above 117
A.11.e Comments on the effects of water quality problems on
biological resources. 117
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Part 2 FEASIBILITY STUDY OF GLENN SHOALS LAKE
B.1. Pollution Control and Restoration Procedures 118
B.1.a. ALTERNATIVES TECHNIQUES CONSIDERED
FOR LAKE RESTORATION 120
B.1.b Expected water quality improvement 136
B.1.c A detailed description of activities to be
undertaken and anticipated lake water quality 137
B.2. Benefits Expected From Restoration 138
B2.a. Statement of project objectives 138
B.2.b Discussion of relationship between proposed restoration
and anticipated water quality changes 138
B.2.c Discussion of relationship of benefits 138
B.2.d Quantitative estimation of benefits 138
B.3. Phase 2 Monitoring Program 139
B.3.a Monitoring program 139
B.3.b. Provision for continued monitoring for at least
one year after Construction 140
B.4. Schedule and Budget 141
B.4.a Proposed milestone work schedule 141
B.4.b Proposed budget 142
B.4.c Proposed payment schedule 142
B.5. SOURCES OF MATCHING FUNDS 142
B.6. Relationship to Other Pollution Control Programs 142
B.7. Public Participation Summary 142
B.8. Operation and Maintenance (O&M) Plan 144
B.8.a&b Operation and maintenance requirements and Proposed
duration for each component of the project 144
B.8.c Agencies which will be responsible for O & M 146
B.8.d Measures for implementing the plan 146
B.8.e Funding sources 146
B.9. Copies of Permits or Pending Applications 146
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Part 3 ENVIRONMENTAL EVALUATION
C. 1. Displacement of People 148
C. 2. Defacement of Residential Areas 148
C. 3. Changes in Land Use Patterns 148
C. 4. Impacts of Prime Agricultural Land 148
C. 5. Impacts on Parkland, Other Public Land, and Scenic
Resources 148
C. 6. Impacts on Historic, Architectural, Archaeological or
Cultural Resources 148
C. 7. Long Range Increases in Energy Demand 149
C. 8. Changes in Ambient Air Quality or Noise Levels 149
C. 9. Adverse Effects of Chemical Treatment 149
C. 10. Compliance with Executive Order 11988 on Floodplain
Management 149
C. 11. Dredging and Other Channel, Bed, or Shoreline
Modifications 149
C. 12. Adverse Effects on Wetlands and Related Resources 149
C. 13. Feasible Alternatives to Proposed Project 150
C. 14. Other Necessary Mitigative Measures Requirements 150
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Tables
Table 1 Lake Identification and Location 2
Table 2 Topography of Glenn Shoals Watershed 4
Table 3 Major Soil Associations 9
Table 4 City of Hillsboro Municipal Boat License Fees 13
Table 5 City of Hillsboro – Permits, Licenses & Fees 14
Table 6 Potential User Population by Counties 17
Table 7 Potential Users by City 17
Table 8 Household Income in 1999 18
Table 9 Record of Lake Revenue by Types of Recreational Usage 21
Table 10 Comparison of Lake Uses Within 80 Km 23
Table 11 Point Source Inventory 26
Table 12 Montgomery County Tillage Practices 29
Table 13 Glenn Shoals Land Use 29
Table 14 Nutrient and Sediment Budget for Glenn Shoals Lake 32
Table 15 Glenn Shoals Lake Historical Data 1981-1999 33
Table 16 Morphometric Data 34
Table 17 Dissolved Phosphorus ROL Lake 56
Table 18 Glenn Shoals Sediment Survey 75
Table 19 Glenn Shoals Organic Sediments 76
Table 20 Glenn Shoals Sediment Metals 20
Table 21 Hydrologic Budget for Glenn Shoals Lake 2000-2001 85
Table 22 Dissolved Phosphorus ROLO (Tributaries) 88
Table 23 Lake Management Status Report 90
Table 24 Fish Tissue Samples from Glenn Shoals Lake 94
Table 25 Bird Count Estimates 96
Table 26. Illinois Natural Area Inventory Sites in 100
Montgomery County.
Table 27 Extinct and Extirpated Species of Illinois 100
as noted by Illinois Endangered Species Board.
Table 28. Endangered and threatened species currently 101
monitored in Montgomery County.
Table 29. Currently listed species potentially
occurring in Montgomery County. 102
Table 30 a. Plant Name 106
Table 30 b. Plant Name 107
Table 30 c. Plant Name 108
Table 30 d. Plant Name 109
Table31 Restoration and Mitigation Alternatives for Glenn 121
Shoals Lake (2000)
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Table 32 Potential Sediment Control Basins 126
Table 33 Projected Long Term Pollutant Removal Rates 128
For Storm Water Wetland in the Mid-Atlantic Region
Table 34 Work Schedule 141
Table 35 Map 143
Figures
Figure 1 Glenn Shoals Lake Location Map 3
Figure 2 Quaternary Deposits in Illinois 5
Figure 3 Loess Thickness in Illinois 6
Figure 4 Physiographic Regions on Illinois 7
Figure 5 Geologic Map of Illinois 8
Figure 6 Glenn Shoals Lake – Subwatershed Soils 10
Figure 7 Montgomery County Soil (Key to Figure 6) 11
Figure 8 Identification and Location Map 12
Figure 9 Household Income Comparison 18
Figure 10 Employment Sectors in Montgomery County 10
Figure 11 Lakes within 80 Kilometers of Glenn Shoals Lake 25
Figure 12 Sub-watershed Delineation 30
Figure 13 Bathymetric map 35
Figure 14A Lake Sampling Sites 36
Figure 14B Tributary Sampling Sites 64
Figure 15 Total Suspended Solids 38
Figure 16 Volatile Suspended Solids 39
Figure 17 Non Volatile Suspended Solids 40
Figure 18 Secchi Depth’s 42
Figure 19 A. Summer ROL-1 Temperature 44
B. Summer ROL-1 Dissolved Oxygen 45
C. Fall ROL-1Dissolved Oxygen 46
D. Fall ROL-1 Temperature 46
E. Winter/Spring ROL-1 Temparature 47
F. Winter/Spring ROL-1 Dissolved Oxygen 47
Figure 20 A. Summer ROL-2 Temperature 48
B. Summer ROL-2 Dissolved Oxygen 48
C. Fall ROL-2 Temperature 49
D. Fall ROL-2 Dissolved Oxygen 49
E. Winter/Spring ROL-2 Temperature 50
F. Winter/Spring ROL-2 Dissolved Oxygen 50
Figure 21 A. Summer ROL-3 Temperature 51
B. Summer ROL-3 Dissolved Oxygen 51
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C. Fall ROL-3 Dissolves Oxygen 52
D. Fall ROL-3 Temperature 52
E. Winter/Spring ROL-3 Temperature 53
F. Winter/Spring ROL-3 Dissolved Oxygen 53
Figure 22 Total Phosphorus 2001-2002 55
Figure 23 Total Nitrogen 2001-2002 58
Figure 24 Nitrate + Nitrite Nitrogen 59
Figure 25 Organic Nitrogen 60
Figure 26 Ammonia Nitrogen 61
Figure 27 pH 2001-2002 62
Figure 28 Total Suspended Solids 65
Figure 29 Volatile Suspended Solids 66
Figure 30 Nitrate + Nitrite Nitrogen 67
Figure 31 Tributary Sites Nitrate + Nitrite Nitrogen 68
Sept. 2001 – April 2002
Figure 32 Organic Nitrogen 69
Figure 33 Total Nitrogen 70
Figure 34 Ammonia Nitrogen 71
Figure 35 pH 73
Figure 36 Shoreline Erosion 79
Top Picture – Riprap
Bottom Picture – Without riprap
Figure 37 Glenn Shoals Shoreline Erosion Survey 80
Figure 38 Trophic State Index 82
Figure 39 Phosphorus 86
Figure 40 Bird Survey of Glenn Shoals Lake 97
Figure 41 Macrophyte sampling sites 103
Figure 42 Chlorophyll a 115
Figure 43 Fecal Coliform 116
Figure 44 Rip-Rap Stabilization 122
Figure 45 Rock Riffles 123
Figure 46 Field Borders 124
Figure 47 Conservation Tillage 124
Figure 48 Riparian Buffers 125
Figure 49 USGS Possible Stormwater Retention Ponds 127
Figure 50 Shallow Marsh Storm Water Wetland 129
Figure 51 Pond/Wetland Storm Water System 129
Figure 52 In-Lake Control Structure at Meisenheimer Road 131
Figure 53 In-Lake Sediment Control and Wetlands 132
Figure 54 Dredging 133
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Illinois Environmental Protection Agency
CLEAN LAKES PROGRAM
Phase 1 Diagnostic Feasibility Study
GLENN SHOALS LAKE
CITY OF HILLSBORO, MONTGOMERY COUNTY, ILLINOIS
EXECUTIVE SUMMARY
Prepared by:
ZAHNISER INSTITUTE FOR ENVIRONMENTAL STUDIES, Greenville College
Lake Status
Glenn Shoals Lake has four main purposes. These purposes include flood control, water
supply, recreation, and esthetics. The following lake uses are discussed from the most important
to the least important. Glenn Shoals Lake was designed to be a flood control lake. Flood control
was the primary use for the lake which qualified it for federal funding through the U. S.
Department of Agriculture and it still continues to serve this function. This is a very important
purpose for Glenn Shoals providing stability for downstream homes and croplands.
The secondary purpose for the lake is public drinking and water supply. Glenn Shoals
provides drinking water to over 10,800 households in the area. It is used for general water
supply for the residents in Hillsboro, Schram City, Taylor Springs, Coffeen, Grahm Correctional
Center and as a rural water supply through the Montgomery Water Co.
Recreation is the third use for the lake. Glenn Shoals serves the surrounding area with a
wide range of recreational activities. Hillsboro residents as well as those from surrounding cities
can enjoy duck hunting, camping, hiking, fishing, and boating. Glenn Shoals offers the same
types of recreation as other lakes within 50 miles. Although it is not provided in Glenn Shoals
Lake, supervised recreational swimming is available in nearby Hillsboro Lake.
Finally, Glenn Shoals provides an esthetically pleasing feature for the community. The
natural beauty of the lake and its surrounding shoreline are a source of pleasure for those who
visit. The scenery and esthetic beauty of Glenn Shoals attracts people to the lake to engage in
recreational activities, build homes nearby or observe birds and other wildlife. The value of the
lake in this respect is not measured in dollars but is appreciated by each visitor according to his
or her own personal preference. However, the esthetic value has a major impact on the economic
value that most people place on property. The presence of the esthetic environment provided by
the lake is also healthy and psychologically beneficial for local residents and visitors alike.
The life of the lake is determined by two factors. First, since the lake is constantly filling
with sediments, there will come a time when it will no longer hold enough water to adequately
meet the demands of the community for drinking and other water supply. At the present
sedimentation rates, many of the shallower portions of the lake could be filled in the next 20-40
years while in other parts of the lake the changes will be hardly noticeable for a number of years.
The second deals with the quality of the water as a result of suspended solids, nutrients and
pesticides entering the lake from the watershed. The watershed is over 75% cropland and the
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fertilizer added to crops is the major source of pollution. Chemical pollution (nutrients and
pesticides) can be addressed by continuing to encourage farmers in the watershed to use best
management practice (BMP). The BMP’s for sedimentation reduction would include but not be
limited to, no-till, grass strips, terracing, stream bank erosion control, and reforestation. Other
means such as storm water wetland basins should also be studied. These federally funded
programs should be extended because they would greatly extend the useful life of the lake.
The nutrient and sediment budget (Table 12) shows that 45,000 tons were added to the
lake in 2001. This compares to the 39,593 tons calculated for the NRCS 1995 unpublished
survey. These data indicate that there is almost a ton of sediment deposited per acre of watershed
per year. The nutrient levels in the water are presented in Table14. The average Nitrogen
measured was (3-5 mg/l) which is higher than the historical (kjeldahl nitrogen of 1.04-1.3 mg/l).
The phosphorus is currently 0.1 - 0.2 mg/l while the historical data shows an average of 0.134
mg/l (Table15; ROL 1b). If BMPs (remediation techniques) could reduce the phosphorous (P)
and total suspended solids (TSS) input, by half, the life of the lake could be doubled.
Lake Quality Problems
Glenn Shoals has three major water quality factors that present problems for the lake.
These factors are: sediment entering the lake, excessive nutrients in the lake, and degraded
recreation and esthetic quality caused by suspended solids and algae blooms that result from
excess sediments and nutrients entering the lake. These problems occur primarily from non-point
source pollution in the watershed.
The first problem identified is sediments entering the lake. The sediment loading in
Glenn Shoals Lake is due mostly to the surrounding watershed. The lake’s watershed covers
51,200 acres of primarily agricultural land. Run-off from the watershed brings excess nutrients
and sediment into the lake. The nutrients disperse or dissolve in the water and the sediment
settles to the bottom of the lake slowly filling it. In 2001 Glenn Shoals Lake received 45,000
tons of sediment. Also, adding to the problem of sedimentation is internal loading and shoreline
erosion. These are minimal contributor to the sedimentation problem.
The second problem with Glenn Shoals is excessive nutrients in the lake. The two major
nutrients associated with good water quality are, Phosphorus (P) levels and Nitrogen (N) levels.
These two major nutrients determine the health of the lake. Plants use N and P for their growth
and development. High levels of nutrients create a good environment for algal blooms and high
eutrophic conditions, causing damage to the lake. High eutrophic conditions create higher
amounts of decaying plant material, which in turn uses more oxygen and produces more
dissolved phosphorus. Low oxygen levels in the water can be detrimental to fish and aquatic
inverterbrates. The major cause of excess nutrients in the lake is run-off from the watershed,
especially that arising from agricultural properties. The minor contributors are waterfowl and
atmospheric deposition from rainfall. Waterfowl and rainfall have had limited impact on the
water quality of Glenn Shoals Lake.
Degraded recreation and esthetic quality is the last problem concerning Glenn Shoals
Lake. As the quality of the lake deteriorates fish populations decline. Also, the esthetic or
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natural beauty of a lake and shoreline is degraded when the lake becomes laden with excess
nutrients. Water recreational activities will also be limited with reduced water quality of the
lake. Since the lake supports duck hunting, boating, hiking, camping, and fishing, the
degradation that results from increased sediments and nutrients is a concern to the managers,
owners and users of Glenn Shoals Lake. The recreational activities of duck hunting, boating,
camping, and fishing are also a source of revenue for the City of Hillsboro.
These three lake quality problems 1) sediment loading, 2) nutrient loading and 3)
reduction in recreational and esthetic quality can be alleviated and the life of the lake extended
for many more years. The current sediment load is approximately 45,000 tons per year. This will
be 46 acre feet per year. The sediment filling the lake will not be uniform. The areas near the
incoming streams will fill first and will pose navigation problems in the next 20 to 40 years,
significantly reducing the total surface area of the lake. This will probably be accompanied by
excess algae blooms that can produce taste and/or odor problems with the drinking water. The
deeper part of the lake will fill later and should last for many years. Even though the lake can
survive for many years without mitigation the size will continue to decline and quality will
continue to deteriorate. However with proper management the useful life can be doubled or
tripled.
The lake was designed so that the volume would support the water needs of the
community even with a 2 year drought. In the normal design structure this requires a 70-75%
capacity of the original volume of 12,500 acre ft. This means that a 25% loss (3125 Acre ft.), if it
occurs at the current rate of 46 acre ft/year, will be exceeded in 70 years. After this the 2 year
drought reserve would not be available. Even before this time, the turbidity, taste and odor
problems will multiply and the treatment cost to produce potable water will be greatly increased.
The most viable alternatives for preserving the lake (Glenn Shoals) are to try to prevent
particulates and nutrients from entering the lake. Since humans by nature tend to increase both
particulates and nutrients and individuals living closer to the lake have a much greater effect per
area, it is our recommendation that Hillsboro do everything possible to keep the natural trees
and other vegetation wherever possible. This would suggest that all public lands should be kept
natural. Thus we recommend no additional sale or leasing of public property.
Mitigation and Restoration
There are 24 possible mitigation or restoration alternatives proposed for Glenn Shoals
Lake (Table 30). The costs of the alternatives range from an estimated $5,000,000 to practically
nothing. Out of the 24 possible alternatives, 10 were chosen as the best fit for the needs of Glenn
Shoals Lake and budget of the City of Hillsboro. The 10 alternatives being recommended are
those that will most effectively address the issues of improving lake quality and prolonging the
life of the lake, while managing the cost to the city.
