Waterway protection Placing erosion control structures on Great Lakes
The Department understands landowner and municipality concerns about structures that may be at risk from bluff erosion on the Great Lakes and recognizes the large investments residents have in their homes. Shore protection projects are a significant investment and have the potential to impact neighboring properties. Landowners should be aware of considerations to invest wisely and protect the Great Lakes environment.
Placing permanent erosion control structuresFact sheet for landowners [PDF]
Material type and shape
The type of material used can impact the longevity of a shore protection structure. Demolition debris like cinder blocks, concrete rubble and dirt are not acceptable materials since when they exposed to wave action and thaw and freeze cycles can crack and break apart easily. Any armor layer must be sufficiently sized to be stable and made of materials that will not crack and fragment.
The shape of the materials is also an important design consideration. Multi-faceted boulders with round surfaces can work well. Conversely, flat surfaces do not work well. Flat surfaces can reflect wave energy resulting in scouring at the base of the structure or could increase wave run-up and cause more erosion.
Assistance with installation
The cost of planning, designing, and installing shore protection structures may become expensive. To help ensure that the landowner investment in a solution is protected, the department encourages landowners to seek experienced coastal engineering professionals to assist with your project. Coastal engineering professionals have the expertise necessary to influence the success of a shoreline project, including:
- navigating the permit process,
- assessing the impacts of the planned project on adjacent properties,
- minimizing construction and maintenance costs, and
- managing the performance and longevity of the project.
Monitoring after installation
Coastal professionals can monitor the project following completion and plan any modifications or repairs needed in the event of a storm. An investment in the services of experienced professionals is the best way to ensure the long-term success of a shore protection project and minimize costs during the period of ownership.
The department has available permit application checklist for great lakes shoreline projects to assist you and the professional you choose in planning and designing your project so that the Department can more quickly review projects without needing to go back and forth during the review process.
Concrete rubble and other construction site debris should not be used.
These types of materials have a tendency to crack and break apart reducing the weight of the material that is needed to resist wave forces and may create voids for the waves to erode behind the material.
Placing temporary emergency materials Fact sheet for landowners [PDF]
DNR authorization for material placed in Great Lakes
State law requires any material that is placed in the Great Lakes be authorized by the department. In recent cases landowners have requested the department to allow temporary emergency material to be put into place while they design and seek approval for a permanent solution.
The department will allow the placement of temporary emergency material in public water without a permit as long as the following guidelines are followed by the landowner:
- The landowner must request in writing to the Department to place temporary emergency materials to control erosion on a great lakes waterbody to protect a structure or infrastructure.
- In the request, the landowner must provide the following information.
- Where the temporary material will be placed;
- The type and amount of temporary materials that will be used; and,
- how the temporary material will be placed.
Once the Department receives the request, a letter authorizing the placement of temporary emergency structures will be sent to the landowner and once received the landowner can proceed with placing the temporary measures.
- If using rock, stone, or heavy concrete it should consist of clean (no re-bar, metal etc.) large, non-flat, angular, interlocking pieces.
- If using sandbags, it should consist of clean fill and the bag material of appropriate tensile strength to prevent bursting.
Requests for placing temporary emergency material should be directed to the water management specialist for your area:
- Statewide: Martin Griffin
- Racine county: Kathi Kramasz
- Kenosha county: Elaine Johnson
- Other counties: County water management specialists