State of the Lake: Fall 2025
The most current EWM survey data for the Minong Flowage — what we measured, what it means, and why it matters.
Each year, professional aquatic plant surveyors map EWM beds across the Minong Flowage. The most recent survey, completed in August 2025, documented 37 distinct EWM beds covering approximately 253–257 acres. That figure is the second highest ever recorded on the Flowage, surpassed only by 2008, when EWM covered 335 acres before management efforts began to take hold.
| Survey Year | EWM Coverage | Notes |
|---|---|---|
| 2008 | 335 acres | Pre-management baseline — worst on record. |
| 2009–2011 | 335 → 81 acres | Three consecutive years of herbicide treatment (2,4-D) reduced EWM by approximately 75%. |
| 2014 | ~16 acres | Survey completed June 2014 following the 2013–14 drawdown (required for dam repairs). Lowest level ever recorded. |
| 2021–22 | Partial reduction | Winter drawdown effective in water under 5 ft only. EWM rapidly repopulated shallower depths faster than experts anticipated. |
| 2024 (PI Survey) | 27.4% frequency | Exceeds the 2008 pre-management baseline of 22.8%. |
| 2025 (Bed Mapping) | ~257 acres / 37 beds | Second worst on record. An increase of approximately 100 acres from 2024. |
The 2024 point-intercept (PI) survey — a standardized measurement of how frequently EWM appears across sampling points in the littoral zone — recorded EWM at 27.4% of surveyed points. That frequency actually exceeds the 2008 pre-management baseline of 22.8%, meaning the Flowage's EWM coverage has in some respects grown more pervasive than it was before years of management effort began. This is a sobering but important fact: it underscores that the problem requires more than maintenance-level management. It requires a meaningful intervention.
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