Alternatives (2), (3), (19) and (20) would have no real impact on the City of Hillsboro’s
funds. These alternatives would be covered by other federal, state, county, or regional agencies.
Alternatives (2) and (3) would reduce the amount of sediment coming into the lake along with
unwanted excess nutrients thus improving the water quality of the lake. Alternative (19) and
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(20) would specifically help reduce the amount of nutrients (P and N) entering the lake from
septic tanks and fields.
Alternatives (22) and (16) would cost between $1,000 and $10,000. Alternative (22)
would help reduce the amount of nutrients and some sedimentation that come into the lake. By
reducing the area affected by water ski boats alternative (16) would greatly help the amount of
shoreline erosion on Glenn Shoals Lake. This water ski area should be the first to be completely
rip-raped.
Although alternatives (7), (8), (15) are the most expensive possible alternatives selected,
these alternatives along with (2) would have the greatest impact on sustaining the life of the lake,
improving the life of the lake, and improving the lake quality.
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TABLE 31 (duplicate) Restoration and Mitigation Alternatives for Glenn Shoals Lake (2000-01)
Legend:
+ = Positive effect * No estimated life projection; cost prohibitive project.
O = No effect ** Watershed project; to assist NRCS City should form a resource committee
- = Negative effect *** Requires passing a City Ordinance.
N/A = Not available
Objectives for Lake Restoration
Objective 1 – Reduce the rate and extent of sedimentation.
Objective 2 – Reduce total suspended solids.
Objective 3 – Reduce nutrient and pesticide input from the watershed.
Objective 4 – Improve the aquatic life of the lake.
Objective 5 – Improve the recreational use of the lake.
Objective 6 – Educate the public on the importance of good water quality
Restoration Alternative Estimated Reduce Reduce Reduce Aquatic Rec Extended
Alt. No. Cost Sediment Solids Pollution Life Use Lake life
Obj. 1 Obj. 2 Obj. 3 Obj. 4 Obj. 5 Years
1 Stream Bank Stabilizatoin ** $150,000 + + O + +
2 Conservation Practices ** Soil N/A + + + + +
Testing of Farmland
3 Riparian buffers ** N/A + + + + +
4 Sediment Control Struct's ** $200,000 + + + + + 2yrs.
5 Storm Water Detention ** $500,000 + + + + + 3yrs.
6 Draw Down Structure 14 $1,000 + O O O + N/A
7 Meisen. Struc. & Wetland $632,000 + + + + + 52yrs
8 Irving Cove Structure $512,500 + + + + + 6yrs
9 Dredging Irving Cove * $1,996,500 + O O O +
10 Dredging Fawn Cove * $2,715,240 + O O O +
11 Dred’g North End of Lake * $4,871,460 + O O O +
12 Draw Down North End $5,000 + O O O + N/A
13 Cove Dredging $120,000 + O O O + N/A
14 Brood Pond $15,000 O O O + + 0
15 Lake Rip-Rap $1,391,960 + + + + + 1 yr
16 Designated Ski Area *** $1,000 + + O O +
17 Increase Patrol and Fees *** $0 + + O O +
18 Construction Site BMP's ** N/A + + O O +
19 Septic Tank Inspection ** $0 O O + + +
20 Public Land Preservation *** $0 + + + + + <1 yr
21 Phase 2 monitoring prog. $35,000 O O O O O 0
22 Add Barley Bales $5,000/yr O + O + +
23 Lake Education Programs $5,000 O O O O O
(This meets objective #6)
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Table 15 (Duplicate) Glenn Shoals Lake Historical Data 1981-1999
ROL-1b ROL-1t ROL-2 ROL-3
Ammonia Nitrogen
Minimum 0.04 mg/L (1981) 0.01mg/L (1993) 0.09 mg/L (1997) 0.07 mg/L (1993)
Maximum 1.1 mg/L (1989) 0.46 mg/L (1997) 0.57 mg/L (1993) 0.52 mg/L (1993)
Average 0.31 mg/L 0.15 mg/L 0.19 mg/L 0.2 mg/L
Median 0.24 mg/L 0.1 mg/L 0.11 mg/L 0.19 mg/L
Kjeldahl Nitrogen
Minimum 0.4 mg/L (1989) 0.4 mg/L (1989) 0.61 mg/L (1997) 0.72 mg/L (1993)
Maximum 1.9 mg/L (1989) 1.4 mg/L (1989) 1.8 mg/L (1989) 1.9 mg/L (1993)
Average 1.04 mg/L 0.89 mg/L 1.04 mg/L 1.3 mg/L
Median 1.01 mg/L 0.89 mg/L 0.96 mg/L 1.3 mg/L
pH
Minimum 7.6 (1983) 6.7 (1983) 6.8 (1983) 6.7 (1983)
Maximum 7.6 (1997) 8.6 (1989) 8.9 (1989) 8.6 (1993)
Average 7.1 7.8 7.8 7.7
Median 7.1 7.7 8 7.7
Secchi
Minimum N/A 2 inches (1983) 2 inches (1983) 1 inch (1983)
Maximum N/A 42 inches (1993) 26 inches (1997) 19 inches (1981)
Average N/A 21.3 inches 15.4 inches 9.6 inches
Median N/A 22 inches 14.5 inches 9.5 inches
Chlorophyll a
Minimum N/A 1.48 μg/L (1993) 3.05 μg/L (1993) 17.2 μg/L (1993)
Maximum N/A 107.54 μg/L (1989) 69.7 μg/L (1989) 82.2 μg/L (1997)
Average N/A 21.96 μg/L 31.5 μg/L 44.3 μg/L
Median N/A 13.66 μg/L 23.1 μg/L 46.3 μg/L
Nitrate + Nitrite
Nitrogen
Minimum 0.01 mg/L (1997) 0.01 mg/L (1997) 0.1 mg/L (1989) 0.01 mg/L (1997)
Maximum 1.8 mg/L (1993) 2.2 mg/L (1993) 2.1 mg/L (1993) 2.5 mg/L (1993)
Average 0.88 mg/L 0.85 mg/L 0.82 mg/L 0.98 mg/L
Median 0.97 mg/L 0.73 mg/L 0.65 mg/L 0.70 mg/L
Phosphorus
Minimum 0.054 mg/L (1981) 0.04 mg/L (1989) 0.07 mg/L (1989) 0.108 mg/L (1989)
Maximum 0.313 mg/L (1983) 0.314 mg/L (1983) 0.315 mg/L (1983) 0.537 mg/L (1993)
Average 0.134 mg/L 0.1 mg/L 0.12 mg/L 0.216 mg/L
Median 0.122 mg/L 0.076 mg/L 0.09 mg/L 0.194 mg/L
Source: EPA STORET Data
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Table14 (Duplicate) NUTRIENT AND SEDIMENT BUDGET FOR GLEN SHOALS LAKE (2000-2001)
INFLOW TOTAL PHOSPHORUS TOTAL NITROGEN TOTAL SUSPENDED SOLIDS
Kg/yr % Kg/yr % Kg/yr %
TRIBUTARIES
Shoal Creek ROL02 61,249 41% 1,015,670 64% 22,149,839 54%
Structure 14 ROL03 34,275 23% 315,213 20% 10,572,686 26%
Little Creek North ROL04 27,392 18% 126,816 8% 4,136,016 10%
Little Creek South ROL05 27,520 18% 127,412 8% 4,155,435 10%
ATMOSPHERIC 304 > 1% 3,300 > 1% N/A
INTERNAL 394 > 1% 3,149 > 1% N/A
SHORELINE N/A N/A 364,820 >1%
Total Inflow 151,134 100% 1,591,560 100% 41,013,976 100%
OUTFLOW
SPILLWAY 54,571 36% 268,576 17% 2,192,614 5%
DRINKING WATER 183 > 1% 2,323 > 1% 21,615 >1%
Total Outflow 54,754 36% 270,899 17% 2,214,229 5%
TOTAL PHOSPHORUS TOTAL NITROGEN TOTAL SUSPENDED SOLIDS
Retained Retained Retained
Kg/yr % Kg/yr % Kg/yr %
NET LOADING 96,563 64% 1,320,661 83% 39,164,567 95%
Tons/yr Tons/yr Tons/yr
106 146 43,170
1
Illinois Clean Lakes Program
Phase I Diagnostic- Feasibility Study of Glenn Shoals Lake, Montgomery County,
Illinois
PART 1
Diagnostic Study
INTRODUCTION
On December 12th of 2000, the City of Hillsboro, Illinois, with the assistance of
Greenville College's Zahniser Institute for Environmental Studies (ZIES) and the United
States Department of Agriculture Natural Resources Conservation Service's (USDA-NRCS)
Montgomery County office, submitted a grant application narrative to the Illinois
Environmental Protection Agency (IEPA) for an IEPA sponsored Phase 1 Diagnostic-
Feasibility Study of Glenn Shoals Lake. The State of Illinois cost-sharing for this type of
study is provided by the Illinois Environmental Protection Agency through its Illinois
Clean Lakes Program (ICLP), a Conservation 2000 funded program. Phase 1 studies are
limited to publicly-owned lakes that have extensive public access and recreational use.
The basic purpose of a Phase 1 study is to identify lake problems, diagnose causes, and
develop feasible courses of action to correct the problems.
On May 14, 2001 the City of Hillsboro and IEPA formally executed an
intergovernmental agreement relative to the Phase 1 Glenn Shoals Lake Study, outlining
the scope of the work and each agency's specific responsibilities and costs. In general
terms, the City of Hillsboro was responsible for the overall performance of the study, and
IEPA was primarily responsible for reviewing the City of Hillsboro's work, and
conducting water quality and sediment sampling analyses. Of the $125,000 slated to be
used on the project, $75,000 (60%) came from the IEPA and $50,000 (40%) was
provided by the City of Hillsboro.
The City of Hillsboro subcontracted the data collection, data analyses and report drafting
to ZIES, under the terms of an agreement dated April 10, 2001. ZIES also served as the
primary liaison to IEPA on behalf of the City of Hillsboro.
A.1. Lake Identification and Location (Table 1)
A. Official name of lake
B. State and county in which located
C. Name of nearest municipality
D. Latitude and longitude of lake center
E. EPA Region
F. EPA major basin name and code
G. EPA minor basin name and code
H. Names of major tributaries
I. Name of water body which receives lake’s discharge
J. Approved State water quality standards for the lake
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Table 1 Lake Identification and Location
Lake Name Glenn Shoals Lake
State Illinois
County Montgomery
Nearest Municipalities Schram City - 1/4 mile East of South End
Hillsboro - 1 1/4 miles South
Latitude, Longitude of the Lake: Latitude 39°12' North / Longitude 89°28' East
EPA Region Region 5
EPA Major Basin Name Lower Mississippi River Code: 07
EPA Minor Basin Name Lower Kaskaskia River Code: 14
Major Tributaries
Middle Fork Shoal Creek
Fawn Creek
Little Creek
Receiving Water Body Middle Fork Shoal Creek
Water Quality Standards Applicable Criteria
State of Illinois, Rules and Regulations
Title 35: Environmental Protection
Chapter I: Pollution Control Board
Part 302
Subpart B: General Use Water Quality
Standards
Subpart C: Public and Food Processing
Water Supply Standards
Ownership City of Hillsboro
Surface Area 1,250 Acres (510 Hectares)
Maximum Depth 23 Feet (7 Meters)
Mean Depth 10 Feet (3 Meters)
Storage Volume 12,700 acre-feet (15,671,800 m3)
Average Retention Time 0.5 years
Watershed Area 51,200 Acres (20,720 Hectares)
Shoreline Length 26.6 miles (~ 42.8 Kilometers)
Ratio of Watershed Area to Water Surface
Area 51200/1250 = 41/1
3
Figure 1 - Glenn Shoals Lake Location Map
Middle Fork
Shoal Creek
Fawn Creek
Little Creek
Glenn Shoals
4
A. 2. Geological and Soils Description of Drainage Basin
A.2.a Geological Description
Lake Glenn Shoals lies in the center of the Springfield Plain (Figure 4), in the Illinois
Basin of the Central Lowland Province. The area's stratigraphy is a product of the
Illinoian glaciation of Pleistocene Epoch. The loess deposits (Figure 3) produced by
regional glaciation range from 0 - 50 inches (1.3 m) thick in the southern portion of the
Glenn Shoals watershed, and 50-150 inches (3.8 m) thick in the northern portion. Glacial
till underlying this is Illinoisan moraine and ground moraine (Figure 2), of the Glasford
formation. Bedrock in this area is Pennsylvanian in origin, of the Bond and Mattoon
formations. This bedrock layer is 150 to 300 feet (46 to 91 m) thick. It is thickest in the
southern portion, averaging 250 feet (76 m) thick. It is composed of limestone calcareous
clays, and shale (Figure 5).
A.2.b. Groundwater Hydrology
Sandstone and gravel aquifers are uncommon in the region of Lake Glenn Shoals. This is
attributed to the imperviousness of the shale layers of the bedrock. Groundwater for well
extraction is more commonly found in the glacial till, 25 to 30 feet (7-9 m) below the
surface, although wells of this nature are prone to drying up during droughts.
A.2.c Topography
The Glenn Shoals Lake watershed is comprised of six sub-basins. For the purposes of
this report these are known as the Glenn Shoals North, Glenn Shoals East, Glenn Shoals
West, Structure 14, Irving North, and Irving South sub-basins. The Structure 14 sub-basin
is so named because of the existence of a sediment pond located there. These sub-basins
are illustrated in Figure 6 (Figure 7- key to Figure 6), Sub-Watershed Delineation.
The general lay of the ground within the Glenn Shoals watershed is slightly to moderately
rolling, with moderately steep to steep areas bordering lake shore and tributaries. A
United States Geological Survey 7.5 min. map was used to estimate percent slopes for the
six sub-basins. (Table 2)
Table 2 Topography of Glenn Shoals Watershed
% Slope Acres Sediment Delivery in Tons/Year
0-2 45,420 4,769
3-5 4,845 3,537
6-10 2,624 4,251
11- 30 3,300 1,436
Source: Natural Resources Conservation Service
5
Figure 2 - Quaternary Deposits in Illinois
6
Figure 3 - Loess Thickness in Illinois
7
Figure 4 - Physiographic Regions on Illinois
8
Figure 5 - Geologic Map of Illinois
9
A.2.d Soils
There are 6 major soil associations found in the Glenn Shoals Lake watershed. The
following table (Table 3) gives a description of each and approximate percentages
comprising each sub-basin. A map of these associations can be found in Figure 6.
Table 3 Major Soil Associations
Soil Association Descri-ption
Glenn Sh.
North
Glenn Sh.
West
Glenn Sh.
East Structure 14 Irving
North
Irving
South
Virden-Herrick Dark-colored, poorly drained to somewhat poorly drained soils on upland flats.
20% 2% 0% 0% 0% 0%
Oconee-Velma-
Tamalco
Nearly level to strongly sloping, moderately dark colored soils that have a slowly permeable,
moderately permeable, or very slowly permeable subsoil.
6% 33% 8% 10% 6% 0%
Hickory-Hosmer Gently-sloping to very steep, light colored, moderately well drained to well drained soils on
uplands adjacent to streams.
0% 0% 0% 0% 0% 27%
Cowden-Piasa Level, moderately dark colored soils that have a slowly or very slowly permeable subsoil.
0% 25% 65% 13% 16% 48%
Herrick-Piasa
Association
Level, dark colored and moderately dark colored soils that are on upland divides and that
have moderately slowly or very slowly permeable subsoil.
74% 40% 12% 77% 78% 25%
Lawson-Radford Level, dark-colored, somewhat poorly drained soils on flood plains.
0% 0% 15% 0% 0% 0%
10
Irving South
Irving North
Structure 14
Glenn Shoals North
Glenn Shoals West
Glenn Shoals East
Figure 6 - Glenn Shoals Lake – Subwatershed Soils
11
Figure 7- Montgomery County Soil (Key to Figure 6)
12
A.3.a Description of Public Access
Figure 8 - Identification and Location Map
13
A.3.b Description of Access Points
Lake Glenn Shoals has two boat launches open to the public. The south access area is
located on the west shore of the lake, just north of the dam. The locations of these
facilities are marked on Figure 8, Facilities Location Map. This area has a two-lane boat
ramp, a 225 ft. x 275 ft. parking area, restrooms, a pay telephone, and a covered picnic
area. A marina with two large buildings and 34 covered slips is also present. The
buildings are capable of serving as a restaurant, bait shop and supplies facilities. The
City of Hillsboro is currently seeking an operator for this establishment. The north boat
launch has a two-lane boat ramp, a 250 ft. x 240 ft. parking lot, and restrooms. The lake
is open to the public for boating, provided that users purchase a municipal lake sticker.
