Stream flow has dropped to a bare 74 cubic feet per second — roughly one-fifth…

June 25, 2026Michigan Lake Plain

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Stream flow has dropped to a bare 74 cubic feet per second — roughly one-fifth of the high-water baseline — as upstream operations push the water column into a narrower, more concentrated state. When flows contract like this in summer heat, dissolved contaminants don't dilute; they concentrate. Mercury, the heavy metal that accumulates through food webs and doesn't break down, climbs steadily into forage fish, then into the herons and eagles that hunt them.

The wastewater treatment plant upstream exceeded its mercury permit limit for two consecutive quarters — 38 percent over in Q3, and 27 percent over in Q4 — during a season when the stream's own ability to dilute that load was already failing. Four waterways in this region are already listed as impaired, with total maximum daily loads set by the state. In a system this tight, even small exceedances have room to compound.

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