15 minute read

Lake by Lake Snapshot

LAKE MENDOTA

cleanlakesalliance.org/lake-mendota

Lake Mendtota

2018 Phosphorus Levels: 0.025 mg/L Good

2018 Water Clarity: 6.6 feet Good

Lake MendotaWatershed area (acres): 72,094

Surface area (acres): 9,842

Shoreline (miles): 22

Maximum depth (feet): 82

Mean depth (feet): 42

Flushing rate: 4.4 years

Lake Mendota is the largest lake in the Yahara chain of lakes. It is surrounded by mostly agricultural land with areas of rapid urban growth. To improve water quality in the lake, the Yahara CLEAN plan calls for reducing phosphorus runoff from both urban and rural areas. Improvements to reduce phosphorus loading into Lake Mendota will help improve water quality in the other three lakes in the chain (Monona, Waubesa, and Kegonsa) by reducing the amount of phosphorus flowing to the lower lakes via the Yahara River. The following projects reported by partners in 2018 will help us make progress toward meeting water quality goals for Lake Mendota:

Dane County, Yahara WINS, and Clean Lakes Alliance continued support for a pilot project at nine farms testing manure composting. The project by Yahara Pride Farms will reduce pathogens and help farmers manage manure in the winter by composting instead of winter spreading.

Yahara Pride Farms continued to implement costeffective, farmer-led practices to protect soil and water quality, and piloted innovative practices like manure composting (1).

Dane County

Worked with farmers to implement practices that divert phosphorus from the lake (1).

Permanently protected 95.5 acres and granted funds to help purchase 100.9 acres at Cherokee Marsh Conservation Park (2).

Permanently protected 11 acres in Token Creek County Park and Natural Resource Area (3).

Removed 2.7 miles of phosphorus-laden legacy sediment from Dorn Creek as part of the “Suck the Muck” project (4).

Began construction on a $1.6 million nutrient concentration system at the Middleton digester that will further treat and filter manure utilizing reverse osmosis technology, and reduce the risk of phosphorus runoff (5).

City of Madison approved $2.36 million to purchase a 31-acre addition to Cherokee Marsh Conservation Park (2).

Village of DeForest

Constructed 12 public/private stormwater facilities, maintained a 40-acre wetland in the Marvin & Marie Scheweers Natural Area, and restored wetlands in Reigstand Park (6).

Maintained a high-quality sedge meadow along the Yahara River Trail (7).

Friends of Cherokee Marsh maintained 95 acres with a prescribed burn at Yahara Heights Park (8) and continued to collect critical information on stream health as part of the Yahara WINS volunteer monitoring program.

Friends of Pheasant Branch Conservancy evaluated the feasibility of a carp bubble barrier system in Pheasant Branch Creek through a Clean Lakes Grant (9).

Experts exploring feasibility of a bubble barrier in Pheasant Branch Creek

UW-Madison Lakeshore Nature Preserve worked with staff to remove woody invasive plants from 17 acres, sow native seed on 11 acres, and control invasive garlic mustard plants on more than 50 acres of the 300-acre reserve (10).

Sunrise over Marshall Beach

HOW WAS THE WATER?

Lake Mendota summer water quality conditions are now linked to the recent invasion of zebra mussels. The full effect of zebra mussels in the Yahara lakes is still uncertain. Results from other infested lakes suggest increases in water clarity in the middle of the lakes will occur. However, shoreline management problems could get worse from increased aquatic plant growth, and possible increases in filamentous algae and scums of cyanobacteria. Summer water quality in 2018 was also impacted by the unusual amount of flow into and out of the lake resulting from above normal precipitation in the region.

In 2018, total phosphorus levels and water clarity were “good” in the middle of the lake, according to DNR criteria, but the 18 reports of cyanobacteria blooms were above the 4-year summer median of 7.5.

Cluster of zebra mussels

In contrast to the conditions in the middle of the lake, a large number of cyanobacteria blooms closed beaches located on the nearshore of the lake. Based on data collected by Public Health Madison & Dane County, Lake Mendota beaches were closed a record number of 78 days from Memorial Day to August 20th, compared to the summer 2010-17 median of 35 days for the whole summer. After August 20th, all the beaches were closed for the remainder of the season (August 21 – Labor Day) due to flood conditions.

