Edinboro Lake

Management Plan

Submitted by: Edinboro Lake Watershed Association

124 Meadville Street Edinboro, PA 16412

Supported by a Growing Greener Grant

from the Pennsylvania Department of Environmental Protection

June 30, 2009

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Edinboro Lake Watershed Association Board of Directors

Nancy Crawford Jon Foulkrod

Steve Halmi Mary Ann Horne

Gary Jamison Kirk Johnson

Caroline Rhodes Punky Strand

Brian Zimmerman

Lake Keeper John Marchese

Edinboro University Student Interns Barbara Hanes Peggy Mogush

Mission

The mission of the Edinboro Lake Watershed Association is to work for the restoration, protection, enhancement, and sustainable development of the Edinboro Lake watershed.

The ELWA will accomplish this by:

• Involving citizens, landowners, businesses, non-profit organizations, and government in developing and carrying out a plan to ensure the continual improvement of water quality in the Edinboro Lake watershed.

• Raising public awareness of the recreational, cultural, and environmental resources of the watershed.

• Soliciting the funds necessary to carry out its mission from appropriate public and private sources

This report was financed by a Growing Greener Grant provided by the Pennsylvania Department of Environmental Protection (DEP). The views expressed herein are those of the ELWA and do not necessarily reflect the views of the Department of Environmental Protection.

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Table of Contents 1  Introduction and Purpose ..................................................................... 1 2  A Brief History of Edinboro Lake ......................................................... 2 

2.1  Pre‐History, Geology, and Formation of Edinboro Lake ......................................... 2 

2.2  Native Americans .................................................................................................. 3 

2.3  Early Settlement to Mid‐Twentieth Century .......................................................... 3 

2.4  Growing Ecological Awareness ‐ 1970's to present ................................................ 7 2.4.1  The Edinboro Lake Foundation – Nessie Dredging Program.......................................... 11 2.4.2  The Edinboro Lake Watershed Association ................................................................... 11 

2.5  Previous Studies .................................................................................................. 12 

3  Lake and Watershed Characteristics ................................................. 13 3.1  The Limnology of Edinboro Lake .......................................................................... 17 

3.1.1  Thermal Characteristics ................................................................................................. 17 3.1.2  Trophic State ‐ Eutrophication ....................................................................................... 17 3.1.3  Impact of Cultural Eutrophication – Algal Blooms ......................................................... 19 

3.2  Lake Characteristics ............................................................................................ 19 3.2.1  Bathymetry .................................................................................................................... 19 3.2.2  Fish ................................................................................................................................. 21 3.2.3  Aquatic Vegetation ........................................................................................................ 21 3.2.4  Zebra Mussels ................................................................................................................ 22 3.2.5  Bacteria .......................................................................................................................... 23 3.2.6  Sedimentation ................................................................................................................ 23 

3.3  Watershed Characteristics .................................................................................. 28 3.3.1  Soils ................................................................................................................................ 28 3.3.2  Wetlands, the Edinboro Lake Fen .................................................................................. 30 

3.4  Lake Water Quality Data ..................................................................................... 33 3.4.1  Temperature .................................................................................................................. 33 3.4.2  Dissolved Oxygen ........................................................................................................... 33 3.4.3  Alkalinity and pH ............................................................................................................ 35 3.4.4  Nitrogen and Phosphorus .............................................................................................. 35 3.4.5  Secchi Disk Transparency ............................................................................................... 36 3.4.6  Chlorophyll‐a .................................................................................................................. 38 3.4.7  Trophic State Index ........................................................................................................ 39 3.4.8  Total Maximum Daily Loads ........................................................................................... 39 

4  Hydrologic and Pollutant Budgets ..................................................... 40 4.1  Hydrologic Budget ............................................................................................... 40 

4.2  Phosphorus Budget ............................................................................................. 41 4.2.1  Precipitation ................................................................................................................... 41 4.2.2  Groundwater .................................................................................................................. 42 4.2.3  Internal Loading ............................................................................................................. 42 4.2.4  Point Sources ................................................................................................................. 42 4.2.5  Geese and Other Waterfowl .......................................................................................... 44 4.2.6  Non‐Point Sources ......................................................................................................... 44 

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5  A Land use Model of Non-Point Source Pollution ............................ 44 5.1  Land Use and Land Cover .................................................................................... 44 

5.2  Modeling Non‐Point Source Phosphorus Production in the Edinboro Lake Watershed. ......................................................................................................... 48 

5.2.1  Land use Model Results ................................................................................................. 49 

6  Reducing Non-Point Source Pollution ............................................... 51 6.1  Riparian Buffers .................................................................................................. 51 

6.1.1  Riparian Buffer Assessment ........................................................................................... 53 6.1.2  Recommendations: Riparian Buffers ............................................................................. 60 6.1.3  Cost and Benefit of Riparian Buffers .............................................................................. 60 6.1.4  Conservation Easements ................................................................................................ 61 6.1.5  Riparian Buffer Ordinances ‐ Keeping What We’ve Got ................................................ 62 

6.2  Wetlands ............................................................................................................ 63 

6.3  Stormwater Management ................................................................................... 64 6.3.1  The Low Impact Approach to Stormwater Management .............................................. 64 6.3.2  Structural Facilities for Control of Runoff ...................................................................... 65 6.3.3  Roadside Drainage Ditches ............................................................................................ 68 

6.4  Land Use Changes – Residential Development .................................................... 68 

6.5  What can a small property owner can do to reduce phosphorus in  

  Edinboro Lake? ................................................................................................... 70 6.5.1  Lawn Management ........................................................................................................ 70 

7            Are We There Yet? Setting Goals and Tracking Progress in Lake Restoration ......................................................................................... 72 8  Watershed Management Plan ............................................................. 73 9  References ........................................................................................... 75 

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Figures

Figure 2.1 Location of glacial lakes in northwest Pennsylvania ............................................. 2 

Figure 2.2 L.V. Kupper Photograph, Harvesting ice from Edinboro Lake .............................. 4 

Figure 2.3 L.V. Kupper Photograph, team of oxen crossing outlet below concrete dam, mill in background, ca. 1910 ................................................................................... 5 

Figure 2.4 L.V. Kupper Photograph, Duck hunting near lake inlet ca. 1910 .......................... 5 

Figure 2.5 L.V. Kupper Photograph, Trolley heading north past Edinboro Lake, Route #99 ca. 1925 ............................................................................................................................ 6 

Figure 2.6 L.V. Kupper Photograph, Muskie fisherman on lake outlet ca. 1929. ................... 6 

Figure 2.7 Aerial photograph of Ed Bailey’s Lake Isle Estates development now the “fingers” at the north end of Edinboro Lake ca. 1959 ........................................................ 8 

Figure 2.8 Water skiers on Edinboro Lake, 1960’s postcard ................................................. 9 

Figure 2.9 Operation beach cleanup, 1961 ........................................................................... 9 

Figure 2.10 The Canoe Club in 1970, current site of Billings Park. ..................................... 10 

Figure 2.11 A colony of ice fishing shacks on Edinboro Lake ca. 1978 ............................... 10 

Figure 3.1 Edinboro Lake Watershed Boundary. ................................................................. 14 

Figure 3.2 Sub-Basins in the Edinboro Lake Watershed. .................................................... 16 

Figure 3.3 Annual cycle of thermal stratification and overturn in dimictic lakes .................. 18 

Figure 3.4 Nutrient input in oligotrophic, mesotrophic, and eutrophic lakes ........................ 18 

Figure 3.5 Bathymetric map of Edinboro Lake. ................................................................... 20 

Figure 3.6 Zebra Mussel Densities in Edinboro Lake 2001-2008 ........................................ 22 

Figure 3.7 Aerial Photographs of Edinboro Lake 1938, 1950, 1969, 1994 .......................... 24 

Figure 3.8 Historic bathymetric map of Edinboro Lake 1960 ............................................... 26 

Figure 3.9 Historic bathymetric map of Edinboro Lake 1973 ............................................... 27 

Figure 3.10 Sedimentation Rate in Edinboro Lake .............................................................. 28 

Figure 3.11 Soils Map of Edinboro Lake Watershed.. ......................................................... 29 

Figure 3.12 Wetlands in the Edinboro Lake Watershed ...................................................... 31 

Figure 3.13 Graphs depicting seasonal variation in temperature and oxygen versus depth in Edinboro Lake ................................................................................................................. 34 

Figure 3.14 Annual variation in August secchi disk transparency....................................... 37 

Figure 3.15 Seasonal variation in secchi disk transparency ............................................... 37 

Figure 3.16 Seasonal variation in chlorophyll-a ................................................................... 38 

Figure 4.1 Location of sanitary sewer system within the Edinboro Lake watershed ............ 43 

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Figure 5.1 Land cover map of Edinboro Lake watershed.. .................................................. 46 

Figure 5.2 Model relationship between total phosphorus budget and annual precipitation for Edinboro Lake. ........................................................................................................... 50 

Figure 6.1 USDA recommendation for a zoned riparian buffer ............................................ 53 

Figure 6.2 Example aerial photographs used in riparian buffer analysis ............................ 55 

Figure 6.3 Results of riparian buffer analysis for the Shenango North sub-basin ................ 57 

Figure 6.4 Results of riparian buffer analysis for the Conneauttee sub-basin.. ................... 58 

Figure 6.5 Results of riparian buffer analysis for the southern Edinboro Lake watershed sub-basins. ...................................................................................................................... 59 

Figure 6.6 Plan of a typical infiltration basin ........................................................................ 66 

Figure 6.7 Plan and photo of a typical vegetative swale ...................................................... 66 

Figure 6.8 Plan and photo of a typical rain garden installed in a residential development .. 67 

Figure 6.9 Profile of a typical three chambered Water Quality Inlet..................................... 68 

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Tables

Table 3.1 Sub-Basins of the Edinboro Lake Watershed ................................................. 15 

Table 3.2 Soil Permeability by Subwatershed ................................................................. 30 

Table 3.3 Plants of Special Concern Found in Edinboro Lake ....................................... 32 

Table 3.4 Summary of Water-Quality Monitoring 2005-2008 .......................................... 36 

Table 3.5 Trophic State Indices for Edinboro Lake ......................................................... 39 

Table 4.1 Edinboro Lake Hydrologic Budget ................................................................... 40 

Table 4.2 Edinboro Lake Phosphorus Budget ................................................................ 41 

Table 5.1 Land Use in the Edinboro Lake Watershed .................................................... 47 

Table 5.2 AVGWLF-RUNQUAL Model of Phosphorus Loading in Edinboro Lake Watershed .................................................................................................................. 49 

Table 6.1 Recommeded Plants for Riparian Buffer Restoration .................................... 52 

Table 6.2 Invasive Plants of Concern in Northwest Pennsylvania ................................. 52 

Table 6.3 Results of Riparian Buffer Analysis by Sub-Watershed .................................. 56 

Table 7.1 Trophic State and Total Phosphorus as a Function of Total Phosphorus Budget for Edinboro Lake ........................................................................................... 73 

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Maps Included on CD Original copies of this report include a CD containing electronic versions of

maps generated as part of this study. The electronic versions allow the reader to magnify the maps to observe details that were not reproducible in the printed report. Instructions for reading the files are included on the disk.

Maps from report Figure 3.1 Edinboro Lake Watershed Boundary

Figure 3.2 Sub-basins within Edinboro Lake Watershed

Figure 3.5 Edinboro Lake Bathymetry

Figure 3.11 Edinboro Lake Watershed Soil Permeability

Figure 3.12 Wetlands within Edinboro Lake Watershed

Figure 5.1 Edinboro Lake Watershed Land Cover

Figures 6.3, 6.4, 6.5 Air photo with Riparian Quality

Additional map files not included in the printed report: Land Cover with Riparian Buffer Quality Overlay

Soil Permeability with Riparian Buffer Quality Overlay

Edinboro Lake Watershed Topography

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Acknowledgements This report was financed by a Growing Greener Grant provided by the Pennsylvania

Department of Environmental Protection (DEP). The Edinboro Lake Watershed Association (ELWA) would like to particularly acknowledge the assistance of Lisa Baughman, our DEP project advisor. Barb Lathrop of Pennsylvania DEP provided useful comments regarding the initial draft of the report. The views expressed herein are those of the ELWA and do not necessarily reflect the views of the Department of Environmental Protection.

The ELWA acknowledges the support Edinboro University of Pennsylvania for this project. The University provided access to its Geographic Information System (GIS) computer lab, scientific equipment including the pontoon boat used in monitoring Edinboro Lake, as well administrative support. Dr. Richard Deal, Department of Geosciences, who oversees the GIS lab, provided advice for the GIS cartography and modeling presented in the plan. Dr. Laurie Parendes, Department of Geosciences, and Dr. John Ashley, Department of Biology and Health Services, provided data regarding zebra mussels and algae in Edinboro Lake. Dave Obringer provided access to the collection of Edinboro Lake historical photographs housed in the Baron-Forness Library archives.

The ELWA also acknowledges the administrative support of the Home Rule Borough of Edinboro. We would especially like to thank Marie Lander for making sure that our student interns were paid in a timely fashion.

A number of individuals contributed to writing, reviewing, and assembling this report. Caroline Rhodes wrote Chapter 2 which outlines the history of Edinboro Lake and collected historical photographs from the Edinboro Area Historical Society archives. Peggy Mogush and Barb Hanes completed the GIS analysis of riparian buffers within the watershed and contributed to section 6.1. The GIS computer cartography included in this report was performed by Peggy Mogush who also assisted with the final editing and formatting of the report. Steve Halmi contributed to the discussion of stormwater management in the watershed contained in section 6.2 and provided a critical review of the final document. The remainder of the document was written and edited by Dr. Brian Zimmerman, Department of Geosciences, Edinboro University of Pennsylvania.

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Executive Summary

A plan for the restoration and management of the Edinboro Lake Watershed (ELWA) has been completed under a Pennsylvania Growing Greener Grant. The proposed plan evaluates the current condition of Edinboro Lake, assesses the condition of riparian buffers within the watershed, and uses a land use model to identify and quantify non-point sources of phosphorus. Based on this assessment, a plan, consisting of recommendations for riparian buffer restoration and stormwater management has been developed for the watershed. Additional recommendations for best management practices which may implemented by small property owners have also been included.

Current condition of the Edinboro Lake Watershed

Edinboro Lake is a natural lake of glacial origin which has been modified by the construction of a dam which raises the lake level by 8 to 10 feet. Edinboro Lake is classified as a eutrophic lake. High concentrations of plant nutrients, particularly phosphorus, cause an over-abundance of algae and other plant growth in the lake. When the algae die they sink to the bottom and decay. The decaying algae cause the depletion of oxygen from water in the deepest part of the lake. Eutrophication is a natural process which occurs in lakes as they age. This natural aging process should take tens of thousands of years for a lake the size of Edinboro Lake. Humans typically accelerate this aging in a process known as cultural eutrophication. By polluting the lake with excess levels of nutrients, algae and plant growth increases significantly and the lake fills with partially decayed organic matter. The sources of excess nutrients include runoff from agricultural areas and over-fertilized lawns, septic and sewage treatment systems within the watershed, stormwater runoff from roads and parking lots, and internal release from lake sediments. Cultural eutrophication is one of the most common water quality issues in the world today. The effects of eutrophication include loss of water clarity and the loss of valuable game fish in favor of less desirable species which can tolerate lower oxygen levels in the lake water. In addition to being detrimental to the overall health of Edinboro Lake and its ecosystems, cultural eutrophication also negatively impacts the recreational use of the lake limiting the economic benefits of the lake to the local community. Studies have shown that cultural eutrophication is controlled by the amount of phosphorus in the lake water. Reducing cultural eutrophication of Edinboro Lake will require reducing the amount of excess phosphorus that enters the lake from the surrounding watershed.

Approximately 81% of the phosphorus entering Edinboro Lake is derived from non-point sources which include all of the phosphorus that enters the lake as surface runoff from the watershed. A land use Geographic Information System model of the watershed indicates that 28% of the non-point source phosphorus is derived from runoff from agricultural land. Runoff from land containing row crops accounts for a majority of this total (18.7%) with the remainder (9.3%) derived from hay fields and pasture land. The other major non-point source of phosphorus within the watershed is storm runoff from developed land accounting for 17.4% of the total. Other major non-point sources of phosphorus include transitional land (10.2%) and farm animals (11.6%).

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Riparian Buffers Riparian buffer zones are vegetated areas directly adjacent to a stream which reduce

the amount of rainwater runoff into the stream and allow water to infiltrate the ground. All streams, no matter the size, can benefit by having a vegetated buffer zone. Depending on the width and quality of the buffer zone, as much as 50-100% of the sediments can settle out before entering the stream. Excess phosphorus bonds to soil particles and up to 80-85% of total phosphorus from runoff can be captured and retained within a buffer zone. Using aerial photographs to assess the condition of riparian buffers reveals that there are 29.4 miles of streams representing 44.5% of the total stream length within the watershed which lack riparian buffers of a minimum 35 foot width. Buffers of greater than 150 feet are currently present on 29.5%, or 19.4 miles of streams in the watershed.

Stormwater Management Stormwater runoff is a manageable source of pollution. Traditionally, stormwater management meant controlling the rate of flow to eliminate flooding. Current stormwater management techniques include best management practices which improve water quality and promote groundwater recharge in addition to reducing peak flow rates. Reducing the amount of phosphorus entering Edinboro Lake from stormwater runoff will require a combination of the following: 1) controlling the peak rate of runoff derived from the watershed, 2) reducing the volume of runoff entering the lake, and 3) removing phosphorus from runoff before it enters the lake.

Best Management Practices for Residential Property Owners There are many relatively easy and inexpensive steps that the average residential homeowner can take to reduce the amount of phosphorus entering the lake. Even if the water leaving your property is relatively clean and free of pollutants, the excess runoff will result in increased erosion of sediments “downstream” ultimately resulting in higher amounts of phosphorus and other pollutants entering the lake. Best management practices for small residential property owners include: 1) the use of no-phosphorus lawn fertilizer, 2) the use of gravel and paving stones instead of concrete for driveways, walkways, patios, etc. to minimize impervious surfaces, 3) the use of vegetated berms and swales to redirect runoff from impervious surface into areas where it can soak into the ground, 4) directing water from downspouts and sump pumps into lawn areas or rain gardens rather than directly onto an impervious surface or into a roadside ditch or storm drain.

Management Plan Recommendations A series of recommendations are presented which together constitute a

management plan to reduce the annual phosphorus load and improve the trophic state of Edinboro Lake. The recommendations of this plan are as follows:

1. Riparian buffers of a minimum width of 35 ft should be restored on all streams in the Edinboro Lake watershed. Where adequate buffers already exist steps must be taken to ensure that these are preserved.

2. The ELWA should work with landowners to increase the use of conservation easements as a means of establishing and protecting riparian buffers within the watershed. The ELWA will accomplish this by providing information and assistance to landowners interested in obtaining easements on their property. The ELWA should establish a working group to explore the possibility of setting

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up a land trust or partnering with an existing conservancy to establish a mechanism for funding easements within the watershed.

