Echo Lake Dam
Tentative Echo Lake Dam Decision / Referendum Timeline
April / May 2022
July / August 2022
September / October 2022
November / December 2022
January / March 2023
September/ October 2023
In 2015 the Wisconsin Department of Natural Resources (WDNR) required the City to perform a Dam Failure Analysis (DFA) for the Echo Lake Dam. The findings of the DFA were that the dam could not contain a modeled “500-year-flood”, which is a requirement of a dam of its classification. WDNR has required the City to achieve compliance with this requirement by July 2025. Compliance can be achieved by making modifications to the dam to increase spillway capacity, or by removing the dam. In either case some change will be necessary for the dam and maintaining the dam in its current state is not an option for compliance.
The City has hired Ayers Associates to explore options in achieving dam compliance. Ayers Associates have significant experience in the field of hydraulic modeling, structural assessment, and dam engineering. Ayers is familiar with the Echo Lake Dam and have performed dam inspection services for the City in the past.
November 15, 2021 Update Regarding Echo Lake Dam Spillway Feasibility Study
|November 16, 2021 PowerPoint Presentation|
November 5, 2021 Burlington (Echo Lake) Dam Spillway Improvement and Dam Removal Feasibility Study
November 16, 2021 Discussion memorandum with full details
On February 16, 2021 the Common Council approved a resolution authorizing Ayres Associates to perform a feasibility study to identify projects that achieve compliance with Wisconsin Department of Natural Resource (WDNR) requirements for the Echo Lake Dam. In 2015, WDNR provided the City of Burlington with a 10-year compliance timeline to bring the Echo Lake Dam into compliance with the requirements of Wisconsin State Statute Chapter NR 333 specifically relating to the dam’s inability to contain the 500-year flood within the spillway without overtopping the embankment. The scope of the feasibility study was to provide multiple viable solutions to achieve compliance through either modification of the dam or removal of the dam.
Throughout 2021 City staff and Ayres have worked to understand the unique hydrological features that exist around the Echo Lake dam in order to present compliant solutions as part of the feasibility study. On August 3, 2021 staff and Ayres presented findings that no viable solution exists for a dam to be compliant with NR 333.07(1) to contain the 500-year flood. However, it was likely that additional modeling of downstream river conditions could provide a case to achieve compliance by showing the spillway was capable of containing flood waters up to the point of dam submergence.
Ayres conducted additional modeling to determine if compliance could be achieved through this alternative route. This additional research was presented to WDNR to begin collaboration with WDNR and ultimately resulted in WDNR agreeing that our concept to achieve compliance with NR 333.07(2)(a) was valid.
Achieving conceptual buy-in from WDNR allowed Ayres to continue with their project concept designs for the report. The resulting feasibility study contains essentially two projects, each with a few variations as follows:
Dam Modification Options
The dam modification project achieves compliance by constructing improvements to the dam and Echo Park that allow the spillway to contain flood waters up to the point of dam submergence. The project consists of removing the existing tainter gate, installing three new gates, reconstructing the concrete retaining wall downstream from the dam, and increasing the elevation of the north embankment and extending it into Echo Park. Extending the north embankment into the park will have impacts on the park which can be mitigated by design choices. The variation for this project comes in the form of which style of gate is to be installed: tainter gates, crest gates, or sliding gates. Each style of gate has its benefits and draw backs for cost, ease of operation, performance, maintenance, and aesthetics.
Dam Removal Option
The dam removal project removes the dam structure, restores the river channel, and restores the drained lakebed to wetland with a variety of potential enhancements. This project contains a vast amount of customization concerning how to restore the former lakebed. Simplistically, the project could allow the lakebed to revert to natural space and wetland. At its most complex, the project could include features like stormwater ponds, pedestrian paths, boardwalks through the wetlands, bridges over the river, fishing ponds, and boat launches.
The detailed report contains cost estimates for each project, as shown below. These estimates include costs for construction, permitting, and a 30% contingency. The report can be viewed Here
Per the feasiblity study, a dredging project is estimated to cost tax payers $2.4 Million. Dam modifications (with any gate) could cost tax payers approximately $1.5 Million to $2.6 Million, plus the approximate $2.4 Million in dredging costs. Dam removal could cost tax payers approximately $1.5 Million to $6 Million. All costs are dependent on the complexity of the project chosen.
