Ask Mike: All about the dos and don’ts of wetlands

Posted: Tuesday, July 5, 2011, 3:07 pm

Minnetonka Mike sits a desk, ready to answer your questions

Minnetonka Mike, the city of Minnetonka’s online request system, is always standing by to help you with any questions, comments or concerns you may have about your city. This month, Mike addresses wetland questions.

Dear Minnetonka Mike:

I have a swamp in my backyard that I want to clean up. What can I do?

Signed, Stuck in a Swamp

Dear Stuck:

What you’re describing sounds like a wetland. Wetlands are typically a low spot on the landscape where water drains, the soils are normally saturated and there may or may not be standing water. Hydric soils, like peat, form in these areas and plants that tolerate wetter conditions thrive. Wetlands are also found on the edges of lakes and creeks.

Wetlands come in many different shapes and sizes. Some are small, woodland, spring-time pools, while others look more like a wet meadow, cattail marsh or open pond. All wetlands provide benefits to us and the natural world by absorbing water to reduce flooding, filtering nutrients and pollutants in storm water, recharging groundwater and providing habitat for fish and wildlife.

When urban areas were developed, storm water was discharged directly into these areas in order to prevent flooding of streets, homes and businesses. We now know that storm water is polluted water normally containing bacteria, sediment and metals, as well as high levels of nutrients that can cause algae and other nuisance aquatic weed growth.

Wetlands have a delicate ecosystem and are regulated by several different agencies including the Army Corps of Engineers, Department of Natural Resources (DNR), the Board of Soil and Water Resources and local watershed districts and cities.

The most common questions the city receives about wetlands relate to aeration systems, tree removal, dock access, alteration of vegetation and algae control. The following information will give you some guidance on city regulation. If you have a specific wetland regulation question please call the city’s natural resource staff at 952.988.8400.

Can I install a fountain in my wetland?

Shallow bodies of water normally do not benefit from aeration systems because the nutrients and sediment never settle out and are continually infused into the water column. Aeration does not reduce algae or duckweed growth—the water movement simply pushes the plant material to the outside edge of the wetland. For these reasons, city ordinance does not allow fountains and aeration systems in wetlands.

Can I remove a tree if it falls into my wetland?

If a tree falls in a wetland its removal is not required, and leaving it creates additional wildlife habitat. If you decide to remove it, it must be hauled out by hand, as heavy equipment will damage the wetland. If you decide to chip the tree or branches, use the resulting mulch for landscaping in your yard. Please do not deposit the chips back into the wetland, as it would be considered “fill,” which is not allowed.

Can I install a dock through the vegetation (like cattails) to access the open water portion of my wetland or lake?

Yes, if you have access rights to the open water portion of the wetland or lake. Contact city staff for more detailed information. Please contact the DNR or Lake Minnetonka Conservation District if you are accessing an area under their regulatory authority.

Can I cut down trees or remove the wetland plants from my wetland?

Vegetation that is dead, diseased or noxious may be removed. Cutting of live trees and wetland vegetation requires a wetland alteration permit. With city staff approval, vegetation in a contiguous width not exceeding 10 feet can be cut in order to install or maintain a dock. In addition, vegetation may be removed without a wetland alteration permit if it is part of a restoration plan approved by city staff.

The city’s natural resources staff is always on hand to assist residents in determining what may or may not be removed around wetlands. Call 952.988.8400 for assistance.

If your wetland is a DNR-protected wetland contact the DNR’s Aquatic Plant Management Division for details.

I hate the algae. Can I treat my pond?

The city of Minnetonka does not regulate the removal of algae or duckweed. Duckweed is a lime-green, pinhead-sized plant that floats on the surface of the water. It is beneficial to wildlife but many people consider it a nuisance because it can form a lime-green coating on the surface of the water. The Minnesota DNR and/or your local watershed district may have specific regulations for your wetland—contact them to find out more.

If you have a question, comment or concern about the city, let Minnetonka Mike know! Visit and click on Minnetonka Mike’s image. Follow the directions to set up your account, then go ahead and submit your comment. Or, call 952.9398386 to leave your comment.