3. The ELWA should work with Edinboro Borough, Washington Township, and Franklin Township officials to develop a Riparian Buffer Ordinance in order to ensure the preservation of existing buffers and provide for the establishment of new buffers as development occurs within the Edinboro Lake watershed.

4. The ELWA should work to educate property owners regarding the nature and importance of wetlands within the Edinboro Lake watershed. This effort should include developing printed educational materials to be distributed to those seeking building permits within the watershed.

5. The ELWA should work with Washington Township, Borough of Edinboro, and Franklin Township to promote planning and development that follows conservation design principles and low impact development approaches such as riparian buffers, minimizing impervious surfaces, clustered development, reforestation, and other non-structural and structural stormwater management Best Management Practices (BMPs).

6. The ELWA should participate in the upcoming updates of stormwater management ordinances that will be required by Erie County following the conclusion of the Erie County stormwater management study. ELWA should provide recommendations for the ordinances particular to the betterment of the Edinboro Lake watershed. Such recommendations should include a mandatory zero net increase in particulate, phosphorus, and nitrate loads, consistent with the water quality control guidelines of the Pennsylvania Stormwater BMP Manual.

7. The ELWA will develop educational materials which describe stormwater BMPs for planning and construction of residential areas to be distributed to individuals seeking building permits within the watershed. The ELWA should establish specific examples of BMPs throughout the watershed to be used as models for others to follow.

8. The ELWA should provide technical guidance and administrative support for stormwater management activity funding requests by Washington Township and/or the Borough of Edinboro. The ELWA should work closely with the Pennsylvania Department of Environmental Protection to achieve a priority status for watershed project applications to receive funds from the Growing Greener program and other programs that fund educational programs, nutrient reduction, and establishment of BMPs. The ELWA should also suggest appropriate stormwater BMP retrofit projects for the improvement of existing stormwater conveyance and detention systems.

9. The ELWA should implement an on-going education program to inform watershed residents of the benefits of lawn care best management practices, particularly the use of phosphorus free lawn fertilizers.

10. The ELWA should expand its current monitoring program in order to more accurately track progress in the restoration of Edinboro Lake.

Restoration of Edinboro Lake is not going to happen overnight. The current condition of the lake is the result of over 200 years of human habitation and alteration of the watershed. Highest priorities should be given those tasks that offer pre-emptive

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protection and restoration such as implementing and updating riparian and stormwater ordinances. Second priority should be given to those tasks that result in a measurable decrease in the phosphorus budget of the lake such as riparian buffer restoration and retrofitting stormwater BMPs. The recommendations found within this report have been implemented successfully at other watersheds in our region and provide a feasible, cost effective means by which water quality in Edinboro Lake can be improved.

Edinboro Lake is the centerpiece of our community. It provides us with opportunities for recreation, is an important economic asset, and an irreplaceable natural resource. Just as we enjoy using the lake for fishing, boating, and swimming, we can also take pride in watching the lake improve due to our efforts to restore it.

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1 Introduction and Purpose The Edinboro Lake watershed consists of approximately 17 square miles (10,880 acres) in southern Erie County, Pennsylvania. Edinboro Lake, the centerpiece of the watershed, is a valuable ecological and economic asset for the region. Year round activities centered on the lake include boating, swimming, angling, and hunting. The watershed includes a variety of biologically important ecosystems including over 50 acres of exceptional value wetlands. The Western Pennsylvania Conservancy (WPC) considers the shrub fen at the northeast corner of the lake to be a natural community of global significance (WPC, 2000). Edinboro Lake and its outlet, Conneauttee Creek, are a significant sub-basin of the French Creek Watershed, accounting for approximately 5 percent of its total area. French Creek is considered to be one of the most ecologically significant watersheds in the state.

Edinboro Lake is classified as a culturally eutrophic lake (see Section 3.1.2). High concentrations of plant nutrients, particularly phosphorus, cause an over-abundance of algae and other plant growth in the lake. When the algae die they sink to the bottom and decay. The decaying algae cause the depletion of oxygen from water in the deepest part of the lake. Other effects of cultural eutrophication include loss of water clarity and the loss of valuable game fish in favor of less desirable species which can tolerate lower oxygen levels in the lake water.

The basic water quality issues within the Edinboro Lake watershed have been known for at least 30 years. Yet despite a great deal of public interest and support, progress in improving the condition of the lake has been slow. The primary reason for this lack of progress is that there is currently no sustainable plan for restoring and maintaining Edinboro Lake. The purpose of this report is to recommend a sustainable plan for the restoration and management of the Edinboro Lake watershed. This is not meant to be a comprehensive plan but rather a plan to address cultural eutrophication, which we believe to be the most significant threat to the overall health of Edinboro Lake. Many of the steps recommended for reducing cultural eutrophication of the lake will also help address other water quality issues such as excessive sedimentation and bacterial contamination. For the plan to be sustainable it must be economically feasible while improving and maintaining water-quality within the watershed into the future.

This report has been written for the residents of the Edinboro Lake watershed, those who use the lake for recreation, and anyone who has an interest in improving and caring for Edinboro Lake. Think of this as your lake “owner’s manual”. We have attempted to provide you with the background information you need to understand the issues and problems that threaten the lake. We have also laid out the simple steps that we can take both as individuals and as a community to improve water quality within the lake watershed. We hope that you will use this information to become active in helping us to restore, protect, and manage Edinboro Lake.

While the focus of this report is on problems and their potential solutions, we should not lose site of the many benefits of having Edinboro Lake within our community. One common misconception is that the lake is broken beyond repair and therefore not worth the effort. This is simply not true. If we make a list of what is “right” with Edinboro Lake and what is “wrong”, the first list will be much longer than the latter. So as you begin to think about what can be done to restore the lake, be sure and take some time to enjoy

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the lake. The real purpose of this document is to ensure that your great grandchildren can do the same.

2 A Brief History of Edinboro Lake 2.1 Pre-History, Geology, and Formation of Edinboro Lake Edinboro Lake is one of 8 glacial kettle lakes in northwestern Pennsylvania (Figure 2.1) (Grund and Bissell, 2004). Kettle lakes form when a block of ice breaks from the front of a retreating glacier. The block of stagnant ice is subsequently buried in sediments deposited from glacial melt water. When glacial activity is complete a topographic depression is left marking the location where the ice block slowly melted. If the bottom of the topographic depression is below the regional water table it will fill with water to form a kettle lake.

Figure 2.1 Location of glacial lakes in northwest Pennsylvania (Grund and Bissell, 2004)

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Continental glaciers entered northwestern Pennsylvania seven times during the Pleistocene Epoch which began 1.8 million years ago and ended 10,000 years before the present (Shepps et al., 1959). During the Lavery advance two lobes of ice approached Edinboro from the north. One lobe of ice moved south down the Shenango Creek valley and a larger lobe moved from McLane into the Conneauttee Creek valley (Shepps et al., 1959). At the southern end of these ice lobes a morainal kame was deposited. The morainal kame forms the low gravel hills that surround Edinboro Lake to the southeast including the locations of the Edinboro Cemetery and Edinboro Mall. A block of ice broken from one of the two lobes formed the Edinboro Lake kettle immediately north of the morainal kame. Formation during the Lavery ice advance suggests an age of approximately 19,000 years for Edinboro Lake (Weinreich, 2006).

2.2 Native Americans Because no professional archeological studies have been conducted in the Edinboro Lake area, there is no documented evidence of settlement here by native people. However, during the 19th and 20th centuries, local residents found numerous arrowheads as they plowed fields or excavated the ground. These artifacts were not studied in context, but they do suggest that native people may have lived or passed through this area. The bifurcate style of the arrow points indicates a Early or Middle Archaic age suggesting that Native Americans may have been in the area of Edinboro Lake as early as 9,000 years ago (LERC, 2008, D. Pedler pers. com.).

This area lies west and south of the territory of the Seneca nation of the Iroquois Confederation. The native American name for Edinboro Lake, its outflow creek and the surrounding valley was “Conneauttee’, which is said to mean the “valley of the living snowflake” (Marsh, 1976). Here winter weather still comes early and snow lasts long, so residents acknowledge that the name is still appropriate.

2.3 Early Settlement to Mid-Twentieth Century In keeping with attitudes of the time, all natural resources, including water, trees,

land, and animals were considered available for human use. Indeed, those settlers and entrepreneurs who saw the possibilities and developed them for profit and economic growth were greatly honored.

This corner of Northwestern Pennsylvania, like the rest of the lands west of the Appalachians, had not been settled during colonial times. However, George Washington’s report of his expedition in 1753, from Virginia to the French commander at Fort LeBoeuf, publicized the existence of the fertile valleys and seemingly limitless timber resources in the area. After the New York/Pennsylvania boundary was settled, and the new Constitution ratified, Congress assigned ownership of vast tracts of this land to the Holland Land Company as repayment for war loans.

One of the Holland Land Company’s surveying parties came to Edinboro Lake in 1795. The group included William Culbertson, from Williamsport, who purchased a thousand acres, and hastily built a cabin on the south shore of Edinboro Lake, just east of the outlet. The next year he returned with his wife and child. His goal was to encourage settlement and sell land, so in 1802 he constructed a split timber dam at the narrow outlet of the lake which provided the power for both a grist mill and a saw mill. Other pioneer settlers came from Williamsport, including the Hamiltons, Campbells, and Reeders. By 1805 there were 50 settlers. Most had begun clearing land for farms in the fertile valley surrounding the lake (Marsh, 1976).

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The population grew: Edinboro Borough was incorporated in 1834; the state Normal School was founded in 1859 as the first teacher preparatory school west of the Appalachians. The 1862 History of Erie County listed Edinboro industries: “two cooper shops, two for the manufacture of sashes and blinds, one for shovel handles, three of cabinet ware, a tannery, a grist mill, a sawmill and a tin shop”. (Marsh and Nordberg, 1989) The lake was not only a source of water power; its thick winter ice was harvested, stored nearby and sold during the summer.

Figure 2.2 L.V. Kupper Photograph, Harvesting ice from Edinboro Lake (Edinboro University of Pennsylvania Archives)

By 1910 the population was nearly a thousand. Hotels, livery stables, retail stores, a bank and four churches had been established. (Marsh and Nordberg, 1989) Over the years the lake was enlarged as a series of newer and higher dams were constructed (Boker, 1978). Wilber Billings constructed the current concrete dam in 1922 raising the lake level by 8 to 10 feet, flooding the undeveloped, forested land on the northeastern and northwestern shores. A trolley line linked Erie, Edinboro and Cambridge Springs where there was access to the national railroad network. The Borough established water and sewer services. An automobile dealership opened. Local manufacturing was gradually supplanted, but agriculture remained an important economic activity, augmented by tourism, education and local business

Edinboro Lake’s recreational potential developed after 1914, when C. Wilber and Mabel Billings subdivided their land on the southwestern shore. They offered many small lots for sale or rent for summer camping or for building simple cottages, and named it Lakeside. The lake’s reputation for good swimming, fishing and boating particularly attracted vacationers from Pittsburgh (Larry Cole, 1999). After World War I local business people advertized cottage sales and summer rentals. There is a historic postcard, praising the pleasures of the lake, preserved in the Harrison Collection of local photographs at the Edinboro University Archives. Separate summer camps for boys and girls established in the 1920's on Culbertson Co. land were successful until the

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Figure 2.3 L.V. Kupper Photograph, team of oxen crossing outlet below concrete dam, mill in background, ca. 1910 (Edinboro Area Historical Society).

Figure 2.4 L.V. Kupper Photograph, Duck hunting near lake inlet ca. 1910 (Edinboro University of Pennsylvania archives)

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Figure 2.5 L.V. Kupper Photograph, Trolley heading north past Edinboro Lake, Route #99 ca. 1925. (Edinboro Area Historical Society)

Figure 2.6 L.V. Kupper Photograph, Muskie fisherman on lake outlet ca. 1929. The 1862 Erie County History notes that Edinboro Lake was known for beautiful water lilies. (Edinboro Area Historical Society)

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depression. Then in 1938 Sox Harrison began his popular co-educational Sunset camps on the eastern shore which he ran until 1961 (Marsh and Nordberg, 1989).

L. V. Kupper was a noted local photographer who captured Edinboro scenes in all seasons, over a period of about 50 years (Marsh, 1976). The Lake was one of his favorite settings. Although his earliest work was destroyed in a fire in 1905, the Edinboro University Library Archives and the Edinboro Area Historical Society have preserved his remaining glass plate negatives from which many photos that illustrate the lake in the first half of the 20th Century have been made. Edinboro University professors John Marsh, Karl Nordberg, and more recently, archivist David Obringer have worked to estimate the dates, subjects and exact locations for them. These pictures reveal that the lake’s wild northern shores (inlet areas) remained undeveloped and available for hunting and recreation until after World War II.

In the late 1950’s the northern shoreline of the lake was extensively modified by a dredging operation. Following construction of the current dam and stabilization of the lake level at its current elevation in 1922, the north end of the lake began filling with sediment and developed into an extensive wetland area. A network of channels known as the “Fingers” was dredged in this area beginning in 1957 (Boker and Hallenberg, 1978) (Figure 2.7). The mouths of Shenango and Whipple creeks were also dredged and the position of the Shenango creek outlet was changed. Peat from the dredged areas was sold and the remaining material was shaped into a series of peninsulas designed for residential development. Fill used to construct the peninsulas was observed to include broken concrete and asphalt pavement, roofing shingles, tree stumps, rusted oil drums, a refrigerator, barge, and the hull of a speedboat (Boker, 1978). The new channels accelerated the flow of water from the tributaries resulting increased rates of sedimentation within portions of Edinboro Lake.

2.4 Growing Ecological Awareness - 1970's to present In keeping with advancing environmental knowledge, Edinboro and Washington Township residents slowly recognized the lake’s problems and began seeking solutions. By 1970 Edinboro had changed from being a primarily rural town with a summer resort and a small teacher’s college to a more complex, fast growing community. The construction of Interstate 79 along the western ridge of the watershed in 1966 connected the area to Erie, Pittsburgh and beyond. Anecdotal reports suggest that erosion during the construction phase of the Interstate washed large quantities of silt downhill to the lake. A consolidated school district was created, combining 2 boroughs and 3 townships. Franchise businesses began to replace local retail stores, banks and inns. Edinboro State College, on its way to becoming a university, had grown and attracted hundreds of new faculty and staff to the area sparking increased housing development, first in Valley View subdivision, then on the eastern lake shore where the Sunset camps had been, and all along Angling Road and the previously undeveloped northwestern shore and uplands. The increasing population required improvements to the wastewater treatment facilities within the community. An opportunity for a 201 Facilities Plan to create a joint sewage operation failed after a series of meetings and public hearings in the late 1970's. Washington Township built and began operating the Angling Road Wastewater Treatment facility for the developments on the northwestern side of the lake, discharging treated wastewater into Whipple Creek, a tributary of Edinboro Lake.

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Figure 2.7 Aerial photograph of Ed Bailey’s Lake Isle Estates development now the “fingers” at the north end of Edinboro Lake ca. 1959 (Edinboro University of Pennsylvania archives)

The seasonal character of Lakeside changed. Some cottage owners, who retired from their city jobs, remodeled their summer places into permanent homes. Others were eager to rent their summer places to college students during the school year, so they insulated and enlarged them.

In 1980, the Borough of Edinboro had a population of 7,000 and the University leveled its numbers at about 7,000 students. Edinboro Lake was a community asset that was well used. The Borough maintained public beaches, installed and rented dock spaces, built a boat launch and provided free boat trailer parking. The Canoe Club (Figure 2.10) was purchased with grant money, and the Borough sponsored a youth recreation program for a period of time. On summer days, the lake was filled with motor boats, many pulling water skiers.

Awareness of the Lake’s emerging problems dawned slowly. It began with anecdotes from long time local residents. “The lake used to be clearer and deeper”. “There used to be more large fish”. “Algae and weed growth have become worse”. About 1973, Mayor Greg Lessig asked Dr. Dan DiFigio of the Edinboro University of Pennsylvania science department to do a study of the Lake for the Borough. That report diagnosed the problem of eutrophication and sounded an alarm about a “dying lake”, filling with silt. The most controversial recommendation was for a restriction on the size of boat motors. That brought out Lakeside Association members plus dozens of other boaters in protest, and was not implemented.

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Figure 2.8 Water skiers on Edinboro Lake, 1960’s postcard (Edinboro Area Historical Society)

Figure 2.9 Operation beach cleanup, 1961 (Edinboro University of Pennsylvania Archives)

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Figure 2.10 The Canoe Club in 1970, current site of Billings Park. (Edinboro Area Historical Society)

Figure 2.11 A colony of ice fishing shacks on Edinboro Lake ca. 1978 (Edinboro University of Pennsylvania Archives).

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2.4.1 The Edinboro Lake Foundation – Nessie Dredging Program

As concern for the health of the lake grew, a small group of citizens formed “SOLE” - Save our Lake Edinboro and held public discussions about the lake. Edinboro University professor Thomas Legg, a limnologist, provided helpful information. Both volunteer and municipal actions were proposed. It seemed possible to tackle the weed problem by “harvesting” and taking the weed mass to an onshore location, so that it wouldn’t sink and decay, thus reducing the oxygen. For two seasons the Borough crew used a weed harvester propelled by a motor boat, however, the process proved to be cumbersome, time consuming and generally ineffective. A more ambitious idea came in the late 1980's. If sedimentation was the problem, perhaps the solution could be to dredge the swimming areas and boating channels and get some of the bottom, oxygen starved layer of sediment out of the lake. An anonymous gift created the Edinboro Lake Foundation which purchased the “Nessie”, a vacuum style dredge system, to pump the watery slurry of sediment from the bottom, through long pipes, to drying beds on private land. Both the Borough and Township co-operated. Community fund raising efforts by Mayor Kip Allen and the Foundation Board (R. Halmi, E. Koon, R. Sanders, F. Curtze, J. Rummel) created the fictitious and humorous Edinboro Yacht Club logo. They raised awareness as well as money to continue the work for several years. At this time, John Marchese volunteered to be the “Lake Keeper” and made important contacts with state agencies. Dredging occurred between 1989 and 1994 primarily in the early spring and late fall so that the floating dredge pipe did not interfere with recreational boating. Dredging targeted shallow areas along Lakeside Drive and within the “fingers” at the north end of the lake. Details of the dredging operation can be found in an unpublished report by Tom Warner, dredge operator, and project manager:

“There is a natural gravel layer that extends from the shore to the middle of the lake. In actual practice we are removing everything down to this layer, including a layer of silt, a layer of decaying organic matter (resembling peat moss), and, often, a layer of blue clay. Where the gravel lies deeper, we are dredging to a depth of 10 feet below the water level. From this, one deduces that as much as 5.5 feet of undesirable bottom material has been removed.” (Warner, 1989)

The Nessie dredging operations principle objective was to remove enough bottom material to curtail the growth of unwanted plants. Secondary benefits included improved fish habitat and removal of fine silt from swimming areas. Stumps and logs encountered were left in place as cover for fish. The initial dredging design indicates that as much as 45,000 cubic yards of material were removed.