Glenn Shoals Lake can be used 365 days and 24 hours a day. There are no restrictions on
the time or season that you can use Lake Glenn Shoals. The fee structure for municipal
lake stickers is presented in Table 4.
Table 4 City of Hillsboro Municipal Boat License Fees
Residents County Non-county Out-of-State
Rowboats and Canoes $5.00 $8.00 $10.00 X
Boats with Motors
1-20 Horsepower $10.00 $20.00 $25.00 X
21-50 Horsepower $20.00 $30.00 $35.00 X
51-100 Horsepower $25.00 $48.00 $60.00 X
101-200 Horsepower $35.00 $75.00 $125.00 X
201-up & Inboard $40.00 $100.00 $150.00 X
Sailboats $8.00 $27.00 $32.00 X
Jet-ski $40.00 $72.00 $90.00 $125.00
Daily Permit All Boats $6.00 $9.00 $12.00 $12.00
Senior Citizens (65 yrs.) 20 Horse & Under
50% of above rates
Over 20 Horse
25% of above rates
The City of Hillsboro, the responsible agency, leases land on the lake for recreation.
Fifteen points on the main body of the lake are leased to duck hunters for installing duck
blinds. A forty-dollar annual fee is charged per location. The locations of these points
are marked on Figure 8, Facilities Location Map. Additionally, 182 lake lots with 100 ft.
of shoreline and 50 ft. of setback are available for lease. A listing of fees may be found
in Table 5 and appendix D, City of Hillsboro Permits, Licenses, & Fees.
14
Table 5 City of Hillsboro – Permits, Licenses & Fees
Sherwood Forest Camping Rates
Permanent Campers $500.00
Extra With Air Conditioning $180.00
Campers for 30 Days $200.00
Extra With Air Conditioning $250.00
Trailers (Daily) $10.00
Tents Without Electricity (Daily) $6.00
Tents With Electricity (Daily) $7.00
Blue Grass Weekends (Daily) $7.00
Pool and Beach Swimming Rates
Resident - Daily Non Resident – Daily
Child $2.00 Child $2.00
Adult $3.00 Adult $3.00
Season Passes
Resident Non Resident
Child $30.00 Child $33.00
Adult $35.00 Adult $38.00
Family -
Up to 5 Members $65.00 Family -
Up to 5 Members $75.00
Lake Lots - Glenn Shoals Lake
Hillsboro Residents $100.00 Deposit $25.00
County Residents $125.00 Deposit $50.00
Non-County Residents $200.00 Deposit $100.00
Other Fees
Water Deposit (Renters
Only) $100.00 Water on Fee $20.00
Water Bill - Vacation Rate $10.00 Water off Fee $20.00
Parking Fines
If Not Paid Within 15 Days
$5.00
$25.00
Dog and Cat Fines -
First Offense
Second Offense
$50.00
$100.00
Liquor License $600.00 Water Tap On Fee $350.00
Road Bonds $250.00 Sewer Tap On Fee $300.00
Fire Subs $40.00 Challcombe House Rental
Four Hours $25.00
Fire Runs $250.00
All Day
($25.00 Refundable Deposit
When You Pick Up The
Key)
$40.00
Duck Blind Fee $40.00
Refund When Blind Removed $15.00
15
A.3.c Routes and distances to Access Points
The approximate center of Glenn Shoals Lake is 4.8 miles northeast of the approximate
center of the City of Hillsboro, 15 miles from the City of Litchfield, 25 miles from the
City of Greenville, 46 miles from the City of Vandalia, and 42 miles from the City of
Taylorville.
Major roads near the lake include Highway 16, Highway 127, and Highway 185. The
City of Hillsboro provides a confluence of these highways, from which the lake is
accessible via city and county roads (Figure 1, Location Map).
A.3.d Public transportation availability
There is no public transportation serving the lake area.
16
A. 4. Description of Size and Economic Structure of Potential Use
Population
A.4.a Size of resident population
The Glenn Shoals Lake user population is comprised mainly of area residents, with
additional constituency from the surrounding counties, with some as far away as the St.
Louis metropolitan area. Within 50 miles (80 km), the potential user population is
estimated to be 773,182. Table 6 shows the populations of counties with at least half of
their area within the 50 miles (80 km). Table 7 shows the populations of cities with
populations greater than 10,000 within the 50 miles (80 km). Population figures were
taken from United States Census Bureau statistics. The nearest major metropolitan area
to Glenn Shoals Lake is St. Louis, approximately 50 miles (80 km) in a straight-line. The
St. Louis metropolitan area includes Franklin, Jefferson, Lincoln, St. Louis, St. Charles,
and Warren counties in Missouri, and Clinton, Jersey, Madison, Monroe, and St. Clair
counties in Illinois with a combined population of 2,603,607. The locations of the cities
and counties shown in Tables 6 and 7 are shown in Figure 1, Location Map.
A.4.b Size of any significant seasonal user
Special seasonal users of campground facilities, ect. In the immediate vicinity of Glenn
Shoals lake occur at near by Hillsboro Lake. This alleviates the pressures for such
facilities at Glenn Shoals. The major seasonal use of Glenn Shoals Lake is from duck
hunters. The revenue from duck blind fees is shown in Table 9.
A.4.c Distribution of population
Even though the immediate counties are not very densely populated there is a great
potential use of Glenn Shoal from cities within 50 miles of the Lake.
17
Table 6
Potential User Population by Counties
Accessible Within 50 Miles (80 km) Radius
County Population
Bond 17,633
Christian 35,372
Clinton 35,535
Effingham 34,264
Fayette 21,802
Greene 14,761
Jersey 21,668
Macoupin 49,019
Madison 258,941
Marion 41,691
Montgomery 30,652
Sangamon 188,951
Shelby 22,893
Table 7
Potential Users by City
City Population
Alton 30,496
Centralia 14,136
Collinsville 24,707
Effingham 12,384
Edwardsville 21,491
Fairview Heights 15,034
Granite City 31,301
O'Fallon 21,910
Springfield 111,454
Swansea 10,579
Taylorville 11,427
Wood River 11,296
total: 316,215
Cities With Population > 10,000 Within 50 Miles (80
Km) Radius
18
A.4.d Pertinent economic characteristics
1. General income
U. S.
Households 11,525 100.0% 4,592,740 100.0%
$0-$10,000 1,411 12.2% 383,299 8.3% 9.5%
$10,000-$14,999 1,045 9.1% 252,485 5.5% 6.3%
$15,000-$24,999 1,773 15.4% 517,812 11.3% 12.8%
$25,000-$34,999 1,806 15.7% 545,962 11.9% 12.8%
$35,000-$49,999 2,186 19.0% 745,180 16.2% 16.5%
$50,000-$74,999 2,076 18.0% 952,940 20.7% 19.5%
$75,000 to $99,999 711 6.2% 531,760 11.6% 10.2%
$100,000 to $149,999 363 3.1% 415,348 9.0% 7.7%
$150,000 to $199,999 76 0.7% 119,056 2.6% 2.2%
$200,000 or more 78 0.7% 128,898 2.8% 2.4%
Median Household Income 33,123 46,590
Montgomery County Illinois
Table 8 Household Income in 1999
Figure 9 - Household Income Comparison
0
5
10
15
20
25
0-10 15-
24.9
35-
49.9
75-
99.9
150-
199.9
Thousands of Dollars
Montgomery County Illinois U.S.
19
2. Major employment sources
Figure 10 - Employment Sectors in Montgomery County
25%
19%
25%
1%
12%
18%
Management & Professional
Service
Sales & Office
Farming, Forestry & Fishing
Construction & Maintenance
Production &Transportation
3. Chronic unemployment NA
4. Housing shortages NA
5. Urban blight NA
6. Relationship of lake to local economy
The lake provides a number of services that directly or indirectly affect the local
economy (figure 10). The major affecters are flood control, potable water and recreation.
Having sufficient water at a reasonable price will encourage industry as well as private
20
individuals to locate in the area. The influx of industry (jobs) and people into the area
will increase the standard of living and tax base, and cause a rise in the economy. The
available recreation on or near the lake will enable those with discretionary financial
resources to spend time there taking part in the recreational activities. These people,
whether local or distant, usually purchase goods and services at local establishments
(figure 9). This will facilitate an increase in the general (over-all) economy. Thus, a rising
tide will raise all economic boats.
21
A. 5. Summary of Historical Lake Uses
A.5.a Inventory of present and past lake uses
The lake was built in 1978. The primary function was flood control. The secondary uses
included; water supply, recreation and esthetics. The lake currently supplies water to
10,889 households. The lake also meets the recreational needs of many boaters, skiers
and fishermen. The shore, because of the esthetic appeal, currently has a number of
homes situated there.
Table 9 RECORD OF LAKE REVENUE BY TYPES OF RECREATIONAL USAGE
A.5.b Statistics on present and historical usage
The data in Table 9 indicates an increase in boat usage and cabin usage while the other
numbers would suggest that usage of other facilities seem to have leveled off or may
have been reduced.
A.5.c Analysis of relationship between historical trends in lake water
quality
1. Flood control
– Total maximum volume is 25,000 acre feet with 11,800 acre feet
devoted to flood control. 11,800 x 1233.5 = 14555300 m sq.
2. Water supply (potable)
– 845 acre feet used for potable water to supply the needs of 10,889
households
3. Recreation
1999 2000 2001 2002 2003
Cabin Fee’s $900.00 $666.00 $1,314.00 $1,320.00 $1,200.00
Lease Lot
Fee’s
(homes)
$14,985.00 $24,085.00 $16,360.00 $16,485.00 $17,360.00
Camping
Fee’s
$62,009.00 $69,843.50 $72,295.00 $64,736.70 $48,838.25
Boat
Permits
$25,628.75 $27,350.25 $29,553.30 $32,749.63 $33,144.99
Lake Lot
Fee’s
$28,967.00 $29,889.25 $30,963.75 $30,355.00 $29,167.00
Duck Blinds $385.00 $515.00 $360.00 $255.00 $315.00
Marina
Slips
~ $6,800.00 $6,600.00 $6,950.00 $6,350.00
22
The water quality has continued to lessen because of the watershed
problems and not by any increased usage of the lake.
4. Aesthetic enjoyment
The numbers would suggest that the aesthetic uses are relatively stable
over the last five years.
5. Research and education
No known research is currently being carried out on the lake.
A.6 Population Segments Adversely Affected by Lake Degradation
There is no niche populating that depends entirely on the lake for economic support.
Those closest to this would be business people that sell boats, fishing supplies, and skiing
supplies. However is seems that the potable water affects everyone in Hillsboro and many
of the surrounding smaller communities. Over 10,800 families use either Glenn Shoals
Lake or Hillsboro Lake as their water source. Lake degradation will affect the 10,800
water users the 30-50 boaters and innumerable fishermen. The hypereutrophication and
filling of the lake will have a significant effect on the cost and/or quality of potable water.
However, the hypereutrophication and partial filling (by sediment) of the lake should not
significantly affect the flood control potential due to the fact that much of the temporary
storage results from limited outflow which temporally raises the level of the lake to the
emergency overflow level. However, the hypereutrophication and filling of the lake with
sediment will have a significant effect on the cost and quality of potable water.
23
A. 7. Comparison of Lake Uses to Uses of Other Lakes in Region
A.7.a Summary of statistics on other publicly-owned lakes within 80 km
Table 10 Comparison of Lake Uses Within 80 Km
Code Acres Fishing Boating Hiking Swimming Hunting Camping Horseback
Glenn Shoals ROL 1,085 X X X X X
ROT 94 X X X X
Springfield REF 3,797 X X X X
Sangchris REB 2,321 X X X X X
Shelbyville ROC 11,100 X X X X X X X
Otter RDF 723 X X
Ramsey ROE 46 X X X X
Taylorville REC 1,286 X X
Sara RCE 614 X X
Mattoon RCF 988 X X
Staunton RJA 84 X X X
Old Gillespie SDT 71 X X X X
New Gillespie SDU 207 X X X
Lou Yaeger RON 1,304 X X X X
Coffeen ROG 1,070 X X X X
Governor Bond ROP 775 X X X X X
Greenville Old ROY 22 X X X
Highland
Silver
ROZA 550 X X X
ROZH 11
St. Elmo New
(Nellie)
ROM 59 X X X
St.Elmo Old ROQ 25 X
Carlyle ROA 24,580 X X X X X X
Vandalia ROD 660 X X X
Beaver Dam RDH 57 X X X X X X
Horseshoe RJC 1,890 X X X X X X
Forbes RCD 542 X X X X X X X
Jacksonville RDI 442 X X X X
Waverly SDC 112 X X
Pana ROF 205 X X
Carlinville RDG 168 X X X X X
Holiday shores RJN 430 X X
24
A.7.b Discussion of relationship of lake under study to other lakes
There are approximately 31 lakes within the 50 miles (80 Km) radius of Glenn Shoals
Lake (Figure 11). Most of the lakes have fishing, boating, hiking, camping and water
supply as common uses. Some lakes also include swimming, hunting and ridding horses
as secondary uses (Table 10). Other lakes are useful for flood control but unlike Glenn
Shoals most are not designed with flood control as one of the primary lake functions.
Glenn Shoals does not have swimming or camping, however there are locations for both
of these functions, nearby, on the city’s other lake (Lake Hillsboro). When these lakes are
considered in tandem they provide, in close proximity, most of the uses of the larger
lakes in this part of Illinois. The lake is underutilized. This seems to be because the lake
is not as well known as others in the region. This is related to the fact that the location is
much farther from the major interstates (Figures 1,11) than other similar lakes in the area.
The owners would like to see more people use the lake.
25
Figure 11 - Lakes within 80 Kilometers of Glenn Shoals Lake
26
A. 8. Inventory of Point Source Pollution Discharges
There is one single potential point source for nutrients. The city of Irving, population of
516, uses a lagoon to break down their sewage. The effluent from this lagoon provides a
potential point loading source for the two nutrients of most concern (nitrogen and
phosphorous) for the hypereutrophication of the lake.
TABLE 11 Point Source Inventory
Name NPDES #
Receiving
water
Discharge
flow Constituents Conc/mass Abatement
Village
of Irving ILG580198 Ditch
2,700
m3/day
Suspended
solids 14 mg/l none
The seasonal emptying of this sewage lagoon produces up to .72 million gallons or 2,700
m3 per day of nutrient enriched water. Besides the nutrients there are 14 mg/l of
suspended solids. The discharge flows into a ditch in Irving under NPDES permit
number ILG580198 (see Table 11). This information was obtained by a phone
conversation with Ron Merriman, waste water treatment manager for Irving.
As a result of this seasonal discharge, months may go by before any discharge
occurs. Heavy seasonal rains may cause numerous days of discharge, where the average
approaches the maximum allowable of 2,840 m3/day. The water enters a ditch which
joins other ditches forming Little Creek which then enters Glenn Shoals Lake.
27
A. 9. Land Uses and Nonpoint Pollutant Loadings
INITIAL FORESTRY STATEMENT
GLENN SHOALS LAKE WATERSHED
This watershed is highly agricultural, although it has been impacted by residential
development in places. The farmland is mostly of former prairie or prairie-forest
transition. Closer to the lake is sloping ground which once was all forest, although much
of it was converted to pasture and is now either in slow succession towards forest
vegetation or is being used for residential purposes. There are some areas still fairly
representative of the original forest type, but these are mostly on the east side of the south
end of the lake.
The original forest was almost totally of the oak-hickory type, species consisting
of white, black, red, and chinkapin oak, hickories, elm, basswood, walnut, cherry, ash,
and miscellaneous others. Post oak was found on high ridges. Soils involved are 8
Hickory, 214 Hosmer, and 64 Stoy. Existing forest cover is variable as to current pattern,
composition, quality, and stage of development.
There is considerable argument and speculation as to the condition the original
stands were in when settlement began. It is generally conceded that the advent of
European settlement had considerable effect on forest areas: stands were cleared of forest
for agricultural production, or were grazed, or were subjected to more or to less burning
than before. Timber harvest has had its effect, in some cases only slightly negligible and
in some cases highly impacted. Lately, hard maple has come in many stands, gradually
preempting former species and with an apparent monocultural (one species only) end
result. Whether such changes occurred cyclically or episodically in the past is not
known, but it is apparent that forest compositions are currently in a state of great flux.