LAKE MONONA

cleanlakesalliance.org/lake-monona

Lake Monona Watershed

2018 Phosphorus Levels: 0.030 mg/L Good

2018 Water Clarity: 6.6 feet Good

Lake Monona Watershed area (acres): 61,643

Surface area (acres): 3,274

Shoreline (miles): 13

Maximum depth (feet): 64

Mean depth (feet): 27

Flushing rate: 9.5 months

Lake Monona is the second lake in the Yahara chain of lakes as water flows south from Lake Mendota. Most of the land surrounding and directly draining to the lake is urban. The Yahara CLEAN plan for the Lake Monona Watershed calls for action to improve leaf management and reduce erosion from construction sites. Here is a brief summary of the 2018 projects reported by partners that will help us meet water quality goals for Lake Monona:

Dane County granted funds to City of Madison for an Ultra Low-Dose Alum Pilot. The pilot project is a collaboration with the University of Wisconsin- Madison to assess the effectiveness of adding a trace amount of aluminum sulfate to detention basins to prevent phosphorus from leaching from captured sediment. Alum is a chemical that binds to phosphorus, making it unavailable for algae growth (1).

City of Madison Completed work on the Jacobson Furey Pond near Starkweather Creek and Dondee Pond near Highway 51 and Cottage Grove Road (2).

Repaired river banks at Heritage Prairie Greenway (3).

Repaired river banks at heritage Prairie Greenway
Photo courtesy City of Monona

Constructed nine terrace rain gardens and expanded public messaging about leaf-free streets (4).

City of Monona (5)

Removed phosphorus-laden sediment from Winnequah Park Lagoon.

Added 29 storm drains to their “Adopt a Storm Drain and Leaf Management Program.”

Inlet mural near Monona Public Library
Photo courtesy of City of Monona

Cleaned one-third of the city’s inlet catch basins.

Friends of Starkweather Creek held monthly outings to spark interest in the creek and restored areas near the Dixon Greenway, Washington Manor Park, and Eken Park with native plantings (6).

Shoreline Swim 2018

HOW WAS THE WATER?

Lake Monona summer water quality conditions are now linked to the recent invasion of zebra mussels. The full effect of zebra mussels in the Yahara lakes is still uncertain. Results from other infested lakes suggest increases in water clarity in the middle of the lakes will occur. However, shoreline management problems could get worse from increased aquatic plant growth, and possible increases in filamentous algae and scums of cyanobacteria. Summer water quality in 2018 was also impacted by the unusual amount of flow into and out of the lake resulting from above normal precipitation in the region.

In 2018, total phosphorus levels and water clarity were “good” in the middle of the lake, according to DNR criteria, but the six reports of cyanobacteria blooms were above the 4-year summer median of 7.5. Beaches were closed a record number of days, primarily due to cyanobacteria blooms.

HOW WERE THE BEACHES?

In contrast to conditions in the middle of the lake, a large number of cyanobacteria blooms closed beaches located on the nearshore of the lake. According to data collected by Public Health Madison & Dane County, Lake Monona’s beaches were closed a record number of 64 days from Memorial Day to August 20th, compared to the long-term median of 33 days for the whole summer. Beaches were closed primarily due to cyanobacteria or a combination of high E. coli and cyanobacteria. After August 20th, all the beaches were closed for the remainder of the season (August 21 – Labor Day) due to flood conditions.

LAKE WINGRA

cleanlakesalliance.org/lake-wingra

Lake Wingra Watershed

2018 Phosphorus Levels: 0.056 mg/L Good

2018 Water Clarity: 3.0 feet Fair/Good

Lake Wingra Watershed area (acres): 3,456

Surface area (acres): 345

 Shoreline (miles): 4

Maximum depth (feet): 21

Mean depth (feet): 9

Flushing rate: 1.3 years

Lake Wingra, a small, shallow lake located within the City of Madison, is connected to Lake Monona via Wingra (Murphy) Creek. The watershed is mostly urban but also includes the University of Wisconsin- Madison Arboretum. Because of its urban environment, the lake faces many challenges, including excess nutrients and road salt (chloride) from urban runoff. Here is a brief summary of the reported 2018 projects that will help us meet water quality goals for Lake Wingra:

City of Madison added several new green infrastructure features during the 2018 Monroe Street reconstruction, including:

A large underground screen structure in Wingra Park to capture sediment and debris within the storm sewer system.

Stream bank stabilization project at Wingra Park
Photo courtesy of City of Madison

Two bioretention systems to remove contaminants and sediment.