2.4.2 The Edinboro Lake Watershed Association

A report on the health of Edinboro Lake released in 2000 by the Western Pennsylvania Conservancy (WPC, 2000) encouraged the formation of watershed associations to involve citizens and stakeholders in the process of improving water quality. The last action of the Edinboro Lake Foundation was to apply for a Growing Greener grant to establish an Edinboro Lake Watershed Association (ELWA). The

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ELWA consists of a Board of Directors, representing the key entities that have the most to gain by an improved lake, including Edinboro Borough, Washington Township, Franklin Township, Edinboro University, the General McLane School District, the Lakeside Association, as well as volunteer directors from the community.

The mission of the ELWA is to work for the restoration, protection, enhancement, and sustainable development of the Edinboro Lake watershed. Since its founding in 2004 the ELWA has been active in advising the community on issues related to the improvement of water quality in Edinboro Lake. The ELWA has organized annual community meetings with invited expert speakers to discuss key lake issues, established an annual spring lake clean-up, recommended the use of annual lake draw downs as a mechanism for controlling zebra mussel populations, implemented a volunteer water quality monitoring program, and completed a Growing Greener grant funded phosphorus budget for Edinboro Lake.

2.5 Previous Studies A variety of studies and reports regarding the condition of Edinboro Lake have been prepared over the past 40 years. Historical lake water quality data was collected and reviewed as part of this investigation. The following reports are the primary sources of historical water quality for Edinboro Lake:

DiFigio, 1972, Preliminary Report on a Ecological Study of Edinboro Lake. This report submitted to Edinboro Borough Council includes information on fish, water quality, eutrophication, and sedimentation in Edinboro Lake.

Wise , 1975, The Phytoplankton Population and Selected Physical-Chemical Properties of Edinboro Lake in the Autumn of 1974. This study, conducted as a Masters of Sciences thesis at Edinboro University, provides an excellent “snapshot” of the chemical and physical conditions of Edinboro lake in 1974.

Boker and Hallenberg, 1978, Edinboro Lake Sensitivity Study report prepared for Washington Township Sewer and Water Authority. The study focuses on the area where Shenango and Conneauttee Creeks enter the lake which is currently the site of Peninsula Park managed by Washington Township.

Hartman ca. 1980, A phase-1 diagnostic feasibility study of Edinboro Lake, Erie County, Pennsylvania. A proposal for the Conneauttee council of governments. This report includes information on the physical characteristics, water chemistry, biology, and trophic state of Edinboro Lake.

U.S. Environmental Protection Agency, 1981, Draft Environmental Impact Statement on wastewater facility planning in the Borough of Edinboro and Washington Township, Erie County, Pennsylvania. This a comprehensive report on Edinboro Lake and the surrounding communities. Included are extensive appendices with data on population, water quality, history, geology, soils, biology, and land use within the watershed.

Wellington, 1991, 1996, Edinboro Lake Trophic State Analysis. Periodic trophic state monitoring conducted by Erie County Department of Health.

Western Pennsylvania Conservancy (WPC). 2000. Summary report; health and management of the Edinboro Lake ecosystem. This report, prepared on behalf of Edinboro Regional Community Services, Inc., includes a comprehensive assessment of the Edinboro Lake ecosystem.

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Grund and Bissell. 2004. Laying the Groundwork for Community Based Conservation Planning for Western Pennsylvania’s Glacial Lakes: Documenting The Native and Introduced Flora Associated with Glacial Lakes in Northwest Pennsylvania with Emphases on Rare Species and Invasive Alien Species. This report includes information on water quality in addition to thoroughly documenting the distribution of aquatic and emergent plants within Edinboro Lake.

Ostrofsky, Bodamer, Butkas, and McMillen, 2004, A Trophic Assessment and Phosphorus Budget for Edinboro Lake Erie County. PA. This investigation, which was funded by a Pennsylvania Growing Greener grant to the ELWA includes bi-weekly trophic state monitoring data, a detailed water budget, and a brief discussion of land use within the watershed.

Mauro, and Covert. 2008. Edinboro Lake Study 2008. This report includes data on bacteria concentrations in Edinboro Lake.

3 Lake and Watershed Characteristics A watershed is the total land area from which surface water drains into a given

stream or lake. The Edinboro Lake watershed includes an area of approximately 17 square miles (10,867 acres) in southern Erie County, Pennsylvania which incorporates portions of Washington and Franklin Townships and the Borough of Edinboro (Figure 3.1). Elevations within the watershed vary between 1625 feet and 1197 feet above mean sea level. The elevation of the lake surface is 1197 feet above mean sea level and the surface area of the lake is 267 acres. The lake watershed can be divided into 12 sub-basins (Figure 3.2 and Table 3.1). This includes the 11 tributary streams which drain into the lake. Only three of the tributary streams (Shenango, Conneauttee and, Whipple) have been formally named. The names of the other sub-watersheds have been applied for this study. Some of these streams (Elm Street, Crawford Beach) have been partially enclosed and incorporated into the storm sewer system. The 12th sub-basin (Lake Adjacent) includes the area immediately surrounding the lake shore which drains directly into the lake rather than into a tributary stream.

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Figure 3.1 Edinboro Lake watershed boundary. Data Sources: Stream base map: Modified from Erie County Government Department of Planning (2005), Road layers: Pennsylvania Department of Transportation (2007). Accessed via Pennsylvania Spatial Data Access, http://www.pasda.psu.edu/default.asp , Watershed boundaries: Ostrofsky et al. (2004). An enlarged version of this map is available on the accompanying CD.

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Table 3.1 Sub-Basins of the Edinboro Lake Watershed. Population data from Ostrofsky, et al., 2004.

Sub-Basin Catchment Area Population Population

Density Acres individuals individuals/acre

Elm Street 196.8 359 1.8 Crawford Beach 99.9 170 1.7 Whipple Creek 779.9 403 0.5 Shenango South 543.5 116 0.2 Shenango North 3,306.6 366 0.1 Conneauttee Creek 4,232.2 482 0.1 Highway 99 32.7 0 0.0 Scarlett Seep 1 20.9 0 0.0 Scarlett Seep 2 13.3 0 0.0 Scarlett Seep 3 13.3 0 0.0 Scarlett Seep 4 347.6 54 0.2 Lake Adjacent 1,280.0 1,972 1.5 Total Watershed 10,866.8 3,922 0.4

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Figure 3.2 Sub-basins in the Edinboro Lake watershed. Data sources: Stream base map: Modified from Erie County Government Department of Planning (2005), Road layers: Pennsylvania Department of Transportation (2007). Accessed via Pennsylvania Spatial Data Access, http://www.pasda.psu.edu/default.asp , Watershed boundaries: Ostrofsky et al. (2004). An enlarged version of this map is available on the accompanying CD.

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3.1 The Limnology of Edinboro Lake

3.1.1 Thermal Characteristics

Lakes in temperate climates such as that of northwestern Pennsylvania are typically “dimictic”. A dimictic lake is one in which the there are two “turn-over” or mixing periods each year during which the lake water becomes thermally and chemically homogenous. These two mixing periods are separated by periods during which the lake is thermally layered or stratified (Figure 3.3). Edinboro Lake is typical of lakes in the region and becomes thermally stratified during the summer and then again during winter months. From May to October sunlight forms a layer of warm water at the surface of the lake which is separated from cooler, more dense water at the lake bottom. The boundary between the warm surface water and colder bottom water is called the thermocline and typically occurs at a depth of 3-4 meters (10 feet) in Edinboro Lake. The upper layer of stratification is called the epilimnion and the lower layer is called the hypolimnion. During the period when this stratification exists there is very little mixing of these layers across the thermocline. This isolates the water in the bottom layer and prevents it from exchanging oxygen with the atmosphere.

As the surface of the lake cools in the fall, water in the epilimnion becomes more dense and sinks through the thermocline to the lake bottom. Eventually the thermocline becomes unstable and the lake “turns-over”. This fall turn-over is often a sudden event which typically occurs overnight during the last week of September or the first week of October each year. Following the fall turn-over, the lake cools and mixes almost every night. Unseasonably warm weather may result in temporary formation of a thermocline. Thermal stratification returns during the winter when Edinboro Lake is ice covered. Unfrozen water is warmer and more dense than the ice and therefore sinks to the lake bottom. During this period the temperature of the water below the ice is a near constant 4o centigrade (39o Fahrenheit). Following the disappearance of the ice the lake again mixes almost daily until late April or early May when the summer thermocline forms and the cycle begins again. Edinboro Lake does not freeze every winter and the lake remains uniformly mixed during ice-free winter periods.

3.1.2 Trophic State - Eutrophication

Scientists categorize lakes according to the amount of algae and other plant growth that occurs within the lake water which is controlled by the availability of plant nutrients (phosphorus and nitrogen). Lakes with low concentrations of nutrients and therefore little plant productivity are referred to as oligotrophic. Highly productive lakes with high concentrations of nutrients are called eutrophic. Lakes with intermediate levels of nutrients and plant growth are mesotrophic (Figure 3.4).

Edinboro Lake is classified as a eutrophic lake. High concentrations of plant nutrients, particularly phosphorus, cause an over-abundance of algae and other plant growth in the lake. When the algae die they sink to the bottom and decay. The decaying algae cause the depletion of oxygen from water in the deepest part of the lake. Other effects of eutrophication include loss of water clarity and the loss of valuable game fish in favor of less desirable species which can tolerate lower oxygen levels in the lake water.

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Figure 3.3 Annual cycle of thermal stratification and overturn in dimictic lakes (Pipkin et al, 2005)

Figure 3.4 Nutrient input in oligotrophic, mesotrophic, and eutrophic lakes (Pipkin et al, 2005)

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All lakes change with time. Lakes such as Edinboro Lake, with glacial origins and temperate climates typically start out oligotrophic and quickly become eutrophic. With time lakes gradually fill with sediments and organic matter eventually becoming wetlands which in turn evolve into dry land. This natural aging process should take tens of thousands of years for a lake the size of Edinboro Lake. Humans typically accelerate this aging in a process known as cultural eutrophication. By polluting the lake with excess levels of nutrients, algae and plant growth increases significantly and the lake fills with partially decayed organic matter. The sources of nutrients include runoff from agricultural areas and over-fertilized lawns, septic and sewage treatment systems within the watershed, stormwater runoff from roads and parking lots, and internal release from lake sediments. Cultural eutrophication is one of the most common water quality issues in the world today. Studies have shown that cultural eutrophication is controlled by the amount of phosphorus in the lake water (Ostrofsky et al., 2004). Plant growth within the lake will continue until the supply of phosphorus is exhausted. Reducing cultural eutrophication of Edinboro Lake therefore will require reducing the amount of phosphorus that enters the lake from the surrounding watershed.

3.1.3 Impact of Cultural Eutrophication – Algal Blooms

In addition to being detrimental to the overall health of Edinboro Lake and its ecosystems, cultural eutrophication also negatively impacts the recreational use of the lake limiting the economic benefits of the lake to the local community. One of the more visible results of eutrophication is the over abundance of phytoplankton (algae) near the surface of the lake. The blooms are often the result of an over abundance of cyanobacteria (blue-green algae) in the lake which typically occurs in late summer. Large blooms typically produce surface scums of cyanobacteria which are aesthetically displeasing, cause unpleasant odors, and discourage swimming and other recreational use of the lake. Although not usually a health threat, cyanobacteria can cause allergic reactions for some individuals.

Phytoplankton communities in eutrophic lakes typically consist of a relatively few number of species and are therefore lacking in diversity compared to mesotrophic and oligotrophic lakes. The dominant summer phytoplankton in Edinboro Lake are the cyanobacteria Anabaena, Aphanizmenon, and Oscillatoria, along with the diatom Fragilaria which are considered indicative of eutrophic conditions . Significant blooms of Anabaena are common from August until after fall-turnover. An unusually prolific Anabaena bloom beginning in mid-August 2008 led to many concerned calls to Pennsylvania DCNR, Erie County Health, and local government. Surface scums formed during this bloom turned an unnatural looking bright teal-green color, leading many individuals to report that it appeared as though paint had been spilled into the lake.

3.2 Lake Characteristics

3.2.1 Bathymetry

Figure 3.5 is a bathymetric map of Edinboro Lake. The maximum lake depth is 29.3 feet (8.9 m) with an average depth of 9.4 feet (2.9 m). Ostrofsky et al. (2004) calculated a total lake volume of 818.2 million gallons (3.1 million m3). Note that the original size of Edinboro Lake before the lake level was raised by dams can be approximated by the outline of the 9 foot contour on the bathymetric map.

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Figure 3.5 Bathymetric map of Edinboro Lake. An enlarged version of this map is available on the accompanying CD.

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3.2.2 Fish

A 1998 survey of Edinboro Lake conducted by the Pennsylvania Fish and Boat Commission reports the following fish species: black crappie, bluegill (Lepomis macrochirus), pumpkinseed (L. gibbosus), brook trout (Salvelinus fontinalus), brown bullhead (Ameiurus nebulosus) , yellow bullhead (A. natalis), common carp (Cyprinus carpio), golden shiner (Notemigigonus crysoleucas), largemouth bass (Micropterus salmoides), smallmouth bass (M. dolomieu), muskellunge (Esox masquinongy), walleye (S. vitreum vitreum), white perch (Morone americana), yellow perch (Perca flavescens), and white sucker (Catostomus commersoni). White crappie (Pomoxis annularis) was reported in a 1991 survey (Lee, 1993) but not found in 1998. The primary sport fish in the lake are largemouth bass, smallmouth bass, black crappie, bluegill, yellow perch, walleye, and muskellunge. Walleye and muskellunge populations are maintained by a stocking program. Edinboro Lake serves as a Pennsylvania Fish Commission brood lake for muskellunge.

3.2.3 Aquatic Vegetation

Excessive growth of rooted aquatic vegetation is a common result of cultural eutrophication. In Edinboro Lake dense stands of vegetation are found in those areas where water depth is less than 10 feet. This excessive growth of plants generally referred to as “weeds” includes both native vegetation (Elodea Canadensis and Najas flexilis) and invasive, non-native species such as Eurasian watermilfoil (Myrophyllum spicatum) (Grund and Bissell, 2004). These plants form dense canopies which shade out native vegetation and impair recreational use of the lake, particularly boating and swimming.

Eurasian water-milfoil is an invasive, non-native species which is the most problematic submersed aquatic plant in our region (Grund and Bissell, 2004). The plant reproduces primarily by fragmentation. Pieces of broken plan material sink to the bottom of the lake and take root. Boaters should use extreme caution to avoid transporting plant material from Edinboro Lake to other lakes in the region.

Control of Eurasian water-milfoil and other invasive plants in Edinboro Lake must be addressed with consideration for the native vegetation which includes a number of rare and endangered species. Currently a weed spraying program using the contact herbicide diquat (REWARD) is utilized at Edinboro Lake. The program is funded jointly by the Borough of Edinboro, Washington Township, and the ELWA. The use of contact herbicides such as diquat may be the safest, most effective mechanism of weed control currently available (Grund and Bissell, 2004). It is important that the herbicide be applied as soon as water temperatures are warm enough. Early in the season invasive species are further along in their growth cycles than the native vegetation which is not the target of spraying. Weed spraying is a “cosmetic” treatment which treats a symptom of cultural eutrophication without addressing the cause. The ELWA has announced that it will not contribute to the weed spraying program after 2009 in order focus its limited financial resources on reducing phosphorus pollution in Edinboro Lake. Discontinuing the weed spraying would negatively impact the recreational use of the lake and the ELWA recommends that the Borough of Edinboro and Washington Township continue the program.

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3.2.4 Zebra Mussels

Invasive species are non-native flora or fauna that have been introduced to a new area, usually by human means. If the new habitat is ideal, an introduced species will colonize and populations can explode without the natural predators or ecosystem checks and balances from the native habitat. These populations add new dynamics to ecosystems, often displacing native species and disrupting food webs. Zebra mussels (Dreissena polymorpha) are an invasive freshwater mussel first encountered in the Great Lakes in the late 1980’s. A native of the Caspian Sea area in Asia, it is believed they were transported to the Great Lakes region when a transoceanic shipping vessel took on ballast water in Europe discharged it into Lake St. Clair near Detroit. The Great Lakes area proved an ideal habitat and the mussels have spread rapidly throughout the Great Lakes and many inland waterways (PA DEP, 2000).

Zebra mussels were first discovered in Edinboro Lake in October 2000, likely transported on a boat hull or other equipment used in Lake Erie and then put in Edinboro Lake. Adult zebra mussels range in size from a nearly visually undetectable young to adults to up to two inches long. The adults can attach to a boat hull and survive outside of water for up to 14 days, making for easy and unsuspected transport to un-infested waterways. Zebra mussels will quickly colonize on any underwater hard surface, forming large masses that can block underwater standpipes or even clog outboard motors, causing significant economic damage (PA DEP, 2000).

Figure 3.6 Zebra mussel densities in Edinboro Lake 2001-2008. Note that no data was collected in 2005.

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3.2.5 Bacteria

A recurring problem at Edinboro Lake is the closing of swimming beaches due to high concentrations of bacteria in the lake water. Beach closings occur nearly every year, with the number of closed days varying dependent on average temperature and rainfall amounts. Pathogenic bacteria are typically present in such low concentrations that detecting them in water samples is difficult. Because of this “fecal coliform” bacteria such as Escherichia coli (E. coli) are used as indicators of fecal pollution. Fecal coliform concentrations of greater than 235 colonies per 100 ml of water are considered unsafe for recreational waters. Several studies (Boker, 1978, USEPA, 1981, Marchese, 2003, Mauro and Covert, 2008) report fecal coliform concentrations for Edinboro Lake and its tributary streams including stormwater inlets. In the most recent study (Mauro and Covert, 2008) 33 samples were collected on 3 separate dates from 11 sites within the watershed. Five of the sites were tributary streams or storm sewers, the remainder were within the lake. Samples were collected in July and August of 2008. Each sampling date was within 48 hours of a rain storm. Fecal coliform concentrations averaged 564 colonies/100ml. Of the 33 samples, 24 had concentrations in excess of the 235 colonies/100 ml limit for recreational use. Quantitative PCR analysis indicated an alarming amount of bacteria derived from human fecal matter sources, particularly in samples taken from within the lake. Additional sampling is required to verify any sources of human fecal pollution within the watershed so that they may be eliminated. Mauro and Covert (2008) show that eliminating these human sources will result in total bacteria concentrations below the limit for safe recreational use of the lake.

3.2.6 Sedimentation

A great deal of attention has been given to the rate of sediment accumulation in Edinboro Lake. Sedimentation is a natural process and all lakes will gradually fill with sediments over time. Sedimentation in Edinboro Lake has been accelerated due to human disturbances within the watershed. Increased sedimentation is a concern due to the negative impact it has on recreational use of the lake and because sediments carry large amounts of phosphorus which contributes to the eutrophication of the lake.