When this correspondent arrived here some thirty plus years ago, many stands were
fenced and intensively grazed, even though “loitering” was the chief livestock value if the
forest was heavily stocked (adjoining grass areas accessible to livestock being requisite in
such cases); now, these areas have largely been abandoned to grazing and are in varying
stages of succession back to forest, the end result being a factor of time, species seed
source, and whim of nature. Few stands are being actively managed with long range
goals in view. Hardwood timber is still harvested, sometimes of high quality and value,
but usually with little regard or provision for the remaining stand or development of
harvest replacement. Suboptimal areas also lack management input. From a watershed
standpoint, a considerable amount of reforestation can be beneficially applied here.
The watershed value of most forested land is considerable. The branches, leaf
litter, root systems, etc., all contribute to breaking the force of rain, protecting the soil
from erosion and inducing the absorption of water into the soil rather than allowing
runoff. In the recent and nearby Lake Yaeger watershed study, it was recognized that
41% of sheet and rill erosion emptying into the lake came from former forest sites
(Hickory/Hosmer/Stoy soil association) now being farmed, and that simple reforestation
28
could eliminate that much of the lake’s problem. A program of encouraging reforestation
and stand management was written into the resource plan of that lake.
Ideally, forest areas should be retained in or restored to their original composition.
The native stands offer the most from almost all forest-value standpoints, not least of
which relates to watershed, but also to economic (timber value), wildlife, and (arguably)
aesthetic values. The prospect of hard maple takeover is a special case; good hard maple
has good timber value, and it can be aesthetically pleasing, but its wildlife value is quite
low and its presence leads to bare soil and erosion concerns. Degraded forests lack
economic value. The usual recommendation in these cases is to change course via
several silvicultural practices (possibly also involving planting). Non forest areas can be
reforested using proven practices.
Although this will be unpopular in some wood quarters and cause controversy, it
would be good from a watershed standpoint if a fringe of woody vegetation (if not proper
forest) be maintained around the lake, residential sites included. Especially, vegetation
should be maintained at and just above the waterline, not kept bare as in many places at
present.
If any silt retention structures are ever acquired and constructed, these too should
be vegetated right down to the waterline.
An active watershed program can do much to promote beneficial forestry
practices as outlined above. Education, encouragement, publicity, and special funding
inducements can be involved, and there are state and federal resources to be tapped into
and there is continuing advisement available form this IDNR forestry office.
Prepared by:
John A. Churan,
District Forester
Box 603
Hillsboro, IL 62049
29
A.9.a Land uses in the watershed
Montgomery County Tillage Practices
According to the Illinois Soil Transect Survey summary, 75% (Table 12) of the cropland
in Montgomery County is farmed using conservation tillage. Conservation tillage can
greatly reduce the amount of soil erosion and help reduce the amount of sediment that
collects in lakes. Conservation tillage also helps reduce nutrient loading from agriculture
runoff.
Table 12 Montgomery County Tillage Practices
Corn/acres Soybean/acres Small grains/acres Total
Conventional 74237 5939 0 80176
Reduced 51223 39345 3712 94280
Mulch 17074 57905 2227 77206
No-Till 13363 49738 11878 74979
N/A/ Unknown 0 742 0 742
Total 155897 153669 17817 327383
% Conservation
Tillage (Not
conventional)
52% 96% 100% 75%
Source: Illinois Soil Conservation Transect Survey Summary (2000)
A.9.b The area of each land use as a percentage of the total drainage
area
Sub-watershed Delineation
In an effort to develop a better understanding of the non-point pollution contribution of
the different areas around the watershed the overall watershed was further divided into
six sub-watersheds (Figure 6). ZIES staff with the help from NRCS used Arcview
software (Figure 12) and land use data to determine the acres of each type of land use for
each sub-watershed (Table 13).
Table 13 Glenn Shoals Land Use
Land Use Glenn
Shoals
North
Glenn
Shoals
East
Glenn
Shoals
West
Structure
14
Irving
North
Irving
South
Acres Acres Acres Acres Acres Acres
Cropland 16,763 1,960 2,731 7,283 4,065 3,695
Grass/Past 1,092 1,974 965 1,575 812 947
Urban 9 85 10 4 52 21
Wetland 97 141 45 67 30 48
Woodland 128 1,140 466 448 153 425
Total 18,089 5,300 4,217 9,377 5,112 5,136
Percent 38.3% 11.2% 8.9% 19.9% 10.8% 10.9%
30
A.9.c Land use map
See Table 13 for subwatershed land use.
Figure 12 Sub-watershed Delineation
31
Glenn Shoals Lake Watershed Land Use
The watershed surrounding Glenn Shoals Lake is dominated by agriculture. Ninety-two
percent of the land is agriculture. Sixteen percent of this agricultural land is grassland
and pasture. Less than one percent is urban. One percent is wetland and six percent is
woodland. Runoff from agricultural land can contribute significantly to the sediment and
nutrient loads for a lake. The NRCS estimates that 39,593 tons of sediment enters the
lake every year. Sediments bring fertilizers and pesticides that are deposited into the
lake. High amounts of phosphorus and nitrogen run off contribute to the eutrophication
of the lake by increasing algae growth. This algae growth also contributes to turbidity
and lack of water clarity. Residential activities in the watershed can also contribute to
sedimentation and nutrition loading of the lake. Lawn fertilizers from homes as well as
nutrients from septic systems contribute to the nutrients entering the lake. Construction
projects can add large amounts of sediment to the lake if control structures are not in
place. Lake front property that is not properly protected with rip-rap or other erosion
control material can contribute significant amounts of sedimentation into the lake.
A.9.d Nonpoint source pollutant loading by land use category
The loading, as represented by the tributaries, reflect the 4 major watersheds. The two
smaller areas, Glenn Shoals East and Glenn Shoals West make only minor contributions.
Since the water ( mineral and suspended solids loadings) did not form a major stream the
data was not collected. This loading may have become a minor part of the other four
tributaries. Table 14 gives the loading from the four major areas. ROL02 = Glenn Shoals
North; ROL03 = structure 14; ROL04 = Irving North and ROL05 = Irving South.
Since ROL02 (Shoal creek) or Glenn Shoals North and ROL03 (structure 14) provide
most of the loading (TSS 83%, N 76%, P 68%) it would seem prudent to contain the
loading form these two areas (Table 14).
32
Table14 NUTRIENT AND SEDIMENT BUDGET FOR GLENN SHOALS LAKE
INFLOW TOTAL PHOSPHORUS TOTAL NITROGEN
TOTAL SUSPENDED
SOLIDS
Kg/yr % Kg/yr % Kg/yr %
TRIBUTARIES
Shoal Creek ROL02 61,249 41% 1,015,670 64% 22,149,839 54%
Structure 14 ROL03 34,275 23% 315,213 20% 10,572,686 26%
Little Creek North ROL04 27,392 18% 126,816 8% 4,136,016 10%
Little Creek South ROL05 27,520 18% 127,412 8% 4,155,435 10%
ATMOSPHERIC 304 > 1% 3,300 > 1% N/A
INTERNAL 394 > 1% 3,149 > 1% N/A
SHORELINE N/A N/A 364,820 >1%
Total Inflow 151,134 100% 1,591,560 100% 41,013,976 100%
32
OUTFLOW
SPILLWAY 54,571 36% 268,576 17% 2,192,614 5%
DRINKING WATER 183 > 1% 2,323 > 1% 21,615 > 1%
Total Outflow 54,754 36% 270,899 17% 2,214,229 5%
TOTAL PHOSPHORUS TOTAL NITROGEN
TOTAL SUSPENDED
SOLIDS
Retained Retained Retained
Kg/yr % Kg/yr % Kg/yr %
NET LOADING 96,563 64% 1,320,661 83% 39,164,567 95%
Tons/yr Tons/yr Tons/yr
106 146 43170
33
33
A. 10. Baseline and Current Limnological Data
A.10.a Summary analysis and discussion of historical baseline
limnological data
.
Table 15 Glenn Shoals Lake Historical Data 1981-1999
ROL-1b ROL-1t ROL-2 ROL-3
Ammonia Nitrogen
Minimum 0.04 mg/L (1981) 0.01mg/L (1993) 0.09 mg/L (1997) 0.07 mg/L (1993)
Maximum 1.1 mg/L (1989) 0.46 mg/L (1997) 0.57 mg/L (1993) 0.52 mg/L (1993)
Average 0.31 mg/L 0.15 mg/L 0.19 mg/L 0.2 mg/L
Median 0.24 mg/L 0.1 mg/L 0.11 mg/L 0.19 mg/L
Kjeldahl Nitrogen
Minimum 0.4 mg/L (1989) 0.4 mg/L (1989) 0.61 mg/L (1997) 0.72 mg/L (1993)
Maximum 1.9 mg/L (1989) 1.4 mg/L (1989) 1.8 mg/L (1989) 1.9 mg/L (1993)
Average 1.04 mg/L 0.89 mg/L 1.04 mg/L 1.3 mg/L
Median 1.01 mg/L 0.89 mg/L 0.96 mg/L 1.3 mg/L
pH
Minimum 7.6 (1983) 6.7 (1983) 6.8 (1983) 6.7 (1983)
Maximum 7.6 (1997) 8.6 (1989) 8.9 (1989) 8.6 (1993)
Average 7.1 7.8 7.8 7.7
Median 7.1 7.7 8 7.7
Secchi
Minimum N/A 2 inches (1983) 2 inches (1983) 1 inch (1983)
Maximum N/A 42 inches (1993) 26 inches (1997) 19 inches (1981)
Average N/A 21.3 inches 15.4 inches 9.6 inches
Median N/A 22 inches 14.5 inches 9.5 inches
Chlorophyll a
Minimum N/A 1.48 μg/L (1993) 3.05 μg/L (1993) 17.2 μg/L (1993)
Maximum N/A 107.54 μg/L (1989) 69.7 μg/L (1989) 82.2 μg/L (1997)
Average N/A 21.96 μg/L 31.5 μg/L 44.3 μg/L
Median N/A 13.66 μg/L 23.1 μg/L 46.3 μg/L
Nitrate + Nitrite
Nitrogen
Minimum 0.01 mg/L (1997) 0.01 mg/L (1997) 0.1 mg/L (1989) 0.01 mg/L (1997)
Maximum 1.8 mg/L (1993) 2.2 mg/L (1993) 2.1 mg/L (1993) 2.5 mg/L (1993)
Average 0.88 mg/L 0.85 mg/L 0.82 mg/L 0.98 mg/L
Median 0.97 mg/L 0.73 mg/L 0.65 mg/L 0.70 mg/L
Phosphorus
Minimum 0.054 mg/L (1981) 0.04 mg/L (1989) 0.07 mg/L (1989) 0.108 mg/L (1989)
Maximum 0.313 mg/L (1983) 0.314 mg/L (1983) 0.315 mg/L (1983) 0.537 mg/L (1993)
Average 0.134 mg/L 0.1 mg/L 0.12 mg/L 0.216 mg/L
Median 0.122 mg/L 0.076 mg/L 0.09 mg/L 0.194 mg/L
Source: EPA STORET Data
34
The IEPA has sampled Glenn Shoals Lake since 1981 under their Ambient Lake
Monitoring Program (ALMP). The historical data from IEPA sampling is presented in
Table 15 for comparison purposes to 2001-2002 data
BASELINE LIMNOLOGICAL DATA
Morphometric Data
The physical characteristics of Glenn Shoals Lake can be summed up as morphometric
data for the lake. This is existing data on size, depth, retention time, etc. (Table 16).
Table 16 Morphometric Data
English Metric
Watershed Area 51,200 acres 20,720 hectares
Surface Area 1,250 acres 510 hectares
Shoreline Length 26.6 miles 42.8 Kilometers
Mean Depth 10 feet 3.05 meters
Maximum Depth 23 feet 7 meters
Storage Volume 12,700 acre-feet 15,671,800 m3
Flood Water Storage 12,160 acre-feet 14,999,141 m3
Total Storage 25,000 acre-feet 30,837,050 m3
Retention Time 0.5 years
Lake Type Reservoir / Dam / Flood Control
Year Constructed 1978
Bathymetric Map
A bathymetric map was made by ZIES using a Trimble GPS unit and sonar depth finding
equipment. GPS points were collected throughout the lake in a zigzag pattern. The GPS
technology allowed the staff to collect points with an exact knowledge of the location of
these points. Along with the GPS points, depth points were taken. All depths were
corrected for height of water above or below the spillway. All depths are in relation to
the surveyed spillway elevation. The data from the GPS unit and depth gage were sent to
Hurst-Rosche Engineer (HR) from Hillsboro. HR produced a contour map (Figure 13)
and calculated the volume (4.14 billion gallons). The area of the lake was calculated to
be 1,250 acres.
35
Bathymetric map
36
A.10.b Presentation, analysis, and discussion of one year of current
baseline limnological data
Lake Monitoring
Under the IEPA’s ambient lake monitoring program Glenn Shoals lake has been
historically sampled at three sites (Table 15): ROL-1t (top sample), ROL-1m (medium
depth) and ROL-1b (bottom sample) near the spillway; ROL-2 near the mouth of the
Irving arm; and ROL-3 at the north end of the lake.
Figure 14 A. Lake Sampling Sites
ZIES staff collected samples at the same historical sites ROL-1t, ROL-1b, ROL-2 and
ROL-3. (Figure 14 A). Samples were collected according to IEPA protocol and sent to
IEPA laboratories for analyses. Samples were analyzed for total suspended solids (TSS),
volatile suspended solids (VSS), total phosphorus, dissolved phosphorus, Kjeldahl
37
nitrogen, nitrate + nitrite nitrogen and ammonia nitrogen. In addition to samples analyzed
at IEPA laboratories ZIES staff tested for pH, temperature, and dissolved oxygen on-site
using a Hydrolab water quality sampling probe.
Suspended Materials
High concentrations of suspended materials in the water can have adverse effects on a
lake’s health. Suspended materials in the water can have a significant impact on the plant
and animal species in a lake environment. Highly turbid waters will decrease the amount
of available sunlight, which will reduce the amount of plant material and limit the depth
at which plant life will be found. Turbid waters will affect reproduction and
development. The reproduction processes affected are primarily behavior and egg laying.
The development includes all phases including zygote, embryo, juvenile and adult. The
growth rates may be reduced by turbidity at all stages of development.
There are several ways that suspended materials in Glenn Shoals Lake were measured.
The components measured included: total suspended solids (TSS), volatile suspended
solids (VSS), non-volatile suspended solids (NVSS) and Secchi depth. Water samples
were collected by ZIES staff and analyzed for TSS and VSS at IEPA laboratories. NVSS
was determined by comparing TSS to VSS (NVSS = TSS – VSS). Secchi depth (Figure
18) was measured and recorded by ZIES staff when water samples were collected.
Peak concentrations of TSS, VSS and NVSS corresponded with rain events on several
dates (Figures 15, 16, 17). However, sources other than rainfall runoff must account for
some of the suspended materials and turbidity in the lake water. Fish, especially carp,
can also stir the sediments near the bottom of the lake adding to the turbidity. ROL-3 had
more turbid waters than the other sites in the lake. This site is located on the north end of
the lake (Figure 14 A) where most of the stream discharge enters the lake. Such an area
would experience highly turbid waters after a rain and would be more susceptible to algal
blooms from nutrient runoff.
The relationship between VSS and NVSS gives an indication of the source of suspended
solids in the water. At all locations NVSS was a higher percentage than VSS. This
indicates that there is a large amount of non-organic material. This distribution is likely
an indication that soil washing in from the tributaries or bottom sediments being stirred
up are more significant contributors of the turbidity than algae. ROL-1t VSS was 24%
and NVSS 76%, ROL-2 VSS 32% and NVSS 68%, ROL-3 VSS 19% and NVSS 81%.
This high percentage of NVSS points to inorganic, sedimentary derived, suspended solids
being the major contributor of turbidity throughout the lake. The issue of turbidity is
another important problem that will be addressed again in Part 2: Feasibility Study.
Total Suspended Solids
Total Suspended Solids (TSS) is a measurement of all of the suspended material in the
water, including both organic and inorganic materials. Total suspended solids would
38
include materials such as algae, decaying plant materials, minerals, and soil particles.
Total suspended solids peaked 3/12/2002 at 258 mg/L at ROL-3 on the north end of the
lake (Figure 15).
