Flowering Rush Treatment

Flowering Rush Treatment
Posted on 09/07/2023

Flowering Rush Treatment

UPDATE:  Due to recent high water levels in the River Raisin resulting from storms, the treatment has been reschedule to September 13 and 14.  Questions?  Please contact our Water Department @  734.384.9150.

The City of Monroe’s Commission on the Environment will be treating the River Raisin to control the spread of Flowering Rush the week of August 28, 2023. 

Treatment will consist of the application of an environmentally sensitive herbicide, an invasive aquatic plant species management method approved for use in Wayne and Monroe counties through the Detroit River-Western Lake Erie Cooperative Weed Management Area (CWMA), which was established in 2011.

Aqua-Weed Control, Inc., a company out of Holly, Michigan, will be treating the length of the River from 3,000 feet west of Cranbrook Boulevard to the dam behind the Water Treatment Plant (Fish Passage #1) and a small portion of the Mason Run Drain adjacent to the River Raisin National Battlefield Education Center.

Properties in the treatment area will be field noticed prior to the application.

About the Herbicide Treatment

All the products used in this application are U.S. Environmental Protection Agency approved, Michigan Department of Agriculture & Rural Development - MDARD approved, and approved and permitted by EGLE's Aquatic Nuisance Control Program, Water Resources Division. Additionally, approved aquatic formulations of glyphosate, including AquaNeat which is being used in this treatment, are different from terrestrial Round Up, with alterations to its chemical mix that make it less damaging to aquatic environments and causes it to have minimal non-target impacts to fish and aquatic macroinvertebrates.

Herbicide applicators, such as Aqua-Weed Control Inc., receive certification training on the safe and proper use of any environmentally sensitive chemicals, including glyphosate, and are licensed by the State of Michigan.

A package of risk-assessment material relevant to EPA’s review of glyphosate is available online

Herbicide use in this application has been the most effective method to remove this invasive plant, and has been marked with significant and noticeable improvement in reducing the quantity of flowering rush in the watershed. Hand-pulling has proven ineffective and only continues to spread the plant by uprooting rhizomes or buds, which will disperse and grow into new plants.

Please give our Water Department a call at 734.384.9150 if you have any additional questions or concerns, or please contact the Michigan Department of Environment, Great Lakes, and Energy for further information on treatment methodology.

What is Flowering Rush?

Flowering Rush, an invasive aquatic plant, can grow as an emergent along shorelines and as a submersed plant in river.  This exotic was likely brought to North America from Europe as a garden plant that grows well in wet environments.  While single flowering rush plants are not a "problem," this exotic can form dense stands which may interfere with recreational lake and lake use. Flowering rush may also crowd out native plants and wildlife.  A permit is required to remove flowering rush because it is difficult to distinguish from native plants.

Discovered in the River Raisin in 2003, it only took ten years for this species to overtake the waterways.  Removal efforts, including hand digging, have not deterred its onset.  In 2014, the City of Monroe Commission on the Environment initiated a Flowering Rush Eradication Program funded by Monroe County Environmental Grant Fund, using an herbicide treatment in an effort to preserve the native habitat.

Residents in the affected area will be receiving notice via a direct mailer to their property, as required by the Michigan Department of Environmental Quality, Great Lakes, and Energy (EGLE).  

Additional information on native and invasive plant species in the River Raisin habitat can be found in the pages of the ‘River Raisin Legacy Project Field Guide’ linked below.   Free hard copies of the informational 36 page booklet are available at Monroe City Hall, 120 East First Street, first floor, Water Department counter.  

Questions?  Please contact our Water Department @  734.384.9150.