The aerial photographs in Figure 3.7 illustrate changes to Edinboro Lake over a 56 year period. Comparison of the photos from 1938 and 1950 show that there was a rapid accumulation of sediments at the north end of the lake during this time accompanied by the conversion of areas of open water to wetlands. Increased sedimentation at the mouth of streams entering the lake is an expected consequence of constructing a dam on the lake outlet. When the lake level was raised, the mouths of the tributary streams were flooded along with many of the wetlands that surrounded the lake. This resulted in a change in the dynamic “equilibrium” that existed with regard to sedimentation within the tributary streams and lake. Sediments were no longer filtered by surrounding wetlands and instead were deposited within the lake in the form of large stream deltas which quickly built up to lake level and were colonized by wetland plants. In a sense the streams were simply reclaiming some of the land that was flooded when the lake level was raised. Although this is a natural process that is described in any introductory geology text, the rate of sedimentation was certainly accelerated by the intensive agriculture occurring within the watershed at this time.

The 1969 and 1994 aerial photos show the development of the dredged channels at the north end of the lake. This dredging occurred between 1957 and 1960 and resulted in the formation of several islands and peninsulas in the area known locally as “the

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Figure 3.7 Historical aerial photographs of Edinboro Lake 1938, 1950, 1969, 1994

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fingers”. It is interesting to note that several of the land areas which were intended as housing developments are no longer present having subsided below the lake level between 1969 and 1994. More recent aerial photos indicate that this process continues today. Disappearance of these land areas is most likely due to compaction and subsidence of loose sediments rather than erosion. The current maximum depth of Edinboro Lake is a little less than 30 feet. Figure 3.8 and Figure 3.9 include bathymetric maps of Edinboro Lake which were constructed in 1960 (Higgins) and 1973 (Ganzemiller and West). The 1960 map indicates a maximum depth for Edinboro Lake of 44 feet while the 1969 map records a depth of 30 feet at the same location. Wise (1975) reported that an earlier map by J. Labesky (ca. 1950) indicated a maximum depth of 40 to 50 feet for the lake. If true, this apparent accumulation of over 10 feet of sediment in the central basin from 1950 to 1973 would be astounding. Throughout the 1970’s and 1980’s this apparent rapid sediment accumulation resulted in a great deal of concern and planning regarding the future of Edinboro Lake culminating in the Nessie dredging program.

In order to more precisely measure the rate of sedimentation in the deepest part of Edinboro Lake a 1.4 meter sediment core was collected in September 2007. The sediment core was divided into 4 cm sections which were dated using 210-lead (210-Pb) radiometric dating techniques. This dating technique is commonly used for determining the age of recent lake sediments. The results of this study are shown in a graph of mass sedimentation rate versus depth in the sediment core (Figure 3.10). Each data point on the graph is labeled with the date for that sediment interval determined by Pb-210 dating. These data indicate that only 96 cm (3.1 ft) of sediment has accumulated in the deepest part of Edinboro Lake since 1772. Since 1948 there has been 64 cm (2.1 ft) of sediment accumulation indicating a sedimentation rate of 1.06 cm (0.42 inches) per year. While this is a very high rate of sediment accumulation compared to other lakes, particularly those in less developed watersheds, it is significantly less than the rate of accumulation suggested by the historic bathymetric maps. The inaccuracy of the older bathymetric maps can be accounted for by the extreme difficulty of achieving an accurate measurement of water depth using a weighted line. For the 2000 map water depths were measured using sonar technology.

The sediment core data indicate a gradual increase in sedimentation rate from 14.8 mg/cm2/yr in 1772, prior to construction of the first dam and land-clearing in the watershed, to 286 mg/cm2/yr today. This is most likely caused by the gradual increase in population and accompanying development within the watershed. Careful of examination of the graph reveals that the rate of increase in sedimentation is less today than it was in the period prior to 1972. Figure 3.10 also clearly shows short term significant increases in the sedimentation rate ca. 1953-1955 and 1987-1992. These times correlate with periods of intensive dredging within Edinboro Lake. Disturbance during dredging caused redistribution of sediment from the shallower to deeper parts of the lake. Suspension of sediments during dredging would have released phosphorus and temporarily increased the trophic state of the lake.

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Figure 3.8 Historic bathymetric map of Edinboro Lake, indicating a maximum depth of 44 feet, see text for discussion (Higgins, 1960)

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Figure 3.9 Historic bathymetric map of Edinboro Lake indicating a maximum depth of 30 feet, see text for discussion (Ganzemuller and West, 1973)

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Figure 3.10 Sedimentation rate in Edinboro Lake (Zimmerman, unpublished data)

3.3 Watershed Characteristics

3.3.1 Soils

The porosity of the soils within the watershed strongly influences the amount of precipitation that runs off into streams and storm sewers. The United States Department of Agriculture classifies soils as well drained if water drains rapidly through the soil and poorly drained if water drains so slowly that it interferes with tillage or plant growth (USDA, 1960).

Figure 3.11 and Table 3.2 summarize the drainage characteristics of soils within the Edinboro Lake watershed. Soils with favorable drainage characteristics are found within a north trending corridor that surrounds the lake and follows Conneauttee and North Shenango creeks. Only 29% of the watershed contains soils which are well drained to moderately well drained. The low percentage of well drained soils significantly impacts water quality within the watershed. Poor soil drainage results in increased erosion and surface run off to tributary streams and reduces the efficiency of septic systems particularly older systems that have not been properly maintained.

Soils found within the Edinboro Lake watershed can be divided into two groups based on the parent material which forms the foundation on which the soil is developed. Soils belonging to the Howard-Phelps-Fredon-Halsey series developed on gravel rich glacial outwash which forms thick sediment deposits on valley floors. The Howard and Phelps soils which account for approximately 50% of the land area in this association are well to moderately well drained. The remaining 50% of the area in this association contains the somewhat poorly to poorly drained Fredon and Halsey soils. The Howard

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Silv

erth

orn

Fry

Crane

Lay

Neyland

Old State

Ham

ilton

Lay cock

Rt 9

9

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Angling

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r sta

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9

0 0.5 10.25

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Edinboro Lake WatershedSoil Permeability

Streams State and Local Roads Watershed Boundaries

Soil PermeabilityWaterPoorly Drained

Very Poorly Drained

Somewhat Poorly Drained

Somewhat Poor to Poorly Drained

Well Drained

Moderately Well Drained

Figure 3.11 Soils map of Edinboro Lake watershed. Data sources: Soil map: U.S. Department of Agriculture, Natural Resources Conservation Service, (2006). Soil survey Geographic (SSURGO) database for Erie County, Pennsylvania. Accessed via Pennsylvania Spatial Data Access, http://www.pasda.psu.edu/default.asp. An enlarged version of this map is available on the accompanying CD.

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and Phelps soils contain a concrete-like hard porous layer, cemented by calcite which occurs at depths of between 3 and 8 feet.

Soils belonging to the Erie-Ellery and Alden-Langford series are developed on upland areas where a thin glacial till covers the local shale bedrock. Soils in this group contain a calcite-rich fragipan which occurs 6 to 30 inches below the surface. This fragipan restricts water and root penetration and these soils are therefore somewhat poorly to very poorly drained.

Table 3.2 Soil Permeability by Subwatershed

Sub-Basin Catchment Area

Well Drained

Moderately Well

Drained

Somewhat Poorly

Drained

Somewhat Poorly to

Poorly Drained

Poorly Drained

Very Poorly

Drained Open water

acres % % % % % % %

Elm Street 196.8 0 6.31 79.62 2.78 10.9 0 0.39

Crawford Beach 99.9 4.35 19.57 61.02 9.87 5.18 0 0.01

Whipple Creek 779.9 0.87 10.79 69.28 2.01 17.05 0 0

Shenango South 543.5 5.34 18.93 60.46 5.27 12.71 0 0

Shenango North 3,306.6 0.34 3.71 8.42 64.62 5.21 17.4 0.56

Conneauttee Creek 4,232.2 22.35 15.72 32.49 9.81 8.22 11.15 0.26

Highway 99 32.7 35.87 0.12 35.81 28.2 0 0 0

Scarlett Seep 1 20.9 36.4 40.72 16.97 5.71 0.2 0 0

Scarlett Seep 2 13.3 67.78 32.22 0 0 0 0 0

Scarlett Seep 3 13.3 69.33 30.67 0 0 0 0 0

Scarlett Seep 4 347.6 67.06 28.58 0 4.36 0 0 0

Lake Adjacent 1,280.0 27.12 14.62 16.56 7.68 1.33 10.02 22.71

Total Watershed 10,866.8 15.17 13.81 44.51 6.98 10.65 5.79 3.09

3.3.2 Wetlands, the Edinboro Lake Fen

The locations of major wetlands within the Edinboro Lake watershed are shown in Figure 3.12. Wetlands slow the flow of water to the lake while filtering and retaining pollutants. In addition to improving water quality, wetlands provide wildlife habitat, store floodwater, facilitate groundwater recharge, and maintain surface water flow during dry periods (USEPA, 2001).

The wetland classification scheme adopted by the United States Fish and Wildlife Service (USFWS) defines wetlands as transitional between aquatic and terrestrial land where the water table is usually at or near the surface or standing water is present (Cowardin et al., 1979). Wetlands are identified as: lacustrine if they are associated with a lake, riverine if they are associated with flowing water, and palustrine if they are inland wetlands not associated with lakes or flowing water. Wetlands are further identified as: forested if they are dominated by trees greater than 20 feet in height, scrub-shrub if they are dominated by shrubs and tree saplings less than 20 feet in height, and emergent if they are dominated by rooted hydrophyte (wetland) plants.

The wetlands depicted in Figure 3.12 were identified using satellite imagery and include only larger wetlands which contain standing water throughout the year. Glacial

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activity in northwestern Pennsylvania created conditions favorable to development of wetlands, many of which are too small to be recognized using satellite imagery or are not flooded for the entire year (Allegheny Watershed Network, 1999). Networks of these smaller wetlands can store and remove nutrients from large volumes of water (USEPA, 2001) and their identification, preservation, and restoration is essential to improving water quality in the Edinboro Lake watershed. Specific recommendations regarding wetland preservation are included in Section 6.2.

Si

lver

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Ham

iltonLaycock

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9

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Edinboro Lake WatershedWetlands

Wetland TypePalustrine Emergent

Palustrine Forested

Palustrine Scrub-Shrub

Palustrine Pond

Lacustrine Littorral

Edinboro Lake Fen

Streams State and Local Roads Watershed Area

Figure 3.12 Wetlands in the Edinboro Lake watershed. Data source: Wetlands layer: U.S. fish and Wildlife Service (2005). National Wetlands Inventory for Pennsylvania. Accessed via Pennsylvania Spatial Data Access, http://www.pasda.psu.edu/default.asp . An enlarged version of this map is available on the accompanying CD.

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The Edinboro Lake Fen, located along the northern shore of the lake contains a natural wetland community of global significance (WPC, 2000, Grund and Bissell, 2004). A fen is a peat-forming wetland that receives nutrients from groundwater flow. The shrub fen bordering Edinboro Lake is unique because of the abundance of calcite in the glacial deposits surrounding the lake which maintains a high pH in the local groundwater. This provides habitat for a variety of rare and endangered plants which require alkaline conditions. Twenty three plant species of special concern, eleven of which are listed as endangered in Pennsylvania occur within the watershed (WPC, 2000, Grund and Bissell, 2004). Edinboro Lake is home to more plants of special concern than any of the glacial kettle lakes in northwestern Pennsylvania (Table 3.3). Although through the efforts of a private land owner the Edinboro Lake fen is protected from development it faces a variety of threats most notably from invasive non-native plant species which could crowd out the endangered plants. Table 3.3 Plants of Special Concern Found in Edinboro Lake (Grund and Bissell, 2004)

Within the Lake

Northern water-milfoil (Myriohyllum exalbsecens)

Whorled water-milfoil ( M. verticillatum)

White-stem pond weed (Potamogeton praelongus) – historic only, now missing

Vassey’s pond weed (P. vaseyi)

Eastern white water-crowfoot (Ranunculus longirostris)

Lesser bladderwort (Utricularia minor)

Edinboro Lake Fen

Rush aster (Aster borealis)

Cuckooflower (Cardamine pratensis var palustris)

Broad-winged sedge (Carex alata)

Lesser-panicled sedge (C. diandra)

Soft-leaved sedge (C. disperma)

Prairie sedge (C. prairea)

Slender spikerush (Eleocharis elliptica)

Slender cotton-grass (Eriophorum gracile)

Small –headed rush (Juncus brachycephalus)

Swamp fly-honeysuckle (Lonicera oblongifolia)

Leafy northern green orchid (Platanthera hyperborean)

Autumn willow (Salix serrissima)

River bulrush (Scirpus fluviatilis)

Lake Perimeter and Adjacent Wetlands

Swamp smartweed (Polygonum setaceum var interjectum)

Bog willow (Salix pedicellaris)

Bog-mat (Wolffiella gladiata)

Riparian Buffers North of Lake

Red current (Ribes triste)

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3.4 Lake Water Quality Data A variety of studies have reported on the chemical and physical conditions that have

existed within Edinboro Lake over the past 40 years. The most recent and most comprehensive study is that of Ostrofsky et al. (2004) who measured conditions within the lake and its major tributaries over a 14 month period from May 2003 to June 2004. The ELWA began a continuing program to monitor the trophic state of the lake in 2005. The following discussion of lake chemistry will use the chemical and physical conditions that exist within the lake using data from Ostrofsky et al. (2004) and previously unpublished ELWA monitoring data. Additional reports which contain historical data dating back to 1972 can be downloaded from the ELWA web page (Wise, 1975, Hartman ca. 1981, USEPA, 1980, Wellington, 1987, 1991, 1996).

3.4.1 Temperature

Representative temperature profiles for spring, summer, and fall taken from the deepest part of the lake are given in Figure 3.13. These profiles which display the typical range of temperature conditions found within Edinboro Lake were collected in 2005. Variations will, of course, occur from one year to the next dependent on air temperature, wind, and precipitation. The spring and fall profiles show well mixed conditions expected in a dimictic lake during these seasons with uniform temperatures throughout the water column. The summer profile illustrates the formation of a thermocline with fairly constant temperatures of around 27o C (80oF) above 3 meters depth (10 ft). Temperatures below the thermocline gradually decrease to a minimum of approximately 13o C (55o F) which is a typical bottom water temperature for Edinboro Lake in midsummer. A winter profile is not included. When the surface of the lake is frozen the water below the ice will be a constant 4oC (39oF) throughout the water column.

3.4.2 Dissolved Oxygen

The amount of dissolved oxygen present in the lake water will vary as a function of temperature, photosynthesis, decay of organic matter, and atmospheric exchange. Figure 3.13 includes a graph of dissolved oxygen versus depth which illustrate seasonal variations in dissolved oxygen throughout the water column. Table 3.4 includes representative dissolved oxygen concentrations found in water samples from both surface and bottom of Edinboro Lake. Cold water will contain higher amounts of dissolved oxygen than warmer water, so there is a seasonal fluctuation in the concentration of dissolved oxygen near the lake surface. During those times when the water column is well mixed, atmospheric exchange produces uniform oxygen concentrations from the surface to the lake bottom. In the summer months when the lake is thermally stratified, decomposition of organic matter consumes oxygen resulting in dissolved oxygen concentrations that often approach 0 mg/L. Production of oxygen by photosynthesis in algae and other plants will often produce over saturation of oxygen near the surface of the lake.

Dissolved oxygen is an important indicator of the overall health of the lake. Extremely low amounts of oxygen in Edinboro Lake are an indicator of eutrophication. During summer stratification the complete lack of oxygen below the thermocline results in the formation of an anaerobic zone with little or no oxygen that extends from a depth of approximately 11 feet to the lake bottom. This anaerobic zone exists from approximately May to October each year. The lack of oxygen in the water below the

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thermocline means that Edinboro Lake cannot support large populations of fish which prefer cool, well oxygenated water. This includes desirable sport fish such as muskellunge.

Figure 3.13 Graphs depicting seasonal variation in temperature and oxygen versus depth in Edinboro Lake.

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3.4.3 Alkalinity and pH

pH is a measure of the hydrogen ion activity and provides a measure of the balance between the acids and bases in a water sample. The pH scale ranges from 1 to 14 with value of 7 representing a neutral pH. Values higher than 7 are basic and values less than 7 are acidic. The typical pH of Edinboro Lake water is between 7 and 9. Because the scale is logarithmic each unit of pH indicates a 10-fold change in hydrogen ion activity. Water with a pH of 8 would therefore contain 10 times less hydrogen ion then water with a neutral pH. Water with a pH of 9 would contain 100 times less hydrogen then water with a neutral pH.

Alkalinity is a measure of the capacity of water to neutralize an acid. Dissolved carbonate minerals such as calcite (CaCo3) are the primary sources of alkalinity in natural waters and alkalinity is commonly expressed in mg/L CaCO3. Edinboro Lake water typically has a high alkalinity (55-110 mg/L CaCO3) and therefore is capable of absorbing significant amounts of acids while maintaining a neutral to alkaline pH. This means that Edinboro Lake and its ecosystems are protected from the damaging effects of acid rain.

The high alkalinity and pH of Edinboro Lake is derived from calcite and other carbonate minerals present in the glacial sediments which surround the lake. Groundwater moving through these sediments dissolves the carbonate minerals before entering the lake. Where alkaline groundwater emerges from springs bordering the lake it forms unique alkaline wetlands including the Edinboro Lake Fen. Lakes with this unique alkaline chemistry are referred to as calcareous lakes and are “critically imperiled” in Pennsylvania (Western Pennsylvania Conservancy, 2000).

3.4.4 Nitrogen and Phosphorus

Nitrogen and phosphorus are the two major nutrients required for algae and plant growth in the lake. Representative total nitrogen and total phosphorus values are presented in Table 3.4. Ostrofsky et al. (2004) measured total phosphorus concentrations in the lake on a bi-weekly basis from May 2003 to June 2004. Measurements dating to 1975 do not indicate a significant change in phosphorus concentrations in Edinboro Lake during the past 34 years.

Phosphorus concentrations vary seasonally due to varying amounts of surface runoff and internal release from sediments. During the winter months phosphorus concentrations are at an annual low due to limited runoff from frozen ground surfaces. Beginning with spring snow melt phosphorus concentrations increase through summer as phosphorus is slowly released from sediments into the water trapped below the thermocline. There is a strong correlation between total phosphorus in the lake and precipitation due to specific storm events which wash large volumes of phosphorus rich runoff into the lake. Ostrofsky et. al. (2004) report an average total phosphorus composition of 0.0355 mg/L for Edinboro Lake. Total phosphorus concentrations at the lake surface range from 0.017 to .060 mg/L. Higher concentrations of up to 0.5 mg/L occur below the thermocline during the summer when phosphorus is released from lake sediments into oxygen poor water.

Table 3.4 indicates total phosphorus concentrations of up to 0.8 mg/L measured in August 2006. Unusually high phosphorus concentrations were measured during August and September of this year. These high phosphorus concentrations were primarily a result of several overflows from the Angling Road wastewater treatment facility into

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Whipple Creek. High amounts of precipitation and associated runoff also contributed. These high phosphorus levels resulted in a major plankton bloom of a micro-organism known as Ceratium. The plankton bloom was accompanied by lower than normal amounts of dissolved oxygen throughout the lake. The concentrations of dissolved oxygen were low enough to cause the death of a significant proportion of the zebra mussels that populate the lake.

