Lake Level Update

Over the past few weeks we’ve all been carefully watching the lake levels. I’ve heard from some of you already experiencing damage to your property, including piers and newly landscaped yards following last year’s flooding. Throughout this process I’ve been in contact with the County Executive’s office, Board Chair Corrigan, the Land and Water Department, and Monona Mayor O’Connor. County and city staff are acting as quickly as possible to handle the new realities of a wetter climate. In this post I’ve summarized where things stand regarding the action underway, what is to come, slow-no-wake, and engagement.

Why is the water high?

Change in Annual Average Precipitation (inches) from 1950 to 2006   Source:

Change in Annual Average Precipitation (inches) from 1950 to 2006


My colleagues, climate experts at UW-Madison, have researched the changing precipitation and temperature. The research shows, “from 1950 to 2006, Wisconsin as a whole has become wetter, with an increase in annual precipitation of 3.1 inches. This observed increase in annual precipitation has primarily occurred in southern and western Wisconsin, while northern Wisconsin has experienced some drying.” This trend is expected to continue.

Lake Monona has been high as a result of high water table across the chain of lakes, and Lake Mendota draining after the wet periods that we’ve experienced. Between Monona and Waubesa there continues to be a chokepoint, which is the first to be addressed through dredging.

My colleague, Supervisor Chawla, serves on the Environment Agriculture Natural Resources (EANR) committee. He has a nice summary on his blog about what is happening right now as well as upcoming actions.  

Funding and pace

The permitting process is slower than any of us would like as we face the threat of another high-water summer. At the same time, it is understandable that the evaluation for permitting is thorough in order to ensure that any action we take does not cause a negative unintended, potentially more harmful, consequence in the future. County staff are working closely with the DNR so this process moves as quickly and smoothly as possible.

The current funding for the project this year covers the work between Monona and Waubesa. The county is actively working to move other dredging projects forward, it will be important for other units of government to partner with the county to cover the costs.

Slow-no-wake (SNW)

In the last week, there were requests for slow-no-wake in some portions of the lake. I talked with both the County Executive’s Office and the Board Chair. Both confirmed that they were watching the lake levels closely and were very close to calling for SNW. The dry weather has helped the levels.

Jointly, the Sheriff, the County Executive and the Board Chair make the determination about when to issue a slow-no-wake.

What is happening right now

Aquatic plant removal

Aquatic plant harvesting is underway to increase the movement of water out of the chain of lakes. 8 aquatic plant harvesters have been in the river since the end of May. Babcock Dam (Lake Waubesa) and Lafollette Dam (Lake Kegonsa) continue to be open, as they have been since 2016. As the water levels lower, the harvesters will be moved back to the lakes for recreation.

Sediment removal between Monona and Waubesa

The process to begin sediment removal (dredging) is underway.

Sediment samples between Monona and Waubesa were taken when the Lake Level Task Force was meeting so that if the recommendation was to move forward with this, it would not slow planning. Sediment samples are tested for heavy metals, PCB’s, and PAH’s to avoid environmental harm, and is needed for DNR permitting. The laboratory takes about three months to complete — without starting these samples during the Lake Level Task Force meetings, the work could not have been completed this year.

Updated data was collected to determine the best place to dredge, and is needed for construction plans for estimating the project. You can access detailed data at Integrated Nowcast/Forecast Operation System for Yahara Lakes. This is the data that is used to monitor the progress of water moving out of the lake system.

Engineering plan drawings for the Yahara River between Monona and Waubesa are being designed, and bids will go out in the next couple of weeks. These plans are needed for permitting and the competitive bid process.

The sediment removal is expected to begin in October, assuming it is approved by the DNR and the County Board. County staff has been working closely with the DNR to ensure there is no delay.

 Upcoming County Action

Future sediment removal

A 5-phase sediment removal plan has been recommended for the chain of lakes, but is dependent upon funding. Work towards these projects is continuing, as experts at the Land and Water Resources Department continue to collect data. Sediment samples were collected for the remaining areas, with laboratory results to come. Updated bathymetry data will need to be collected. In addition the DNR requires biological and archeological evaluation for permitting. The County and the Ho-Chunk are involved in conversations about the Native American Fish Weir.

 The county will look to partner with other units of government to share costs associated with the care of our lakes.

 Tenney Dam

An additional recommendation from the Lake Level report is to reinforce the Tenney Dam. This action will increase the storage capacity of Mendota. The goal is to complete this project later this summer.


Land restoration and preservation is one of the best ways that we can protect communities around the county from extreme rain events as they provide a “sponge” to absorb the rains. The recent land purchases in Pheasant Branch and Babcock Park will help with infiltration. 

Monona’s Response 

Dane County / City of Monona partnership, Blue Water Barge Program. Photo credit: Scott Adrian

Dane County / City of Monona partnership, Blue Water Barge Program. Photo credit: Scott Adrian

Mayor O’Connor confirmed that the taking care of storm water outfall problems at Stonebridge park are a major priority.

Dane County and Monona are partnering in the Blue Water Barge Program. to clean up debris and lake weeds which helps with the phosphorus levels of the lake and helps keep the beaches in Monona useable.

The algal blooms and weed growth have made the shorelines in some areas unusable. The county will be looking to move weed cutters and collection barges to Monona as the water levels improve downstream — prioritizing lake levels. If you are able to collect weeds and put them on your pier, you can check the county pick up schedules at the Monona City website to see the schedule of collection days.

Citizen Action

Quarterly update

One of the recommendations from the Lake Level Task Force included a quarterly update, the next will happen at the EANR meeting on August 22. If you have any questions you would like submitted, please send them my way.

Contact Yahara Lakes Association (YLA)

If you are interested in coordinating efforts with other community members, YLA is an extremely active group in Dane County working to improve and support ongoing efforts for lake maintenance and improvement.

Stay in touch

Please, as always, stay in touch. I want to know about what is happening on your property, and any other new developments. You can reach me by email: or phone: 608-237-6712.