A rock infiltration trench along the edge of Edgewood College to help stormwater infiltrate into the ground (1).

Two rain gardens and 350 feet of stabilized shoreline on Wingra Creek.

Rain garden at Wingra Park

Friends of Lake Wingra is working with the City of Madison to implement the recommendations of the Lake Wingra Watershed Management Plan. The plan addresses water quality challenges such as chlorides, infiltration, and phosphorus runoff (2).

Musky jumping the Wingra Creek Dam
Photo courtesy of Jeff Halverson Photography LLC

HOW WAS THE WATER?

Lake Wingra summer water quality conditions are linked to the success of the March 2008 carp removal from the lake. Prior to the carp removal, during 1996-2007, median summer phosphorus was 0.056 mg/L and clarity transparency was 2.0 ft. After the carp removal, during 2008-2017, median phosphorus and clarity were 0.034 mg/L and 3.7 feet, respectively – a major improvement for the shallow lake. In 2018, total phosphorus levels were “good” and clarity conditions were on the border between “fair” and “good,” according to Wisconsin DNR criteria.

HOW WERE THE BEACHES?

FairPoorAccording to data collected by Public Health Madison & Dane County, Lake Wingra’s beach was closed 11 times in 2018, primarily due to high E. coli levels. After August 20th, all the beaches were closed for the remainder of the season (August 21 – Labor Day) due to flood conditions.

LAKE WAUBESA

cleanlakesalliance.org/lake-waubesa

Lake Waubesa Watershed

2018 Phosphorus Levels: 0.065 mg/L Fair

2018 Water Clarity: 3.9 feet Good

Lake Waubesa Watershed area (acres): 28,160

Surface area (acres): 2,080

Shoreline (miles): 9

Maximum depth (feet): 34

Mean depth (feet): 16

Flushing rate: 2.8 months

Lake Waubesa is the third lake in the chain as the Yahara River flows south from Lake Monona through Upper Mud Lake. Work in the Mendota and Monona Watersheds to prevent phosphorus runoff is helping Lake Waubesa since much of the phosphorus in the lake flows from the upper lakes in the chain. The watershed is a mix of urban and rural landscapes. The Yahara CLEAN plan for the Lake Waubesa Watershed calls for action to improve agricultural practices and improve control of construction erosion. Here is a brief summary of the 2018 projects reported by partners that will help us meet water quality goals for Lake Waubesa:

Spent $5.5 million to build a renewable natural gas (RNG) off-loading station as part of a $28 million county RNG facility. Other RNG producers, like dairy digesters located north of Lake Mendota, can bring their fuel and inject it into the pipeline making it economically feasible to produce renewable energy and clean up our lakes (1).

RNG off-loading station
Photo courtesy of Dane County

Permanently protected 35 acres in the southern Waubesa Wetlands Natural Resource Area (2).

WAUBESA WETLANDS

The watershed for the lake includes the Waubesa Wetlands, which, according to the Wisconsin DNR, are one of the highest-quality and most diverse wetlands remaining in southern Wisconsin and are very important to helping the water quality of the lake.

Installed an exclosure to improve Goodland County Beach water quality (3).

Village of Cottage Grove restored a 1.5-acre wetland on the north edge of the village, called “Conservancy Court Wetland” (4).

Capital Area Regional Planning Commission worked with the University of Wisconsin-Madison to study the Waubesa Wetlands and make management recommendations. As a result of their study and community engagement, the Friends of Waubesa Wetlands was formed in 2018 (5).

Friends of Waubesa Wetlands formed at the end of 2018 and held workdays throughout the year to remove invasive species and improve wildlife habitat.

Sunrise over Lake Waubesa
Photo courtesy of Jane Adams

HOW WAS THE WATER?

Lake Waubesa summer water quality conditions are now linked to the recent invasion of zebra mussels. The full effect of zebra mussels in the Yahara lakes is still uncertain. Results from other infested lakes suggest increases in water clarity in the middle of the lakes will occur. However, shoreline management problems could get worse from increased aquatic plant growth, and possible increases in filamentous algae and scums of cyanobacteria. Summer water quality in 2018 was also impacted by the unusual amount of flow into and out of the lake resulting from above normal precipitation in the region.

In 2018, total phosphorus levels were “fair” and water clarity was “good” in the middle of the lake, according to DNR criteria, but the nine reports of cyanobacteria blooms were above the 4-year summer median of four.

HOW WERE THE BEACHES?