Figure 15 – Total Suspended Solids
Total Suspended Solids
0
50
100
150
200
250
300
5/9/01
5/14/01
5/22/01
6/5/01
7/1/01
7/20/01
8/6/01
8/24/02
9/10/01
9/24/01
10/9/01
10/17/01
11/12/01
12/4/01
1/17/02
2/25/02
3/12/02
4/10/02
Date
Total Suspended Solids (mg/L)
ROL-1b
ROL-1t
ROL-2
ROL-3
Volatile Suspended Solids
Volatile suspended solids (VSS) is a measurement of only the organic material suspended
in the water. This material would include algae, decaying plant material and all other
organic material suspended in the water (Figure 16). VSS peaked on the same dates as
TSS and NVSS and corresponded with, low Secchi depths and high chlorophyll a data
(Figures 15, 16, 17, 18).
39
Figure 16 – Volatile Suspended Solids
Volatile Suspended Solids
0
5
10
15
20
25
30
35
40
45
5/9/01
5/14/01
5/22/01
6/5/01
7/1/01
7/20/01
8/6/01
8/24/02
9/10/01
9/24/01
10/9/01
10/17/01
11/12/01
12/4/01
1/17/02
2/25/02
3/12/02
4/10/02
Date
Volatile Suspended Solids (mg/L)
ROL-1b
ROL-1m
ROL-1t
ROL-2
ROL-3
Non-Volatile Suspended Solids
Non-Volatile Suspended Solids (NVSS) is obtained by subtracting the VSS from the
TSS. NVSS is the non-organic portion of TSS. NVSS is used by the IEPA as a
parameter in their Aquatic Life Use Impairment Index (ALI). Lake site ROL-3 had
higher concentrations of NVSS on most dates than the other sites (Figure 17).
40
Figure 17 – Non Volatile Suspended Solids
Non Volatile Suspended Solids
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
160
170
180
190
200
210
220
230
5/9/01
5/14/01
5/22/01
6/5/01
7/1/01
7/20/01
8/6/01
8/24/02
9/10/01
9/24/01
10/9/01
10/17/01
11/12/01
12/4/01
1/17/02
2/25/02
3/12/02
4/10/02
Date
Non Volatile Suspended Solids (mg/L)
ROL-1b
ROL-1m
ROL-1t
ROL-2
ROL-3
High
41
Secchi Readings
The Secchi disk is one of the most widely used tools to measure water clarity. Secchi
transparency and color are used to determine criteria for lake water quality. The Secchi
disk is a simple circular disk divided into alternate black and white quadrants. The disk
is lowered into the water and the depth at which it can no longer be seen is the Secchi
depth. It is one of the criteria in Carlson’s Trophic State Index, which is used to
determine the trophic status (Carlson 1977). Photosynthesis can generally occur at 2-3
times the Secchi depth (Kirschner 1995).
Secchi readings are a parameter used in calculating the trophic status of a lake. The
IEPA uses the trophic status as a parameter in both their guidelines for Aquatic Life Use
Impairment (ALI) and their Recreation Use Impairment (RUI). The IEPA also uses
Secchi readings as a parameter in their swimming guidelines. All the Secchi readings
must be greater than 24 inches to gain full support for swimming (Illinois 305(b) Report).
For Glenn Shoals Lake there were five dates in the swimming season that the Secchi
reading at any of the sites was greater than 24 inches and these all occurred at ROL-1 at
the south end of the lake (Figure 18). The high Secchi reading tended to correspond to
low TSS, VSS and NVSS readings (Figures15, 16, 17). ROL-3 had consistently
shallower Secchi readings throughout the study than sites ROL-1 and ROL-2.
Historically the water clarity in Glenn Shoals has averaged 21.3 inches at ROL-1t, 15.4
inches at ROL-2 and 9.5 inches at ROL-3 (Table 15).
42
Figure 18 – Secchi Depth’s
Glenn Shoals Secchi Depth's
0
5
10
15
20
25
30
35
5/9/01 5/14/01 5/22/01 6/5/01 7/1/01 7/20/01 8/6/01 8/24/01 9/10/01 9/24/01 10/9/0110/17/0111/12/01 12/4/01
Date
Secchi Depth in Inches
ROL-1t
ROL-2
ROL-3
43
Turbidity
The turbidity as expressed by the Secchi depth readings (more turbid = shallower
readings) is an indication of the combination of organic particles (mostly algae) and
inorganic particles (mostly soil-clay) in the water column. Turbidity is an indication of a
lake’s health. High turbidity (shallow secchi readings) indicates poor health. This is a
major problem with the lake (Figure 18).
Using information from the shoreline erosion study (Figure 37), calculations were made
to estimate the amount of sediment delivered to the lake from shoreline erosion. Using
estimates of 40 lbs of soil per linear foot entering the lake from areas with severe erosion,
30 lbs per linear foot for areas with moderate erosion, and 20 lbs per linear foot for areas
that are undercut, approximately 364,820 kg per year of soil enters the lake from
shoreline erosion (Hill 1994). This amounts to 1% of the total sediment entering the
Lake (Table14).
Dissolved Oxygen and Temperature
Dissolved oxygen is an important factor in the overall health of a lake. Oxygen levels are
a key factor in the health of fish and other organisms. Low oxygen levels can cause fish
kills and limited oxygen levels can decrease the number and size of fish for a given lake.
Low levels of oxygen near the bottom allow nutrients to be released; adding to the
eutrophication of the lake.
Lake oxygen level is controlled by a variety of factors. Plants and algae release oxygen
into the water through photosynthesis. Wind, moving across the water with sufficient
force to produce waves, causes a natural mixing of oxygen with the water. This will
increase oxygen up to the maximum soluble at a given temperature. Microbial respiration
uses oxygen during decomposition of organic materials in the lake. The interactions of
these processes determine the oxygen level of the lake.
Water temperature is important for many other biological and chemical processes as well
as determining oxygen concentration in the lake. Different types of algae grow better at
different temperatures. Density gradients due to temperature differences cause the
stratification of lakes. Cold water remains near the bottom of the lake and microbial
decomposition of organic materials depletes the oxygen levels. As long as the lake
remains stratified the oxygen continues to be depleted.
Regulations set by the IEPA and Illinois Pollution Control Board (IPCB) state that
dissolved oxygen (DO) shall not fall below 6 mg/L for longer than a 16 hour period and
never allowing the DO to fall below 5 mg/L at 1 foot depth (IPCB Part 302). Levels
below 3mg/L will likely cause fish kills. The south end of Glenn Shoals Lake
demonstrated conditions found in a typical stratified lake. During the winter, the
temperature was uniform throughout the lake and the dissolved oxygen was well mixed at
all depths. During the late spring and summer months, the lake stratified (Figure 19, 20,
21). The cold water sank to the bottom of the lake and warm water remained near the
surface. Wind action and algae growth keeps the upper levels oxygen rich while
microbial decomposition processes near the bottom depleted the available oxygen.
Chemical reactions which are allowed to take place under low oxygen conditions release
44
nutrients bound to the sediment. During the fall as the temperature changed the water
mixed and the dissolved oxygen and temperature levels became more uniform at all
depths. This mixing also mixed the released nutrients from the bottom, resulting in
internal nutrient loading. This stratified condition was found on the south end of the lake
at sites ROL-1 and ROL-2 (Figures 19, 20). The north end of the lake had more uniform
oxygen and temperature throughout the year (Figure 21). This is most likely due to the
fact that the water is much shallower at this end of the lake. Here, wave action mixed the
water and stratification did not occur.
Figure 19
Summer ROL-1 Temperature
0
5
10
15
20
25
30
35
0ft 1ft 3ft 5ft 7ft 9ft 11ft 13ft 15ft 17ft 19ft 21ft 22ft
Depth in Feet
Temperature in Celsius
6/5/01
6/18/01
6/19/01
7/1/01
7/17/01
7/20/01
8/6/01
8/21/01
8/24/01
A
45
Summer ROL-1 Dissolved Oxygen
0
2
4
6
8
10
12
0ft 1ft 3ft 5ft 7ft 9ft 11ft 13ft 15ft 17ft 19ft 21ft 22ft
Depth in Feet
Dissolved Oxygen (mg/L)
6/5/01
6/18/01
6/19/01
7/1/01
7/17/01
7/20/01
8/6/01
8/21/01
8/24/01
46
Fall ROL-1 Temperature
0
5
10
15
20
25
30
0ft 1ft 3ft 5ft 7ft 9ft 11ft 13ft 15ft 17ft 19ft 21ft 22ft
Depth in Feet
Temperature in Celsius
9/10/01
9/24/01
10/9/01
10/22/01
11/12/01
D
Fall ROL-1 Dissolved Oxygen
0
1
2
3
4
5
6
7
0ft 1ft 3ft 5ft 7ft 9ft 11ft 13ft 15ft 17ft 19ft 21ft 22ft
Depth in Feet
DO mg/L
9/10/01
9/24/01
10/9/01
10/22/01
11/12/01
C
47
Winter/Spring ROL-1 Temperature
0
5
10
15
20
25
0ft 1ft 3ft 5ft 7ft 9ft 11ft 13ft 15ft 17ft 19ft 21ft 22ft
Depth in Feet
Temperature in Celsius
12/4/01
3/12/02
4/10/02
4/25/02
5/14/01
5/22/01
E
Winter/Spring ROL-1 Dissolved Oxygen
0
2
4
6
8
10
12
14
0ft 1ft 3ft 5ft 7ft 9ft 11ft 13ft 15ft 17ft 19ft 21ft 22ft
Depth in Feet
DO mg/L
12/4/01
3/12/02
4/10/02
4/25/02
5/14/01
5/22/01
F
48
Figure 20
Summer ROL-2 Temperature
0
5
10
15
20
25
30
35
0ft 1ft 3ft 5ft 7ft 9ft 11ft 13ft 14ft
Depth in Feet
Temperature in Celsius
6/5/01
6/18/01
6/19/01
7/1/01
7/17/01
7/20/01
8/6/01
8/21/01
A
Summer ROL-2 Dissolved Oxygen
0
2
4
6
8
10
12
0ft 1ft 3ft 5ft 7ft 9ft 11ft 13ft 14ft
Depth in Feet
DO mg/L
6/5/01
6/18/01
6/19/01
7/1/01
7/17/01
7/20/01
8/6/01
8/21/01
8/24/01
B
49
Fall ROL-2 Temperature
0
5
10
15
20
25
0ft 1ft 3ft 5ft 7ft 9ft 11ft 13ft 14ft
Depth in Feet
Temperature in Celsius
9/24/01
10/9/01
10/22/01
11/12/01
C
Fall ROL-2 Dissolved Oxygen
0
1
2
3
4
5
6
7
8
9
0ft 1ft 3ft 5ft 7ft 9ft 11ft 13ft 14ft
Depth in Feet
DO mg/L
9/24/01
10/9/01
10/22/01
11/12/01
D
50
Winter/Spring
0
5
10
15
20
25
0ft 1ft 3ft 5ft 7ft 9ft 11ft 13ft 14ft
Depth in Feet
Temperature in Celsius
12/4/01
3/12/02
4/10/02
4/25/02
5/14/01
5/22/01
E
Winter/Spring ROL-2 Dissolved Oxygen
0
2
4
6
8
10
12
14
0ft 1ft 3ft 5ft 7ft 9ft 11ft 13ft 14ft
Depth in Feet
DO mg/L
12/4/01
3/12/02
4/10/02
4/25/02
5/14/01
5/22/01
F
51
Figure 21
Summer ROL-3 Temperature
0
5
10
15
20
25
30
35
0ft 1ft 3ft 5ft
Depth in Feet
Temperature in Celsius
6/5/01
6/18/01
6/19/01
7/1/01
7/17/01
7/20/01
8/6/01
8/21/01
8/24/01
A
Summer ROL-3 Dissolved Oxygen
0
2
4
6
8
10
12
0ft 1ft 3ft 5ft
Depth in Feet
DO mg/L
6/5/01
6/18/01
6/19/01
7/1/01
7/17/01
8/6/01
8/21/01
8/24/01
B
52
Fall ROL-3 Temperature
0
5
10
15
20
25
0ft 1ft 3ft 5ft
Depth in Feet Temperature in Celsius
9/10/01
9/24/01
10/9/01
10/22/01
11/12/01
C
Fall ROL-3 Dissolved Oxygen
0
1
2
3
4
5
6
7
8
9
10
0ft 1ft 3ft 5ft
Depth in Feet
DO mg/L
9/10/01
9/24/01
10/9/01
10/22/01
11/12/01
D
C
53
Winter/Spring
0
5
10
15
20
25
0ft 1ft 3ft 5ft
Depth in Feet
Temperature in Celsius
12/4/01
3/12/02
4/10/02
4/25/02
5/22/01
E
Winter/Spring ROL03 Dissolved Oxygen
0
2
4
6
8
10
12
14
0ft 1ft 3ft 5ft
Depth in Feet
DO mg/L
12/4/01
3/12/02
4/10/02
4/25/02
5/22/01
F
54
Phosphorus
Phosphorus is a required nutrient for plant growth. The over- or under-abundance of
phosphorus is a likely factor in determining the quantity as well as the quality of
macrophytes and algae growth in the lake. High phosphorus concentrations can lead to
the eutrophication of a lake. Phosphorus is not always readily available for plant
consumption. Most phosphorus in sediment is tightly bound to soil particles and
therefore not available to plants. This phosphorus is considered to be in an insoluble
form. If dissolved oxygen levels near the bottom of the lake become low, anaerobic
decomposition of organic materials will release phosphorus in a soluble form readily
available for plant use (Hill 1994). Phosphorus control is a key component to good lake
management and restoration. The Illinois standard for phosphorus states that phosphorus
as P shall not exceed 0.05 mg/L in any reservoir or lake with a surface area of 8.1
hectares or more (Title 35 Water Quality Standards). The phosphorous level did exceed
the standard. The 10/17/01 sample from ROL-3 at .65 mg/L and the 3/12/02 sample from
ROL-3 was 0.5 mg/L (Figure 22). While the highest reading was from ROL-1b at 1.1
mg/L. This last and highest reading is probably related to the conversion of insoluble
phosphorous to soluble phosphorous on the bottom of the lake. This was caused by
stratification which in turn causes lack of oxygen and the release of phosphorous by
anaerobic organisms.
The problem of excess phosphorous is compounded by the fact that there is more total
phosphorous in the tributaries than in the lake. Another part of the problem is that the
incoming water has a 69.6% dissolved phosphorous (useable by plants) while the lake has
only a 59.3% P in the dissolved form (Table 17, 21). This would suggest that the algae in
the lake are using the dissolved phosphorous for growth and the dead cells are settling to
the bottom and adding to the phosphorous in the sediment. This will be a continuing
problem as yearly stratification and overturn cycles will continue to release an abundance
of newly dissolved phosphorous.
55
Total Phosphorus 2001-2002
0
0.2
0.4
0.6
0.8
1
1.2
05/09/2001
05/14/2001
05/22/2001
06/05/2001
07/01/2001
07/20/2001
08/06/2001
08/24/2002
09/10/2001
09/24/2001
10/09/2001
10/17/2001
11/12/2001
12/04/2001
01/17/2002
02/25/2002
03/12/2002
04/10/2002
Date
Phosphprus (mg/L)
ROL-1b
ROL-1m
ROL-1t
ROL-2
ROL-3
Figure 22
56
Table 17 Dissolved Phosphorus ROL (Lake)
Date
Depth
ft
Soluble
P
Total
P
%
Soluble Date
Depth
ft
Soluble
P
Total
P
%
Soluble
ROL1 mg/l mg/l ROL2 mg/l mg/l
9-May 1ft 0.094 0.102 92.2 9-May 1ft 0.07 0.109 64.2
9-May 11 ft 0.092 0.102 90.2
18-
Jun 1ft 0.054 0.081 66.7
9-May 21 ft 0.101 0.141 71.6 20-Jul 1ft 0.057 0.114 50.0
18-
Jun 9 ft 0.051 0.067 76.1
24-
Aug 1ft 0.054 0.142 38.0
18-
Jun 17 ft 0.03 0.06 50.0
17-
Oct 1ft 0.077 0.13 59.2
1-Jul 14 ft ? 0.111 ROL3
1-Jul 1 ft ? 0.062 9-May 1ft 0.104 0.417 24.9
20-Jul 1 ft 0.032 0.07 45.7
18-
Jun 1ft 0.096 0.219 43.8
20-Jul 9 ft 0.017 0.078 21.8 20-Jul 1ft 0.142 0.186 76.3
20-Jul 15 ft 0.02 0.08 25.0 20-Jul 3ft 0.268 0.421 63.7
24-
Aug 1ft 0.053 0.116 45.7
17-
Oct 1ft 0.511 0.651 78.5
24-
Aug 11 ft 0.052 0.113 46.0
24-
Oct 1ft 0.142 0.269 52.8
24-
Aug 19 ft 0.077 0.173 44.5 SUMS 1.575 2.739 618.2
17-
Oct 1ft 0.058 0.091 63.7
17-
Oct 9ft 0.043 0.075 57.3 Total 2253.2
Average
of totals 59.3%
17-
Oct 18ft 0.043 0.078 55.1
SUMS 0.763 1.519 785.0
57
Nitrogen
Nitrogen is an important nutrient for plant growth as its availability will affect plant and
algae growth leading to eutrophication of a lake. The forms of nitrogen sampled included
ammonia, nitrate, and nitrite nitrogen. These three are summed to give the value of the
total kjeldahl nitrogen. The total kjeldahl is used to calculate the organic nitrogen.