All projects are eligible for up to $1 Million in WDNR Municipal Dam Grant funding. Other grant opportunities may exist for shoreline work, pollutant removal, or stewardship depending on the particulars of the selected project. Staff will evaluate these options as design occurs in the future.
|It is anticipated that an authorizing resolution for which project to pursue will be presented to the Common Council at the February 1, 2022 Committee of the Whole Meeting for discussion and at the February 16, 2022 Common Council Meeting for final consideration. This resolution would also authorize staff to apply for grant funding for the selected project.|
October 12, 2021 Update Regarding Echo Lake Dam Spillway Feasibility Study
The City’s consultants at Ayres Associates are wrapping up the final elements of the Echo Lake Dam Feasibility Study. This study contains multiple options to achieve compliance with dam spillway capacity requirements including dam spillway modifications and dam removal. Each option presented in the study has a concept level design and cost estimate. City staff and staff from Ayres worked closely with staff from the Wisconsin Department of Natural Resources (WDNR) to ensure the spillway modification options presented in the study will be able to achieve compliance with spillway capacity requirements. This is a very important project for the community and it was critical we only presented options that are viable, realistic, and able to achieve compliance. We are grateful for the collaboration and guidance provided by WDNR staff to help us achieve these goals.
The study is scheduled to be presented to the Common Council and the community at the November 16, 2021 Committee of the Whole Meeting. Following the Committee of the Whole presentation, staff will then host public open houses and stakeholder meetings to discuss the study and gather feedback from the community. Dates and locations for these meeting are not yet finalized and will be released in the near future.
Staff will then compile this feedback from these public input meetings and provide it to the Common Council. The Council will then need to make a decision on which option to pursue to achieve dam compliance and approve an authorizing resolution for a municipal dam grant application for the selected project. This decision will likely be scheduled for February 2022.
Frequently Asked Questions
Recently, there has been a lot of discussion within the community regarding the Echo Lake dam. Please see the FAQ below to help answer some of the questions you may have.
What is wrong with the Echo Lake dam?
The Echo Lake Dam is out of compliance with Wisconsin Department of Natural Resources (WDNR) regulations. WDNR requires that during a 500-year flood all water is contained within the dam spillway and water does spill out around the sides of the dam. Currently, the Echo Lake Dam cannot contain a 500-year flood. Keeping the dam as it exists today will not be an option for the City. It must either be modified or removed. These changes must be made before July of 2025.
Is it true the Echo Lake dam will be removed?
Removal of the Echo Lake Dam is one way to achieve compliance with WDNR requirements. Compliance may also be achieved by keeping the dam, but making modifications. Dam modifications or removal are complex and potentially very impactful to the area where the dam is located. The City has contracted with Ayers Associates to conduct a spillway feasibility study of the Echo Lake Dam to better understand what options are available, and what impacts those options carry for the community.
Is the City considering keeping the dam and improving Echo Lake?
Ayers and Associates will provide three options for modifying the Echo Lake Dam that would achieve compliance without removing the dam. It is unknown how much of an impact these modifications will have on the existing dam, Echo Lake, and Echo Park. Ayers and Associates is also testing the lake bed sediment to explore lake dredging as a potential project to go along with dam modifications or removal.
When will the information from the analysis be available?
The results of the study will be available and discussed in the Fall of 2021.
What will happen to Echo Lake if the dam is removed?
If dam removal is the selected option, a restoration plan will be necessary to address the changing path of the river. Ayers and Associates will provide restoration plan concepts as part of the feasibility study.
Will removing the dam cause the river to flood?
The Echo Lake dam does not have the ability to control flooding on the Fox River and only slows the flow of the White River coming into the Fox River. Dam removal would have impacts on the river level, but to what extent is currently not known. This impact is one of many considerations being explored as part of the project Ayers Associates is working on.
How much will repairs or removal cost the City?
Ayers Associates will present three different dam modification options and a dam removal option as part of the study. These options will have cost estimates. This information will not be known until Fall of 2021.