Frankenmuth

Nearly 70 years old, Frankenmuth's iconic levee is showing its age. Improvements to the levee system (also called dike) have been in planning since 2005, when the City was notified by the Federal Emergency Management Agency (FEMA) that the levee no longer meets required standards to protect it. Essentially, the levee and wall are too low and soils that make up the large berm are unstable. The conditions create a situation that the existing levee may no longer provide the flood protection necessary for the community, as required by federal standards. Since that time, the City has been working closely with FEMA and the U.S Army Corps of Engineers (USACE) to design a new levee and flood wall system that provides the City the protection it needs. In 2016, the USACE completed a risk assessment on the levee system identifying a number of specific concerns that place the City at risk for potential flooding. To remove the potential for a natural disaster, the City has chosen to improve the levee system protecting the safety and public welfare of the area. The current condition of the levee system is faulted in multiple ways. Risks include: • There is a significant concern that during high water levels in the river, water would begin to flow under the floodwall (known as "seepage"), which could erode the levee from the inside out and likely cause the levee to breach or fail. A significant weak spot is at the Hubinger Nickless Mill where the basement wall is also constructed into the levee. In 1986, the wall failed to keep water out. • In 1986, river levels came within a few inches of flowing over the levee, and emergency sandbagging and placement of large amounts of clay near the floodwall were needed to keep the seepage from worsening. While the levee successfully kept the floodwaters out of the city, the event exposed vulnerabilities in the levee system. There is also the threat that water could reach levels high enough to flow over the top of the levee and quickly erode the backside resulting in a breach (overtopping). • Many trees, large and small, are located on the levee and near the floodwalls. Tree roots within and below the soils increase the likelihood of seepage forming by providing pathways for the water to flow under or through the levee structures. A levee breach could result in flooding depths of up to 11 feet near the river, with an average depth of 6 feet. Floodwaters would quickly flood the Main Street area of the city damaging the historical museum and the surrounding downtown area shown in the figure above. The Frankenmuth Historical Association has more than 100 photos of life before the levee, when spring rains regularly flooded the area. The levee has served the City well. With each year that passes, however, the risk of a highwater event increases. While it is not likely, if people are still in the area when high water arrives, the outcome could be life threatening. After years of studying, the City is ready, in partnership with the Downtown Development Authority (DDA) and local property owners, to construct a new and improved levee. We anticipate bidding the project this spring. As pointed out in the USACE risk assessment, trees need to be removed. Frankenmuth is part of a potential habitat for the Eastern Indiana Bat and the Northern Long-Eared Bat, both federally protected species. Under protected species regulations, the City cannot disturb the natural habitat for these bats between April 1 and October 30. If the trees are not removed before April 1, the levee project could not begin until November 1 to begin construction. The City began tree removal in March. The project has taken on a renewed sense of urgency because FEMA is planning on releasing floodplain maps for Saginaw County for the first time since 1997. If the levee improvements are not complete by the time the maps are adopted, our downtown and surrounding properties would be located in the regulated floodplain. 11 The Frankenmuth Levee

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