Table 3.4 Summary of Water-Quality Monitoring 2005-2008

Conditions at Lake Surface Date Temperature DO pH TP TN Alk degrees C mg/L mg/L mg/L mg/L 4/28/2005 9.9 11.3 7.8 0.24 0.071 64.4 8/3/2005 26.8 7.6 8.5 0.034 0.32 72.2 10/19/2005 14.5 6.5 8.2 0.028 0.51 73.4 5/10/2006 17.13 11.27 8.81 0.04 68 8/9/2006 25.2 6.55 8.19 0.803 79.2 10/10/2006 15.12 11.71 8.09 0.09 91.2 5/15/2007 17.84 10.88 9.2 0.06 72.8 8/3/2007 26.7 8.99 8.9 0.05 90 10/22/2007 15.54 6.96 7.38 0.06 78 5/2/208 14.08 10.62 7.23 0.013 64 8/4/2008 25.07 7.2 8.15 0.036 74.2 Conditions at Lake Bottom Date Temperature DO pH TP TN Alk degrees C mg/L mg/L mg/L mg/L 4/28/2005 9.8 11.4 7.7 0.023 0.72 64 8/3/2005 13.8 0.3 7.3 0.534 1.33 105.2 10/19/2005 14.6 6.5 8.6 0.031 0.51 73.2 5/10/2006 10.15 0.25 6.68 0.06 56 8/9/2006 12.86 0.37 9.63 0.375 88.8 10/10/2006 13.6 5.74 7.72 0.01 82.8 5/15/2007 7 1.8 7.78 0.06 77.2 8/3/2007 10.9 0.17 11.58 0.23 118 10/22/2007 15.06 6.67 7.02 0.06 72.3 5/2/208 8.74 1.69 6.41 0.02 56 8/4/2008 13.09 0.13 10.58 0.56 110

3.4.5 Secchi Disk Transparency

The clarity or transparency of lake water is commonly measured using a black and white disk known as a Secchi disk. The disk is simply lowered into the water until it is no longer visible (Figure 3.14). The depth at which the disk disappears is a measure of the transparency of the water. Water transparency is generally considered to be a function of the amount of phytoplankton and sediment suspended in the water. Because this

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technique is inexpensive, easily measured, and provides reproducible results it is the most commonly used method of determining the trophic state of a lake. However, in Edinboro Lake the transparency is also affected by the presence of a large population of zebra mussels which filter and clarify the water. Secchi disk transparency is therefore less reliable as an indicator of trophic state in Edinboro Lake.

Figure 3.14 Annual variation in August secchi disk transparency.

Figure 3.15 Seasonal variation in secchi disk transparency (Ostrofsky et al., 2004)

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Measured Secchi disk values for Edinboro lake vary from 0.5 meters to 5.5 meters (Ostrofsky et al. 2004, ELWA monitoring). Secchi depths are highest during the winter months and lowest in the summer when phytoplankton concentrations are at their seasonal peak. Figure 3.14 shows variation in August Secchi values dating back to 1986. These values are consistently less than 2 meters which is considered the minimum desirable for recreational lake uses. The increase in Secchi transparency after 2003 is due to the presence of zebra mussels in the lake. Low values of approximately 0.5 meters measured in August 2006 and again in August 2008 correlate with major plankton blooms. As previously mentioned, the 2006 plankton bloom of Ceratium was primarily caused by release of phosphorus from the Angling road wastewater treatment facility. The 2008 bloom consisted of a blue-green algae Anabaena spiroides (John Ashley, pers. com.).

3.4.6 Chlorophyll-a

Chlorophyll-a is a chemical pigment present in all plants and is commonly measured as an indicator of the total amount of phytoplankton in a lake. The concentration of chlorophyll-a correlates strongly with Secchi transparency, but is considered a more reliable indicator of trophic state because it eliminates the effects of suspended sediment. Chlorophyll-a concentrations for Edinboro Lake vary from 0.0 to approximately 70 micrograms/L (Ostrofsky et al., 2004). As expected, chlorophyll-a concentrations vary seasonally corresponding to the local growing season (Figure 3.16). Lowest chlorophyll-a concentrations are found in the winter. During the spring there is a gradual increase with highest concentrations during the summer months followed by a gradual decline in the fall.

Figure 3.16 Seasonal variation in chlorophyll-a (Ostrofsky et al., 2004)

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3.4.7 Trophic State Index

Trophic state is a relative expression of the “productivity” or the total amount of algae and plants a lake can support. Trophic state is most commonly expressed as the Trophic State Index (TSI) developed by Carlson (1977). Three separate indices are calculated based on total phosphorus, chlorophyll-a, and secchi disk transparency measurements. Carlson (1977) recommends calculating TSI from average summer values of these parameters. A TSI of greater than 50 indicates eutrophic conditions, a TSI between 35 and 50 indicates mesotrophic conditions, and a TSI of less than 35 would indicate oligotrophic conditions. A dangerously over-productive or hypereutrophic lake would have a TSI of greater than 70.

Table 3.5 lists average summertime values of total phosphorus, chlorophyll-a, and secchi disk transparency along with calculated TSI for Edinboro Lake. TSI calculated from total phosphorus is 57, from chlorophyll-a is 65, and from secchi depth is 60. These values are in general agreement and indicate that Edinboro lake is eutrophic. It should be noted that these TSI values have been calculated from average summer conditions. There have been occasions, most notably the 2006 summer season and during algal blooms, when the TSI for Edinboro Lake indicates that hypereutrophic conditions have temporarily existed.

Table 3.5 Trophic State Indices for Edinboro Lake

Parameter Average Summer Value Trophic State Index Total Phosphorus 0.038 mg/L 57 Chlorophyll-a 33.8 ug/L 65 Secchi 1.04 m 60

3.4.8 Total Maximum Daily Loads

Section 303(d) of the US Clean Water Act requires states to develop lists of impaired waters. Edinboro Lake has been listed as impaired for “Atmospheric deposition due to high levels of mercury” and also as impaired for “natural sources/noxious aquatic plants” due to high levels of nutrients and eutrophication (PA DEP, 2008). Edinboro Lake was also listed in 2006 for suspended solids and nutrients from wastewater, designations which may be removed due to the relocation of discharge from the Washington Township wastewater treatment plant in 2007. Eventually 303(d) listing will result in the Pennsylvania DEP developing Total Maximum Daily Loads (TMDL) for Edinboro Lake. TMDL is a regulatory term in the Clean Water Act.

Atmospheric deposition of mercury derived primarily from coal burning power plants is common in the eastern United States. In our region, Presque Isle Bay, Kinzua Reservoir, Conneaut Lake, Lake Pleasant, LeBoef Lake, Sugar Lake, and Tamarack Lake all are 303(d) listed for atmospheric deposition of mercury. The Pennsylvania Fish and Boat Commissions recommends that individuals consume no more than 2 meals of large mouth bass from Edinboro Lake in a given month and no more than 1 meal of any fish caught in Pennsylvania waterways each week.

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4 Hydrologic and Pollutant Budgets 4.1 Hydrologic Budget A hydrologic budget is an accounting of all of the water which enters or leaves a watershed. For Edinboro Lake inputs of water include surface runoff from each of the 12 sub-watersheds, precipitation which falls on the lake and groundwater which discharges into the lake. Outputs include water that discharges over the dam at the lake’s outlet and evaporation from the surface of the lake.

Ostrofsky et al. (2004) constructed a hydrologic budget for Edinboro Lake (Table 4.1). To construct this budget, measurements were made of precipitation, stream flow from the Shenango North sub-watershed, and lake level at the outlet from May 2003 to June 2004. Loss of water due to evaporation was taken from published data from the U.S. National Weather Service (Linsley et al. 1982). Groundwater input was calculated as the difference between the total volume of water entering and leaving the lake. The input of water from the sub-watersheds was estimated from the discharge from Shenango North, assuming that runoff is proportional to the area of each sub-watershed. This approach to estimating runoff is necessary since it is not practical to directly monitor discharge from each sub-watershed but does not account for the effects of differing land use and soil permeability on surface runoff. Using this approach the amount of runoff from sub-watersheds such as Conneauttee with a higher soil permeability than Shenango North are likely overestimated. Similarly, the amount of runoff from sub-watersheds such as Whipple Creek with higher percentages of developed land are likely underestimated.

Table 4.1 Edinboro Lake Hydrologic Budget (Ostrofsky et al. 2004)

Source Input Output Percent m3/yr m3/yr Direct Precipitation 1,258,855 4.78% Elm Street 463,978 1.76% Crawford Beach 236,240 0.90% Whipple Creek 1,845,195 7.00% Shenango South 1,285,902 4.88% Shenango North 7,794,821 29.58% Conneauttee Creek 10,012,564 38.00% Highway 99 77,344 0.29% Scarlett Seep 1 49,458 0.19% Scarlett Seep 2 31,569 0.12% Scarlett Seep 3 31,569 0.12% Scarlett Seep 4 822,367 3.12% Lake Adjecent 2,426,476 9.21% Groundwater 15,367 0.06% Lake Discharge 25,583,605 Evaporation 768,100 Totals 26,351,705 26,351,705

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From the hydrologic budget and bathymetric data Ostrofsky et al. (2004) calculated a residence time of 43.9 days for Edinboro Lake. This means that on average the lake water is completely replaced every 43.9 days. While residence time is a useful number for understanding the hydrology of the lake, note that this is an average which is dependent on variation in precipitation. Also note that the calculation of residence time does not account for the summer months when a significant volume of water is trapped below the thermocline.

4.2 Phosphorus Budget Accounting for all of the sources of phosphorus which enters Edinboro Lake is a difficult undertaking. Table 4.2 summarizes a phosphorus budget for Edinboro Lake which is modified after Ostrofsky et al. (2004).

Table 4.2 Edinboro Lake Phosphorus Budget (modified after Ostrofsky et al. 2004)

Source Annual P Load Percent P Export kg/yr kg/ha/yr Direct Precipitation 189.2 14.1% Elm Street 22.3 1.7% 0.28 Crawford Beach 10.0 0.7% 0.25 Whipple Creek 139.3 10.4% 0.44 Shenango South 61.6 4.6% 0.28 Shenango North 324.8 24.2% 0.24 Conneauttee Creek 381.5 28.5% 0.22 Highway 99 5.3 0.4% 0.40 Scarlett Seep 1 0.8 0.1% 0.09 Scarlett Seep 2 0.4 0.0% 0.08 Scarlett Seep 3 0.5 0.0% 0.08 Scarlett Seep 4 21.5 1.6% 0.15 Lake Adjacent 120.5 9.0% 0.23 Groundwater 0.3 0.0% Internal (Sediment Release) 62.9 4.7% Totals 1,341

4.2.1 Precipitation

Rain and snow contain phosphorus which is added directly to the lake when precipitation falls on the lake surface. Ostrofsky et al. (2004) measured the phosphorus in local precipitation and calculated a loading of 189.2 kg/yr from this source accounting for 14.1% of the total budget. They found that shorter rainfall events had higher phosphorus concentrations than longer events. The amount of phosphorus entering the lake from this source will vary as a function of annual precipitation.

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4.2.2 Groundwater

Based on measured concentrations in two groundwater wells located within 300 m of the northwestern end of the lake Ostrofsky et al. (2004) estimated that net groundwater flow supplies phosphorus to the lake at a rate of 0.3 kg/yr. Note that this includes only groundwater discharging directly into the lake and not the contribution of the numerous springs, seeps, and drainage tile systems located throughout the watershed which contribute water to the tributary streams.

4.2.3 Internal Loading

Release of phosphorus from sediments into the water column is a significant source of phosphorus in some eutrophic lakes. During the summer while the lake is stratified phosphorus is released into the anoxic water near the lake bottom. This release does not occur during those times of the year when oxidized conditions exist at the bottom of the lake. Throughout the summer the concentration of phosphorus in the water below the thermocline steadily increases. When the lake overturns in the fall this phosphorus is mixed throughout the water column. Ostrofsky et al. (2004) estimated that 62.9 kg are released into Edinboro Lake each year from this internal source accounting for only 4.7% of the total phosphorus budget. Compared to many eutrophic lakes the relative contribution of phosphorus from internal sources in Edinboro Lake is quite low. For example, internal loading from sediment release accounts for 19% of the total phosphorus budget of nearby Lake Pleasant (Sampsell and Miller, 2004). The relatively low contribution of phosphorus from this source in Edinboro Lake suggests that attempts to control or eliminate phosphorus release from sediments would not be the most effective strategy for reducing the trophic state of the lake. This is especially true when the high cost of such strategies is considered.

4.2.4 Point Sources

Point sources include discharges from specific identifiable sources. There are currently two wastewater treatment facilities within the Edinboro Lake watershed. The locations of sanitary sewer systems within the Edinboro Lake watershed are shown in Figure 4.1. As of July 2007 the Washington Township treatment plant on Angling Road discharges its effluent outside of the lake watershed. Prior to July 2007 this facility produced 10 to 20% of the phosphorus entering the lake. Elimination of this phosphorus source was an important step in reducing the trophic state of Edinboro Lake and may result in a measurable improvement in water quality. By August 2009 all wastewater from the Washington Township and Edinboro Borough sanitary sewers will be treated at the Edinboro wastewater treatment plant and the effluent discharged to Conneauttee Creek downstream of Edinboro Lake.

A second wastewater treatment facility is located at General McLane High School on a branch of Conneauttee Creek. Flow records for this plant for 2008 indicate a total phosphorus output of 35.8 kg/yr. During 2008 there were repeated equipment issues at the plant that resulted in higher phosphorus levels in the effluent. These issues have been addressed. Under normal operating conditions the plant will produce approximately 11 kg of phosphorus each year. (T. Swan, pers. com.)

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Figure 4.1 Location of sanitary sewer system within the Edinboro Lake watershed (Borough of Edinboro, Franklin Township and Washington Township Multi-Municipal Comprehensive Plan (2005)

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4.2.5 Geese and Other Waterfowl

One potential source of lake phosphorus are the droppings from Canada geese and other waterfowl. The phosphorus loading from geese is estimated at 0.5 g/goose/day (Manny et al. 1994). Other waterfowl produce lesser amounts proportional to their size. The number of geese and waterfowl on the lake varies greatly throughout the year. If the number of geese on the lake averaged 75/day then geese would account for approximately 1% of the total phosphorus budget for the lake. Informal counts of Canada geese indicate that it is unlikely that waterfowl contribute more than 1-2% of the total phosphorus load to the lake. Managing the goose population will therefore have limited impact on the trophic state of the lake.

4.2.6 Non-Point Sources

Non-point sources include all of the phosphorus that enters the lake as surface runoff from the watershed. Ostrofsky et al. (2004) estimated that 1,088 kg of phosphorus are released into Edinboro Lake each year from non-point sources accounting for 81% of the total phosphorus budget. For this reason, reduction of phosphorus from non-point sources is a major focus of this report. Land use and land cover are major controls on non-point source pollution. Sources of phosphorus are fertilizers (including manure) spread on fields and lawns, sediments carried into streams and storm drains, and effluent from septic systems discharged through groundwater into streams.

5 A Land Use Model of Non-Point Source Pollution To develop a plan to successfully reduce the trophic state of Edinboro Lake we must first be able to identify and quantify the major non-point sources of phosphorus entering the lake. The underlying premise in all watershed models is that areas of similar land use or cover will consistently produce or “export” similar amounts of phosphorus. Measured export rates for land of various cover types are used to calculate the amount of phosphorus produced in areas with similar land use. For example land with forested land cover has been documented to export phosphorus at a rate of approximately 0.2 kg/ha/yr. Land used for row crops such as corn or pasture will produce phosphorus at rates of approximately 0.3 kg/ha/yr. Land with high density development will produce even higher amounts of phosphorus at rates of 1.6 kg/ha/yr (Reckhow et al.,1980).

Two approaches to quantifying the sources of non-point source pollution can be used. The first is to conduct a detailed long-term watershed monitoring study that allows the amount of pollution derived from specific land uses to be measured. This approach is both expensive and time consuming. The second approach is to use a computer simulation to model the non-point sources of pollution for a given watershed based on measured phosphorus export rates from similar areas. This more affordable approach has become an essential tool for developing strategies to reduce non-point source pollution.

5.1 Land Use and Land Cover Land use and land cover are major factors for non-point source pollution. Land use and land cover within the Edinboro Lake Watershed were obtained from the USGS National Land Cover Data Set (2001). This data set is based on satellite imagery and classifies land in the following designations:

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Low Density Development: Areas with a mixture of constructed materials, with vegetation mostly in the form of lawn grasses, shrubs and/or trees. Impervious surfaces account for less than 75% of the total cover. These areas commonly include schools, hospitals, commercial areas and industrial parks with extensive, surrounding open land.

High Density Development: Areas with a mixture of constructed materials, with vegetation mostly in the form of lawn grasses, shrubs, and/or trees. Impervious surfaces account for greater than 75% of the total cover. These areas are typically high-intensity commercial/industrial/institutional zones in large and small urban areas. They may include some dense residential development which should not exceed 20% of the total area.

Hay/Pasture: Planted/cultivated areas of grass-legume mixtures planted for livestock grazing or the production of seed or hay crops, typically on the perennial cycle. Herbaceous vegetation accounts for 75-100% of the cover.

Row Crop: All land being actively tilled, including areas used for the production of annual crops, such as corn, soybeans, vegetables, and also perennial woody crops such as orchards or vineyards. Herbaceous vegetation accounts for 75-100% of the cover.

Conifer Forest: Areas dominated by trees generally greater than 5 meters tall, and greater than 20% of total vegetation cover. More than 75 percent of the tree species maintain their leaves all year. Canopy is never without green foliage.

Mixed Forest: Areas dominated by trees generally greater than 5 meters tall, and greater than 20% of total vegetation cover. Neither deciduous nor evergreen species are greater than 75 percent of total tree cover.

Deciduous Forest: Areas dominated by trees generally greater than 5 meters tall, and greater than 20% of total vegetation cover. More than 75 percent of the tree species shed foliage simultaneously in response to seasonal change.

Wooded Wetland and Emergent Wetland: Areas where forest or shrubland vegetation accounts for greater than 20 percent of vegetative cover and the soil or substrate is periodically saturated with or covered with water.

Transitional: Areas of sparse vegetative cover (less than 25 percent of cover) that are dynamically changing from one land cover to another, often because of land use activities. Examples include forest clearcuts, a transition phase between forest and agricultural land, the temporary clearing of vegetation, and changes due to natural causes (e.g. fire, flood, etc.). Within the Edinboro Lake Watershed land identified as transitional is mostly gravel road shoulders, road ditches, gravel driveways and parking areas, or areas of land under construction at the time of the 2003 land use survey.

Turf/Golf: Any highly maintained, intensively fertilized area similar to a golf course or a sod farm.

