20 Years of Management: Our History

EWM was first confirmed in the Minong Flowage in 2002. Since then, the MFA has pursued active management through five separate state grants and a sustained commitment of community resources, volunteer labor, and association funding. No single approach has solved the problem — but every season of effort has contributed to our understanding of what works, what doesn't, and what the Flowage requires for long-term health.

What We've Tried — and What We've Learned

Method	When Used	Outcome
Herbicide (2,4-D)	2009, 2010, 2011, 2016, 2023	Three consecutive years of treatment (2009–2011) reduced EWM from 335 acres to approximately 81 acres — a 75% reduction. A permit was received in 2016 to treat the DNR Bay area (approximately 27 acres). A smaller treatment of approximately 15 acres was completed in 2023 at two locations (county park north side and the bay near Pogo's).
Hand & Physical Removal	Ongoing	Property owners and volunteers contribute meaningfully along shorelines. Volume of EWM far exceeds what manual removal can address alone.
Diver / DASH Removal	Including 2015 demonstration	Limited effectiveness due to dark water conditions and physical obstructions in the Flowage. Documented in 2015 APM demonstration.
Extended Drawdown	Apr 2013 – Feb 2014	Required by Washburn County for dam repairs — not undertaken for EWM control. However, EWM was dramatically reduced as a secondary effect: a June 2014 survey documented EWM in approximately 16 acres, the lowest level ever recorded. The 11-month drawdown extended through winter, which appears to have been primarily responsible for EWM control.
Winter Drawdown	Nov 2021 – Mar 2022	Controlled EWM in water under 5 feet. Little effect in deeper water. EWM rapidly repopulated shallower depths faster than experts anticipated.
EWM Weevil Program	2009–2012, 2016	Research-level effort. No large-scale population control achieved, consistent with broader findings that weevil programs work best in smaller, isolated water bodies.
Mechanical Harvesting	2026 (possible addition to herbicide)	Not previously deployed on the Flowage due to underwater stumpage posing equipment and safety risks. The DNR's position on this has recently changed; mechanical harvesting is now part of the MFA's 2026 management plan for navigation corridor clearing.

The lesson from more than twenty years of effort is clear: no single method is sufficient. An integrated approach — combining the right tools at the right times, with careful monitoring and adaptive management — is the only path to meaningful, lasting results.

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