Note: for all measures of “nitrogen, kjeldahl total mg/l” after may 2000 the value may not
be accurate because the reported values failed to meet the quality controls criteria for
precision or accuracy.
Total Nitrogen
Total nitrogen is a calculated value. It is the sum of kjeldahl nitrogen, nitrite and nitrate
nitrogen. It is used to determine the ratio of nitrogen to phosphorus. This determination
will yield the limiting nutrient for a lake. A ratio of total nitrogen to total phosphorus of
greater than 7:1 is defined as a phosphorus limited lake. Glenn Shoals Lake had a ratio of
14.2:1 and therefore phosphorus is the limiting nutrient. Nitrogen does, however, play a
role as a polluter and therefore should be controlled when possible. It should be noted
that nitrogen is much harder to control than phosphorus. Total nitrogen levels peaked in
the lake at ROL-2 on 5/22/2001 at 9.74 mg/L (Figure 23). Historical total nitrogen
averages of 1.95 mg/L are lower than the 2001-2002 data of 2.81 mg/L. This increase
over the historical data is an indication that nitrogen levels also need to be controlled
(Table 15).
58
Total Nitrogen 2001-2002
0
2
4
6
8
10
12
05/09/2001
05/14/2001
05/22/2001
06/05/2001
07/01/2001
07/20/2001
08/06/2001
08/24/2002
09/10/2001
09/24/2001
10/09/2001
10/17/2001
11/12/2001
12/04/2001
01/17/2002
02/25/2002
03/12/2002
04/10/2002
Date
Total Nitrogen (mg/L)
ROL-1b
ROL-1m
ROL-1t
ROL-2
ROL-3
Figure 23
59
Nitrate + Nitrite Nitrogen
Nitrate + Nitrite nitrogen are inorganic forms of nitrogen which can enter a lake through
agricultural runoff, septic tank effluent and other forms of waste. Due to the fact that
increased levels of nitrates can cause physiological effects for infants less than 6 months
old, nitrate concentrations are of particular concern for drinking water reservoirs. The
standard for nitrate is 10mg/L. Concentrations greater than 10 mg/L can have dangerous
effects for infants. All samples for Glenn Shoals Lake fell well below 10 mg/L; the peak
being 8.0mg/L at ROL-2 on 5/22/2001(Figure 24). The 2001-2002 nitrate + nitrite
nitrogen average values are higher than historic averages. The historic nitrate + nitrite
nitrogen for lake site ROL-1t is 0.85mg/L while the 2001-2002 average is 1.50mg/L.
Lake site ROL-2 historic nitrate + nitrite nitrogen average is 0.82mg/L while the 2001-
2002 average is 1.41mg/L. Lake site ROL-3 historic nitrate + nitrite nitrogen average is
0.98mg/L while the 2001-2002 average is 1.70mg/L (Table 15).
Figure 24
Nitrate + Nitrite Nitrogen
0
1
2
3
4
5
6
7
8
9
5/9/01
5/14/01
5/22/01
6/5/01
7/1/01
7/20/01
8/6/01
8/24/02
9/10/01
9/24/01
10/9/01
10/17/01
11/12/01
12/4/01
1/17/02
2/25/02
3/12/02
4/10/02
Date
Nitrate + Nitrate Nitrogen mg/L
ROL-1b
ROL-1m
ROL-1t
ROL-2
ROL-3
60
Organic Nitrogen
Organic nitrogen can enter a lake through decaying organic matter, septic systems,
agricultural waste and waterfowl. Levels in Glenn Shoals Lake were recorded above
0.5mg/L and were consistently higher than the historical levels. Levels peaked at
3.64mg/L on 4/10/2002 at ROL-3 (Figure 25). ROL-1t 2001-2002 organic nitrogen
levels were higher than historical averages with a 2001-2002 average of 1.00mg/L and a
historic average of 0.04mg/L. Lake site ROL-2 2001-2002 organic nitrogen levels were
higher than historical averages with a 2001-2002 average of 1.19mg/L and a historic
average of 0.22mg/L. Lake site ROL-3 2001-2002 organic nitrogen levels were also
higher than historical averages with a 2001-2002 average of 1.95mg/L and a historic
average of 0.32mg/L (Table 15).
Since organic nitrogen is a calculated value based on TKN the value may be suspect. See
the note under the heading Nitrogen.
Organic Nitrogen 2001-2002
0
0.5
1
1.5
2
2.5
3
3.5
4
05/09/2001
05/14/2001
05/22/2001
06/05/2001
07/01/2001
07/20/2001
08/06/2001
08/24/2002
09/10/2001
09/24/2001
10/09/2001
10/17/2001
11/12/2001
12/04/2001
01/17/2002
02/25/2002
03/12/2002
04/10/2002
Date
Organic Nitrogen (mg/L)
ROL-1b
ROL-1m
ROL-1t
ROL-2
ROL-3
Figure 25
61
Ammonia Nitrogen
Ammonia nitrogen is the form of nitrogen that is most readily usable for plant growth.
High ammonia concentrations can also have adverse affects on fish and other aquatic
organisms. Ammonia is made available after bacterial decomposition of organic matter
which is found in the sediment at the bottom of the Lake. The pollution control board
Part 302 states that total ammonia shall in no case exceed 15 mg/L, with a guideline of
0.25 mg/L. Twenty three percent of the samples from Glenn Shoals Lake were above the
0.25 mg/L guideline. None of the samples exceeded the 15mg/L standard (Figure 26).
The peak concentration of 2.9mg/L 8/6/2001 was found at ROL-1b at the bottom of the
lake, which would be expected. These peak concentrations are most commonly a result
of bacterial decomposition processes. Lake site ROL-1t 2001-2002 ammonia nitrogen
levels were higher than historical averages with a 2001-2002 average of 0.18mg/L and a
historic average of 0.15mg/L. Lake site ROL-2 2001-2002 ammonia nitrogen levels were
lower than historical averages with a 2001-2002 average of 0.13 mg/L and a historic
average of 0.19mg/L. Lake site ROL-3 2001-2002 ammonia nitrogen levels were higher
than historical averages with a 2001-2002 average of 0.25 mg/L and a historic average of
0.20mg/L (Table 15, Figure 26).
Ammonia Nitrogen 2001-2002
0
0.5
1
1.5
2
2.5
3
3.5
05/09/2001
05/14/2001
05/22/2001
06/05/2001
07/01/2001
07/20/2001
08/06/2001
08/24/2002
09/10/2001
09/24/2001
10/09/2001
10/17/2001
11/12/2001
12/04/2001
Date
Ammonia Nitrogen in mg/L
ROL-1b
ROL-1t
ROL-2
ROL-3
Figure 26
62
pH
A lake’s pH is a measure of the acidity of the water. The pH measures the hydrogen ions
present in solution on a scale of 0-14. A reading of 7 is neutral. A reading higher than 7
is basic or alkaline. A reading less than 7 is acidic. The pH range for most lakes is
between 6 and 9. The pH standard in Illinois is within the range of 6.5 to 9 except for
natural causes. The loss of carbon dioxide during photosynthesis results in an increase in
pH of the photic, or lighted, zone. As decomposition occurs near the bottom of the lake,
the pH will decrease. Therefore pH levels near the bottom of the lake are often lower
than near the surface. Organic material is decomposing and photosynthesis is not
occurring. With the exception of two sampling dates, 7/1/2001 and 8/6/2001, the pH in
Glenn Shoals Lake was within the range of 6.5 to 9 during the study. On these two dates,
at three of the sample sites, the pH was higher than 9 but lower than 9.5 (Figure 27). The
water in Glenn Shoals Lake during the study period was more alkaline than acidic.
Historical lake average pH for site ROL-1t is 7.8, ROL-2 is 7.8 and ROL-3 is 8.6. The
2001-2002 lake average pH for site ROL-1t was 8.1, ROL-2 was 8.2 and ROL-3 was 8.0.
Historical data peaks were higher than the 2001-2002 peaks (Table 15).
pH 2001-2002
5
5.5
6
6.5
7
7.5
8
8.5
9
9.5
10
05/09/2001
05/14/2001
05/22/2001
06/05/2001
07/01/2001
07/20/2001
08/06/2001
08/24/2002
09/10/2001
09/24/2001
10/09/2001
10/17/2001
11/12/2001
12/04/2001
Date
pH
ROL-1b
ROL-1m
ROL-1t
ROL-2
ROL-3
Figure 27
63
TRIBUTARY MONITORING
Turbidity
Turbidity is a measure of suspended materials in the water. Turbidity was measured
using a Hydrolab water measurement instrument and was calibrated to a known turbidity
test standard (NTUs). Turbidity is a measure of materials in the water causing light to
scatter. Turbidity in the tributaries is an indicator of bank and soil erosion in the
watershed and along the stream. (Figure18).
Sampling stations were located in all of the major tributaries in an effort to develop an
understanding of the volume of water, nutrients and other material entering the lake
(Figure 14). These stations were located near the mouths of tributaries where reasonable
access was available. A staff gauge was placed at each of these sites. A staff gauge is a
measuring rod that allows relational water depths to be observed and recorded in tenths of
a foot. Cross-sectional areas were taken at each of the staff gauge sites. Four staff gauge
sites were placed in the tributaries around the lake. The relationship between the staff
gauge reading and the cross-sectional area was used to determine volumes of water
entering the lake from each tributary. The staff gauge locations were labeled ROL01
through ROL05 (Figure 14). ROL01 is located near the spillway and was used to
determine the lake outflow. ROL02 is located on Witt Road bridge, crossing shoal creek,
ROL03 is located at the mouth of structure 14 a detention basin on fawn creek, both
ROL02 and ROL03 converge at lake site ROL-3. ROL04 is located on 1400N on the
bridge that crosses little creek, ROL05 is located on 1325 N east of the new bridge
constructed crossing the south arm of little creek, both ROL04 and ROL05 join together
and empty into the lake near site ROL-2.
City personnel recorded daily staff gauge readings at ROL01 – ROL05. These five sites
gave data for all of the major tributaries entering the lake as well as the outflow. During
storm events (more than ½ inch of rain) ZIES staff collected water samples from all five
sites and recorded staff heights for each site. Water samples were collected and shipped
according to IEPA protocol to IEPA laboratories for analysis. Water samples were
analyzed for total suspended solids, volatile suspended solids, phosphorus, nitrate +
nitrite nitrogen, ammonia nitrogen and kjeldahl nitrogen. ZIES staff tested for pH on site
using a Hydrolab probe during collection of the other water samples. ZIES also
measured flow using a Global water works flow probe. The flow data was used to
determine sediment and nutrient loading for each site.
64
Figure 14 B - Tributary Sampling Sites
65
Total Suspended Solids
Total suspended solids (TSS) is a measurement of all of the suspended material in the
water including both organic and inorganic materials. This would include materials such
as algae, decaying plant materials, minerals, and soil particles. (Figure 28). Peak levels
corresponded with rain events. Values of TSS were used to calculate Sediment loading.
Figure 28 – Total Suspended Solids
Tributary Sites Total Suspended Solids (TSS) May 2001-Oct 2001
0
100
200
300
400
500
600
700
800
900
1000
5/6/01
5/9/01
5/14/01
5/22/01
5/31/01
6/5/01
6/4/01
6/6/01
6/15/01
6/18/01
6/21/01
7/1/01
7/17/01
7/20/01
7/24/01
8/3/01
8/6/01
8/24/02
8/24/01
9/10/01
9/19/01
9/24/01
10/5/01
10/10/01
10/9/01
Date
TSS mg/L
ROL01
ROL02
ROL03
ROL04
ROL05
1020 4360
Volatile Suspended Solids
Volatile suspended solids (VSS) is a measurement of the organic material and salts
suspended in the water. This is as opposed to the non volatile which remains after heating
the TSS to 550o C. This material would include algae, decaying plant material and all
other organic material that is suspended in the water. (Figure 29). Peak VSS levels
corresponded to rain indicating that organic materials were washing into the tributaries
and/or algae growth increased during such rainfall events.
66
Figure 29 – Volatile Suspended Solids
Tributary Sites Volatile Suspended Solids (VSS) May 2001- Sept 2001
0
50
100
150
200
250
300
350
05/06/2001
05/09/2001
05/14/2001
05/22/2001
05/31/2001
06/05/2001
06/04/2001
06/06/2001
06/15/2001
06/18/2001
06/21/2001
07/01/2001
07/17/2001
07/20/2001
07/24/2001
08/03/2001
08/06/2001
08/24/2002
08/24/2001
09/10/2001
Date
VSS mg/L
ROL01
ROL02
ROL03
ROL04
ROL05
Tributary Sites Volatile Suspended Solids (VSS) Sept 2001- Apr 2002
0
50
100
150
200
250
300
350
09/19/2001
09/24/2001
10/05/2001
10/10/2001
10/09/2001
10/24/2001
11/12/2001
11/20/2001
11/29/2001
12/04/2001
12/12/2001
12/17/2001
01/17/2002
01/31/2002
02/19/2002
02/25/2002
03/09/2002
03/12/2002
04/10/2002
04/21/2002
Date
VSS mg/L
ROL01
ROL02
ROL03
ROL04
ROL05
67
Nitrate + Nitrite Nitrogen
Nitrate and nitrite are inorganic forms of nitrogen, which can enter a lake through
agricultural runoff, septic tank effluent and other forms of waste (Meyers 1999). The
higher concentrations were found in May, June, and December through April (Figure 30,
31). The high concentration in May and June correspond to fertilizer application for such
crops as corn and soybeans.
Figure 30 – Nitrate + Nitrite Nitrogen
Tributary Sites Nitrate + Nitrite Nitrogen May 2001-Sept 2001
0
2
4
6
8
10
12
05/06/2001
05/09/2001
05/14/2001
05/22/2001
05/31/2001
06/05/2001
06/04/2001
06/06/2001
06/15/2001
06/18/2001
06/21/2001
07/01/2001
07/17/2001
07/20/2001
07/24/2001
08/03/2001
08/06/2001
08/24/2002
08/24/2001
09/10/2001
Date
Nitrat + Nitrite Nitrogen mg/L
ROL01
ROL02
ROL03
ROL04
ROL05
68
Tributary Sites Nitrate + Nitrite Nitrogen Sept 2001- April 2002
0
2
4
6
8
10
12
09/19/2001
09/24/2001
10/05/2001
10/10/2001
10/09/2001
10/24/2001
11/12/2001
11/20/2001
11/29/2001
12/04/2001
12/12/2001
12/17/2001
01/17/2002
01/31/2002
02/19/2002
02/25/2002
03/09/2002
03/12/2002
04/10/2002
04/21/2002
Date
Nitrate + Nitrite Nitrogen mg/L
ROL01
ROL02
ROL03
ROL04
ROL05
Organic Nitrogen
Kjeldahl nitrogen is ammonia nitrogen plus organic nitrogen. Organic nitrogen is
calculated by subtracting ammonia nitrogen from kjeldahl nitrogen. Organic nitrogen can
enter tributaries through decaying organic matter, septic systems and agricultural waste
(Myers 1997). Organic nitrogen peaked in the tributaries at ROL 04 on 11/24/01 at
10.35 mg/L (Figure 32).
Figure 31
69
Figure 32 – Organic Nitrogen
Tributary Sites Organic Nitrogen May 2001-Sept 2001
0
2
4
6
8
10
12
05/06/2001
05/09/2001
05/14/2001
05/22/2001
05/31/2001
06/05/2001
06/04/2001
06/06/2001
06/15/2001
06/18/2001
06/21/2001
07/01/2001
07/17/2001
07/20/2001
07/24/2001
08/03/2001
08/06/2001
08/24/2002
08/24/2001
09/10/2001
Date
Organic Nitrogen mg/L
ROL01
ROL02
ROL03
ROL04
ROL05
Tributary Sites Organic Nitrogen Sept 2001-April 2002
0
2
4
6
8
10
12
09/19/2001
09/24/2001
10/05/2001
10/10/2001
10/09/2001
10/24/2001
11/12/2001
11/20/2001
11/29/2001
12/04/2001
12/12/2001
12/17/2001
01/17/2002
01/31/2002
02/19/2002
02/25/2002
03/09/2002
03/12/2002
04/10/2002
04/21/2002
Date
Organic Nitrogen mg/L
ROL01
ROL02
ROL03
ROL04
ROL05
70
Total Nitrogen
Total nitrogen is the sum of all nitrogen. It is calculated by adding kjeldahl nitrogen and
nitrate and nitrite. It was found at consistently higher concentrations at ROL 02 and
peaked at this site on 3/09/02 at 16.2 mg/L (Figure 33).