Water: Areas of open water; generally with less than 25 % cover of vegetation or soil. Table 5.1 and Figure 5.1 summarize the land use and land cover within the Edinboro Lake watershed. Roughly equal proportions of land are currently forested (39.4%) and in agricultural use (38.5%) accounting for the majority of land within the watershed. A majority of the agricultural land is used for hay and pasture (25.3%) with the remainder used for row crops (13.2%). While only 11.3 percent of the watershed

46

Fry

Crane

I-79

Rt 6NPlum St

Angling

Rt 9

9

Laycock

Ham

ilton

Neyland

Lay

Old State

Silv

erth

orn

Edinboro Lake WatershedLand Cover

0 0.5 10.25

Miles

Land Cover Type

Turf/Golf WaterTransitional Conifer Forest

Low Density Development

High Density Development

Mixed Forest

Deciduous Forest

Hay/Pasture

Row Crop

Wooded Wetland

Emergent Wetland

Watershed BoundariesState and Local Roads

Figure 5.1 Land cover map of Edinboro Lake watershed. Data source: Land cover: United States Geological Survey, 2001. National Land Cover Database, 2001. Accessed via the Multi-Resolution Land Characteristics Consortium at http://www.mrlc.gov/nlcd.php. An enlarged version of this map is available on the accompanying CD.

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Table 5.1 Land Use in the Edinboro Lake Watershed

Land Use

Open Water

Low Intensity Development

High Intensity

Development Hay

Pasture Row

Crops Coniferous

Forest Mixed Forest

Deciduous Forest

Wooded Wetland

Emergent Wetland Transitional Turf

/Golf

Sub‐Watershed %  %  %  %  %  %  %  %  %  %  %  % 

Elm Street 0.2 23.6 0.0 6.1 0.0 4.5 1.3 29.6 0.0 0.0 1.0 33.7

Crawford Beach 0.0 86.0 0.0 0.6 0.0 0.0 0.0 9.6 0.0 0.0 0.2 3.6

Whipple Creek 0.0 16.7 4.6 23.7 3.3 3.8 1.8 31.3 0.4 0.0 3.1 11.3

Shenango South 0.0 15.2 0.0 24.9 12.3 5.3 6.1 29.0 0.8 0.0 5.6 0.8

Shenango North 0.4 5.3 0.0 35.3 15.7 5.1 2.0 32.0 0.7 0.0 3.5 0.0

Conneauttee Creek 0.2 5.2 0.2 24.7 13.1 9.1 4.0 37.4 2.8 0.1 3.2 0.0

Highway 99 6.1 25 36 7.3 1.8 0 11.6 0 0 12.2 0 0

Scarlett Seep 1 0.0 11.0 0.0 26.3 36.5 5.8 1.6 15.4 0.0 0.2 3.2 0.0

Scarlett Seep 2 0.0 0.0 0.0 32.8 51.6 3.1 0.0 12.5 0.0 0.0 0.0 0.0

Scarlett Seep 3 0.0 0.0 9.5 19.0 60.4 0.0 0.0 0.0 0.0 0.0 11.1 0.0

Scarlett Seep 4 0 11 29 4 46 1 0 2 0 0 7 0

Lake Adjacent 23.3 26.6 3.7 7.9 8.3 4.3 1.5 8.6 8.1 2.0 3.4 2.3

Total Watershed 2.9 10.3 1.0 25.3 13.2 6.4 2.9 30.1 2.4 0.3 3.4 1.8

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is developed land, it is important to note that development is concentrated in the area immediately surrounding the lake. This concentration of development near the lake is revealed by the relatively high percentage of developed land in the Elm Street (23.6%), Crawford Beach (86%), Highway 99 (61%), Scarlett Seep 3 (40%), Whipple Creek (21.3%), and Lake Adjacent (30.4%) sub-watersheds. Runoff from these developed areas will have a relatively short flow path to the lake, leaving little opportunity for removal of pollutants.

It is also important to note the significant amount of turf/golf land use (33.7%) in the Elm Street sub-watershed. The Elm Street basin has a history of flooding problems in the area between the intersection of Angling Road and Route 6N and the lake. Much of the runoff in this subwatershed originates as precipitation on to the Culbertson Hills golf course. Because runoff from land covered with turf grass will contain a high amount of phosphorus and other pollutants redirecting this water so that it does not flow directly into the lake offers a significant opportunity to improve water quality. Note that although Table 5.1 also indicates a high percentage of turf grass in the Whipple Creek sub-watershed, the Highlander Golf course has been closed and this land area is currently in transition to land used for high intensity development.

5.2 Modeling Non-Point Source Phosphorus Production in the Edinboro Lake Watershed.

For this study the AVGWLF “Arc View Generalized Watershed Loading Function” modeling software was used to quantify the non-point sources of phosphorus and other pollutants in the Edinboro Lake watershed. This tool was developed by the Pennsylvania Department of Environmental Protection (DEP) along with researchers from Penn State University and is used by DEP to derive Total Maximum Daily Loads (TMDL’s) for various pollutants in Pennsylvania watersheds. The model has been calibrated using monitoring data for 32 Pennsylvania watersheds (Evans, et al, 2002). An added benefit of this software package is that it allows the potential effectiveness of various pollution reduction strategies to be evaluated. Details of the methodology used in the model are provided by Evans et al., (2002), Evans et al., (2008), and the AVGWLF web site http://www.avgwlf.psu.edu/. The AVGWLF software is available free of charge from the web site.

Climate data used by the software are from the National Weather Service station at the Erie Airport for a 25 year period (1975-1998). Land use/land cover data is obtained from the USGS 2001 data set. The farm animal population of the watershed was estimated using data from the 2002 USDA Census of Agriculture (http://www.nass.usda.gov/Census/). Using data from this source a total animal population of 89 head of dairy cows/beef cattle and 23 head of horses/ponies was input into the model.

Comparison of the phosphorus loadings calculated by the GWLF model to those measured by Ostrofsky et al. (2004) showed that the model consistently underestimated the phosphorus export from those subwatersheds containing a significant amount of developed land. This was most likely due to the concentration of the developed land near the lake shore. Fortunately the AVGWLF software included a separate model (RUNQUAL) for highly developed areas. The RUNQUAL model subdivides the two categories of developed land used in the GWLF model into six subcategories based on the percentage of impervious surfaces present. These are low density residential (<30%

49

impervious surfaces), medium density residential (30-75% impervious), high density residential (>75% impervious), low density mixed residential/commercial/industrial (<30% impervious), medium density mixed (30-75% impervious), and high density mixed (>75% impervious). After some experimentation it was found that the best overall comparison was obtained by dividing the watershed into an inner zone containing the highly developed land areas near the lake and an outer zone containing mostly rural land uses. The RUNQUAL modeling routine was then used for the developed area and the GWLF model for the outer, rural land area and the results of the two models were combined. The results of this hybrid GWLF-RUNQUAL model calculation for the Edinboro Lake watershed are presented in Table 5.2. The model predicts an average annual phosphorus budget of 1,409.9 kg phosphorus per year which is remarkably consistent with the 1,341 kg phosphorus per year measured by Ostrofsky et al. (2004).

Table 5.2 AVGWLF-RUNQUAL Model of Phosphorus Loading in Edinboro Lake Watershed

Source/Land use Area Runoff Phosphorus % Phosphorus acres cm/yr kg/yr

Hay/Pasture 2,715.7 5.0 131.7 9.3 Row Crops 1,373.9 9.2 263.9 18.7 Forest 4,232.9 4.2 6.4 0.5 Wetland 229.8 1.1 0.9 0.1 Turf Grass/Open Land 469.5 3.6 13.0 0.9 Transition 331.1 14.5 143.9 10.2 LD Mixed 2.4 7.6 0.1 0.0 MD Mixed 37.0 36.1 10.4 0.7 HD Mixed 131.0 55.6 113.3 8.0 LD Residential 96.4 7.6 17.5 1.2 MD Residential 400.3 15.0 104.9 7.4 HD Residential 2.4 22.0 1.0 0.1 Stream Bank 11.5 0.8 Groundwater 424.1 30.1 Septic Systems 4.2 0.3 Farm Animals 163.1 11.6 Totals 1,409.9

5.2.1 Land Use Model Results

According to the GWLF-RUNQUAL model 28% (395.6 kg/yr) of the phosphorus produced within the Edinboro Lake watershed is derived from runoff from agricultural land. Runoff from land containing row crops accounts for a majority of this total (263.9 kg/yr, 18.7%) with the remainder (131.7 kg/yr, 9.3%) derived from hay fields and pasture land. The other major non-point source of phosphorus within the watershed is developed land accounting for 17.4% (247.2 kg/yr) of the total. High density mixed residential/commercial/industrial (113.3 kg/yr) and medium density residential (104.9 kg/yr) account for the majority of this source. Other major non-point sources of

50

phosphorus include transitional land (10.2%, 143.9 kg/yr) and farm animals (11.6%, 163.1 kg/yr). Note that although groundwater discharge to streams is a significant phosphorus source (30.1%, 424.1 kg/yr) this is considered a natural source rather than a pollutant. Also note that according to the GWLF-RUNQUAL model septic systems are not a significant source of phosphorus within the Edinboro Lake watershed.

The GWLF-RUNQUAL model results also demonstrate the relationship between the amounts of annual precipitation and the phosphorus load entering the lake. Figure 5.2 contains a graph of precipitation versus phosphorus export for the watershed. The wettest year in the data set was 1996 with 135.3 cm of precipitation which resulted in 1,921 kg of phosphorus export within the watershed. This is amount is nearly three times higher than the phosphorus export of the driest year, 1991, during which 75.2 cm of precipitation produced 649 kg of phosphorus. The graph in Figure 5.2 depicts a nearly linear relationship between precipitation and phosphorus export. The small amount of scatter in the data is due to the timing of precipitation. Large amounts of precipitation during the summer growing season produce smaller amounts of phosphorus because moisture and nutrients are taken up by plants. Growing plants also reduce the amount of sediment, a major nutrient source, which is eroded from agricultural fields. Precipitation during the winter and early spring produces larger amounts of phosphorus due to the lack of plant uptake and presence of bare fields. Unusually high amounts of short term precipitation at any time of the year will increase runoff resulting in increased amounts phosphorus entering the lake. As noted earlier, major blooms of algae within the lake are usually associated with extended periods of wet weather. Edinboro Lake is particularly susceptible to increases in phosphorus concentration during periods of wet weather due to the short residence time of water in the lake.

0

500

1000

1500

2000

2500

70 80 90 100 110 120 130 140

Precipitation (cm)

Pho

spho

rus

Pro

duct

ion

(kg/

yr)

Figure 5.2 Model relationship between total phosphorus budget and annual precipitation for Edinboro Lake.

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6 Reducing Non-Point Source Pollution 6.1 Riparian Buffers Monitoring of phosphorus inputs to Edinboro Lake indicate that 81.2% of the phosphorus entering Edinboro Lake is derived from non-point sources (Ostrofsky et al., 2004). The GWLF-RUNQUAL land use model further indicates that a significant amount (39.6%) of the total phosphorus load is derived from agricultural land and farm animals. There are many best management practices (BMPs) that will reduce the amount of phosphorus entering the lake from agricultural land. These include conservation tillage (no-till), use of cover crops, crop rotations, contour plowing, nutrient management, and retirement of agricultural land. These BMPs are likely in use in some areas of the watershed and should be encouraged and expanded where appropriate. In addition to these BMPs, riparian buffers may be used as a mechanism for long-term, sustainable reduction in phosphorus runoff from agricultural land. Riparian buffer zones are vegetated areas directly adjacent to a stream which reduce the amount of rainwater runoff into the stream and allow water to infiltrate the ground. Because plant roots help to hold soil in place stream banks are stabilized and erosion is greatly reduced within a buffer zone. The trees, shrubs, and grasses in the riparian buffer zone filter polluted runoff and serve as a transition zone between human land use and the stream. Planting grasses, shrubs, and trees along a stream bank forms a sort of umbrella, shielding soil particles from the direct impact of rain and decreasing erosion. Leaves and other decaying vegetation on and in the soil increase the soils’ ability to absorb and retain moisture. Additionally, riparian buffers are important ecosystems providing habitat for a variety of plants and animals. Wood and other debris within the stream channel slows flow and provides cover for a variety of aquatic organisms. Other benefits of riparian buffers include, reduced flooding, increased stream flow during dry weather, and maintenance of cooler stream temperatures due to shading.

All streams, no matter the size, can benefit by having a vegetated buffer zone. Depending on the width and quality of the buffer zone, as much as 50-100% of the sediments and attached nutrients can settle out before entering the stream. Excess phosphorus bonds to soil particles and up to 80-85% of total phosphorus from runoff can be captured and retained within a riparian buffer zone (VanRy, 1999).

Vegetated buffer zones along the lake shore will also help to reduce the amount of sediment and phosphorus entering the lake (Bachman et al., 1999). Natural vegetated buffers should be preserved and restored along the lake shore wherever possible. Lakeside buffers also discourage Canada geese from entering a property from the lake.

The types of plants that will be effective in establishing riparian buffers will vary depending on soil type, slope, moisture availability, and channel size. Forested buffers are generally considered more effective then riparian zones containing grasses and shrubs. Plants used in revegetation should be native to the watershed, should thrive in wet conditions, and should have wide, deep root systems capable of stabilizing the soil (VanRy,1999). Table 6.1 contains a list of plants recommended for riparian planting in the Edinboro Lake watershed. It is necessary to monitor the development of riparian buffers to control the establishment of invasive plant species (Table 6.2). Although the preferred restoration method is to plant desirable species, it is acceptable to simply stop mowing or cultivating within the riparian buffer and allow natural vegetation to develop in situations where invasive plants can be controlled. Where horses or livestock have

52

direct access to a stream, stream-bank fencing is necessary in order to restore a riparian buffer (Dawes, 1999).

The width of effective riparian buffers will vary dependent on factors such as slope and soil type. Although opinions vary on what is an acceptable minimum buffer width, it is generally agreed that “wider is better”. Buffers of less than 35 feet offer no sustainable protection for a stream (Dawes, 1999). The Pennsylvania Campaign for Clean Water is currently lobbying the state lawmakers to require buffers of at least 100 feet in all new development. The Chesapeake Bay Program has set a goal of establishing riparian buffers of a minimum width of 35 feet within the bay watershed (Ehrhart, 1999).

Table 6.1 Recommended Plants for Riparian Buffer Restoration in Northwest Pennsylvania

Trees Small Trees and Shrubs

Cottonwood River Birch

Willow Red Osier Dogwood

Red Maple Winterberry

Sugar Maple Shadbush

Tulip Tree American Hazelnut

White Pine Witch Hazel

Staghorn Sumac

Table 6.2 Invasive Plants of Concern in Northwest Pennsylvania

Canada thistle Japanese knotweed

Multiflora rose Dames rocket

Purple loosestrife Oriental bittersweet

Norway maple Bush honeysuckles

Privet

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Figure 6.1 USDA recommendation for a zoned riparian buffer. http://www.virginiaoutdoorsfoundation.org

Plans for riparian buffer restoration often use an approach that defines specific zones adjacent to a stream (Figure 6.1). An inner streamside zone is kept in an entirely natural state with little if any human disturbance. Within this zone there should be no cutting or removal of vegetation, soil disturbance (grading, filling, tilling), use of pesticides or fertilizers, presence of livestock, use of motorized vehicles, or construction of permanent structures. Within a second zone certain human disturbances, such as harvesting mature trees, are possible as long as best management practices are employed to limit disruption of the riparian buffer. In some plans there is a third zone of grass or shrubs that can be cleared periodically.

6.1.1 Riparian Buffer Assessment

For this study aerial photographs and Geographic Information System software (GIS) were used to measure the width of riparian buffers for every stream in the Edinboro Lake watershed. The GIS (ArcGIS 9.3) made it possible to overlay stream and topographic map layers onto the aerial photograph. For this analysis the 2005 PAMAP aerial photograph (http://www.pasda.psu.edu/), the USGS 7.5 minute series topographic maps of the watershed and a stream map obtained from the Erie County Department of Planning were used. Multiple ring buffers were created around streams at 10, 35, 75 and 150 foot intervals (Figure 6.2). Where possible, map data was field-checked visually from roads or publicly accessible lands.

The riparian buffers were measured and scored based on the presence of visually detectable human modification within the selected buffer. The streams were scored on the following 5-point scale:

1) Human modification (cropland, road, mowing, etc) visible within the 10 foot stream buffer

2) First human modifications between the 10 and 35 foot stream buffer

3) First human modifications between the 35 and 75 foot stream buffer

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4) First human modification between the 75 and 150 foot stream buffer

5) No visible human modification was detected within 150 feet of the stream.

In cases where buffer width was significantly different on the two sides of the stream, the smaller of the two buffers was used as the stream score. Because the PAMAP photos were flown in April of 2005 prior to tree leaf-out, buffer vegetation was sometimes difficult to discern. In these areas verification was made by visual field observance from public roads and with the aid of Microsoft Virtual Earth, an online satellite imagery service which offers multiple oblique photographs, taken during different seasons and therefore showing different leaf cover (http://www.microsoft.com/virtualearth/ ), (Figure 6.2).

The results of the riparian buffer analysis are presented in Figure 6.3, Figure 6.4, Figure 6.5, and Table 6.3. There are 29.4 miles of streams representing 44.5% of the total stream length within the watershed which lack riparian buffers of a minimum 35 foot width. Buffers of greater than 150 feet are currently present on 29.5%, or 19.4 miles of streams in the watershed. There are significant differences in the conditions of riparian buffers between the sub-basins within the watershed. Conneauttee Creek lacks buffers of a minimum 35 foot width on only 33.2% (10.7 miles) of the total stream length. In comparison Shenango North Creek lacks 35 foot buffers on 61.4% (11.8 miles) of its total length.

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Figure 6.2 Example aerial photographs used in riparian buffer analysis. Top: aerial photograph with topographic and stream overlay. Middle: aerial photograph with ring buffer overlay. Bottom: oblique aerial photograph of same area from Microsoft Virtual Earth (http://www.microsoft.com/virtualearth/ )

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Table 6.3 Results of Riparian Buffer Analysis by Sub-Watershed

Sub-Basin Catchment

Area Total Stream

Length Riparian Buffer Width

Within Basin

acres miles <10ft 10-35 ft 35-75 ft 75-150 ft >150 ft

Elm Street 196.8 2.0 29.1% 10.5% 17.4% 24.3% 18.7%

Whipple Creek 779.9 6.2 41.9% 13.2% 10.9% 5.1% 28.9%

Shenango South 543.5 3.1 35.9% 10.2% 13.8% 12.2% 27.9%

Shenango North 3,306.6 19.5 48.2% 13.2% 17.5% 4.1% 17.0%

Conneauttee Creek 4,232.2 32.8 22.5% 10.7% 12.3% 17.5% 37.0%

Lake Adjacent 1,280.0 2.9 34.0% 2.5% 13.5% 10.1% 39.9%

Total Watershed 10,866.8 66.0 33.2% 11.3% 14.0% 12.0% 29.5%

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Crane

I - 7

9

Fry

Silv

erth

orn

0 0.50.25

Miles

Shenango North Sub-basinRiparian Buffer Quality

Buffer Quality

PoorLess than 10 ft

Marginal10 ft - 35 ft

Moderate35 ft - 75 ft

ExcellentOver 150 ft

Good75 ft - 150 ft

Figure 6.3 Results of riparian buffer analysis for the Shenango North sub-basin. Data Sources: Aerial Photograph: Penn State Institutes of Energy and the Environment (2005). PAMAP Aerial Photographs. Accessed via Pennsylvania Spatial Data Access, http://www.pasda.psu.edu/default.asp . See Figure 3.2 for location of sub-basins. An enlarged map showing riparian buffer analysis of the entire Edinboro Lake watershed is included on the accompanying CD.

