Echo Lake Dam
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.
Ayres provided the City with a $13,500 proposal for a feasibility study to explore dam compliance options. The study will include hydraulic modeling of the 100-year and 500-year flood, analysis of multiple spillway configurations to contain the 500-year flood, analysis of dam removal, cost estimates for all compliance alternatives, and a report evaluating the various alternatives with recommendations for further action. Ayres will present the report and findings to the Common Council at a future Common Council meeting upon completion. The report will provide the Common Council with the information necessary to select a path for achieving dam compliance.
Ideally, this selection will occur in 2021 and allow for funds to be budgeted in 2022 to design the selected project. The project could then be planned and budgeted for in 2023 and/or 2024 Annual Budget and be in compliance by July 2025.
Reports & Studies
|Echo Lake Pre-dredging Study - 2021|
Echo Lake Dam Post Flood Safety Report - 2017
Dam Failure Approval & Hazard Rating Assignment - 2015
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.