Figure 33 – Total Nitrogen
Tributary Sites Total Nitrogen May 2001-Sept 2001
0
2
4
6
8
10
12
14
16
18
05/06/2001
05/09/2001
05/14/2001
05/22/2001
05/31/2001
06/05/2001
06/04/2001
06/06/2001
06/15/2001
06/18/2001
06/21/2001
07/01/2001
07/17/2001
07/20/2001
07/24/2001
08/03/2001
08/06/2001
08/24/2002
08/24/2001
09/10/2001
Date
Total Nitrogen mg/L
ROL01
ROL02
ROL03
ROL04
ROL05
Tributary Sites Total Nitrogen Sept-2001-April 2002
0
2
4
6
8
10
12
14
16
18
09/19/2001
09/24/2001
10/05/2001
10/10/2001
10/09/2001
10/24/2001
11/12/2001
11/20/2001
11/29/2001
12/04/2001
12/12/2001
12/17/2001
01/17/2002
01/31/2002
02/19/2002
02/25/2002
03/09/2002
03/12/2002
04/10/2002
04/21/2002
Date
Total Nitrogen mg/L
ROL01
ROL02
ROL03
ROL04
ROL05
71
Ammonia Nitrogen
Ammonia nitrogen is the form of nitrogen that is most readily usable for plant
growth. High ammonia concentrations can also have adverse affect on fish and
other aquatic organisms. The IPCB Part 302 states that total ammonia shall in no
case exceed 15 mg/L. No tributary sample exceeded this standard (Figure 34,
35).
Figure 34 – Ammonia Nitrogen
Tributary Sites Ammonia Nitrogen May 2001-Sept 2001
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
05/06/2001
05/09/2001
05/14/2001
05/22/2001
05/31/2001
06/05/2001
06/04/2001
06/06/2001
06/15/2001
06/18/2001
06/21/2001
07/01/2001
07/17/2001
07/20/2001
07/24/2001
08/03/2001
08/06/2001
08/24/2001
08/24/2001
09/10/2001
Date
Ammonia Nitrogen mg/L
ROL01
ROL02
ROL03
ROL04
ROL05
72
Tributary Sites Ammonia Nitrogen Sept 2001-April 2002
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
09/19/2001
09/24/2001
10/05/2001
10/10/2001
10/09/2001
10/24/2001
11/12/2001
11/29/2001
12/04/2001
12/12/2001
12/17/2001
01/31/2002
02/19/2002
02/25/2002
03/09/2002
03/12/2002
04/10/2002
04/21/2002
Date
Ammonia Nitrogen mg/L
ROL01
ROL02
ROL03
ROL04
ROL05
pH
The pH measures the acidity of water. The pH measures the hydrogen ions present in
solution on a scale of 0-14. A reading of 7 is neutral. A reading higher than 7 is basic or
alkaline. A reading less than 7 is acidic. The Illinois standard states that the pH should be
within the range of 6.5 to 9. pH was measured by ZIES staff at the time of other water
sample collection using a Hydrolab water sampling probe. On five occasions the pH was
greater than 9.0 (Figure 35).
73
Figure 35 – pH
Tributary Sites pH May 2001-Sept 2001
4
5
6
7
8
9
10
05/06/2001
05/09/2001
05/14/2001
05/22/2001
05/31/2001
06/05/2001
06/04/2001
06/06/2001
06/15/2001
06/18/2001
06/21/2001
07/01/2001
07/17/2001
07/20/2001
07/24/2001
08/03/2001
08/06/2001
08/24/2002
08/24/2001
09/10/2001
Date
pH
ROL01
ROL02
ROL03
ROL04
ROL05
Tributary Sites pH Sept 2001-April 2002
4
4.5
5
5.5
6
6.5
7
7.5
8
8.5
9
09/19/2001
09/24/2001
10/05/2001
10/10/2001
10/09/2001
10/24/2001
11/12/2001
11/29/2001
12/04/2001
12/12/2001
12/17/2001
01/31/2002
02/19/2002
02/25/2002
03/09/2002
03/12/2002
04/10/2002
04/21/2002
Date
pH
ROL01
ROL02
ROL03
ROL04
ROL05
74
SEDIMENTATION SURVEY
In 1995 under the direction of Rodger Windhorn the NRCS conducted a sediment survey
of Glenn Shoals Lake. The following are excerpts from his report. They used GPS
technology and the GIS program GRASS to compute sediment volumes. At the same
time, sediment samples from randomly selected locations were collected to be analyzed
at Soil Mechanics Lab in Lincoln, NE. These samples helped to make a general
characterization of the sediment.
All samples submitted to the Soil Mechanics Lab had the following analyses run on them:
Particle-size determination (amount of sand, silt, and clay); Atterberg limits; dispersion
characteristics (dispersive clay present); and natural moisture content. All samples were
collected using a bucket auger, through up to 20 feet of water. The sediment samples
represent the “hard bottom” sediments that could not be penetrated with the depth finder.
The “soft sediments” can not be sampled with this type of sampling equipment due to
their very high water content.
For Lake Glenn Shoals, the sediment data was not uniform, with some samples indicating
almost no sand, and some containing as much as 20% sand. Nearly all of the samples in
this lake were a LEAN CLAY (CL), which means they do not contain as much highly
plastic and pliable clay. The clay content generally runs from 17% to 30% except on a
few samples. The increased amount of sand present is probably due to at least two
factors: one, the transport of larger and heavier particles is greater, and second, the larger
lake has more bank and shoreline erosion, which in many cases, is cutting into the glacial
till surrounding the lake. Glacial till contains significantly more sand than the loess
material. Also, there are at least two tributaries flowing into the lake that appear to be
carrying more sand. These samples contain between 14% and 17% sand. In general, the
sediment in Glenn Shoals is somewhat coarser than most lakes in this area it also contains
less clay, and probably also reflects the result of more wave and wind action on the
shoreline.
Sediment Sampling
To develop a better understanding of the types of materials in the sediment, grab samples
were collected and analysis at IEPA laboratories. This data reveals the types of materials
(pesticides and heavy metals) that have been trapped in the sediment (Tables 18,19). The
information will give baseline data to make informed decisions about restoration
techniques, including dredging of the lake bottom. High concentrations of pesticides and
heavy metals in the sediment could limit or totally eliminate the dredging options.
The 1995 report estimates 39,593 tons of sediment is entering the lake every year.
According to these estimates forty-five percent of the lake volume has been lost to
sediments since the construction. This was later revised to fifteen to forty-five percent
(Windhorn 1996).
75
Slope Acres Tons/Acre/Year Gross Sheet and
Rill Erosion
Del Rate Sediment
Delivered
Tons/Year
0-2% 45,420 2.1 95,382 .05 4,769
2-5% 4,845 7.3 35,369 .10 3,537
5-10% 2,624 10.8 28,339 .15 4,251
10-30% 3,300 2.9 9,570 .15 1,436
Total Sheet
and Rill
13,993
Total
Ephemeral
and Gully
8,600
Total
Shoreline
17,000
Total 39,593
Source: NRCS 1995 Sediment Survey
Sediment
The causes of sedimentation are of two types. First is the actual input, primarily of
inorganic materials (soil particles) brought in by water and rarely, by wind. The second is
nutrients released into the lake by fertilizers added to crops and by nitrogen fixing
organisms in the tributaries and in the lake. The nitrogen fixing as well as phosphorous
release and uptake is tied closely to the rate of growth (photosynthesis). The potential
photosynthetic rate in the lake is measured by the amount of chlorophyll a. The two
nutrients are of primary importance to the development and health of the lake. Both N
and P need to be studied. Since they are cyclic it is important to follow their movements
through the lake.
Let us look at N first. The air is the major reservoir and consists of 80% nitrogen gas.
This form of N is not usable by most plants. Only Blue green algae (bacteria) can convert
N2 to a usable form. There are enough of these organisms in most wetlands or aquatic
systems to supply the needs for all plants (both micro – and mactrophytes). Since it is
often difficult if not impossible to control N we need to try to restrain the available P.
The reservoir for P is in the soil. P also comes in available (soluble) and unavailable
(non-soluble or attached to soil particles such as clay) forms. We can hope to a) reduce
the P coming into the lake and b) reduce the amount that is in an available form in the
lake. Most incoming P is brought in by the tributaries through flooding. This brings in
clay particles with attached P as well as dissolved phosphorous. When this dissolved P is
taken in by plants and the plants die and become part of the sediment on the bottom of a
lake it is no longer available to plants. This will stay in the unavailable form until lake
stratification occurs (no mixing of upper and lower layers). In Glenn Shoals this occurs in
the summer when the deeper cold water does not mix with the upper warm water because
the cold water is denser than warm water. In time, the oxygen on the bottom of the lake is
used up and nutrients are released.
Table 18 Glenn Shoals Sediment Survey
76
Table 19 Glenn Shoals Organic Sediments
ROL-1 ROL-2 ROL-3
μg/kg
Total PCBS 10K 10K 10K
Hexachlorobenzene 1.0K 1.0K 1.0K
Trifluralin 10K 10K 10K
Alpha-BHC 1.0K 1.0K 1.0K
Gamma-BHC (Lindane) 1.0K 1.0K 1.0K
Atrazine 50K 50K 50K
Heptachlor 1.0K 1.0K 1.0K
Aldrin 1.0K 34 1.0K
Alachlor 10K 10K 10K
Metribuzin 10K 10K 10K
Metolachlor 25K 25K 25K
Heptachlor Epoxide 1.0K 1.0K 1.0K
Pendimethalin 10K 10K 10K
Gamma-Chlordane 2.0K 2.0K 2.0K
Alpha-Chlordane 2.0K 2.0K 2.0K
Total Alpha and Gammas
Chlordane
5.0K 5.0K 5.0K
Dieldrin 1.0K 1.3 1.0K
Captan 10K 10K 10K
Cyanazine 25K 25K 25K
Endrin 1.0K 1.0K 1.0K
P P'-DDE 1.0K 1.0K 1.0K
P P'-DDD 1.0K 1.0K 1.0K
P P'-DDT 1.0K 1.0K 1.0K
Total DDT 10K 10K 10K
Methoxychlor 5.0K 5.0K 5.0K
77
INSERT TABLE 20 – GLEN SHOALS SEDIEMT METALS
78
During fall turnover phosphorus, along with nitrogen, is released back into the
epilimnion of the lake where it can be used by algae and other plants. This process is
referred to as internal loading. The stratification necessary to promote this process occurs
in the south end of the lake. The surface area of the lake bottom that would experience
anaerobic conditions was determined from the bathymetric map to be 218,700 m2.
Assuming a phosphorus release rate of 15mg/m2/day (Nurnberg 1984) and a nitrogen
release rate of 120 mg/m2/day (Filles 1975), approximately 394 kg of phosphorus and
3149 kg of nitrogen were released from the sediments (Table 14). This nutrient release
would generally occur during the three months when oxygen was depleted at the bottom
of the lake (Figure 19, 20).
SHORELINE EROSION
Shoreline erosion is important to consider when looking at the overall health of a lake.
Erosion can affect a lake in many ways including sedimentation, loss of shoreline
vegetation, interference with light, release of nutrients, stress on fish, oxygen depletion
and loss of underwater habitat (Fuller 1997). Sedimentation due to erosion can have a
significant impact on the volume of the lake over time. Although shoreline erosion is not
the only source, it can contribute significantly to this problem. Erosion can affect
shoreline vegetation and habitats by destroying plants and trees near the shoreline.
Suspended sediments will interfere with light, interfering with the food chain. Nutrients
eroded into the lake can increase algae growth and lead to oxygen depletion. Fish, such
as bass, relay on sight to feed. Increased turbidity can affect their feeding. Erosion
degrades both plant and fish habitats.
There are several causes for shoreline erosion – both controllable and uncontrollable.
Some of the primary causes of shoreline erosion are wave action and ice sheets activity,
the waves are the primary problem and the size and energy of the waves determine the
amount of erosion. Waves are caused by wind (Fuller 1997) and by the activity of power
boats. The size and power of the wave is a function of water displaced by the boat and the
power produced by the motor. This in turn determines the damage to the shoreline. The
shoreline erosion can be reduced by protecting the surface. Vegetation and Rip Rap are
very beneficial in protecting the shore.
To obtain a better understanding of the shoreline erosion situation on Glenn Shoals Lake,
ZIES staff did an intensive survey of the shoreline around Glen Shoals Lake (Figure 36,
37). A map was generated to show shoreline erosion. The shoreline was labeled in the
following manor: rip-rap, undercut, slight bank erosion 1-3 ft, moderate bank erosion 3-8
ft and severe bank erosion 8 or more feet.
The survey indicates that there are 15,612 linear feet of rip-rap, 2,952 linear feet of severe
erosion, 11,017 feet of moderate erosion and 17,878 feet of slight erosion (Figure 36, 37).
The problem of sedimentation caused by bank erosion is being gradually improved but it
needs to be attacked on a broader front. The problem of moderate and severe erosion
(14,000 feet) should be corrected as soon as possible.
79
Figure 36 – Shoreline Erosion
Top – Riprap
Bottom – Without riprap
80
Figure 37 – Glenn Shoals Shoreline Erosion Survey
81
A.10.c Trophic Condition of the Lake
By all measurements (chlorophyll a, Secchi depth, nutrients) of the Carlson’s
Trophic State Index (TSI) Glenn Shoals Lake is hypereutrophic. The Carlson’s
Trophic State Index allows one to compare lakes and to estimate the trophic
status of a lake from either the Secchi depth, chlorophyll a or total phosphorous.
The average secchi reading of .546m (21.3 inches), chlorophyll a at a reading of
40 μg/L and the average total phosphorus of 200 μg/L all places it in the hypereutrophic
range. This does not agree with the IEPA assessment by Phyllis Borland-Lau that states
that the lake is eutrophic.
This data, placing the lake in a hypereutrophic state, would suggest that the lake and/or
watershed is in immediate need of major modification to address this problem..
Phosphorus or Nitrogen is normally the limiting factor in most lakes. Glenn Shoals has
Phosphorus as it’s limiting factor. Howerver, all three of these are interrelated. That is,
the more nutrients the more chlorophyll a is produced and the less transparency the lake
has.
Lakes in this area that have watersheds which are mostly covered by row crop agriculture
tend to be slightly eutrophic to hypereutrophic. As can be seen from the levels indicated
in Figure 38 on each index, all three place Glenn Shoals Lake in the hypereutrophic
(upper ) level.
The mark to strive for in Glenn Shoals is probably in the TSI of 50. This is an area
between the mesotrophic (preferred) and the eutrophic (slightly over fertile). As can be
seen the phosphorus needs to be reduced by approximately 70%. If this is done the two
other indices should follow since nutrients (in this case P, the limiting factor) are the
controlling factors for each of these indices. If the barley bales are able to reduce algae
growth then P may not need to be reduced by quite that much.
The following graphic (Figure 38)gives one a pictoral view of the relationships of these
indices. The phosphorus scale is a direct measurement in μg/l. The chlorophyll a scale is
also in μg/l. However, the Secchi (transparency) readings are in meters. Note, the uneven
scaling of the three parameters to provide a common equal scaling of the trophic state
index. For each trophic scale increase the phosphorus doubles and the algae biomass (as
represented by chlorophyll a) increases about 2.8 fold. The trophic scale ranges from 0 to
100 , however the important section (where most lakes seem to fall) is between 20 and 80
so the following only includes this area.