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Rt 99

Crane

Old State

Lay

Laycock

Ham

ilton

Neyland

0 0.50.25

Miles

Conneauttee Sub-basinRiparian Buffer Quality

Buffer Quality

PoorLess than 10 ft

Marginal10 ft - 35 ft

Moderate35 ft - 75 ft

Good75 ft - 150 ft

ExcellentOver 150 ft

Figure 6.4 Results of riparian buffer analysis for the Conneauttee sub-basin. Data Sources: Aerial Photograph: Penn State Institutes of Energy and the Environment (2005). PAMAP Aerial Photographs. Accessed via Pennsylvania Spatial Data Access, http://www.pasda.psu.edu/default.asp . See Figure 3.2 for location of sub-basins. An enlarged map showing riparian buffer analysis of the entire Edinboro Lake watershed is included on the accompanying CD.

59

Crane

Rt 6N

I - 7

9

Angling Rd

Rt 9

9Plum St

0 0.50.25

Miles

Southern Edinboro Lake Watershed

Riparian Buffer Quality

Buffer Quality

PoorLess than 10 ft

Marginal10 ft - 35 ft

Moderate35 ft - 75 ft

Good75 ft - 150 ft

ExcellentOver 150 ft

Figure 6.5 Results of riparian buffer analysis for the southern Edinboro Lake watershed sub-basins. Data Sources: Aerial Photograph: Penn State Institutes of Energy and the Environment (2005). PAMAP Aerial Photographs. Accessed via Pennsylvania Spatial Data Access, http://www.pasda.psu.edu/default.asp . See Figure 3.2 for location of sub-basins. An enlarged map showing riparian buffer analysis of the entire Edinboro Lake watershed is included on the accompanying CD.

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6.1.2 Recommendations: Riparian Buffers

Recommendation: Riparian buffers of a minimum width of 35 ft should be restored on all streams in the Edinboro Lake watershed. Where adequate buffers already exist steps must be taken to ensure that these are preserved. The following recommendations for riparian buffer restoration are taken from the Pennsylvania Stream ReLeaf program (1997): 1) the buffer must be at least 35 feet wide from the top of the streambank to the buffer’s uphill edge (a width of 50 to 100 feet is strongly encouraged); 2) the buffer must contain at least two species of trees or shrubs, or a combination of trees and shrubs 3) natural regeneration is acceptable where nearby trees native to the area can provide a natural source of seeds, and where invasive plants can be controlled; 4) conservation of existing forested streamside areas should occur within at least a 100 foot wide corridor.

A number of factors should be considered in prioritizing streams for riparian buffer restoration. The most significant factor is obviously the willingness of the landowner to participate in a buffer restoration program. Additionally, priority should be given to 1) areas of agricultural land use, 2) headwater streams, and 3) areas where there are small gaps in otherwise adequate riparian buffers. Riparian buffers will be most effective in reducing the phosphorus load to Edinboro Lake when installed in areas where row crops, hay fields, and pasture land are in close proximity to streams. These ares should therefore be given the highest priority in riparian buffer restoration. Research has shown that riparian buffers are most effective in reducing pollution in the source areas or headwaters of streams and areas where the buffer would fill a gap between stream sections where adequate buffers are already present. The riparian buffer map shows several areas where headwater streams lack adequate buffers, particularly within the Shenango North and Whipple Creek basins. The map also shows that there are several small gaps in the buffers within the Conneauttee creek basin.

Agricultural drainage tile systems have been used throughout the watershed. The size and locations of tiled areas is not known. Where tile systems are present they may provide a conduit through which phosphorus and other pollutants enter the tributary streams bypassing riparian buffers. Low concentrations of phosphorus in groundwater (Ostrofsky et al., 2004) suggests that this may not be a significant problem in many areas particularly where tiles are present in abandoned agricultural areas. When selecting areas for riparian buffer restoration care should be taken to account for drainage tiles which could negate the benefit of the buffers.

Land use models indicate that approximately 7.9% of the phosphorus entering the lake is derived from runoff from residential areas. Much of this is derived from lawn areas. BMPs that can be implemented by individual home owners to reduce their phosphorus export will be discussed below. Riparian buffers will still be necessary in these areas in order to achieve sustainable reductions in phosphorus from residential lawns.

6.1.3 Cost and Benefit of Riparian Buffers

The AVGWLF software used to model non point source pollution sources within the Edinboro Lake watershed includes a PRedICT module (Pollution Reduction Impact Comparison Tool) that can be used to estimate the cost and effectiveness of implementing various BMPs (Evans et al., 2008). The cost estimation portion of the software was last updated in February 2008. The PRedICT module estimates that there

61

will be 10.2 kg of phosphorus removed from Edinboro Lake for each 1 mile of riparian buffer restored in areas of row crop land use within the watershed at a cost of approximately $3,000. Riparian buffer restoration in areas of other land uses will achieve less phosphorus reduction. It should be noted that the PRedICT module calculates a 52% reduction in phosphorus for restoration of riparian buffers. Other sources suggest that as much as an 85% reduction can be obtained (Dawes, 1999, VanRy,1999). Within the watershed there are 13.6 miles of stream in areas of row crop land use. Restoration of riparian buffers in these areas would result in the removal of 139 kg of phosphorus from the lake annually at an initial cost of $40,800. This would amount to a reduction of approximately 10% of the total phosphorus load to the lake. Within the Edinboro Lake watershed there are an additional 15.8 miles of stream lacking a minimum 35 foot riparian buffer in areas of land use other than row crops. Restoration of buffers in these areas would produce additional reductions in the phosphorus load to Edinboro Lake.

The cost estimate for repairing buffer restoration includes plants, materials, and labor for installation. Maintenance, which should be minimal after the first year or two, is not included. The cost of landowner compensation through conservation easements (see below) is also not included. The cost of restoration in areas where stream bank fencing and stabilization are necessary to deny pastured animals access to the stream the cost increases significantly to a minimum of $15,000 per mile. Because the potential for phosphorus (and bacteria) reduction in these areas is significantly higher, the additional expense will likely be justifiable.

6.1.4 Conservation Easements

The lack of adequate riparian buffers along streams in most cases can be attributed to two factors 1) economic conditions in the agricultural industry that encourage farmers to keep every possible acre in production and 2) the commonly held view that well manicured lawns and fields are desirable and natural landscapes are messy and reflect poorly on property owners (Ehrhart, 1999). To successfully restore and protect riparian buffers within the Edinboro Lake watershed these factors must be addressed. With regard to item number one, it is essential that property owners be compensated for lost income when agricultural land is incorporated into riparian buffers. This is most commonly accomplished through the use of conservation easements. An easement is a legal agreement to limit certain types of land uses. Land owners can choose to donate or sell easements on portions of their property and often increase the income generated by their land in doing so. Conservation easements protect land for future generations, improve water quality, and allow the property owner to retain certain private property rights while living on or using the land. Easements are tailored to meet the needs of the landowner while achieving specific conservation goals, such as improving water quality by preserving riparian buffers, or providing wildlife habitat. In return for the easement a property owner may receive direct compensation or tax benefits and increased property values. Because the land remains in private ownership it continues to provide an economic benefit to the community. In many regions conservation easements are credited with helping to preserve family farms, thereby preserving the rural character of communities threatened by uncontrolled development. (The Nature Conservancy, 2003).

One of the most successful conservation easement programs is the Conservation Reserve Enhancement Program (CREP) administered by the United States Department of Agriculture (USDA) Farm Service Agency (FSA). From the Pennsylvania CREP web site http://www.pgc.state.pa.us/crep/site/default.asp :

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CREP, or Conservation Reserve Enhancement Program, is a federal-state natural resource conservation program targeted to address state and nationally significant agricultural related environmental problems. Participants receive financial incentives from USDA to voluntarily enroll their lands in CREP contracts for 10 to 15 years. Participants remove cropland or marginal pastureland from agricultural production and convert the land to native grasses, forested buffers, and other habitat amendments for the benefit of soil, water, and wildlife resources.

CREP combines state and federal dollars with additional funding from non-government sources to tackle specific agriculturally-related environmental issues. In Pennsylvania, CREP initiatives are tailored to address the environmental concerns of the Chesapeake Bay and Ohio River drainages, as well as the surrounding upland habitat. The program is voluntary and offers financial incentives to encourage agricultural landowners and operators to enroll targeted environmentally-sensitive and potentially wildlife-friendly acres of pastureland and cropland. This includes the establishment of native grass stands, riparian buffers, wetlands, wildlife habitat, grass filter strips, and other land improvement practices. In January 2008 the CREP program enrolled its one millionth acre of land nationwide. A number of land owners within the Edinboro Lake watershed are currently participating in the CREP program. In addition to governmental programs such as CREP there are many local, state, and national conservation organizations and land trusts which establish easements and in some cases purchase highly sensitive environmental areas outright. Conservation organizations active in northwestern Pennsylvania include the French Creek Valley Conservancy http://frenchcreekconservancy.allegheny.edu , the Lake Erie Region Conservancy http://lerc.mercyhurst.edu/ , and the Western Pennsylvania Conservancy http://www.paconserve.org/.

Recommendation: The Edinboro Lake Watershed Association should work with landowners to increase the use of conservation easements as a means of establishing and protecting riparian buffers within the watershed. The ELWA will accomplish this by providing information and assistance to landowners interested obtaining easements on their property. The ELWA should establish a working group to explore the possibility of setting up a land trust or partnering with an existing conservancy to establish a mechanism for funding easements within the watershed.

6.1.5 Riparian Buffer Ordinances - Keeping What We’ve Got

In addition to restoring riparian buffers in those areas where they are currently lacking, it is equally important to conserve those areas where buffers currently exist. Retaining existing buffers is the most cost effective way to protect waterways from additional runoff. Implementing a Riparian Buffer Ordinance would ensure that buffers will be preserved and expanded as development occurs within the watershed. Riparian Buffer Ordinances have been implemented by several communities in Pennsylvania. These are most often communities such as ours that include a water resource which: 1) provides recreational opportunities; 2) represents a significant economic asset; and 3) is

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highly valued by local residents. The Pennsylvania Campaign for Clean Water (http://www.pacleanwatercampaign.org/) is currently lobbying state lawmakers to require a minimum buffer of 100 feet on all streams within the state. Buffer ordinances save local governments money by reducing pollution and stormwater runoff, eliminating the need of retrofitting a costly engineering solution. Because the presence of riparian buffers leads to higher property values, buffer ordinances provide the added benefit of increased local tax revenues.

Buffer ordinances can be tailored to the specific needs of the local community. They can be incorporated into zoning plans, stormwater regulations, or established as independent ordinances. As an example, the Centre Region Council of Governments (Centre County, PA) is currently developing a model riparian buffer ordinance to recommend to local community governments. This ordinance would establish two riparian buffer zones. Zone One would extend 35 feet from the edge of the stream. Uses permitted in Zone One would be natural open spaces with no human modification of the landscape. Conditional uses within Zone One would include selective cutting of trees of high value and stream crossings. Zone Two would extend from Zone One out an additional 65 feet. Permitted uses in Zone Two are open space uses including yard areas and agricultural uses existing at the time the ordinance is adopted. Conditional uses in Zone Two include new agricultural operations, stream crossings, public utility lines, select tree cutting, passive recreation such as camping and picnic areas, and naturalized stormwater basins. The ordinance includes a list of plants for riparian buffer restoration and provides for Riparian Buffer Management Plans to be prepared when future development is proposed along a stream corridor.

Recommendation: The Edinboro Lake Watershed Association should work with Edinboro Borough, Washington Township, and Franklin Township officials to develop a Riparian Buffer Ordinance in order to ensure the preservation of existing buffers and provide for the establishment of new buffers as development occurs within the Edinboro Lake watershed.

6.2 Wetlands Wetlands within the Edinboro Lake watershed perform essentially the same function as riparian buffers. Wetlands slow the flow of water to the lake and improve water quality by absorbing nutrients. In addition, wetlands provide wildlife habitat, store floodwater, facilitate groundwater recharge, and maintain surface water flow during dry periods (USEPA, 2001). Although this report does not include a detailed assessment of wetlands, their identification, preservation, and restoration is essential to improving water quality in the Edinboro Lake watershed. The destruction of wetlands at the north end of the lake in the 1950’s resulted in increased sedimentation and cultural eutrophication. Many of the wetlands identified in Figure 3.12 are located near streams and will be included in efforts to protect and preserve riparian buffers. Wetlands outside of riparian zones are often smaller and more susceptible to infilling or other damage during development. Approximately half of the original wetlands within the watershed have most likely already disappeared (Allegheny Watershed Network, 1999).

Recommendation: The ELWA should work to educate property owners regarding the nature and importance of wetlands within the Edinboro Lake watershed. This effort should include developing printed educational materials to be distributed to those seeking building permits within the watershed.

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6.3 Stormwater Management The GWLF-RUNQUAL model of non-point source pollution in the Edinboro Lake watershed calculates that 17.4% (247.2 kg/yr) of the phosphorus entering the lake is derived from developed land. Another 10.2% (143 kg/yr) is derived from runoff from transitional land which includes active construction sites, gravel driveways and parking areas, and gravel road shoulders. Stormwater runoff is a manageable source of pollution. Traditionally, stormwater management meant controlling the rate of flow to eliminate flooding. Current stormwater management techniques include Best Management Practices (BMPs) which improve water quality and promote groundwater recharge in addition to reducing peak flow rates. Reducing the amount of phosphorus entering Edinboro Lake from stormwater runoff will require a combination of the following: 1) controlling the peak rate of runoff derived from the watershed, 2) reducing the volume of runoff entering the lake, and 3) removing phosphorus from runoff before it enters the lake. To be sustainable, these controls must be applied to future development such that post-development loadings of phosphorus and other pollutants are decreased, or at a minimum not increased, relative to pre-development conditions. Extensive information describing stormwater BMPs are contained in the Pennsylvania Stormwater BMP Manual (PADEP, 2006) available at http://www.stormwaterpa.org.

6.3.1 The Low Impact Approach to Stormwater Management

Best Management Practices for stormwater management can be generally categorized as non-structural and structural. The Pennsylvania Stormwater Best Management Practices Manual describes what it terms “Low Impact Development” and “Conservation Design” as non-structural BMPs, referring to site design and construction practices which minimize the effects of development on the quantity and quality of stormwater runoff. Key elements of non-structural BMPs include minimizing ground disturbance during construction, reducing the amount of impervious cover, clustering development to preserve open spaces, and protecting natural water quality enhancement features such as riparian buffers.

Non-structural BMPs can be as simple as distancing storm drainage inlets from pollution sources such as parking areas and roadways. When possible, natural flow pathways should be used rather than manmade conveyances. Disconnecting impervious areas such as rooftops from storm sewers slows the discharge of water to waterways and promotes infiltration and filtration of runoff by natural vegetation. Another example of a non-structural BMP is the revegetation and reforestation of previously disturbed areas, particularly in riparian buffer areas.

Perhaps the best way to control stormwater runoff is to generate less in the first place. This is the idea behind Low Impact Development. Rather than traditional “urban sprawl” type developments, building should be encouraged to take place on the smallest footprint possible. Clustering development will promote the preservation of sensitive natural features such as riparian areas and wetlands, while keeping street, driveway, and parking area coverage to a minimum.

A variation of Low Impact Development referred to as Conservation Design is described in The Borough of Edinboro, Franklin Township and Washington Township Multi-Municipal Comprehensive Plan (2005). The Conservation Design approach has been adopted as an optional alternative to traditional development by Washington Township where new residential development capable of affecting Edinboro Lake is most likely to occur. Although intended primarily as a means to preserve interconnected

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networks of open space, Conservation Design reduces runoff by limiting the amount of impermeable surfaces in a new development. Paired with a riparian buffer ordinance this approach to development would help to significantly improve the water quality in the Edinboro Lake watershed. The Joint Municipal Comprehensive Plan notes that because Washington Township’s Conservation Design ordinance is voluntary the amendments to their comprehensive plan should be reviewed periodically and attempts should be made to make this option more attractive to developers. Conservation Design should be considered for all developments, but may be particularly effective in existing large, open space areas to be developed such as the area near Culbertson Hills Golf Course or the former Highlander Golf Course.

6.3.2 Structural Facilities for Control of Runoff

Structural BMPs capture runoff and allow it to soak into the ground or filter it before discharge. Many of these techniques are based on natural systems and include soils and plants as part of their function (PADEP, 2006). To fit the needs of particular sites, there are many design options available, examples of which include, but are not limited to the following:

Infiltration Basins are shallow impoundments which temporarily store water and allow it to infiltrate permeable soil. Infiltration basins reduce runoff rates and volume, promote groundwater recharge, and filter pollutants using soil. Infiltration BMPs can remove up to 85% of phosphorus from stormwater runoff. Installing an infiltration basin to treat runoff from 10 acres of high density commercial development would remove approximately 8.6 kg/year of phosphorus from the lake. A disadvantage is that infiltration is only possible in the more permeable soil types with low groundwater tables. An example of where infiltration basins could be effective in the Edinboro Lake watershed is downstream of the Giant Eagle plaza on Route 99 east of the lake.

Vegetative Swales are broad shallow channels designed to transport runoff while allowing for infiltration. Swales are densely planted to filter sediments and hold soil in place. Vegetative swales are used in place of traditional curbs, gutters, storm sewers, and roadside ditches. An example of where vegetative swales could be used is in subdivisions such as Angling Acres and Conneauttee Heights to replace existing systems of roadside ditches and storm sewers.

Rain Gardens are excavated shallow depressions planted with vegetation selected to treat runoff. With the right type of underlying soils, rain gardens can also promote infiltration. Installing rain gardens and vegetative swales to treat runoff from 10 acres of medium density residential land would remove approximately 2.6 kg/yr of phosphorus from the lake. Rain gardens might be particularly effective in subdivisions with larger lot sizes such as Obed Heights and Forrest Drive.

Runoff Capture and Reuse BMPs are devices which collect and store water for non-potable use such as irrigation or washing. Rain barrels and cisterns to collect roof drain runoff are examples which could be utilized even in dense subdivisions with small lots such as the Lakeside area in Edinboro.