Based on data collected by Public Health Madison & Dane County, Lake Waubesa beaches were closed nine days from Memorial Day to August 20th, compared to the 2010-17 median of 15, all due to cyanobacteria. After August 20th, all the beaches were closed for the remainder of the season (August 21 – Labor Day) due to flood conditions.

LAKE KEGONSA

cleanlakesalliance.org/lake-kegonsa

Lake Kegonsa Watershed

2018 Phosphorus Levels: 0.089 mg/L Fair

2018 Water Clarity: 4.6 feet Good

Lake Kegonsa Watershed area (acres): 34,560

Surface area (acres): 3,210

Shoreline (miles): 10

Maximum depth (feet): 31

Mean depth (feet): 17

Flushing rate: 4 months

Lake Kegonsa is the lowest and fourth lake in the Yahara chain of lakes and is surrounded primarily by agricultural land. Most of the phosphorus in Lake Kegonsa comes from the upper lakes in the chain. The Yahara CLEAN Plan calls for improvements to agricultural cropping practices in this watershed. Here is a brief summary of the 2018 projects reported by partners that will help us meet water quality goals for Lake Kegonsa:

Wisconsin Department of Natural Resources, through the Rough and Detrimental Fish Removal Program, contracted anglers to remove close to 100,000 pounds of carp to reduce resuspension and internal loading of phosphorus from the lake sediments into the water column. The Wisconsin DNR estimates 5,552 pounds of phosphorus reduction per year of internal loading within the lake as a result of the removal (1) .

Dane County installed more than six miles of buffers in Door Creek through the Harvestable Buffer Program (2).

Town of Dunn* enhanced their leaf collection program with $30,000 from Yahara WINS. The town bought a leaf vacuum, increased the frequency of collection, and expanded collection from 409 to 800 homes (3).

City of Stoughton leaf vacuum

Town of Pleasant Springs* enhanced their leaf collection program (started in 2017) with a leaf vacuum service, leaf drop-off site, and extended compost site hours and days (4).

Friends of Lake Kegonsa Society* worked with Wisconsin DNR on the carp removal project by offering incentive payments to anglers, and worked with the Town of Dunn and Town of Pleasant Springs to enhance leaf collection in both towns.

City of Stoughton put in stormwater projects at Stoughton Public Works Facility, Kettle Park Senior Living, Edge One Addition, and Grosso Storage Building.

* Denotes a project partially funded by Clean Lakes Grants.

In June, Lake Kegonsa was impacted by a large rain event that led to flooding in the watershed. Dane County responded with extensive aquatic plant harvesting, and in-channel sediment and rock removal to improve the flow of water in the Yahara River.
View of Lake Kegonsa

HOW WAS THE WATER?

In 2018, Lake Kegonsa summer water clarity conditions show a marked improvement over the past decade median levels. Total phosphorus levels were “fair” but clarity conditions were “good” in the middle of the lake, according to Wisconsin DNR criteria. This improved clarity could be due to the removal of carp from the lake in recent years, the carp die-off from the koi virus in September 2017, the recent infestation of zebra mussels, and/or the unusual amount of flow into and out of the lake resulting from above normal precipitation in the region.

HOW WERE THE BEACHES?

The middle of the lake water quality conditions are in contrast to reports of 25 cyanobacteria blooms in the nearshore compared to the 4-year median of 2.5. An increase in cyanobacteria blooms have been linked to the invasion of zebra mussels in other lakes systems.

Shortly after the August 2018 flooding, an opaque cyanobacteria bloom was spotted at Lake Kegonsa State Park Beach.

REPORT CARD SOURCES

UW Center for Limnology – R. Lathrop, UW Center for Limnology. Data WDNR (1975-1994), NTL-LTER (1995-2018)

Dane County Land & Water Resources – lake levels, aquatic plant harvesting, phosphorus projects

Yahara Lakes Association – historic lake level highs

Historic Flooding in Madison: Cleaning Up, Moving Forward from Summer Storms (Fall 2018). MadisonWaterWays: News from your Stormwater Utility & Sewer Utility.

Public Health Madison & Dane County – beach closure data

Wisconsin State Climatology Office – ice-on/off data for Mendota, Monona, and Wingra, Climate data

Christy’s Landing – ice-on/off for Waubesa

Friends of Lake Kegonsa Society – ice-on/off for Kegonsa

United States Geological Survey – preliminary data on phosphorus loading; rain monitoring data on Pheasant Branch