82
Figure 38 Trophic State Index
Oligotrophic Mesotrophic Eutrophic Hypereutrophic
20 25 30 35 40 45 50 55 60 65 70 75 80
| | | | | | | | | | | | _ |___
Transparency (Secchi depth in m ) average .546
15 10 8 7 6 5 4 3 2 1.5 1 .5 .3
| | | | | | | | | | | x | |
Chlorophyll a (μg/l) average 40
.5 1 2 3 4 5 7 10 15 20 30 40 50 100 150
| | | | | | | | | | | |x | | |
Total Phosphorus ((μg/l) average 200
1 5 7 10 15 20 25 30 40 50 60 80 100 150
| | | | | | | | | | | | | | x
A.10.d Limiting Algae Nutrients
Estimated Nutrient Loading from Birds
Birds can contribute significant amounts of nutrients to the lake when found in large
numbers. A bird survey was conducted on Glenn Shoals Lake to estimate the number and
types of birds using the lake (Table 25). Bird counts on Glenn Shoals were not found in
large enough numbers to significantly contribute to the lakes nutrient loading.
Estimated Nutrient Loading from Lake Sediment
The lake itself can be a major contributor of nutrient loading. Nutrients bound in the
sediments on the bottom on of the lake, as well as nutrients in dying plant material;
contribute to the nutrient loading of the lake. When the dissolved oxygen level near the
bottom of the lake is depleted, phosphorus trapped in the sediments is released. During
fall turnover phosphorus, along with nitrogen is released back into the epilimnion of the
lake where is can be used by algae and other plants. This process is referred to as internal
loading. The stratification necessary to promote this process occurs in the south end of
the lake. The surface area of the lake bottom that would experience anaerobic conditions
was determined from the bathymetric map to be 218,700 m2. Assuming a phosphorus
release rate of 15mg/m2/day (Nurnberg 1984) and a nitrogen release rate of 120
mg/m2/day (Filles1975), approximately 394 kg of phosphorus and 3149 kg of nitrogen
were released from the sediments (Table 14). This nutrient release would generally occur
during the three months when oxygen was depleted near the bottom of the lake.
83
Estimated Sediment from Shoreline Erosion
Using information from the shoreline erosion study (Figure 37), calculations were made
to estimate the amount of sediment delivered to the lake from shoreline erosion. Using
conservative estimates of 40lbs of soil per linear foot entering the lake from areas with
severe erosion, 30lbs per linear foot for areas with moderate erosion, and 20lbs per linear
foot for areas that are undercut, approximately 364,820 kg per year of soil enters the lake
from shoreline erosion (Hill 1994). This amounts to 1% of the total sediment entering the
Lake (Table 14).
Nutrients and sediment can enter the tributaries from a variety of different sources: sheet
erosion, fertilizers, livestock waste, septic systems, atmospheric sources, stream bank
erosion, wildlife, etc. Nutrients from atmospheric sources, lake sediments, and wildlife
(Table 14) are described below.
Estimated Sediment and Nutrient Loading from the Tributaries
Nutrients and sediments coming form the tributaries were measured during rain events
and concentration relationships were developed between acre-feet of water and measured
concentrations of nutrients and sediments. Using daily water volumes calculated from
staff gage flow relationship, the nutrients and sediments in kilograms were calculated for
each tributary using best fit equation (Figures 13, 14, 15). The highest concentration of
nutrients (41% P, 64% N) entered the lake form Shoal Creek, which is to be expected
since it represents the largest sub watershed.
Nutrients in the atmosphere should be considered non-point sources of pollution. These
nutrients can enter the lake indirectly by washing in from the watershed or by being
directly deposited on the water surface. Of the principle nutrients, phosphorus and
nitrogen, nitrogen is found in high concentrations in the atmosphere. Most of this is in a
form that is unavailable to most organisms. Available nitrogen is deposited into the
atmosphere primarily from burning fossil fuels (mostly NO2 – Nitrites). Automobiles and
power plants are the two main sources of available nitrogen. In the area around Glen
Shoals Lake, deposits of nitrogen can be expected in the range of 1.3 – 1.8 tons per
square mile or an average of 1.55 tons per square mile (Pucket 1994).
Phosphorus is found in much lower concentrations than nitrogen. Phosphorus
concentrations in the rural area surrounding Glenn Shoals Lake would be found at .03
milligrams of phosphorus per liter of rainwater (Litke 1999). Using these estimates,
3,300 Kg of nitrogen and 304 Kg of phosphorus are deposited directly onto the lake
surface every year (Table 14).
A.10.e Hydraulic budget
An annual water budget was calculated for Glenn Shoals Lake. This is a best estimate of
the amount of water coming into and leaving the lake. To determine the amount of water
entering the lake, stream staff gauges were placed in the major tributaries as close to the
84
lake as possible. City staff members recorded the stream height on the staff gauge on a
daily basis. Cross-sections of the streams were measured at each of the gauge sites. A
relationship was established for the area of the cross-section in relationship to staff gauge
height. Next, flow measurements in feet-per-second were measured using a Global
Water flow measuring instrument. Next, flow and area measurements were combined to
establish a relationship between staff height and cubic feet-per-second of water passing
the cross-section. Calculations were then used to determine the acre-feet per day of water
entering the lake for each measured tributary.
At Little Creek entering Irving Cove two staff gauge stations were established for ease of
access. One was established for Little Creek north (Rolo4) and one for Little Creek south
(Rolo5). Flow relationship data at the southern station ROL05 was not accurate. A
consistent flow curve was not established in part due to construction of a new bridge
during the project. Land use for the northern station ROL04 Irving North sub-watershed
was almost identical, so flow data was used from this station to estimate water volumes
for ROL05. Also, data from Structure 14 (Rolo3) was not accurate so the data from
Rolo2 was used to estimate the flow for Rolo3. In addition to water flowing in from the
watershed, rain which fell directly onto the lake surface was calculated from daily rain
amounts recorded at the park office just south of the lake.
An additional staff gauge was placed near the outflow of the lake. It was used to
determine the height of water flowing out of the lake. This information was used to
calculate the amount of water flowing out of the lake over the spillway. The calculations
were made using weir equations: Q=CLH(3/2) , where Q is the water discharged in cubic
feet-per-second, C is the coefficient based on H, L is the length of the outlet (Haan 1994).
It is possible that in a large rain event at the weir an orifice equation would be needed.
During the study period the lake level never was high enough that the orifice would
control the flow so the weir equation was used. Evaporation was calculated using 50
years of historical evaporation rates in Illinois (Roberts 1967). Water withdrawn by the
water treatment plant was also considered as part of the out-flow. From discussions with
city personal two thirds of the City’s water was estimated to come from Glenn Shoals
Lake. All of the in-flow and out-flow data is presented in Table 21.
85
In Flow Out Flow
Acre feet added Acre Feet Withdrawn
Month Tributaries Rainfall Total In Drinking water Flow over spillway Evaporation Total Out
May 21484 930 22414 70 1634 529 2233
Jun 40871 582 41453 71 12952 608 13631
July 6960 551 7511 84 204 698 986
Aug 12941 500 13414 83 108 585 776
Sep 4232 422 4654 73 999 410 1482
Oct 11482 740 12222 71 5680 262 6013
Nov 5777 150 5927 67 2187 135 2389
Dec 35067 1125 36192 67 13058 65 13190
Jan 10168 360 10528 66 3200 68 3334
Feb 21238 405 21643 60 12231 101 12392
Mar 37099 1046 38145 67 15897 214 16178
Apr 29752 1403 31155 66 20053 360 20479
Total 237071 8214 245285 845 88203 4035 93083
Table 21 Hydrologic Budget for Glenn Shoals Lake 2000-2001
86
A.10.f Phosphorus budget
Phosphorus
Phosphorus is a component founding in both agricultural and residential fertilizer. It can
also leach from septic systems and feed lots. Large amounts of phosphorus runoff can
lead to poor water quality in the lake. High phosphorus levels can lead to algae blooms
and poor water quality. The IPCB part 302 states phosphorus as P shall not exceed 0.05
mg/L in any reservoir or lake with a surface area of 8.1 Hectares or more, or in any
stream at the point where it enters any such reservoir or lake. Each tributary site on one or
more dates exceeded this standard (Figure 39, 40).
Figure 39 – Phosphorus A.
Tributary Sites Total Phosphorus May 2001- Sept 2001
0
0.5
1
1.5
2
2.5
05/06/2001
05/09/2001
05/14/2001
05/22/2001
05/31/2001
06/05/2001
06/04/2001
06/06/2001
06/15/2001
06/18/2001
06/21/2001
07/01/2001
07/17/2001
07/20/2001
07/24/2001
08/03/2001
08/06/2001
08/24/2002
08/24/2001
09/10/2001
Date
Total Phosphorus mg/L
ROL01
ROL02
ROL03
ROL04
ROL05
87
Tributary Sites Total Phosphorus Sept 2001-April 2002
0
0.5
1
1.5
2
2.5
09/19/2001
09/24/2001
10/05/2001
10/10/2001
10/09/2001
10/24/2001
11/12/2001
11/20/2001
11/29/2001
12/04/2001
12/12/2001
12/17/2001
01/17/2002
01/31/2002
02/19/2002
02/25/2002
03/09/2002
03/12/2002
04/10/2002
Date
Total Phosphorus mg/L
ROL01
ROL02
ROL03
ROL04
ROL05
Figure 39
88
Table 22 Dissolved Phosphorus ROLO
(Tributaries)
Depth ft
Soluble
P Total P % Soluble
ROL02 mg/l mg/l
1ft 0.107 0.158 67.7
1ft 0.142 0.186 76.3
1ft 0.101 0.17 59.4
1ft 0.812 0.936 86.8
ROL03
1ft 0.119 0.242 49.2
1ft 0.165 0.403 40.9
1ft 0.101 0.368 27.4
1ft 0.49 0.64 76.6
ROL04
1ft 0.301 0.46 65.4
1ft 0.623 0.829 75.2
1ft 0.227 0.527 43.1
1ft 0.891 0.946 94.2
ROL05
1ft 0.112 0.131 85.5
Sum
.191
Sum
.996
Sum
47.7
69.9%
% of
Totals
89
A.11. Biological Resources and Ecological Relationships
BIOLOGICAL MONITORING
In addition to the physical and chemical measurements taken several biological parameters
were studied as a part of the project. These studies included a phytoplankton survey,
chlorophyll a analysis, macrophyte survey, fish survey, bacteriological analysis and wildlife
summary.
Endangered Birds in Illinois
In August an osprey (Pandion haliaetus) was spotted. The osprey is listed as an endangered species
in Illinois. The osprey was seen from the northern boat launch flying over the east bank of the lake.
A.11.a Composition of lake fish fauna
Fisheries are a major concern for Glen Shoals Lake. Fishing is one of the main recreational
activities that take place on the lake. Glen Shoals Lake is known for its good fishing. Sport
fishers come from a large area for the bass, bluegill, crappie, and catfish. Maintaining quality-fishing
stocks is an important component for overall lake management. The Illinois Department
of Natural Resources has done a very good job managing the fisheries for Glen Shoals Lake, in
part through the efforts of Charlie Marbut, IDNR Fisheries Manager. Water quality can have a
direct impact on the fish population in the lake.
As part of the Clean Lakes requirement Charlie Marbut of the IDNR conducted a fish flesh
analysis. Fish were sampled using electro fishing and gill nets. All samples were within the
regulatory limits for the specific compounds analyzed (Table 24). The IDNR in cooperation
with the City sets fishing regulations (number and size limits) in addition to developing a lake
management plan which involves conducting regular fish surveys.
The following is the Lake Management Status Report submitted by Charlie Marbut on April 10,
2002 (Tables 23, 24).
90
Table 23
LAKE MANAGEMENT STATUS REPORT
Date of Report: Fisheries Manager: District No:
04-10-02 Charley Marbut 15____________________________________
Lake Name: County: Water No:
Glenn Shoals Montgomery 180
Ownership (S, PUC, PUO) ACREAGE:
PUC 1200
---------------------------------------------------------------------------
LM STATUS REPORTS WILL INCLUDE THE FOLLOWING SECTIONS:
1. Listing of the Sport Fish Regulations in Effect
2. Listing of Management Activities Completed with Evaluation of Success
3. Lake Management Plan Progress Table
4. Recommendation for Observed Problem Trends
_____________________________________________________________________________________
1. Largemouth Bass - 15 inch minimum length limit, 3 fish/day.
Striped Bass Hybrid - 17 inch minimum length limit, 3 fish/day.
2. Stocked 12,000 (2”) striped bass hybrids - 05-25-01 - successful.
Stocked 3,800 (4-6") largemouth bass from brood pond - 09-13-01
Stocked 24,000 (4") largemouth bass from hatchery - 8-14-01
Fall population survey; 3 hours - 09/13/01 - successful.
Table 23 A.
BLG LMP
GOALS
1999 2000 2001
YAR 1 - 5 - - -
PSD 20 - 40 5 3 8
RSD-7 10 - 15 0 0 0
Wr 90 -
110
99 106 97
CPUE
(#/HR)
105 200 97
Bluegill: The bluegill population appears to have declined since the 1992 survey. In 1992, 10% of the
bluegill collected were less than 4.0 inches as compared to 31% in 1997, 27% in 1998, 28% in 1999, 23%
in 2000, and 19% in 2001. 70% were 4.0 - 5.9 inches in 1992 compared to 65% in 1997, 72% in 1998,
66% in 1999, 72% in 2000, and 73% in 2001. 20% were 6.0 inches or larger in 1992 compared to 4% in
1995, 1% in 1998, 6% in 1999, 3% in 2000, and 8% in 2001. Wr values (flesh condition) was good at 97.
Good numbers of 4.0 - 5.9 inch fish were present and hopefully will grow and provide quality fishing in
one or two years. The number of fish larger than 6 inches did increase by 5% in 2001, however no bluegill
91
were collected larger than 7.0 inches. This bluegill population is typical of a large semi turbid reservoir
with a fluctuating water level.
Table 23 B.
WHC LMP
GOALS
1999 2000 2001
PSD 40 – 60 46 25 63
RSD-
<9.0
50 63 79 63
9.0 -
10.9
40 31 16 25
> 11.0 10 6 5 12
Wr 90 – 110 96 94 102
CPUE(#/
hr)
53 31 27
The crappie population remains good. The peak of the population is 6.5 to 8.5 inches (55%), 62% were 7.0
to 9.0 inches and 37% were larger than 9.0 inches. 12% of the fish collected were larger than 11.0 inches.
Flesh condition (Wr) was good at 102. The crappie population continues to develop. 37% of the
population would be harvestable if there were a 9 inch minimum length limit.
Table 23 C.
CCF LMP
GOALS 1999
2000 2001
PSD 40 - 60 21 20 33
RSD-15 15 - 20 30 28 37
Wr 90 - 110 95 101 95
CPUE(#/
hr)
21 23 11
Channel Catfish: The channel cat population remains stable. Reproduction and recruitment is good.
Successful spawning has occurred each year since 1995. Length frequency distribution continues to
improve. 34 (11 per hour) fish were collected and 41% were between 5 and 12 inches. 27% were between
12 and 15 inches, 27% were 15 to 20 inches, and 6% were 20 inches or larger. The fish were in good flesh
condition.
92
Table 23 D.
LMB LMP
GOALS
1999 2000 2001
YAR 1-5 - - -
PSD 40 - 70 72 82 67
RSD-18 5 11 9 9
8.0 – 11.9 30 29 22 34
12 - 14.9 32 21 36 24
> 15.0 38 49 42 42
CPUE(#/
hr)
68 66 64 47
< 8.0 18 13 25 7
8 - 11.9 20 17 9 14
12 - 14.9 18 10 14 9
> 15.0 12 26 16 17
Wr 90 - 110 107 107 107
Largemouth Bass: The bass population continues to remain stable. CPUE is below the desired number,
indicating a low density. Reproduction remains low. 14% of the bass collected were 7.9 inches or smaller,
30% were between 8 and 11.9 inches, 20% were 12 to 14.9 inches, and 36% were larger than 15.0 inches.
Of these, 8% were 18 inches or larger. The length frequency distribution is good and will provide good
angling in 2002. The fish are in good flesh condition with an average Wr of 107.
Striped Bass Hybrid: One hybrid striped bass was collected at 5.5 inches in length. None of the larger fish
were collected.
93
Tiger Muskie: No tiger muskie were collected.
Flathead Catfish: 1 fish was collected at 39.5 inches in length.
Table 23 E.
GZS LMP
GOALS
1999 2000 2001
PSD 30 - 60 0 2 8
CPUE(#/hr) 150 384 640 412
<4(#/hr\%) 45 \ 30 95 \ 25 363 \ 57 279 \ 68
4.0 - 5.9 60 \ 40 222 \ 58 224 \ 35 93 \ 23
6.0 - 7.9 30 \ 20 18 \ 5 18 \ 3 22 \ 5
> 8.0 15 \ 10 49 \ 12 35 \ 5 17 \ 4
Wr 90