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Figure 6.6 Plan of a typical infiltration basin (PADEP, 2006)

Figure 6.7 Plan and photo of a typical vegetative swale. (PADEP, 2006)

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Figure 6.8 Plan and photo of a typical rain garden installed in a residential development. (PADEP, 2006)

Water Quality Inlets are stormwater inlets specially designed to remove pollutants from runoff as it enters a storm sewer system. At Harvey’s Lake in Luzerne County, PA a water quality inlet was installed to remove phosphorus from storm water runoff from a 28 acre subdivision containing 26 homes. Subsequent monitoring revealed that this water quality inlet removed approximately 45% of the phosphorus contained in the runoff. Water quality inlets might be particularly useful where the concentration of developed land near the lake shore makes it difficult to implement other BMPs that require more space. The disadvantage of water quality inlets is that they must be properly and frequently maintained to be effective, which can be somewhat costly.

Not only can these stormwater BMPs be applied to new development, BMPs can also be applied to existing stormwater collection and conveyance systems as retrofit projects. A good example in the French Creek watershed is a retrofit of an existing stormwater collection system for a parking area owned by the Redevelopment Authority of the City of Meadville. This project, funded by a PA DEP Growing Greener Grant obtained by the French Creek Project, constructed infiltration trenches, bioretention ponds, and rain gardens to collect and treat runoff from the parking area, which reduced the peak rate and volume of stormwater, and improved the water quality of the remaining runoff.

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Figure 6.9 Profile of a typical three chambered Water Quality Inlet. In addition to removing phosphorus bearing sediments, oil, grease, and trash are also removed. (USEPA, 1999)

6.3.3 Roadside Drainage Ditches

A significant amount of stormwater runoff entering Edinboro Lake is derived from roadside drainage ditches. Most of the land classified as transitional, which accounts for 10.2% (143 kg/yr) of the phosphorus budget in the GWLF-RUNQUAL model, is adjacent to these roadside ditches. Proper construction and maintenance of roadside ditches can reduce the amount of phosphorus entering Edinboro Lake. Maintaining vegetative cover within the ditches will hold phosphorus bearing sediments in place, reduce erosion, and filter pollutants from runoff. In areas where steep slopes (<5%) or high flow prevent vegetative covers, gravel and riprap linings must be used to prevent erosion. Where possible, flows from roadside ditches should be diverted to BMPs such as constructed wetlands or infiltration basins rather than discharging directly to streams.

6.4 Land Use Changes – Residential Development From 1978 to the present the amount of developed land within the watershed as increased from 8.8% to 13.1% of the total (USEPA, 1981). Much of this development occurred without the implementation of adequate stormwater management controls. An increase in the percentage of developed land is inevitable in an economically healthy community. Change in land use through time represents a potential threat to water quality within the watershed. However, if carefully managed and planned, development can provide an opportunity to improve water quality.

The development and enforcement of stormwater management requirements is the responsibility of both state and local governments. For land development projects that disturb over 1 acre of land, Federal and State law requires the issuance of a National Pollutant Discharge Elimination System (NPDES) permit by PA DEP and/or the Erie County Conservation District. The permit addresses stormwater runoff during construction in the form of erosion and sedimentation controls. The permit also requires

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the applicant to develop a post-construction stormwater management plan to implement BMPs for control of stormwater runoff peak rates, volume, and quality.

Local municipalities are also empowered to develop their own stormwater management regulations for new land development projects. In the Edinboro Lake watershed, local stormwater management requirements are ambiguous with regard to the protection of water resources. The Borough of Edinboro’s Subdivision and Land Development Ordinance addresses on-site drainage requirements, but does not provide for mitigation of off-site impacts of stormwater runoff. Washington Township and Franklin Township both provide for the development of a stormwater management plan by the developer to address on-site drainage, impacts to downstream facilities and properties, and peak rate control for up to the 100-year storm. However, none of the municipalities in the watershed require runoff volume control or water quality BMPs.

Erie County is currently developing a county-wide watershed-based stormwater management plan. This plan is intended to be a strategy for municipalities to implement consistent, comprehensive stormwater management throughout the county. The plan will present model ordinances to municipalities, and require municipal adoption of certain minimum criteria. Municipalities will also be able to adopt other stormwater management requirements provided that the minimum criteria are met.

Recommendation: The Edinboro Lake Watershed Association should work with Washington Township, Borough of Edinboro, and Franklin Township to promote planning and development that follows conservation design principles. ELWA should participate in the review of significant land development proposals during the planning process in order to suggest low impact development approaches such as riparian buffers, minimizing impervious surfaces, clustered development, reforestation, and other non-structural and structural stormwater management BMPs. Recommendation: The ELWA should participate in the upcoming updates of stormwater management ordinances that will be required by Erie County following the conclusion of the Erie County stormwater management study. ELWA should provide recommendations for the ordinances particular to the betterment of the Edinboro Lake watershed. Such recommendations should include a mandatory zero net increase in particulate, phosphorus, and nitrate loads, consistent with the water quality control guidelines of the Pennsylvania Stormwater BMP Manual. Many watersheds in Pennsylvania, including Walnut Creek in Erie County, with 303(d) impaired streams and lakes already have this mandatory zero net increase requirement. Recommendation: The ELWA will develop educational materials which describe stormwater BMPs for planning and construction of residential areas to be distributed to individuals seeking building permits within the watershed. The ELWA should establish specific examples of BMPs throughout the watershed to be used as models for others to follow. Recommendation: The ELWA should provide technical guidance and administrative support for stormwater management activity funding requests by Washington Township and/or the Borough of Edinboro. The ELWA should work closely with PA DEP to achieve a priority status for watershed project applications to receive funds from the Growing Greener program and other programs that fund educational programs, nutrient reduction, and establishment of BMPs. The ELWA

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should also suggest appropriate stormwater BMP retrofit projects for the improvement of existing stormwater conveyance and detention systems.

6.5 What can a small property owner can do to reduce phosphorus in Edinboro Lake?

There are many relatively easy and inexpensive steps that the average residential homeowner can take to reduce the amount of phosphorus entering the lake. Even if the water leaving your property is relatively clean and free of pollutants, the excess runoff will result in increased erosion of sediments “downstream” ultimately resulting in higher amounts of phosphorus and other pollutants entering the lake.

• Minimize impervious surfaces. Use gravel and paving stones instead of concrete for walkways, patios, etc. Driveways can be constructed of porous asphalt which allows water to soak into the ground.

• Use vegetated berms and swales to redirect runoff from impervious surface into areas where it can soak into the ground. Simply planting a narrow garden alongside an impervious surface can catch runoff. Gravel lined trenches can also be constructed along edges of driveways to help speed infiltration. Be sure and check for the presence of underground utilities before digging.

• Direct water from downspouts and sump pumps into lawn areas rather than directly onto an impervious surface or into a roadside ditch or storm drain. If your soils are too impermeable to allow infiltration consider building a rain garden. Rain gardens are bowl shaped depressions in your lawn which capture runoff from your roof, driveway, and sidewalks and allow it to soak into the ground. Rain gardens can be planted with a variety of beautiful plants which prefer to live in wet conditions. Remember that it is illegal to connect downspouts and sump pumps directly to the sanitary sewer.

• Wash your car on the lawn rather than in the driveway.

• Plant a riparian buffer along any streams on your property.

• Clean up pet waste.

• Care for your lawn in ways that protect the watershed.

6.5.1 Lawn Management

The GWLF-RUNQUAL model of non-point source pollution within the Edinboro Lake Watershed predicts that 123.4 kg of phosphorus representing 8.7% of the total entering the lake is derived from runoff from residential land. A significant amount of this is runoff from residential lawns. Misuse of lawn fertilizer represents a manageable non-point source of phosphorus (Coastal Environmental Services, 1994). Growth of terrestrial plants such turf grasses is typically limited by the availability of nitrogen. Most soils contain adequate phosphorus for healthy turf grass growth. Any phosphorus added as fertilizer will eventually end up in the lake where it will result in increased algal growth and eutrophication.

By adopting the following lawn care practices, homeowners can help reduce that amount of phosphorus pollution in Edinboro Lake:

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• Use a mulching lawnmower. The increased organic matter left behind will improve the water-retention capabilities of your soil and reduce runoff. While you’re at it, mulch the fall leaves into your yard. This increased organic matter also reduces the need for fertilizer.

• Raise the height of your mower. Longer grass has deeper roots, is more drought resistant, and improves the water retention of your lawn. Longer grass also makes it more difficult for weeds to establish themselves. Professionals recommend cutting your grass to between 2 and 3 inches.

• Aerate your lawn. The soil under most suburban lawns is severely compacted which prevents rainwater from soaking into the ground. This causes an excess of surface runoff from the lawn which carries pollutants and sediments into the storm-water system and eventually into the lake. Aerating your lawn on an annual basis increases permeability and reduces surface runoff. Lawn aerators can be rented or you can call a local lawn-care company.

• Use a phosphorus-free fertilizer. Soil tests reveal that most lawns have sufficient phosphorus. Adding phosphorus to these does not improve the quality of the lawn. Runoff from fertilized lawns is very rich in phosphorus. If you’re skeptical, try a soil test. If your soil has at least 20 parts per million (ppm) phosphorus then you don’t need a phosphorus fertilizer. If the test does indicate a need for phosphorus, consider an organic source such as mulch or bone meal. Both these additions release phosphorus more slowly so that more is available to your grass and less ends up in the lake. Fertilizers are labeled with the relative amounts of nutrients they provide in the order Nitrogen – Phosphorus – Potassium (N-P-K). Choose a fertilizer where the second digit is a “zero”. For example a fertilizer labeled 22-0-15 would contain no phosphorus. Proper use of fertilizer is also important. Follow the instructions supplied with the fertilizer. Don’t over fertilize, fertilize when the ground is wet, but not when a large rain storm is expected. Typical turf grasses grown in northwest Pennsylvania only require nutrients in spring and fall. Fertilizers applied at other times of the year will not benefit your lawn and will likely end up in the lake where 1 pound of phosphorus results in the growth of 500 pounds of algae.

These practices will be most effective if they are adopted by a significant number of watershed residents. It is possible that as much as a 30% reduction in phosphorus can be achieved by the use of phosphorus free lawn fertilizers (Coastal Environmental Services, 1994). If we assume that all the non-point source pollution from residential areas is derived from lawns this would result in a 37 kg reduction in phosphorus entering Edinboro Lake.

Recommendation: The Edinboro Lake Watershed should implement an aggressive on-going education program to inform watershed residents of the benefits of lawn care best management practices, particularly the use of phosphorus free lawn fertilizers.

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7 Are We There Yet? Setting Goals and Tracking Progress in Lake Restoration

One of the challenges in lake management is setting realistic, economically feasible, and measurable goals. The major difficulty in establishing goals for restoration is estimating the condition of the lake prior to human settlement of the watershed (Ostrofsky and Bradley, 2006). One common and often mistaken assumption is that all lakes were originally oligotrophic with average total phosphorus concentration of <0.01 mg/L. Establishing unrealistic goals based on this assumption will lead to frustration and may lead to a watershed community abandoning the restoration effort.

What was the “pristine state” of Edinboro Lake? There are several techniques that can be used to quantitatively estimate the trophic state of a lake prior to human settlement of a watershed. Ostrofsky and Bradley (2006) used a land use modeling approach to estimate pre-settlement conditions for 7 natural lakes in northwest Pennsylvania. By assuming that the entire watershed consisted of forested land cover they calculate that Edinboro Lake was in a mesotrophic state (average total phosphorus 0.016 mg/L) prior to human settlement. Pre-historic lake conditions can also be estimated from analysis of algae in sediment cores. Several sediment cores from Edinboro Lake have been recently collected but detailed analysis of their algal content has not been completed. However, the high organic content of these cores suggest that the lake has been in a mesotrophic-eutrophic state for at least the past 10,000 years. These studies suggest that any attempt to restore Edinboro Lake to a crystal clear, oligotrophic lake would be doomed to failure. A more reasonable and possibly obtainable goal would be to restore Edinboro Lake to a mesotrophic state (Ostrofsky and Bradley, 2006).

Using equations from Nurnberg (1998) and Ostrofsky (1978) it is possible to calculate the average total phosphorus concentrations that would result from incremental 10% reductions of the phosphorus budget to Edinboro Lake. The results of this calculation are given in Table 7.1. If we assume a starting average phosphorus budget of 1,400 kg/year, each 10% reduction in phosphorus results in removal of 140 kg of phosphorus from the lake. To achieve a mesotrophic state (trophic state index <50) would require a 40% reduction (536.4 kg) in the phosphorus budget for the lake.

It is important to maintain an active monitoring program in order to track progress in lake restoration. Note that a 10% reduction in the lake phosphorus budget would produce only a 0.004 mg/L reduction in the average phosphorus concentration, a 10cm increase is secchi disk transparency, and less than a 2 point reduction in the trophic state index. Given the natural variation in the phosphorus budget and the limitations of the testing procedures a 10% change would not be detected by the current lake monitoring program.

Recommendation: The ELWA should expand its current monitoring program in order to more accurately track progress in the restoration of Edinboro Lake. The monitoring program should be designed to specifically evaluate the effectiveness of implemented BMPs. Improvements to the existing monitoring program that could be implemented immediately include more frequent Secchi disk measurements of water clarity to track the frequency and duration of algal blooms and periodic measurement of phosphorus levels in tributary streams. The ELWA should consider additional techniques such as using biological indicators (algae and macroinvertebrates) which may be more sensitive indicators of changes in water quality.

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Table 7.1 Trophic State and Total Phosphorus as a Function of Total Phosphorus Budget for Edinboro Lake

Phosphorus Load

% Reduction P Reduction

Total Phosphorus

Trophic State Index

kg/yr kg mg/L

1400 0% 0 0.038 56.18

1260 10% 140 0.035 54.66

1120 20% 280 0.031 52.96

980 30% 420 0.027 51.03

840 40% 560 0.023 48.81

700 50% 700 0.019 46.18

560 60% 840 0.015 42.96

420 70% 980 0.012 38.81

280 80% 1120 0.008 32.96

140 90% 1260 0.004 22.96

8 Watershed Management Plan In the previous chapter a series of recommendations are presented which together constitute a management plan to reduce the annual phosphorus load and improve the trophic state of Edinboro Lake. The recommendations are restated as specific tasks below separated into four categories:

Riparian Buffer and Wetland Restoration

1. The ELWA should work with interested property owners to establish riparian buffers of a minimum width of 35 ft on streams in the Edinboro Lake watershed.

2. The ELWA should work with landowners to increase the use of conservation easements as a means of establishing and protecting riparian buffers within the watershed.

3. Develop a Riparian Buffer Ordinance in order to ensure the preservation of existing buffers and provide for the establishment of new buffers as development occurs within the Edinboro Lake watershed.

4. The ELWA should work to educate property owners regarding the nature and importance of wetlands within the Edinboro Lake watershed. This effort should include developing printed educational materials to be distributed to those seeking building permits within the watershed.

Stormwater Management 5. Promote planning and development that follows conservation design principles

which encourage low impact development approaches such as riparian buffers,

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minimizing impervious surfaces, clustered development, reforestation, and other non-structural and structural stormwater management BMPs.

6. Update stormwater management ordinances to include a mandatory zero net increase in particulate, phosphorus, and nitrate loads, consistent with the water quality control guidelines of the Pennsylvania Stormwater BMP Manual.

7. Develop educational materials which describe stormwater BMPs for planning and construction of residential areas to be distributed to individuals seeking building permits within the watershed.

8. Establish specific examples of stormwater BMPs throughout the watershed to be used as models for others to follow.

9. Provide technical guidance and administrative support for stormwater management activity funding requests by Washington Township and/or the Borough of Edinboro.

10. Achieve a priority status for watershed project applications to receive funds from the Growing Greener program and other programs that fund educational programs, nutrient reduction, and establishment of BMPs.

11. Develop stormwater BMP retrofit projects for the improvement of existing stormwater conveyance and detention systems.

Education 12. Implement an on-going education program to inform watershed residents of the

benefits of phosphorus reduction BMPs that can be practiced by residential property owners, including lawn care and fertilizer management and stromwater drainage.

Watershed Monitoring

13. Expand the current monitoring program in order to more accurately track progress in the restoration of Edinboro Lake.

Restoration of Edinboro Lake is not going to happen overnight. The current condition of the lake is the result of over 200 years of human habitation and alteration of the watershed. Reducing non-point source pollution within any watershed is a difficult undertaking and there will be successes and setbacks along the way. The ultimate goal to “restore” Edinboro Lake to as close to its original state as possible will be challenged by increased development and population within the watershed. Highest priorities should be given those tasks that offer pre-emptive protection and restoration such as implementing and updating riparian and stormwater ordinances. Second priority should be given to those tasks that result in a measurable decrease in the phosphorus budget of the lake such as riparian buffer restoration and retrofitting stormwater BMPs. Keeping residents of the watershed informed regarding efforts to restore the lake will ensure the success of this plan.

The recommendations found within this report have been implemented successfully at other watersheds in our region and provide a feasible, cost effective means by which water quality in Edinboro Lake can be improved. Edinboro Lake is the centerpiece of our community. It provides us with opportunities for recreation, is an important economic asset, and an irreplaceable natural resource. Just as we enjoy using the lake for fishing, boating, and swimming, we can also take pride in watching the lake improve due to our efforts to restore it.

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9 References Allegheny Watershed Network, 1999. Wetlands: Natures Water Quality Protectors. A

Watershed Primer for Pennsylvania: A collection of essays on watershed issues. Pennsylvania Environmental Council, Allegheny Watershed Network, and the Pennsylvania Department of Environmental Protection.

Ashley, J. 2009. Personal communication. Department of Biology and Health Services, Edinboro University of Pennsylvania, Edinboro, PA.

Bachman, M., M. Hoyer, and D.E. Canfield. 1999. Living at the Lake: A Handbook for Florida Lakefront Property Owners, University of Florida Institute of Food and Agricultural Sciences. 182 p.

Boker, H. N. and J. K. Hallenburg. 1978. Edinboro Lake Sensitivity Study. Prepared

for Washington Township Sewer and Water Authority by Hill & Hill Engineers, Inc. 41p.

Borough of Edinboro, Franklin Township and Washington Township Multi-Municipal Comprehensive Plan. 2005. Prepared by the Joint Municipal Planning Commission.

Byars, R. and Zimmerman, B.S. 2000. Unpublished bathymetric map. Department of Geosciences, Edinboro University of Pennsylvania.

Carlson, R. E. 1977. A trophic state index for lakes. Limnology and Oceanography 22:361-369

Coastal Environmental Services. 1994. Phase I diagnostic-feasibility study of Harveys Lake Luzerne County, PA. Submitted to U.S. EPA Region III and Pennsylvania DER Bureau of Land and Water Conservation.

Cole, Larry. 1999. The Development of Lakeside. Presentation to Edinboro Area Historical Society. July 29, 1999. Preserved on DVD in E.A.H.S. archives.

Cowardin, L. M., V. Carter, F. C. Golet, E. T. LaRoe. 1979. Classification of wetlands and deepwater habitats of the United States. U.S. Department of the Interior, Fish and Wildlife Service, Washington, D.C. 131pp.

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